Surface->LockSurface(overlapRect, sd);
LPDWORD pixels = (LPDWORD)(sd.lpSurface);
DWORD colour;
for(int i = 0; i < (overlapRect.right-overlapRect.left)*(overlapRect.bottom-overlapRect.top); i++)
{
colour = pixels;
if(colour == COL_COLLISION)
{
Surface->UnlockSurface(overlapRect);
return true;
}
}
comparing apples and oranges!?
Author
From what I understand lpSurface is the memory address of the pixels in the surface. If this is the case how can I get access to the actual pixel colour value so I can compare it to an RGB color value as in the line: if(colour == COL_COLLISION)
Actually, you need to know different things such as the color format the surface is stored it. Dependently on that, you have either to decode it or compare it to a value that represents the collision color in that given color format.
What you need to know is that the number of bytes representing a color depends on the bitdepth of the surface. A 16 bit surface (being it 565, 1555, X555, ...) stores one pixel in 2 bytes. A 24 bit surface in 3 bytes and a 32 bit surface in 4 bytes.
Dependently on the bitdepth you have to a) read in the pixels, b) iterate through the bitmap and c) compare the value.
What you need to know is that the number of bytes representing a color depends on the bitdepth of the surface. A 16 bit surface (being it 565, 1555, X555, ...) stores one pixel in 2 bytes. A 24 bit surface in 3 bytes and a 32 bit surface in 4 bytes.
Dependently on the bitdepth you have to a) read in the pixels, b) iterate through the bitmap and c) compare the value.
Author
The bit depth is 16 bits,
the color I want to compare in collision is RGB(1, 1, 1)
How would i go about iterating through the array and comparing the pixel values with the collision color?
the color I want to compare in collision is RGB(1, 1, 1)
How would i go about iterating through the array and comparing the pixel values with the collision color?
This topic is closed to new replies.
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