add tile example + readme typo

README.md

@@ -6,7 +6,7 @@ This repo is destined to host a bunch of simple examples, each describing how to
 
 The code here will be using PsyQ, the "Official" Sony SDK, but we will not be using libGS, the Extended Graphics Library.
 
-Instead we'll try to devises methods to reproduce libgs functions. This will not necessarly more efficient, but we'll learn
+Instead we'll try to devise methods to reproduce libgs functions. This will not necessarly be more efficient, but we'll learn
 a lot more stuff !
 
  

hello_tile.c

@@ -0,0 +1,125 @@
+#include <sys/types.h>
+#include <stdio.h>
+#include <libgte.h>
+#include <libetc.h>
+#include <libgpu.h>
+
+#define VMODE 0         // Video Mode : 0 : NTSC, 1: PAL
+
+#define SCREENXRES 320
+#define SCREENYRES 240
+
+#define CENTERX SCREENXRES/2
+#define CENTERY SCREENYRES/2
+
+#define MARGINX 0            // margins for text display
+#define MARGINY 32
+
+#define FONTSIZE 8 * 7       // Text Field Height
+
+#define OTLEN 8              // Ordering Table Length 
+
+DISPENV disp[2];             // Double buffered DISPENV and DRAWENV
+DRAWENV draw[2];
+
+u_long ot[2][OTLEN];          // double ordering table of length 8 * 32 = 256 bits / 32 bytes
+
+char primbuff[2][32768] = {1};// double primitive buffer of length 32768 * 8 =  262.144 bits / 32,768 Kbytes
+
+char *nextpri = primbuff[0];  // pointer to the next primitive in primbuff. Initially, points to the first bit of primbuff[0]
+
+short db = 0;                 // index of which buffer is used, values 0, 1
+
+void init(void)
+{
+    ResetGraph(0);
+    
+    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 (VMODE)
+    {
+        SetVideoMode(MODE_PAL);
+        disp[0].screen.y += 8;
+        disp[1].screen.y += 8;
+        }
+        
+    setRGB0(&draw[0], 50, 50, 50);
+    setRGB0(&draw[1], 50, 50, 50);
+    
+    draw[0].isbg = 1;
+    draw[1].isbg = 1;
+    
+    PutDispEnv(&disp[db]);
+    PutDrawEnv(&draw[db]);
+    
+    FntLoad(960, 0);
+    FntOpen(MARGINX, SCREENYRES - MARGINY - FONTSIZE, SCREENXRES - MARGINX * 2, FONTSIZE, 0, 280 );
+    
+}
+
+void display(void)
+{
+    DrawSync(0);
+    VSync(0);
+    
+    PutDispEnv(&disp[db]);
+    PutDrawEnv(&draw[db]);
+    
+    SetDispMask(1);
+    
+    DrawOTag(ot[db] + OTLEN - 1);
+    
+    db = !db;
+    
+    nextpri = primbuff[db];
+}
+
+
+int main(void)
+{
+    
+    TILE * blue_tile;
+    TILE * pink_tile;
+    
+    init();
+    
+    while (1)
+    {
+        ClearOTagR(ot[db], OTLEN);                      // Initialize the reversed ordering table. Last element will be drawn first.
+        
+        blue_tile = (TILE * ) nextpri;		            // blue_tile is a pointer to primbuf content at adress nextpri, that's cast (type converted) to a blue_tile struc.   
+		
+		setTile(blue_tile);                              // initialize the blue_tile structure ( fill the length and tag(?) value )
+		setXY0(blue_tile, CENTERX - 16, CENTERY - 32);   // Set X,Y
+		setWH(blue_tile, 32, 64);                        // Set Width, Height
+		setRGB0(blue_tile, 60, 180, 255);                // Set color
+		addPrim(ot[db], blue_tile);                      // Add primitive to ordering table
+            
+		nextpri += sizeof(TILE);                    // Increment the adress nextpri points to by the size of TILE struct
+    
+        // pink_tile is after blue_tile in the code, 
+        // but we're using a reversed ordering table
+        // so it is drawn before, thus bellow blue_tile.
+    
+        pink_tile = (TILE * ) nextpri;		            // pink_tile is a pointer to primbuf content at adress nextpri, that's cast (type converted) to a TILE struc.   
+		
+		setTile(pink_tile);                              // initialize the TILE structure ( fill the length and tag(?) value )
+		setXY0(pink_tile, CENTERX, CENTERY - 64);   // Set X,Y
+		setWH(pink_tile, 64, 64);                        // Set Width, Height
+		setRGB0(pink_tile, 255, 32, 255);                // Set color
+		addPrim(ot[db], pink_tile);                      // Add primitive to ordering table
+            
+		nextpri += sizeof(TILE);     
+    
+        FntPrint("Hello tile !");
+    
+        FntFlush(-1);
+        
+        display();
+        }
+    return 0;
+    }