3dcam/3dcam-tri-quads.c

// 3dcam
// With huge help from :
// @NicolasNoble : https://discord.com/channels/642647820683444236/646765703143227394/796876392670429204
// @Lameguy64
// @Impiaa
// @paul

		
 /*		   PSX screen coordinate system 
 *
 *                           Z+
 *                          /
 *                         /
 *                        +------X+
 *                       /|
 *                      / |
 *                     /  Y+
 *                   eye		*/

// Blender debug mode
// bpy. app. debug = True 

#include <sys/types.h>
#include <libgte.h>
#include <libgpu.h>
#include <libetc.h>
#include <stdio.h>
#include <stdint.h>
#include <stddef.h>

// Precalculated sin/cos values

#include "atan.c"

// Sample level

#include "coridor2.c"

#define VMODE       0

#define SCREENXRES 320

#define SCREENYRES 240

#define CENTERX		SCREENXRES/2

#define CENTERY		SCREENYRES/2

#define FOV CENTERX                             // With a FOV of 1/2, camera focal length is ~= 16 mm / 90°
                                                // Lower values mean wider angle

// pixel > cm : used in physics calculations

#define SCALE 4

#define FNT_POS_X 960

#define FNT_POS_Y 0


#define OT2LEN	    8	                   

#define OTLEN	    256	                        // Maximum number of OT entries

#define PRIMBUFFLEN	4096 * sizeof(POLY_GT4)	    // Maximum number of POLY_GT3 primitives

// MACROS 

// swap(x, y, buffer)

#define SWAP(a,b,c)			{(c)=(a); (a)=(b); (b)=(c);} 

// dotproduct of two vectors

#define dotProduct(v0, v1)  \
	(v0).vx * (v1).vx +	\
	(v0).vy * (v1).vy +	\
	(v0).vz * (v1).vz

// min value

#define min(a,b)    \
        (a)-(b)>0?(b):(a)
// max

#define max(a,b)    \
        (a)-(b)>0?(a):(b)

// substract vector

#define subVector(v0, v1) \
	(v0).vx - (v1).vx,	\
	(v0).vy - (v1).vy,	\
	(v0).vz - (v1).vz	


// Display and draw environments, double buffered

DISPENV disp[2];

DRAWENV draw[2];

// OT for BG/FG discrimination

u_long otdisc[2][OT2LEN] = {0};

// Main OT

u_long	    ot[2][OTLEN]  = {0};   		        // Ordering table (contains addresses to primitives)

char	primbuff[2][PRIMBUFFLEN] = {0};	        // Primitive list // That's our prim buffer

//~ int		    primcnt=0;			            // Primitive counter

char * nextpri = primbuff[0];			        // Primitive counter

char		    db	= 0;                        // Current buffer counter


CVECTOR BGc = {50, 50, 75, 0};                  // Far color

VECTOR BKc = {128, 128, 128, 0};                // Back color

// Local color matrix   

//~ static MATRIX	cmat = {
//~ /* light source    #0, #1, #2, */
		//~ ONE,  0,  0, /* R */
		//~ 0,    ONE,  0, /* G */
		//~ 0,    0,  ONE, /* B */
//~ };

//~ // local light matrix : Direction and reach of each light source. 
//~ // Each light is aligned with the axis, hence direction is in the same coordinate system as the PSX (Y-axis down)
//~ // One == 4096 is reach/intensity of light source

//~ static MATRIX lgtmat = {
//~ //  X     Y     Z   
    //~ ONE, 0,  0,	    // Light 0  
	//~ 0,0,0,	    // Light 1 
	//~ 0,0,0	    // Light 2 
//~ };

// Light 

//~ MATRIX	    rottrans;	

MATRIX		rotlgt;	

SVECTOR	    lgtang = {0, 0, 0};	

MATRIX		light;
	
static int m_cosTable[512];                     // precalc costable

static const unsigned int DC_2PI = 2048;        // this is from here : https://github.com/grumpycoders/Balau/blob/master/tests/test-Handles.cc#L20-L102

static const unsigned int DC_PI  = 1024;

static const unsigned int DC_PI2 = 512;

short vs;

typedef struct{
    
    int x, xv;                                 // x: current value += xv : new value 
    
    int y, yv;                                 // x,y,z, vx, vy, vz are in PSX units (ONE == 4096)
    
    int z, zv;
    
    int pan, panv;
    
    int tilt, tiltv;
    
    int rol;

    VECTOR pos;
    
    SVECTOR rot;
    
    SVECTOR dvs;

    MATRIX mat;

} CAMERA;

CAMERA camera = {

    0,0,

    0,0,

    0,0,

    0,0,

    0,0,

    0,
    
    {0,0,0},

    {0,0,0},

    {0,0,0}
};


// physics

long time = 0;

const int gravity = 10;
    
//Pad

int pressed = 0;

u_short timer = 0;

// Cam stuff 

int camMode = 2;

long timeB = 0;

int lerping    = 0;

short curCamAngle = 0;

// Inverted Cam coordinates for Forward Vector calc

VECTOR InvCamPos = {0,0,0,0};

VECTOR fVecActor = {0,0,0,0};

u_long triCount = 0;

// Prototypes

// Stolen from grumpycoder

// Sin/Cos Table

void generateTable(void);

int  ncos(u_int t);

int  nsin(u_int t);

// Atan table

long long patan(long x, long y);

// Sqrt

u_int psqrt(u_int n);

// fixed point math

static inline int32_t dMul(int32_t a, int32_t b);

static inline uint32_t lerpU(uint32_t start, uint32_t dest, unsigned pos);

static inline int32_t lerpS(int32_t start, int32_t dest, unsigned pos);

static inline int32_t lerpD(int32_t start, int32_t dest, int32_t pos);

static inline long long lerpL(long long start, long long dest, long long pos);

// PSX setup

void init(void);

void display(void);

// Utils

void LoadTexture(u_long * tim, TIM_IMAGE * tparam);

int cliptest3(short * v1);

int lerp(int start, int end, int factor); // FIXME : not working as it should

SVECTOR SVlerp(SVECTOR start, SVECTOR end, int factor); // FIXME 

VECTOR getVectorTo(VECTOR actor, VECTOR target);

int alignAxisToVect(VECTOR target, short axis, int factor);

// Drawing

void transformMesh(MESH * meshes);

void drawBG(void);

void drawPoly(MESH * meshes, long * Flag, int atime);

// Camera 

void getCameraXZ(int * x, int * z, int actorX, int actorZ, int angle, int distance);

void applyCamera(CAMERA * cam);

void setCameraPos(VECTOR pos, SVECTOR rot);

// Physics

VECTOR getIntCollision(BODY one, BODY two);

VECTOR getExtCollision(BODY one, BODY two);

void   ResolveCollision( BODY * one, BODY * two );

VECTOR angularMom(BODY body);                    // Not this kind of mom ;)

void applyAcceleration(BODY * actor);

// Pad 

void callback();

int main() {
	                      
    // FIXME : Poly subdiv
    
    //~ DIVPOLYGON4	div4 = { 0 };
    //~ div4.pih = SCREENXRES;
	//~ div4.piv = SCREENYRES;
    //~ div4.ndiv = 2;
    //~ long OTc = 0;
    
    //~ DIVPOLYGON3	div3 = { 0 };
    //~ div3.pih = SCREENXRES;
	//~ div3.piv = SCREENYRES;
    //~ div3.ndiv = 1;
    
	init();

    generateTable();

    VSyncCallback(callback);

    // Load textures
    
    for (int k = 0; k < sizeof(meshes)/sizeof(TMESH *); k++){
    
        LoadTexture(meshes[k]->tim_data, meshes[k]->tim);
    
    }
    
    // Load current BG
    
    if (camPtr->tim_data){

        LoadTexture(camPtr->tim_data, camPtr->BGtim);

    }
    
    // Physics

    short physics = 1;

    long dt;

    VECTOR col_lvl, col_sphere, col_sphere_act = {0};
    
    // Cam stuff 
    
    VECTOR posToActor    = {0, 0, 0, 0};      // position of camera relative to actor    
    
    VECTOR camAngleToAct = {0, 0, 0, 0};      // rotation angles for the camera to point at actor
    
    // Sprite system
    
    VECTOR posToCam      = {0, 0, 0, 0};
    
    VECTOR objAngleToCam = {0, 0, 0, 0};
    
    //~ long objAngleToCam = 0;
    
    
    
    int angle     = 0;                      //PSX units = 4096 == 360° = 2Pi
    
    int dist      = 0;                      //PSX units 

    short timediv = 1;

    int atime = 0;
    
    // Polycount
    
    for (int k = 0; k < sizeof(meshes)/sizeof(meshes[0]); k++){
    
            triCount += meshes[k]->tmesh->len;
    
    }
    
    // Set camera starting pos
    
    setCameraPos(camPtr->campos->pos, camPtr->campos->rot);
    
	// Main loop
	
    //~ while (1) {
    
    while ( VSync(1) ) {
        
        // Clear the main OT
		
        ClearOTagR(otdisc[db], OT2LEN);
		
        // Clear Secondary OT
        
        ClearOTagR(ot[db], OTLEN);
        
        // timeB = time;
        
        time ++;
        
        // atime is used for animations timing
        
        timediv = 1;
        
        if (time % timediv == 0){
        
            atime ++;
        
        }
        
        // Angle between camera and actor
        
        // using atantable (faster)

        camAngleToAct.vy = (patan(-posToActor.vx, -posToActor.vz) / 16) - 3076 ;
        
        camAngleToAct.vx = patan(dist, posToActor.vy) >> 4;

        // Sprite system WIP

        //~ posToCam = getVectorTo(*meshPlan.pos, camera.pos);
        
        //~ posToCam = getVectorTo(camera.pos, *meshPlan.pos);

        posToCam.vx = -camera.pos.vx - modelPlan_pos.vx ;
        posToCam.vz = -camera.pos.vz - modelPlan_pos.vz ;
        posToCam.vy = -camera.pos.vy - modelPlan_pos.vy ;
        
        //~ psqrt(posToCam.vx * posToCam.vx + posToCam.vy * posToCam.vy);
        
        objAngleToCam.vy = patan( posToCam.vx,posToCam.vz );
        objAngleToCam.vx = patan( posToCam.vx,posToCam.vy );

        //~ objAngleToCam.vz = patan( posToCam.vz,posToCam.vy );
        //~ objAngleToCam.vx = patan( psqrt(posToCam.vx * posToCam.vx + posToCam.vy * posToCam.vy), posToCam.vy );

        //~ meshPlan.rot->vx = -( (objAngleToCam.vx >> 4) - 3076 ) ;
        //~ meshPlan.rot->vx = (( (objAngleToCam.vx >> 4) - 3076 ) * ( (objAngleToCam.vz >> 4) - 3076 ) >> 12) * (nsin(posToCam.vz) >> 10 < 0 ? -1 : 1);
        //~ meshPlan.rot->vx = ( (objAngleToCam.vx >> 4) - 3076 ) * ( (objAngleToCam.vz >> 4) - 3076 ) >> 12 ;
        
        meshPlan.rot->vy = -( (objAngleToCam.vy >> 4) + 1024 ) ;
        
        // Actor Forward vector 

        fVecActor = *actorPtr->pos;
        
        fVecActor.vx = actorPtr->pos->vx + (nsin(actorPtr->rot->vy/2));
        
        fVecActor.vz = actorPtr->pos->vz - (ncos(actorPtr->rot->vy/2));

    // Camera modes

        if(camMode != 2) {
            
            camera.rot.vy = camAngleToAct.vy;
            
            // using csin/ccos, no need for theta
            
            //~ camera.rot.vy = angle; 
            
            camera.rot.vx = camAngleToAct.vx;   
        
        }
        
        if(camMode < 4 ) {
       
            lerping = 0;
       
        }
        
        // Camera follows actor with lerp for rotations
        if(camMode == 0) {
            
            dist = 150;
            
            camera.pos.vx = -(camera.x/ONE);
            
            //~ camera.pos.vy = -(camera.y/ONE);
            
            camera.pos.vz = -(camera.z/ONE);
            
            //~ InvCamPos.vx = camera.x/ONE;
            
            //~ InvCamPos.vz = camera.z/ONE;
        
            //~ applyVector(&InvCamPos, -1,-1,-1, *=);
            
            angle = -actorPtr->rot->vy / 2;
            
            //~ angle = actorPtr->rot->vy;

            getCameraXZ(&camera.x, &camera.z, actorPtr->pos->vx, actorPtr->pos->vz, angle, dist);

            // FIXME! camera lerping to pos
            //~ angle += lerp(camera.rot.vy, -actorPtr->rot->vy, 128);
            //~ angle = lerpD(camera.rot.vy << 12, actorPtr->rot->vy << 12, 1024 << 12) >> 12;
            
        }
        
        // Camera rotates continuously around actor
        if (camMode == 1) {                      
            
            dist = 150;
           
            camera.pos.vx = -(camera.x/ONE);
           
            //~ camera.pos.vy = -(camera.y/ONE);
           
            camera.pos.vz = -(camera.z/ONE);
            
            //~ fVecActor = *actorPtr->pos;
            
            //~ fVecActor.vx = actorPtr->pos->vx + (nsin(actorPtr->rot->vy));
            //~ fVecActor.vz = actorPtr->pos->vz - (ncos(actorPtr->rot->vy));
            
            
            getCameraXZ(&camera.x, &camera.z, actorPtr->pos->vx, actorPtr->pos->vz, angle, dist);
           
            angle += 10;
        }
        
        // Fixed Camera with actor tracking
        if (camMode == 3) {                              
            
            // Using precalc sqrt

            dist = psqrt( (posToActor.vx * posToActor.vx ) + (posToActor.vz * posToActor.vz) );
            
            camera.pos.vx = 190;

            camera.pos.vz = 100;

            camera.pos.vy = 180;
        }
        
        // Fixed Camera angle
        if (camMode == 2) {                              
          
            //~ if (camPtr->tim_data){
                
                //~ drawBG();
                
            //~ }
            
            setCameraPos(camPtr->campos->pos, camPtr->campos->rot);

        }
        
        // Flyby mode with LERP from camStart to camEnd
        
        if (camMode == 4) {                               
            
            // If key pos exist for camera
           
            if (camPath.len) {
                
                // Lerping sequence has not begun
           
                if (!lerping){
                    
                    // Set cam start position ( first key pos )
           
                    camera.pos.vx = camPath.points[camPath.cursor].vx;
           
                    camera.pos.vy = camPath.points[camPath.cursor].vy;
           
                    camera.pos.vz = camPath.points[camPath.cursor].vz;
                    
                    // Lerping sequence is starting
                    lerping = 1;
                    
                    // Set cam pos index to 0
                    camPath.pos = 0;
                    
                    }
                    
                // Pre calculated sqrt ( see psqrt() )
                dist = psqrt( (posToActor.vx * posToActor.vx ) + (posToActor.vz * posToActor.vz));
                
                // Fixed point precision 2^12 == 4096
           
                int precision = 12;
                
                camera.pos.vx = lerpD(camPath.points[camPath.cursor].vx << precision, camPath.points[camPath.cursor+1].vx << precision, camPath.pos << precision) >> precision;
           
                camera.pos.vy = lerpD(camPath.points[camPath.cursor].vy << precision, camPath.points[camPath.cursor+1].vy << precision, camPath.pos << precision) >> precision;
           
                camera.pos.vz = lerpD(camPath.points[camPath.cursor].vz << precision, camPath.points[camPath.cursor+1].vz << precision, camPath.pos << precision) >> precision;
                
                //~ FntPrint("Cam %d, %d\n", (int32_t)camPath.points[camPath.cursor].vx, camPath.points[camPath.cursor+1].vx);
                //~ FntPrint("Cam %d, %d, %d\n", camera.pos.vx, camera.pos.vy, camera.pos.vz);
                //~ FntPrint("Theta y: %d x: %d\n", theta.vy, theta.vx);
                //~ FntPrint("Pos: %d Cur: %d\nTheta y: %d x: %d\n", camPath.pos, camPath.cursor, theta.vy, theta.vx);

                // Linearly increment the lerp factor
           
                camPath.pos += 20;
                
                // If camera has reached next key pos, reset pos index, move cursor to next key pos
                if (camPath.pos > (1 << precision) ){
           
                    camPath.pos = 0;
           
                    camPath.cursor ++;
           
                }                    
                
                // Last key pos is reached, reset cursor to first key pos, lerping sequence is over
                if ( camPath.cursor == camPath.len - 1 ){
           
                    lerping = 0;
           
                    camPath.cursor = 0;
                }
                
            } else { 
           
                // if no key pos exists, switch to next camMode
           
                camMode ++; }
        }
        
        // Camera "on a rail" - cam is tracking actor, and moving with constraints on all axis
    
        if (camMode == 5) {
            
            // track actor. If theta (actor/cam rotation angle) is above or below an arbitrary angle, 
            // move cam so that the angle doesn't increase/decrease anymore.
            
            if (camPath.len) {
         
            // Lerping sequence has not begun
         
                if (!lerping){
                    
                    // Set cam start position ( first key pos )
         
                    camera.pos.vx = camPath.points[camPath.cursor].vx;
         
                    camera.pos.vy = camPath.points[camPath.cursor].vy;
         
                    camera.pos.vz = camPath.points[camPath.cursor].vz;
                    
                    // Lerping sequence is starting
                    
                    lerping = 1;
                    
                    // Set cam pos index to 0
                    
                    camPath.pos = 0;
                    
                    }
                    
                // Pre calculated sqrt ( see psqrt() )
                
                dist = psqrt( (posToActor.vx * posToActor.vx ) + (posToActor.vz * posToActor.vz));
                
                // Fixed point precision 2^12 == 4096
                
                short precision = 12;
                                    
                camera.pos.vx = lerpD(camPath.points[camPath.cursor].vx << precision, camPath.points[camPath.cursor + 1].vx << precision, camPath.pos << precision) >> precision;
         
                camera.pos.vy = lerpD(camPath.points[camPath.cursor].vy << precision, camPath.points[camPath.cursor + 1].vy << precision, camPath.pos << precision) >> precision;
         
                camera.pos.vz = lerpD(camPath.points[camPath.cursor].vz << precision, camPath.points[camPath.cursor + 1].vz << precision, camPath.pos << precision) >> precision;
                
                //~ FntPrint("Cam %d, %d\n", (int32_t)camPath.points[camPath.cursor].vx, camPath.points[camPath.cursor+1].vx);
                //~ FntPrint("Cam %d, %d, %d\n", camera.pos.vx, camera.pos.vy, camera.pos.vz);
                //~ FntPrint("Pos: %d Cur: %d\nTheta y: %d x: %d\n", camPath.pos, camPath.cursor, theta.vy, theta.vx);

                FntPrint("%d", camAngleToAct.vy);

                if ( camAngleToAct.vy < -50 ) {  
          
                    camPath.pos += 40;
          
                }
          
                if ( camAngleToAct.vy > 50 ) {  
          
                    camPath.pos -= 40;
          
                }
                
                // If camera has reached next key pos, reset pos index, move cursor to next key pos
                
                if (camPath.pos > (1 << precision) ){
          
                    camPath.pos = 0;
          
                    camPath.cursor ++;
          
                    //~ camPath.dir = 1;
                } 
                
                if (camPath.pos < -100 ){
          
                    camPath.pos = 1 << precision;
          
                    camPath.cursor --;
                
                    //~ camPath.dir *= -1;
                }                   
                
                // Last key pos is reached, reset cursor to first key pos, lerping sequence is over
                
                if ( camPath.cursor == camPath.len - 1 || camPath.cursor < 0 ){
          
                    lerping = 0;
          
                    camPath.cursor = 0;
                }
                
            } else { 
                // if no key pos exists, switch to next camMode
          
                camMode ++;
            
            }
            
        }
    
        //~ dt = time/180+1 - time/180;
        
        // Spatial partitioning
        
        for ( int msh = 0; msh < curNode->siblings->index; msh ++ ) {
        
            // Actor
        
            if ( !getIntCollision( *actorPtr->body , *curNode->siblings->list[msh]->plane->body).vx &&
                 !getIntCollision( *actorPtr->body , *curNode->siblings->list[msh]->plane->body).vz )
            {
            
                if ( curNode != curNode->siblings->list[msh] ) {
                
                    curNode = curNode->siblings->list[msh];

                    levelPtr = curNode->plane;
                }
            
            }
            
            // Moveable prop
            
            if (  !getIntCollision( *propPtr->body , *curNode->siblings->list[msh]->plane->body).vx &&
                  !getIntCollision( *propPtr->body , *curNode->siblings->list[msh]->plane->body).vz ) {

                if ( propPtr->node != curNode->siblings->list[ msh ]){
                    
                    propPtr->node = curNode->siblings->list[ msh ];
                }
            } else if ( !getIntCollision( *propPtr->body , *curNode->plane->body).vx &&
                        !getIntCollision( *propPtr->body , *curNode->plane->body).vz ) {
            
                    propPtr->node = curNode;
            
            }
            
        }
        
    // Physics
        
        if ( physics ) {
            
            // if(time%1 == 0){
                
                 for ( int k = 0; k < sizeof(meshes)/sizeof(meshes[0]);k ++ ) {
                //~ for ( int k = 0; k < curNode->objects->index ; k ++){
                                        
                     if ( ( *meshes[k]->isRigidBody == 1 ) ) {
                    //~ if ( ( *curNode->rigidbodies->list[k]->isRigidBody == 1 ) ) {

                        //~ applyAcceleration(curNode->rigidbodies->list[k]->body);
                        
                        applyAcceleration(meshes[k]->body);
                    
                        // Get col with level                         ( modelgnd_body )        
                        
                        col_lvl = getIntCollision( *meshes[k]->body , *levelPtr->body );
                        
                        //~ col_lvl = getIntCollision( *actorPtr->body , *curNode->plane->body );
                        
                        //~ for (int plane = 0; plane < curNode->siblings->index; plane++) {
                        
                            //~ col_sphere = getIntCollision( *propPtr->body, *curNode->siblings->list[ plane ]->plane->body);
                        
                        //~ }
                        
                        col_sphere = getIntCollision( *propPtr->body, *propPtr->node->plane->body );
                        
                        //~ col_sphere = getIntCollision( *propPtr->body, *levelPtr->body );
                        
                        col_sphere_act = getExtCollision( *actorPtr->body, *propPtr->body );
                        
                        //~ // If !col, keep moving
                        
                        //~ if ( !col_lvl.vx ){ curNode->rigidbodies->list[k]->pos->vx = curNode->rigidbodies->list[k]->body->position.vx; } 
                        
                        //~ if ( !col_lvl.vy ){ curNode->rigidbodies->list[k]->pos->vy = curNode->rigidbodies->list[k]->body->position.vy; };//meshes[k]->body->gForce.vy = 0;} // FIXME : Why the 15px offset ? 
                        
                        //~ if ( !col_lvl.vz ){ curNode->rigidbodies->list[k]->pos->vz = curNode->rigidbodies->list[k]->body->position.vz; }
                                               
                        //~ // If no col with ground, fall off
                
                        if ( col_lvl.vy ) {
                        
                            if (!col_lvl.vx && !col_lvl.vz){actorPtr->body->position.vy = actorPtr->body->min.vy;}
                        
                        }
                        if (col_sphere.vy){
                            if (!col_sphere.vx && !col_sphere.vz){propPtr->body->position.vy = propPtr->body->min.vy; }
                        }
                        
                        if (col_sphere_act.vx && col_sphere_act.vz ){

                            propPtr->body->velocity.vx += actorPtr->body->velocity.vx;// * ONE / propPtr->body->restitution ;
                            propPtr->body->velocity.vz += actorPtr->body->velocity.vz;// * ONE / propPtr->body->restitution ;
                            
                            if (propPtr->body->velocity.vx){
                                
                                VECTOR L = angularMom(*propPtr->body);
                                propPtr->rot->vz -= L.vx;
                            }
                            
                            if (propPtr->body->velocity.vz){
                                
                                VECTOR L = angularMom(*propPtr->body);
                                propPtr->rot->vx -= L.vz;
                            }
                        }
                        
                        //~ if (!col_sphere_act.vx){
                            //~ propPtr->body->velocity.vx = 0;
                            //~ }
                        
                        

                        meshes[k]->pos->vx = meshes[k]->body->position.vx;
                        
                        meshes[k]->pos->vy = meshes[k]->body->position.vy ;
                        
                        meshes[k]->pos->vz = meshes[k]->body->position.vz;
                        
                        
                    }
                    
                    meshes[k]->body->velocity.vy = 0;
                    
                    meshes[k]->body->velocity.vx = 0;
                    
                    meshes[k]->body->velocity.vz = 0;
                    
                    //~ curNode->rigidbodies->list[k]->body->velocity.vx = curNode->rigidbodies->list[k]->body->velocity.vz = 0;
                    
                    //~ FntPrint("V:%d ", curNode->rigidbodies->list[k]->body->velocity.vy);
                }
            // }
        }
        
    // Camera setup 
        
        // position of cam relative to actor
        
        posToActor.vx = actorPtr->pos->vx + camera.pos.vx;
        
        posToActor.vz = actorPtr->pos->vz + camera.pos.vz;
        
        posToActor.vy = actorPtr->pos->vy + camera.pos.vy;
        
    // Polygon drawing
        
        static long Flag;
        
        if ( (camMode == 2) && (camPtr->tim_data ) ) {
      
            //~ if (camPtr->tim_data){
                
                drawBG();
        
                //~ // Loop on camAngles
        
                //~ for ( int angle = 0 ; angle < sizeof(camAngles)/sizeof(camAngles[0]) - 1 ; angle++ ) {
                
                    for ( int mesh = 0 ; mesh < camAngles[curCamAngle]->index; mesh ++ ) {
                        
                        transformMesh(camAngles[curCamAngle]->objects[mesh]);
                        
                        drawPoly(camAngles[curCamAngle]->objects[mesh], &Flag, atime);
                        
                    }
                
                //~ }
            
            //~ }
        }
        
        else {
        //~ long t = 0;
        
        // Draw current node's plane

        drawPoly( curNode->plane, &Flag, atime);
        
        // Draw surrounding planes 
        
		for ( int sibling = 0; sibling < curNode->siblings->index; sibling++ ) {
        
            drawPoly( curNode->siblings->list[ sibling ]->plane, &Flag, atime);
        
        }
        
        // Draw adjacent planes's children
        
        for ( int sibling = 0; sibling < curNode->siblings->index; sibling++ ) {
            
            for ( int object = 0; object < curNode->siblings->list[ sibling ]->objects->index; object++ ) {
            
                long t = 0;
                
                transformMesh(curNode->siblings->list[ sibling ]->objects->list[ object ]);
                
                drawPoly( curNode->siblings->list[ sibling ]->objects->list[ object ], &Flag, atime);
            
            }
        }
        
        // Draw current plane children
        
		for ( int object = 0; object < curNode->objects->index; object++ ) {
        
            transformMesh(curNode->objects->list[ object ]);

            drawPoly( curNode->objects->list[ object ], &Flag, atime);
        
        }
        
        // Draw rigidbodies
        
        for ( int object = 0; object < curNode->rigidbodies->index; object++ ) {
        
            transformMesh(curNode->rigidbodies->list[ object ]);

            drawPoly( curNode->rigidbodies->list[ object ], &Flag, atime);
        
        }
    
    }
        
        // Find and apply light rotation matrix

        RotMatrix(&lgtang, &rotlgt);	

        MulMatrix0(&lgtmat, &rotlgt, &light);

        SetLightMatrix(&light);

        // Set camera

        applyCamera(&camera);
        
        // Add secondary OT to main OT
        
        AddPrims(otdisc[db], ot[db] + OTLEN - 1, ot[db]);

        //~ FntPrint("CurNode : %x\nIndex: %d", curNode, curNode->siblings->index);
        
        FntPrint("Time    : %d dt :%d\n", VSync(-1) / 60, dt);
        
        FntFlush(-1);
		
		display();

        //~ frame = VSync(-1);

	}
    return 0;
}

void init() {
    
    ResetCallback();
    
    // Reset the GPU before doing anything and the controller
	
    ResetGraph(0);

    PadInit(0);
	
	// Initialize and setup the GTE
	
    InitGeom();
	
    SetGeomOffset( CENTERX, CENTERY );        // x, y offset
	
    SetGeomScreen( FOV );            // Distance between eye and screen  - Camera FOV
	
    // Set the display and draw environments
	
    SetDefDispEnv(&disp[0], 0, 0         , SCREENXRES, SCREENYRES);
	
    SetDefDispEnv(&disp[1], 0, SCREENYRES, SCREENXRES, SCREENYRES);
    
	
    SetDefDrawEnv(&draw[0], 0, SCREENYRES, SCREENXRES, SCREENYRES);
	
    SetDefDrawEnv(&draw[1], 0, 0, SCREENXRES, SCREENYRES);
    
    
    // If PAL 
    
    if ( VMODE ) {
        
        SetVideoMode(MODE_PAL);
        
        disp[0].screen.y += 8;
        
        disp[1].screen.y += 8;
    }
	
    // Set Draw area color
    
    setRGB0(&draw[0], BGc.r, BGc.g, BGc.b);
    
    setRGB0(&draw[1], BGc.r, BGc.g, BGc.b);

    // Set Draw area clear flag

    draw[0].isbg = 1;
    
    draw[1].isbg = 1;

    // Set the disp and draw env

    PutDispEnv(&disp[db]);

	PutDrawEnv(&draw[db]);
		
	// Init font system

	FntLoad(FNT_POS_X, FNT_POS_Y);

	FntOpen(16, 180, 240, 96, 0, 512);
	
    // Lighting setup
    
    SetColorMatrix(&cmat);
    
    SetBackColor(BKc.vx,BKc.vy,BKc.vz);
    
    SetFarColor(BGc.r, BGc.g, BGc.b);
    
    SetFogNearFar(1200, 1600, SCREENXRES);
    
};

void display(void){
    
    //~ DrawSync(0);
    
    vs = VSync(2);  // Using VSync 2 insures constant framerate. 0 makes the fr polycount dependant.

    ResetGraph(1);


    PutDispEnv(&disp[db]);
    PutDrawEnv(&draw[db]);

    SetDispMask(1);
    
    // Main OT
    DrawOTag(otdisc[db] + OT2LEN - 1);
    
    // Secondary OT
    //~ DrawOTag(ot[db] + OTLEN - 1);
    
    db = !db;

    nextpri = primbuff[db];
    
        
};

void LoadTexture(u_long * tim, TIM_IMAGE * tparam){     // This part is from Lameguy64's tutorial series : lameguy64.net/svn/pstutorials/chapter1/3-textures.html login/pw: annoyingmous
		OpenTIM(tim);                                   // Open the tim binary data, feed it the address of the data in memory
		ReadTIM(tparam);                                // This read the header of the TIM data and sets the corresponding members of the TIM_IMAGE structure
		
        LoadImage(tparam->prect, tparam->paddr);        // Transfer the data from memory to VRAM at position prect.x, prect.y
		DrawSync(0);                                    // Wait for the drawing to end
		
		if (tparam->mode & 0x8){ // check 4th bit       // If 4th bit == 1, TIM has a CLUT
			LoadImage(tparam->crect, tparam->caddr);    // Load it to VRAM at position crect.x, crect.y
			DrawSync(0);                                // Wait for drawing to end
	}

};

void transformMesh(MESH * mesh){
    
    //~ if (*mesh->isRigidBody || *mesh->isStaticBody){
                            
        // Apply rotation matrix
        
        RotMatrix_gte(mesh->rot, mesh->mat);            
        
        // Apply translation matrix
        
        TransMatrix(mesh->mat, mesh->pos);
                          
        // Compose matrix with cam
        
        CompMatrix(&camera.mat, mesh->mat, mesh->mat);  

        // Set default rotation and translation matrices
        
        SetRotMatrix(mesh->mat);                             
        
        SetTransMatrix(mesh->mat);                           
        
    //~ }
};

// Drawing

void drawPoly(MESH * mesh, long * Flag, int atime){

    long nclip, t = 0;
    
    // mesh is POLY_GT3 ( triangle )
    
    if (mesh->index[t].code == 4) {
        
        POLY_GT3 * poly;                        
    
        // len member == # vertices, but here it's # of triangle... So, for each tri * 3 vertices ...
        
        for ( int i = 0; i < (mesh->tmesh->len * 3); i += 3 ) {               
            
            // If mesh is not part of precalculated background, draw them, else, discard
            
            if ( !( *mesh->isBG ) || camMode != 2) {
            
                poly = (POLY_GT3 *)nextpri;
                
                // If Vertex Anim flag is set, use it
                
                if (*mesh->isAnim){
                
                    // If interpolation flag is set, use it
                    
                    if(mesh->anim->interpolate){
                        
                         // Ping pong 
                         
                         //~ //if (mesh->anim->cursor > 4096 || mesh->anim->cursor < 0){
                         
                         //~ //   mesh->anim->dir *= -1;
                         
                         //~ //}
                         
                         
                         // Fixed point math precision
                         
                         short precision = 12;

                         // Find next keyframe 
                         
                         if (mesh->anim->cursor > (1 << precision)) {
                            
                            // There are still keyframes to interpolate between
                            
                            if ( mesh->anim->lerpCursor < mesh->anim->nframes - 1 ) {
                            
                                mesh->anim->lerpCursor ++;
                            
                                mesh->anim->cursor = 0;
                            
                            }
                            
                            // We've reached last frame, go back to first frame
                            
                            if ( mesh->anim->lerpCursor == mesh->anim->nframes - 1 ) {

                                mesh->anim->lerpCursor = 0;
                            
                                mesh->anim->cursor = 0;
                            
                            }
                         
                         }
                         
                        // Let's lerp between keyframes

                        // Vertex 1
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vx ].vx = lerpD( mesh->anim->data[mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[t].order.vx].vx << precision , mesh->anim->data[(mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[t].order.vx].vx  << precision, mesh->anim->cursor << precision)  >> precision;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vx ].vz = lerpD( mesh->anim->data[mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[t].order.vx].vz << precision , mesh->anim->data[(mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[t].order.vx].vz  << precision, mesh->anim->cursor << precision)  >> precision;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vx ].vy = lerpD( mesh->anim->data[mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[t].order.vx].vy << precision , mesh->anim->data[(mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[t].order.vx].vy  << precision, mesh->anim->cursor << precision)  >> precision;
                        
                        // Vertex 2
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vz ].vx = lerpD( mesh->anim->data[mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[t].order.vz].vx << precision , mesh->anim->data[(mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[t].order.vz].vx  << precision, mesh->anim->cursor << precision)  >> precision;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vz ].vz = lerpD( mesh->anim->data[mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[t].order.vz].vz << precision , mesh->anim->data[(mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[t].order.vz].vz  << precision, mesh->anim->cursor << precision)  >> precision;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vz ].vy = lerpD( mesh->anim->data[mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[t].order.vz].vy << precision , mesh->anim->data[(mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[t].order.vz].vy  << precision, mesh->anim->cursor << precision)  >> precision;
                        
                        // Vertex 3
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vy ].vx = lerpD( mesh->anim->data[mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[t].order.vy].vx << precision , mesh->anim->data[(mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[t].order.vy].vx  << precision, mesh->anim->cursor << precision)  >> precision;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vy ].vz = lerpD( mesh->anim->data[mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[t].order.vy].vz << precision , mesh->anim->data[(mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[t].order.vy].vz  << precision, mesh->anim->cursor << precision)  >> precision;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vy ].vy = lerpD( mesh->anim->data[mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[t].order.vy].vy << precision , mesh->anim->data[(mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[t].order.vy].vy  << precision, mesh->anim->cursor << precision)  >> precision;
                         
                        mesh->anim->cursor += 2 * mesh->anim->dir;
                         
                        // Coord transformation from world space to screen space
                        
                        nclip = RotAverageNclip3(
                                   
                                    &mesh->tmesh->v[ mesh->index[t].order.vx ],  
                                   
                                    &mesh->tmesh->v[ mesh->index[t].order.vz ],
                                   
                                    &mesh->tmesh->v[ mesh->index[t].order.vy ],
                                   
                                    ( long* ) &poly->x0, ( long* ) &poly->x1, ( long* ) &poly->x2,
                                   
                                    mesh->p,
                                   
                                    mesh->OTz,
                                   
                                    Flag
                                );
                            
                        } else { 
                           
                        // No interpolation
                        
                            // Use the pre-calculated vertices coordinates from the animation data
                           
                            nclip = RotAverageNclip3(
                                        
                                        &mesh->anim->data[ atime % mesh->anim->nframes * mesh->anim->nvert + mesh->index[t].order.vx ],
                                        
                                        &mesh->anim->data[ atime % mesh->anim->nframes * mesh->anim->nvert + mesh->index[t].order.vz ],
                                        
                                        &mesh->anim->data[ atime % mesh->anim->nframes * mesh->anim->nvert + mesh->index[t].order.vy ],
                                        
                                        ( long* ) &poly->x0, ( long* ) &poly->x1, ( long* ) &poly->x2,
                                        
                                        mesh->p,
                                        
                                        mesh->OTz,
                                        
                                        Flag
                                    );
                    }
                        
                } else {
                                            
                // No animation
                
                    // Use model's regular vertex coordinates

                    nclip = RotAverageNclip3(

                                &mesh->tmesh->v[ mesh->index[t].order.vx ],  
                                
                                &mesh->tmesh->v[ mesh->index[t].order.vz ],
                                
                                &mesh->tmesh->v[ mesh->index[t].order.vy ],
                                
                                ( long * ) &poly->x0, ( long * ) &poly->x1, ( long * ) &poly->x2,
                                
                                mesh->p,
                                
                                mesh->OTz,
                                
                                Flag
                            );
                }
                
                // Do not draw invisible meshes 
                
                if ( nclip > 0 && *mesh->OTz > 0 && (*mesh->p < 4096) ) {

                    
                    SetPolyGT3( poly );
                    
                    // If isPrism flag is set, use it

                    if ( *mesh->isPrism ) { 
                        
                        // Transparency effect :
                        
                        // Use current DRAWENV clip as TPAGE instead of regular textures

                        ( (POLY_GT3 *) poly )->tpage = getTPage( mesh->tim->mode&0x3, 0,
                                                                 
                                                                 draw[db].clip.x,
                                                                 
                                                                 draw[db].clip.y
                                                       );
                        
                        // Use projected coordinates (results from RotAverage...) as UV coords and clamp them to 0-255,0-224 

                        setUV3(poly,  (poly->x0 < 0? 0 : poly->x0 > 255? 255 : poly->x0),
                         
                                      (poly->y0 < 0? 0 : poly->y0 > 224? 224 : poly->y0), 
                        
                                      (poly->x1 < 0? 0 : poly->x1 > 255? 255 : poly->x1), 
                        
                                      (poly->y1 < 0? 0 : poly->y1 > 224? 224 : poly->y1), 
                        
                                      (poly->x2 < 0? 0 : poly->x2 > 255? 255 : poly->x2), 
                        
                                      (poly->y2 < 0? 0 : poly->y2 > 224? 224 : poly->y2)
                        
                                      );
                        
     
                    } else {
                    
                    // No transparency effect
                    
                        // Use regular TPAGE
                        
                        ( (POLY_GT3 *) poly )->tpage = getTPage(mesh->tim->mode&0x3, 0,
                        
                                                         mesh->tim->prect->x,
                        
                                                         mesh->tim->prect->y
                        );
                        
                        setUV3(poly,  mesh->tmesh->u[i].vx  , mesh->tmesh->u[i].vy   + mesh->tim->prect->y,
                        
                                      mesh->tmesh->u[i+2].vx, mesh->tmesh->u[i+2].vy + mesh->tim->prect->y,
                        
                                      mesh->tmesh->u[i+1].vx, mesh->tmesh->u[i+1].vy + mesh->tim->prect->y);
                    }

                    // CLUT setup
                    // If tim mode == 0 | 1 (4bits/8bits image), set CLUT coordinates

                    if ( (mesh->tim->mode & 0x3 ) < 2){
                        
                        setClut(poly,             
                        
                                mesh->tim->crect->x,
                        
                                mesh->tim->crect->y);
                    }
                    
                    if (*mesh->isSprite){ 
                                 
                        SetShadeTex( poly, 1 );
                    
                    }
                    // Defaults depth color to neutral grey

                    CVECTOR outCol  = { 128,128,128,0 };
                    
                    CVECTOR outCol1 = { 128,128,128,0 };
                    
                    CVECTOR outCol2 = { 128,128,128,0 };
                    
                    NormalColorDpq(&mesh->tmesh->n[ mesh->index[t].order.vx ], &mesh->tmesh->c[ mesh->index[t].order.vx ], *mesh->p, &outCol);

                    NormalColorDpq(&mesh->tmesh->n[ mesh->index[t].order.vz ], &mesh->tmesh->c[ mesh->index[t].order.vz ], *mesh->p, &outCol1);

                    NormalColorDpq(&mesh->tmesh->n[ mesh->index[t].order.vy ], &mesh->tmesh->c[ mesh->index[t].order.vy ], *mesh->p, &outCol2);                           
                
                    // If transparent effect is in use, inhibate shadows
                
                    if (*mesh->isPrism){ 
                        
                        // Use un-interpolated (i.e: no light, no fog) colors

                        setRGB0(poly, mesh->tmesh->c[i].r,   mesh->tmesh->c[i].g, mesh->tmesh->c[i].b);

                        setRGB1(poly, mesh->tmesh->c[i+1].r, mesh->tmesh->c[i+1].g, mesh->tmesh->c[i+1].b);

                        setRGB2(poly, mesh->tmesh->c[i+2].r, mesh->tmesh->c[i+2].g, mesh->tmesh->c[i+2].b);
                    
                    } else {
                        
                        setRGB0(poly, outCol.r, outCol.g  , outCol.b);
                        
                        setRGB1(poly, outCol1.r, outCol1.g, outCol1.b);
                        
                        setRGB2(poly, outCol2.r, outCol2.g, outCol2.b);
                    } 
                           
                    if ( (*mesh->OTz > 0) && (*mesh->OTz < OTLEN) && (*mesh->p < 4096) ) {
                        
                        AddPrim(&ot[db][*mesh->OTz-2], poly);
                    }
                    
                    nextpri += sizeof(POLY_GT3);
                }
            
                t+=1;

            }
        }
    
    }
    
    // If mesh is quad
    
    if (mesh->index[t].code == 8) {
        
        POLY_GT4 * poly4;
        
        for (int i = 0; i < (mesh->tmesh->len * 4); i += 4) {               
            
            // if mesh is not part of BG, draw them, else, discard
            
            if ( !(*mesh->isBG) || camMode != 2 ) {
            
                poly4 = (POLY_GT4 *)nextpri;
                                
                // Vertex Anim 

                if (*mesh->isAnim){
                    
                    // with interpolation

                    if ( mesh->anim->interpolate ){
                        
                        // ping pong
                        //~ if (mesh->anim->cursor > 4096 || mesh->anim->cursor < 0){
                           //~ mesh->anim->dir *= -1;
                        //~ }
                        
                        short precision = 12;

                        if ( mesh->anim->cursor > 1<<precision ) {

                            if ( mesh->anim->lerpCursor < mesh->anim->nframes - 1 ) {

                                mesh->anim->lerpCursor ++;

                                mesh->anim->cursor = 0;

                            }

                            if ( mesh->anim->lerpCursor == mesh->anim->nframes - 1 ) {

                                mesh->anim->lerpCursor = 0;

                                mesh->anim->cursor = 0;
                            }
                        }
                        
                        // Vertex 1
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vx ].vx = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.vx ].vx << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.vx ].vx  << 12, mesh->anim->cursor << 12)  >> 12;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vx ].vz = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.vx ].vz << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.vx ].vz  << 12, mesh->anim->cursor << 12)  >> 12;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vx ].vy = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.vx ].vy << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.vx ].vy  << 12, mesh->anim->cursor << 12)  >> 12;
                        
                        // Vertex 2
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vz ].vx = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.vz ].vx << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.vz ].vx  << 12, mesh->anim->cursor << 12)  >> 12;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vz ].vz = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.vz ].vz << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.vz ].vz  << 12, mesh->anim->cursor << 12)  >> 12;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vz ].vy = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.vz ].vy << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.vz ].vy  << 12, mesh->anim->cursor << 12)  >> 12;
                        
                        // Vertex 3
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vy ].vx = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.vy ].vx << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.vy ].vx  << 12, mesh->anim->cursor << 12)  >> 12;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vy ].vz = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.vy ].vz << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.vy ].vz  << 12, mesh->anim->cursor << 12)  >> 12;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.vy ].vy = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.vy ].vy << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.vy ].vy  << 12, mesh->anim->cursor << 12)  >> 12;
                        
                        // Vertex 4
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.pad ].vx = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.pad ].vx << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.pad ].vx  << 12, mesh->anim->cursor << 12) >> 12;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.pad ].vz = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.pad ].vz << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.pad ].vz  << 12, mesh->anim->cursor << 12) >> 12;
                        
                        mesh->tmesh->v[ mesh->index[ t ].order.pad ].vy = lerpD( mesh->anim->data[ mesh->anim->lerpCursor * mesh->anim->nvert + mesh->index[ t ].order.pad ].vy << 12 , mesh->anim->data[ (mesh->anim->lerpCursor + 1) * mesh->anim->nvert + mesh->index[ t ].order.pad ].vy  << 12, mesh->anim->cursor << 12) >> 12;
                        
                        mesh->anim->cursor += 2 * mesh->anim->dir;
                        
                        // Coord transformations
                        nclip = RotAverageNclip4(
                                
                                    &mesh->tmesh->v[ mesh->index[t].order.pad ],  
                                    
                                    &mesh->tmesh->v[ mesh->index[t].order.vz],
                                    
                                    &mesh->tmesh->v[ mesh->index[t].order.vx ],
                                    
                                    &mesh->tmesh->v[ mesh->index[t].order.vy ],
                                    
                                    ( long* )&poly4->x0, ( long* )&poly4->x1, ( long* )&poly4->x2, ( long* )&poly4->x3,
                                    
                                    mesh->p,
                                    
                                    mesh->OTz,
                                    
                                    Flag
                                
                                );
                            
                    } else {
                        
                        // No interpolation, use all vertices coordinates in anim data
                         
                        nclip = RotAverageNclip4(
                            
                                    &mesh->anim->data[ atime % mesh->anim->nframes * mesh->anim->nvert + mesh->index[t].order.pad ],
                                    
                                    &mesh->anim->data[ atime % mesh->anim->nframes * mesh->anim->nvert + mesh->index[t].order.vz ],
                                    
                                    &mesh->anim->data[ atime % mesh->anim->nframes * mesh->anim->nvert + mesh->index[t].order.vx ],
                                    
                                    &mesh->anim->data[ atime % mesh->anim->nframes * mesh->anim->nvert + mesh->index[t].order.vy ],
                                    
                                    ( long* )&poly4->x0, ( long* )&poly4->x1, ( long* )&poly4->x2, ( long* )&poly4->x3,
                                    
                                    mesh->p,
                                    
                                    mesh->OTz,
                                    
                                    Flag
                                );
                    }
                            
                } else {                        
                
                    // No animation
                    // Use regulare vertex coords
                    
                    nclip = RotAverageNclip4(
                               
                                &mesh->tmesh->v[ mesh->index[t].order.pad ],  
                               
                                &mesh->tmesh->v[ mesh->index[t].order.vz],
                               
                                &mesh->tmesh->v[ mesh->index[t].order.vx ],
                               
                                &mesh->tmesh->v[ mesh->index[t].order.vy ],
                               
                                (long*)&poly4->x0, (long*)&poly4->x1, (long*)&poly4->x2, (long*)&poly4->x3,
                               
                                mesh->p,
                               
                                mesh->OTz,
                               
                                Flag
                            );
                }
                
                if (nclip > 0 && *mesh->OTz > 0 && (*mesh->p < 4096)) {
             
                    SetPolyGT4(poly4);
                        
                    // FIXME : Polygon subdiv - is it working ?
                    
                    //~ OTc = *mesh->OTz >> 4;
                    //~ FntPrint("OTC:%d", OTc);
                    
                    //~ if (OTc < 4) {
                    
                        //~ if (OTc > 1) div4.ndiv = 1; else div4.ndiv = 2;
                            
                            //~ DivideGT4(
                                //~ // Vertex coord
                                //~ &mesh->tmesh->v[ mesh->index[t].order.pad ],  
                                //~ &mesh->tmesh->v[ mesh->index[t].order.vz ],
                                //~ &mesh->tmesh->v[ mesh->index[t].order.vx ],
                                //~ &mesh->tmesh->v[ mesh->index[t].order.vy ],
                                //~ // UV coord
                                //~ mesh->tmesh->u[i+3],
                                //~ mesh->tmesh->u[i+2],
                                //~ mesh->tmesh->u[i+0],
                                //~ mesh->tmesh->u[i+1],
                                
                                //~ // Color
                                //~ mesh->tmesh->c[i], 
                                //~ mesh->tmesh->c[i+1], 
                                //~ mesh->tmesh->c[i+2], 
                                //~ mesh->tmesh->c[i+3], 

                                //~ // Gpu packet
                                //~ poly4,
                                //~ &ot[db][*mesh->OTz],
                                //~ &div4);
                                        
                            //~ // Increment primitive list pointer
                            //~ nextpri  += ( (sizeof(POLY_GT4) + 3) / 4 ) * (( 1 << ( div4.ndiv )) << ( div4.ndiv ));
                            //~ triCount = ((1<<(div4.ndiv))<<(div4.ndiv));
                    
                    //~ } else if (OTc < 48) {
                
                    // Transparency effect
                    
                    if (*mesh->isPrism){ 
                        
                        // Use current DRAWENV clip as TPAGE
                        
                        ( (POLY_GT4 *) poly4)->tpage = getTPage(mesh->tim->mode&0x3, 0,
                                                                 draw[db].clip.x,
                                                                 draw[db].clip.y
                                                       );
                        
                        // Use projected coordinates
                        
                        setUV4( poly4, 
                              
                                (poly4->x0 < 0? 0 : poly4->x0 > 255? 255 : poly4->x0), 
                              
                                (poly4->y0 < 0? 0 : poly4->y0 > 224? 224 : poly4->y0), 
                              
                                (poly4->x1 < 0? 0 : poly4->x1 > 255? 255 : poly4->x1), 
                              
                                (poly4->y1 < 0? 0 : poly4->y1 > 224? 224 : poly4->y1), 
                              
                                (poly4->x2 < 0? 0 : poly4->x2 > 255? 255 : poly4->x2), 
                              
                                (poly4->y2 < 0? 0 : poly4->y2 > 224? 224 : poly4->y2),
                              
                                (poly4->x3 < 0? 0 : poly4->x3 > 255? 255 : poly4->x3), 
                              
                                (poly4->y3 < 0? 0 : poly4->y3 > 224? 224 : poly4->y3)
                        );
                        
     
                    } else {
                        
                        // Use regular TPAGE
                        ( (POLY_GT4 *) poly4)->tpage = getTPage( 
                                                        
                                                         mesh->tim->mode&0x3, 0,
                        
                                                         mesh->tim->prect->x,
                        
                                                         mesh->tim->prect->y
                                                     );
                        
                        // Use model UV coordinates
                        
                        setUV4( poly4, 
                                mesh->tmesh->u[i+3].vx, mesh->tmesh->u[i+3].vy   + mesh->tim->prect->y,
                                
                                mesh->tmesh->u[i+2].vx, mesh->tmesh->u[i+2].vy + mesh->tim->prect->y,
                            
                                mesh->tmesh->u[i+0].vx, mesh->tmesh->u[i+0].vy + mesh->tim->prect->y,
                            
                                mesh->tmesh->u[i+1].vx, mesh->tmesh->u[i+1].vy + mesh->tim->prect->y
                        );

                    }
                    
                    if (*mesh->isSprite){ 
                                 
                        SetShadeTex( poly4, 1 );
                    
                    }
                    
                        // If tim mode  == 0 | 1, set CLUT coordinates
                        if ( (mesh->tim->mode & 0x3) < 2 ) {
                            
                            setClut(poly4,             
                            
                                    mesh->tim->crect->x,
                            
                                    mesh->tim->crect->y
                            );
                            
                        }
                        
                        CVECTOR outCol  = {128,128,128,0};
                        
                        CVECTOR outCol1 = {128,128,128,0};
                        
                        CVECTOR outCol2 = {128,128,128,0};
                        
                        CVECTOR outCol3 = {128,128,128,0};

                        NormalColorDpq(&mesh->tmesh->n[ mesh->index[t].order.pad ]  , &mesh->tmesh->c[ mesh->index[t].order.pad ], *mesh->p, &outCol);
                        
                        NormalColorDpq(&mesh->tmesh->n[ mesh->index[t].order.vz ], &mesh->tmesh->c[ mesh->index[t].order.vz ], *mesh->p, &outCol1);
                        
                        NormalColorDpq(&mesh->tmesh->n[ mesh->index[t].order.vx ], &mesh->tmesh->c[ mesh->index[t].order.vx ], *mesh->p, &outCol2);
                        
                        NormalColorDpq(&mesh->tmesh->n[ mesh->index[t].order.vy ], &mesh->tmesh->c[  mesh->index[t].order.vy ], *mesh->p, &outCol3);

                    if (*mesh->isPrism){ 
                        
                        setRGB0(poly4, mesh->tmesh->c[i].r, mesh->tmesh->c[i].g, mesh->tmesh->c[i].b);

                        setRGB1(poly4, mesh->tmesh->c[i+1].r, mesh->tmesh->c[i+1].g, mesh->tmesh->c[i+1].b);

                        setRGB2(poly4, mesh->tmesh->c[i+2].r, mesh->tmesh->c[i+2].g, mesh->tmesh->c[i+2].b);

                        setRGB3(poly4, mesh->tmesh->c[i+3].r, mesh->tmesh->c[i+3].g, mesh->tmesh->c[i+3].b);
                    
                    } else {
                        
                        setRGB0(poly4, outCol.r, outCol.g  , outCol.b);

                        setRGB1(poly4, outCol1.r, outCol1.g, outCol1.b);

                        setRGB2(poly4, outCol2.r, outCol2.g, outCol2.b);

                        setRGB3(poly4, outCol3.r, outCol3.g, outCol3.b);
                    } 
                           
                    if ( (*mesh->OTz > 0) && (*mesh->OTz < OTLEN) && (*mesh->p < 4096) ) {

                        AddPrim( &ot[ db ][ *mesh->OTz-3 ], poly4 );      
                    }
                    
                    nextpri += sizeof( POLY_GT4 );
                    
                }
            
            t += 1;

            }
        }
    } 

};

void drawBG(void){
    
    // Draw BG image in two SPRT since max width == 256 px 
    
    SPRT * sprt;                        
    
    DR_TPAGE * tpage;
    
    // Left part
                
    sprt = ( SPRT * ) nextpri;
    
    setSprt( sprt );
    
    setRGB0( sprt, 128, 128, 128 );
    
    setXY0( sprt, 0, 0 );
    
    setWH( sprt, 256, SCREENYRES );
    
    setUV0( sprt, 0, 0 );
    
    setClut( sprt, 
            
             camPtr->BGtim->crect->x, 
                
             camPtr->BGtim->crect->y
    
    );
    
    addPrim( &otdisc[ db ][ OT2LEN-1 ], sprt );        
                
    nextpri += sizeof( SPRT );
    
    
    // Change TPAGE
    
    tpage = (DR_TPAGE *) nextpri;
    
    setDrawTPage(
            
        tpage, 0, 1,   
     
        getTPage( 
            
            camPtr->BGtim->mode & 0x3, 0,       
     
            camPtr->BGtim->prect->x,
            
            camPtr->BGtim->prect->y
        
        )
    
    );
                                            
    addPrim(&otdisc[db][OT2LEN-1], tpage);

    nextpri += sizeof(DR_TPAGE); 
    
    
    // Right part
    
    sprt = ( SPRT * ) nextpri;
    
    setSprt( sprt );
    
    setRGB0( sprt, 128, 128, 128 );
    
    setXY0( sprt, SCREENXRES - ( SCREENXRES - 256 ), 0 );
    
    setWH( sprt, SCREENXRES - 256, SCREENYRES );
    
    setUV0( sprt, 0, 0 );
    
    setClut( sprt, 
             
             camPtr->BGtim->crect->x,
             
             camPtr->BGtim->crect->y
    );
                
    addPrim( &otdisc[ db ][ OT2LEN-1 ], sprt );        
                
    nextpri += sizeof( SPRT );
    
    tpage = ( DR_TPAGE * ) nextpri;
    
    // Change TPAGE
    
    setDrawTPage(
    
        tpage, 0, 1,
        
        getTPage(
        
            camPtr->BGtim->mode & 0x3, 0,       
        
            camPtr->BGtim->prect->x + 128, 
            
            camPtr->BGtim->prect->y
    
        )
    
    );
                                            
    addPrim( &otdisc[ db ][ OT2LEN-1 ], tpage );

    nextpri += sizeof( DR_TPAGE ); 

};

// Maths

void getCameraXZ(int * x, int * z, int actorX, int actorZ, int angle, int distance) {
    
    // Using Nic's Costable : https://github.com/grumpycoders/Balau/blob/master/tests/test-Handles.cc#L20-L102
    //                        https://godbolt.org/z/q6cMcj    
    
    *x = (actorX << 12) + (distance * nsin(angle));
    
    *z = (actorZ << 12) - (distance * ncos(angle));

};

// @Will : you might want to use sin/cos to move the camera in a circle but you could do that by moving it along it’s tangent and then clamping the distance

void applyCamera( CAMERA * cam ) {
    
    VECTOR vec;                                         // Vector that holds the output values of the following instructions

    RotMatrix_gte(&cam->rot, &cam->mat);                // Convert rotation angle in psx units (360° == 4096) to rotation matrix)
    
    ApplyMatrixLV(&cam->mat, &cam->pos, &vec);          // Multiply matrix by vector pos and output to vec

    TransMatrix(&cam->mat, &vec);                       // Apply transform vector
    
    SetRotMatrix(&cam->mat);                            // Set Rotation matrix
    
    SetTransMatrix(&cam->mat);                          // Set Transform matrix
    
   
};

void setCameraPos( VECTOR pos, SVECTOR rot ) {
  
    camera.pos =  pos;
  
    camera.rot =  rot;
    
};

VECTOR getVectorTo( VECTOR actor, VECTOR target ) {
    
    VECTOR direction = { subVector(target, actor) };
    
    VECTOR Ndirection = {0,0,0,0};
    
    u_int distSq = (direction.vx * direction.vx) + (direction.vz * direction.vz);
    
    direction.pad = psqrt(distSq);
    
    VectorNormal(&direction, &Ndirection);
    
    return Ndirection ;

};
    
//~ int alignAxisToVect(VECTOR target, short axis, int factor){    
    //~ }

// Lerp

int lerp(int start, int end, int factor){
    
    // lerp interpolated cam movement
    // InBetween = Value 1 + ( ( Value2 - Value1 ) * lerpValue ) ;
    // lerpValue should be a float between 0 and 1.
    
    
    return ( start ) + (( end - start ) * factor ) >> 12;

};

long long easeIn(long long i, int div){
 
    return ((i << 7) * (i << 7) * (i << 7) / div ) >> 19;
 
};

int easeOut(int i){

    return (4096 >> 7) - ((4096 - (i << 7)) * (4096 - (i << 7))) >> 12;

};
    
int easeInOut(int i, int div){
    
    return lerp(easeIn(i, div), easeOut(i) , i);
    
};
    
SVECTOR SVlerp(SVECTOR start, SVECTOR end, int factor){

    SVECTOR output = {0,0,0,0};

    output.vx = lerp(start.vx, end.vx, factor);

    output.vy = lerp(start.vy, end.vy, factor);

    output.vz = lerp(start.vz, end.vz, factor);

    return output;

};


// Physics

VECTOR getIntCollision(BODY one, BODY two){
    
    VECTOR d1, d2, col;
   
    short correction = 50;
    
    d1.vx = (one.position.vx + one.max.vx) - (two.position.vx + two.min.vx);

    d1.vy = (one.position.vy + one.max.vy) - (two.position.vy + two.min.vy);

    d1.vz = (one.position.vz + one.max.vz) - (two.position.vz + two.min.vz);
    

    d2.vx = (two.position.vx + two.max.vx) - (one.position.vx - one.max.vx);

    d2.vy = (two.position.vy + two.max.vy) - (one.position.vy + one.min.vy);

    d2.vz = (two.position.vz + two.max.vz) - (one.position.vz - one.max.vz);


    col.vx = !(d1.vx > 0 && d2.vx > 0);

    col.vy = d1.vy > 0 && d2.vy > 0;

    col.vz = !(d1.vz > 0 && d2.vz > 0);
        
    return col;

};
    
VECTOR getExtCollision(BODY one, BODY two){
    
    VECTOR d1, d2, col;
    
    d1.vx = (one.position.vx + one.max.vx) - (two.position.vx + two.min.vx);
   
    d1.vy = (one.position.vy + one.max.vy) - (two.position.vy + two.min.vy);
   
    d1.vz = (one.position.vz + one.max.vz) - (two.position.vz + two.min.vz);
   
    
    d2.vx = (two.position.vx + two.max.vx) - (one.position.vx + one.min.vx);
   
    d2.vy = (two.position.vy + two.max.vy) - (one.position.vy + one.min.vy);
   
    d2.vz = (two.position.vz + two.max.vz) - (one.position.vz + one.min.vz);


    col.vx = d1.vx > 0 && d2.vx > 0;

    col.vy = d1.vy > 0 && d2.vy > 0;

    col.vz = d1.vz > 0 && d2.vz > 0;

        
    return col;

};

void applyAcceleration(BODY * actor){
    
    short dt = 1;

    VECTOR acceleration = {actor->invMass * actor->gForce.vx ,  (actor->invMass * actor->gForce.vy) + (gravity * ONE), actor->invMass * actor->gForce.vz};
    
    //~ FntPrint("acc: %d %d %d\n", acceleration.vx, acceleration.vy, acceleration.vz );
    
    actor->velocity.vx += (acceleration.vx * dt) >> 12;
    
    actor->velocity.vy += (acceleration.vy * dt) >> 12;
    
    actor->velocity.vz += (acceleration.vz * dt) >> 12;
    
    //~ FntPrint("acc: %d %d %d\n", acceleration.vx / ONE, acceleration.vy / ONE, acceleration.vz / ONE );
    
    actor->position.vx += (actor->velocity.vx * dt);
    
    actor->position.vy += (actor->velocity.vy * dt);
    
    actor->position.vz += (actor->velocity.vz * dt);
    
    //~ FntPrint("vel: %d %d %d\n", actor->velocity.vx, actor->velocity.vy, actor->velocity.vz );
    
};

//~ // https://gamedevelopment.tutsplus.com/tutorials/how-to-create-a-custom-2d-physics-engine-the-basics-and-impulse-resolution--gamedev-6331

void ResolveCollision( BODY * one, BODY * two ){
  
    //~ FntPrint("rv: %d, %d, %d\n", one->velocity.vx, one->velocity.vy, one->velocity.vz);

    // Calculate relative velocity

    VECTOR rv = { subVector( one->velocity, two->velocity) };

    //~ FntPrint("rv: %d, %d, %d\n", rv.vx,rv.vy,rv.vz);

    // Collision normal

    VECTOR normal = { subVector( two->position, one->position ) };

    // Normalize collision normal

    normal.vx = normal.vx > 0 ? 1 : normal.vx < 0 ? -1 : 0 ;

    normal.vy = normal.vy > 256 ? 1 : normal.vy < -256 ? -1 : 0 ;

    normal.vz = normal.vz > 0 ? 1 : normal.vz < 0 ? -1 : 0 ;

    //~ FntPrint("norm: %d, %d, %d\n", normal.vx,normal.vy,normal.vz);

    // Calculate relative velocity in terms of the normal direction

    long velAlongNormal = dotProduct( rv, normal );

    //~ FntPrint("velN: %d\n", velAlongNormal);

    // Do not resolve if velocities are separating

    if(velAlongNormal > 0)

    return;

    // Calculate restitution
    long e = min( one->restitution, two->restitution );

    //~ FntPrint("e: %d\n", e);

    //~ // Calculate impulse scalar
    long j = -(1 + e) * velAlongNormal * ONE;

    j /= one->invMass + two->invMass;
    //~ j /= ONE;

    //~ FntPrint("j: %d\n", j);

    // Apply impulse
    applyVector(&normal, j, j, j, *=);

    //~ FntPrint("Cnormal %d %d %d\n",normal.vx,normal.vy,normal.vz); 

    VECTOR velOne = normal;

    VECTOR velTwo = normal;

    applyVector(&velOne,one->invMass,one->invMass,one->invMass, *=);

    applyVector(&velTwo,two->invMass,two->invMass,two->invMass, *=);

    //~ FntPrint("V1 %d %d %d\n", velOne.vx/4096,velOne.vy/4096,velOne.vz/4096);
    //~ FntPrint("V2 %d %d %d\n", velTwo.vx/4096,velTwo.vy/4096,velTwo.vz/4096);

    applyVector(&one->velocity, velOne.vx/4096/4096, velOne.vy/4096/4096, velOne.vz/4096/4096, +=);

    applyVector(&two->velocity, velTwo.vx/4096/4096, velTwo.vy/4096/4096, velTwo.vz/4096/4096, -=);

    //~ FntPrint("V1 %d %d %d\n", velOne.vx/4096/4096,velOne.vy/4096/4096,velOne.vz/4096/4096);
    //~ FntPrint("V2 %d %d %d\n", velTwo.vx/4096/4096,velTwo.vy/4096/4096,velTwo.vz/4096/4096);

};

VECTOR angularMom(BODY body){
    
    // L = r * p
    
    // p = m * v  
    
    VECTOR w = {0,0,0,0};
    
    int r = (body.max.vx - body.min.vx) >> 1;
    
    w.vx = (r * body.mass * body.velocity.vx) >> 2; 
    
    w.vy = (r * body.mass * body.velocity.vy) >> 2; 
    
    w.vz = (r * body.mass * body.velocity.vz) >> 2; 
    
    //~ FntPrint("v: %d, r:%d, w:%d\n", body.velocity.vz * r, r * r, w.vz);
    
    return w;
    
};
    
// From : https://github.com/grumpycoders/pcsx-redux/blob/7438e9995833db5bc1e14da735bbf9dc78300f0b/src/mips/shell/math.h
static inline int32_t dMul(int32_t a, int32_t b) {
 
    long long r = a;
 
    r *= b;
 
    return r >> 24;

};


// standard lerp function
//  s = source, an arbitrary number up to 2^24
//  d = destination, an arbitrary number up to 2^24
//  p = position, a number between 0 and 256, inclusive
//  p = 0 means output = s
//  p = 256 means output = d
static inline uint32_t lerpU(uint32_t start, uint32_t dest, unsigned pos) { return (start * (256 - pos) + dest * pos) >> 8; };

static inline int32_t lerpS(int32_t start, int32_t dest, unsigned pos) { return (start * (256 - pos) + dest * pos) >> 8; };

// start, dest and pos have to be << x, then the result has to be >> x where x defines precision: 
// precision = 2^24 - 2^x
// << x : 0 < pos < precision
// https://discord.com/channels/642647820683444236/646765703143227394/811318550978494505
// my angles are between 0 and 2048 (full circle), so 2^11 for the range of angles; with numbers on a 8.24 representation, a 1.0 angle (or 2pi) means it's 2^24, so to "convert" my angles from 8.24 to my internal discrete cos, I only have to shift by 13

static inline int32_t lerpD(int32_t start, int32_t dest, int32_t pos) { return dMul(start, 16777216 - pos) + dMul(dest, pos); };

static inline long long lerpL(long long start, long long dest, long long pos){  return dMul( (start << 12), 16777216 - (pos << 12) ) + dMul((dest << 12), (pos << 12) ) >> 12; };

// A few notes on the following code :

int ncos(unsigned int t) {

    t %= DC_2PI;

    int r;

    if (t < DC_PI2) {

        r = m_cosTable[t];

    } else if (t < DC_PI) {

        r = -m_cosTable[DC_PI - 1 - t];

    } else if (t < (DC_PI + DC_PI2)) {

        r = -m_cosTable[t - DC_PI];

    } else {

        r = m_cosTable[DC_2PI - 1 - t];

    };

    return r >> 12;
};

// sin(x) = cos(x - pi / 2)
int nsin(unsigned int t) {

    t %= DC_2PI;

    if (t < DC_PI2){

        return ncos(t + DC_2PI - DC_PI2);

    };

    return ncos(t - DC_PI2);
};

// f(n) = cos(n * 2pi / 2048) <- 2048 is == DC_2PI value
// f(n) = 2 * f(1) * f(n - 1) - f(n - 2)
void generateTable(void){
    
    m_cosTable[0] = 16777216;               // 2^24 * cos(0 * 2pi / 2048) => 2^24 * 1 = 2^24 : here, 2^24 defines the precision we want after the decimal point

    static const long long C = 16777137;    // 2^24 * cos(1 * 2pi / 2048) = C = f(1);

    m_cosTable[1] = C;
    
    for (int i = 2; i < 512; i++){

        m_cosTable[i] = ((C * m_cosTable[i - 1]) >> 23) - m_cosTable[i - 2];

        m_cosTable[511] = 0;
    }
};

// https://github.com/Arsunt/TR2Main/blob/411cacb35914c616cb7960c0e677e00c71c7ee88/3dsystem/phd_math.cpp#L432
long long patan(long x, long y){

    long long result;

    int swapBuf;

    int flags = 0;
    
    // if either x or y are 0, return 0

    if( x == 0 && y == 0){

        return 0;

    }

    if( x < 0 ) {

        flags |= 4; 

        x = -x;
        
    }
    
    if ( y < 0 ) {

        flags |= 2;

        y = -y;

    }
    
    if ( y > x ) {

        flags |= 1;

        SWAP(x, y ,swapBuf);

    }
    
    result = AtanBaseTable[flags] + AtanAngleTable[0x800 * y / x];

    if ( result < 0 ){

        result = -result;
        
    return result;
    
    }
    
};

u_int psqrt(u_int n){
    
    u_int result = 0;
    
    u_int base = 0x40000000;
    
    u_int basedResult;
    
    for( ; base != 0; base >>= 2 ) {
    
        for( ; base != 0; base >>= 2 ) {
    
            basedResult = base + result;
    
            result >>= 1;
            
            if( basedResult > n ) {
       
                break;
       
            }
            
            n -= basedResult;
       
            result |= base;
       
        }
    
    }
    
    return result;
};

int cliptest3( short *v1 ) {

	if( v1[0]<0 && v1[2]<0 && v1[4]<0 ) return 0;
	
    if( v1[1]<0 && v1[3]<0 && v1[5]<0 ) return 0;

	if( v1[0] > SCREENXRES && v1[2] > SCREENXRES && v1[4] > SCREENXRES) return 0;
	
    if( v1[1] > SCREENYRES && v1[3] > SCREENYRES && v1[5] > SCREENYRES) return 0;

	return 1;
};

void callback() {
    
    u_short pad = PadRead(0);
    
    static u_short lastPad;
    
    static short forceApplied = 0;
    
    int div = 4096 >> 7;
    
    static int lerpValues[4096 >> 7];
    
    static short cursor = 0;
    
    //~ static short curCamAngle = 0;
    
    if( !lerpValues[0] ) {
        
        for ( long long i = 0; i < div ; i++ ){

            lerpValues[(div-1)-i] = lerp(-24, -264, easeIn(i, div));
        
        }
    }
    
    if( timer ) {
        
        timer--;
    
    }    

    if( cursor>0 ) {
        
        cursor--;
    
    }    

    if ( pad & PADR1 && !timer ) {
        
        if (!camPtr->tim_data){
            
            if(camMode < 6){ 
                
                    camMode ++;
            
                    lerping = 0;
                
            } else {
            
                setCameraPos(camPtr->campos->pos, camPtr->campos->rot);
            
                camPath.cursor = 0;
            
                camMode = 0;
            
                lerping = 0;
            }

        } else {
            
            if (curCamAngle > 4) {

                curCamAngle = 0;

            }

            if (curCamAngle < 5) {

                curCamAngle++;

                camPtr = camAngles[ curCamAngle ];

                LoadTexture(camPtr->tim_data, camPtr->BGtim);

            } 
        }

        lastPad = pad;

        timer = 10;
    }
        
    if ( !(pad & PADR1) && lastPad & PADR1 ) {
        
        //~ pressed = 0;
    
    }
    
    if ( pad & PADL2 ) {
    
        lgtang.vy += 32;
    
    }
    
    if ( pad & PADL1 ) {
    
        lgtang.vz += 32;
    
    }
    
    if ( pad & PADRup && !timer ){
    
        if (*actorPtr->isPrism){
    
            *actorPtr->isPrism = 0;
    
        } else {
     
            *actorPtr->isPrism = 1;
     
        }
     
        timer = 10;
     
        lastPad = pad;
    }
    
    if ( pad & PADRdown && !timer ){
        //~ if (actorPtr->body->gForce.vy >= 0 && actorPtr->body->position.vy >= actorPtr->body->min.vy  ){
                //~ forceApplied -= 150;
        //~ }
        cursor = div - 15;
        timer = 30;
        lastPad = pad;
    }
    
    if ( !(pad & PADRdown) && lastPad & PADRdown ) {
        //~ lastPad = pad;
    }
    
    if ( pad & PADRleft && !timer ) {
        
        if (actorPtr->anim->interpolate){
        
            actorPtr->anim->interpolate = 0;
        
        } else {
        
            actorPtr->anim->interpolate = 1;
        
        }
        
        timer = 10;
        
        lastPad = pad;
    }
        
    if ( pad & PADLup ) {
        
        actorPtr->body->gForce.vz = getVectorTo(fVecActor, *actorPtr->pos).vz >> 8 ;
        
        actorPtr->body->gForce.vx = -getVectorTo(fVecActor, *actorPtr->pos).vx >> 8 ;
        
        lastPad = pad;
    }
    
    if ( !(pad & PADLup) && lastPad & PADLup) {

        actorPtr->body->gForce.vz = 0;

        actorPtr->body->gForce.vx = 0;
    }
    
    if ( pad & PADLdown ) {

        actorPtr->body->gForce.vz = -getVectorTo(fVecActor, *actorPtr->pos).vz >> 8 ;

        actorPtr->body->gForce.vx = getVectorTo(fVecActor, *actorPtr->pos).vx >> 8 ;

        lastPad = pad;
    }
    
    if ( !(pad & PADLdown) && lastPad & PADLdown) {

        actorPtr->body->gForce.vz = 0;

        actorPtr->body->gForce.vx = 0;

        lastPad = pad;

    }
    
    if ( pad & PADLleft ) {

        actorPtr->rot->vy -= 32;

        lastPad = pad;

    }
    
    if ( pad & PADLright ) {

        actorPtr->rot->vy += 32;

        lastPad = pad;
    }
    
    if ( cursor ) {
        
        actorPtr->body->position.vy = lerpValues[cursor];}
    
};