Update of /cvsroot/super-tux/supertux/src
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv17499/src
Modified Files:
bitmask.cpp
Log Message:
Finally tested and implemented the bitmask_create_SDL function right. It should actually work now and is a good option for an advanced collision detection implementation.
Index: bitmask.cpp
===================================================================
RCS file: /cvsroot/super-tux/supertux/src/bitmask.cpp,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -d -r1.1 -r1.2
--- bitmask.cpp 17 Mar 2004 19:19:10 -0000 1.1
+++ bitmask.cpp 8 Aug 2004 13:07:22 -0000 1.2
@@ -48,38 +48,33 @@
bitmask *bitmask_create_SDL(SDL_Surface* surf)
{
+ bitmask* pbitmask = bitmask_create(surf->w, surf->h);
int w,h;
- int bpp;
- Uint8* p;
+ SDL_PixelFormat* fmt;
+ Uint32 temp, pixel;
+ Uint8 alpha;
- bitmask *temp = (bitmask*) malloc(sizeof(bitmask));
- if (! temp)
+ if(surf->format->BytesPerPixel != 4) //This function only works for true-color surfaces with an alpha channel
return 0;
- temp->w = surf->w;
- temp->h = surf->h;
- temp->bits = (long unsigned int*) calloc(surf->h*((surf->w - 1)/BITW_LEN + 1),sizeof(BITW));
- if (! temp->bits)
- {
- free(temp);
- return 0;
- }
- else
- return temp;
-
- bpp = surf->format->BytesPerPixel;
+
+ fmt = surf->format;
for(h = 0; h <= surf->h; ++h)
{
- for(w = 0; w <= surf->h; ++w)
+ for(w = 0; w <= surf->w; ++w)
{
- p = (Uint8 *)surf->pixels + h*surf->pitch + w*bpp;
- if(*p == 255)
- bitmask_setbit(temp,w,h);
+ pixel = *((Uint32*)((Uint8 *)surf->pixels + h * surf->pitch + w * 4));
+ /* Get Alpha component */
+ temp=pixel&fmt->Amask; /* Isolate alpha component */
+ temp=temp>>fmt->Ashift;/* Shift it down to 8-bit */
+ temp=temp<<fmt->Aloss; /* Expand to a full 8-bit number */
+ alpha=(Uint8)temp;
+ if (fmt->Amask == 0 || alpha != 0)
+ bitmask_setbit(pbitmask,w,h);
}
}
-
+ return pbitmask;
}
-
void bitmask_free(bitmask *m)
{
free(m->bits);
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