I guess that what happens when you code with little sleep and don't have access to a test platform
The x_inc I used (and must of accidentally deleted) is for how much the bitmap pointer needs to be incremented every time a new row is drawn. It is left at zero unless the bitmap overlaps either or both the left and right edges, Here is what I modified to hopefully work. Also one thing that I forgot to do is add some pointer type casts as even though I'm pretty sure gcc will compile this, g++ could have some issues de to the stronger C++ rules about type casts.
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| #define WIDTH 384
#define HEIGHT 216
short * VRAM = (short*) GetVRAMAddress();
void alphaSprite(int x, int y, int width, int height, short * bitmap, short alpha)
{
int x_inc = 0;
if (y < 0)
{
bitmap -= (short*)(y * width);
height += y;
y = 0;
}
if (height > HEIGHT - y) height = HEIGHT - y;
if (x < 0)
{
bitmap -= (short*)x;
width += x;
x = 0;
x_inc += -x;
}
if (width > WIDTH - x)
{
width = WIDTH - x;
x_inc += WIDTH - (width + x);
}
int y_index;
int x_index;
short * base = (short*)(y * WIDTH) + x + VRAM;
for (y_index = height; y_index > 0; --y_index, base += (short*)WIDTH - width, bitmap += (short*)x_inc)
{
for (x_index = width; x_index > 0; --x_index, ++base, ++bitmap)
{
if (*bitmap != alpha) *base = *bitmap;
}
}
}
|
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