DWORD* traceBits = game->d3d->GetBits(trace);
if(traceBits[currentPixel] != D3DCOLOR_ARGB(0,0,0,0)){
//Do stuff...
}
DWORD* Direct3D::GetBits(LPDIRECT3DTEXTURE9 pTex)
{
D3DLOCKED_RECT rect;
D3DSURFACE_DESC desc;
HRESULT hResult = pTex->GetLevelDesc(0, &desc);
if(FAILED(hResult))
return NULL;
int width = desc.Width,
height = desc.Height,
size = width*height;
DWORD* bits = new DWORD[size];
pTex->LockRect(0, &rect, 0, 0);
memcpy(bits, rect.pBits, sizeof(DWORD)*size);
pTex->UnlockRect(0);
return bits;
}
Problem with D3DCOLOR_ARGB
Author
I am getting trouble when trying to find out the color of a particular pixel. I want to find out if it's NOT alpha. The check works with any 'color' aslong as it's not alpha. Any reason why it could be failing :S?
Thanks.
D3DCOLOR_ARGB is a macro that resolves to ((D3DCOLOR)((((a)&0xff)<<24)|(((r)&0xff)<<16)|(((g)&0xff)<<8)|((b)&0xff))) (essentially an integer). For the given constant values you supply to that macro, you get an integer value of zero.
Your test is thus if traceBits[currentPixel] is not zero, which is every color except transparent (0 alpha) black.
If you want to test the alpha component only, you will have to mask that component off.
Your test is thus if traceBits[currentPixel] is not zero, which is every color except transparent (0 alpha) black.
If you want to test the alpha component only, you will have to mask that component off.
Author
Thanks I replaced the code with:
Although it still doesn't work. I checked the value and it doesn't give 0, I think there must be something wrong with the alpha channel or one of the others..
How could I mask the alpha?
if(traceBits[currentPixel] != 0) state += 1; if(traceBits[currentPixel + 1] != 0) state += 10; if(traceBits[currentPixel + width] != 0) state += 100; if(traceBits[currentPixel + width + 1] != 0) state += 1000;Although it still doesn't work. I checked the value and it doesn't give 0, I think there must be something wrong with the alpha channel or one of the others..
How could I mask the alpha?
You need to mask out the other color channels before you compare only alpha against zero.
Something like this: (Color & 0xFF000000) != 0
Something like this: (Color & 0xFF000000) != 0
This topic is closed to new replies.
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