GfxLib transparency works well

A small video. Shows two semitransparent layers interacting using GfxLib. Also shown is the boot process. Enjoy.






The quickly-written and messy source code to this simple test app is as follows:

#include <kTypes.h>
#include <errors.h>
#include <RtLib.h>
#include <GfxLib.h>



static char __x[128];
#define printf(...)   do{sprintf(__x,__VA_ARGS__);_DGOS_DEBUG_TMP_printStr(__x);}while(0)
#define perr(...)   do{printf(__VA_ARGS__); while(1) SchedYield();}while(0)

int _start(){
   
   GfxImage* i;
   GfxLayer* L;
   GfxLayer* L2;
   UInt32 iw, ih, sw = 324, sh = 484;
   Int32 x = 0, y = 0, dx = 1, dy = 1;
   UInt16* d;
   Err e;
   
   printf("TEST RUNNING\n");
   
   if(!GfxLayersInit(GFX_LIB_ROTATION_NORMAL)){
      perr("cannot init GfxLayers\n");
   }
   
   printf("setting color\n");
   GfxLayersSetBackground(GfxColorMakeRGB(192,255,192));
   
   printf("creating layer\n");
   L2 = GfxLayerCreate(0, 0, 324, 484);
   if(!L2) perr("cannot create layer with bg\n");

   
   printf("calculating layer\n");
   printf("L=0x%08x\n", L2);
   printf("I=0x%08x\n", GfxLayerGetImage(L2));
   printf("D=0x%08x\n", GfxImageGetData(GfxLayerGetImage(L2)));
   printf("A=0x%08x\n", GfxImageGetAlpha(GfxLayerGetImage(L2)));
   
   d = GfxImageGetData(GfxLayerGetImage(L2));
   MemSet(GfxImageGetAlpha(GfxLayerGetImage(L2)), 324*484, 0xFF);

   for(y = 0; y < 484; y++){
      for(x = 0; x < 324; x++){
         UInt32 r,g,b;
         
         r = y * 256 / 484;
         g = y * 256 / 484;
         b = y * 256 / 484;
         
         r = ((r * x) + (256 * (323 - x))) / 323;
         g = ((256 * x) + (g * (323 - x))) / 323;
         
         
         *d++ = (((y / 10) & 1) == ((x / 10) & 1)) ? \
                  GfxColorMakeRGB(r,g,b) : \
                  GfxColorMakeRGB(0,0,b);
      }
   }
   
   printf("drawing layer\n");
   GfxLayerRedraw(L2);
   
   
   printf("loading img\n");
   
   e = GfxLibLoadPng(3,L"/test.png", &i, false);
   if(e) perr("cannot load image: 0x%04x\n",e);
   
   GfxImageGetDimensions(i, &iw, &ih);

   printf("img is %dx%d\n",iw,ih);
   
   L = GfxLayerCreateWithImage(0, 0, i);
   if(!L) perr("cannot create layer with image\n");


   x = 0;
   y = 0;

   while(1){
      
      x += dx;
      y += dy;
      
      if((x + iw >= sw) || x <0){
         dx = -dx;
         x += 2 * dx;
      }
      if((y + ih >= sh) || y < 0){
         dy = -dy;
         y += 2 * dy;
      }
      
      GfxLayerSetLocation(L, x, y);
   }

   while(1) SchedYield();   //idle well
}