nolibgs_hello_worlds/hello_bs/hello_bs.c
2021-07-25 17:39:20 +02:00

152 lines
6.5 KiB
C

// Load a BS file from CD, decompress and display it.
// Schnappy 07-2021
#include <sys/types.h>
#include <stdio.h>
#include <libgte.h>
#include <libetc.h>
#include <libgpu.h>
// CD library
#include <libcd.h>
// CODEC library
#include <libpress.h>
#include <malloc.h>
#define VMODE 0 // Video Mode : 0 : NTSC, 1: PAL
#define SCREENXRES 320 // Screen width
#define SCREENYRES 240 + (VMODE << 4) // Screen height : If VMODE is 0 = 240, if VMODE is 1 = 256
#define CENTERX SCREENXRES/2 // Center of screen on x
#define CENTERY SCREENYRES/2 // Center of screen on y
#define MARGINX 8 // margins for text display
#define MARGINY 16
#define FONTSIZE 8 * 7 // Text Field Height
DISPENV disp[2]; // Double buffered DISPENV and DRAWENV
DRAWENV draw[2];
short db = 0; // index of which buffer is used, values 0, 1
// CD specifics
#define CD_SECTOR_SIZE 2048
// Converting bytes to sectors SECTOR_SIZE is defined in words, aka int
#define BtoS(len) ( ( len + CD_SECTOR_SIZE - 1 ) / CD_SECTOR_SIZE )
// Name of file to load
static char * loadFile;
// libcd's CD file structure contains size, location and filename
CdlFILE filePos = {0};
//~ struct EXEC * exeStruct;
// Define start address of allocated memory
// Let's use an array so we don't have to worry about using a memory segment that's already in use.
static unsigned char ramAddr[0x40000]; // https://discord.com/channels/642647820683444236/663664210525290507/864936962199781387
// We could also set a memory address manually, but we have to make sure this won't get in the way of other routines.
// void * ramAddr = (void *)0x80030D40;
// Load data to this buffer
u_long * dataBuffer;
// Those are not strictly needed, but we'll use them to see the commands results.
// They could be replaced by a 0 in the various functions they're used with.
u_char CtrlResult[8];
// Value returned by CDread() - 1 is good, 0 is bad
int CDreadOK = 0;
// Value returned by CDsync() - Returns remaining sectors to load. 0 is good.
int CDreadResult = 0;
// BS decompression
// Store size of uncompressed data
long bsBufferSize;
// Allocated memory address
void * bsWorkBuffer;
// Define image draw area
RECT bsDrawArea = { 0, 0, 16, SCREENYRES};
// Used to store a 16x240 image strip
u_long bsStrip[16*240];
void init(void)
{
ResetGraph(0); // Initialize drawing engine with a complete reset (0)
SetDefDispEnv(&disp[0], 0, 0 , SCREENXRES, SCREENYRES); // Set display area for both &disp[0] and &disp[1]
SetDefDispEnv(&disp[1], 0, SCREENYRES, SCREENXRES, SCREENYRES); // &disp[0] is on top of &disp[1]
SetDefDrawEnv(&draw[0], 0, SCREENYRES, SCREENXRES, SCREENYRES); // Set draw for both &draw[0] and &draw[1]
SetDefDrawEnv(&draw[1], 0, 0 , SCREENXRES, SCREENYRES); // &draw[0] is below &draw[1]
// Set video mode
if (VMODE){ SetVideoMode(MODE_PAL);}
SetDispMask(1); // Display on screen
setRGB0(&draw[0], 155, 0, 150); // set color for first draw area
setRGB0(&draw[1], 155, 0, 150); // set color for second draw area
draw[0].isbg = 0; // set mask for draw areas. 1 means repainting the area with the RGB color each frame
draw[1].isbg = 0;
PutDispEnv(&disp[db]); // set the disp and draw environnments
PutDrawEnv(&draw[db]);
FntLoad(960, 0); // Load font to vram at 960,0(+128)
FntOpen(MARGINX, MARGINY, SCREENXRES - MARGINX * 2, FONTSIZE, 0, 280 ); // FntOpen(x, y, width, height, black_bg, max. nbr. chars
}
void display(void)
{
DrawSync(0); // Wait for all drawing to terminate
VSync(0); // Wait for the next vertical blank
PutDispEnv(&disp[db]); // set alternate disp and draw environnments
PutDrawEnv(&draw[db]);
db = !db; // flip db value (0 or 1)
}
int main(void)
{
// Init display
init();
// Init CD system
CdInit();
// Init heap
InitHeap((u_long *)ramAddr, sizeof(ramAddr));
// If the other method was chosen at l.39
// InitHeap((void *)0x80030D40, 0x40000);
// Set name of file to load
loadFile = "\\BACE.BS;1";
// Get file position from filename
CdSearchFile( &filePos, loadFile);
// Allocate memory
dataBuffer = malloc( BtoS(filePos.size) * CD_SECTOR_SIZE );
// Issue CdlSetloc CDROM command : Set the seek target position
// Beware of a misnomed 'sector' member in the CdlLOC struct that should really be named 'frame'.
// https://discord.com/channels/642647820683444236/663664210525290507/864912470996942910
CdControl(CdlSetloc, (u_char *)&filePos.pos, CtrlResult);
// Read data and load it to dataBuffer
CDreadOK = CdRead( (int)BtoS(filePos.size), (u_long *)dataBuffer, CdlModeSpeed );
// Wait for operation to complete
CDreadResult = CdReadSync(0, 0);
// Image Decompression
// Initialize image processing subsystem
DecDCTReset(0);
// Find the needed buffer size
bsBufferSize = DecDCTBufSize(dataBuffer);
// Allocate buffer size at &bsWorkBuffer
bsWorkBuffer = malloc( bsBufferSize );
// Decode Huffman (also called VLC: variable length coding ) compressed image
DecDCTvlc( dataBuffer, (u_long *) bsWorkBuffer );
// Send decoded data to MDEC for RLE decoding.
DecDCTin( (u_long*) bsWorkBuffer, 0);
// Fetch decoded image in 16x240 strips
for( bsDrawArea.x = 0; bsDrawArea.x < SCREENXRES; bsDrawArea.x += 16 ){
// Request decoded data from MDEC
// Request 16 * 240 pixel high lines.
// But size is in long words (4B), so divide by 2 to get words (2B) ?
DecDCTout( bsStrip, (16*SCREENYRES)/2);
// Wait for transfer to complete
DecDCToutSync(0);
// Load image data to fb
LoadImage( &bsDrawArea, bsStrip );
}
free( bsWorkBuffer );
while (1) // infinite loop
{
// Copy BS image to the other buffer
MoveImage2(&disp[db].disp, 0, disp[!db].disp.y );
DrawSync(0);
FntPrint("Hello BS! \n");
// Print filesize in bytes/sectors
FntPrint("Bs Size: %dB sectors: %d\n", filePos.size, BtoS(filePos.size));
// Print heap and buffer addresses
FntPrint("Heap: %x - Buf: %x\n", ramAddr, dataBuffer);
FntPrint("bsWork: %x\nbsBufSize: %dB\n", bsWorkBuffer, bsBufferSize);
FntFlush(-1); // Draw print stream
display(); // Execute display()
}
return 0;
}