if i have a bmp that i load from file, how can i can get color value of the pixel at xth column and yth row? thuned life is unfair, take advantage of it. UNMB2 - if the link doesn''t work, try clicking it

If you have it in a single buffer, you can use the formula:
colour = buffer[x + y * width of buffer];
width of buffer is usually the width of the bitmap, but to avoid alignment problems you should know the actual width of the buffer.

i'm using nehe's bmp loading function
AUX_RGBImageRec *LoadBMP(char *Filename)
is that return type a "single buffer"?

AUX_RGBImageRec *TextureImage;BYTE* Image[height*width];Image[0] = (BYTE*)(TextureImage);  

so would something like that work?

and i know that some bmp has garbage on the ends of each line. does AUX_RGBImageRec take care of it or do i have to do it myself?


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Edited by - thuned on February 8, 2001 12:21:45 AM

The definition of AUX_RGBImageRec is something like:

typedef struct _AUX_RGBImageRec{    unsigned char* data;    GLint sizeX;    GLint sizeY;}  

So something like:
BYTE Colour = TextureImage.data[XPos + YPos * TextureImage.sizeY];

should work

And you probably wont have to worry about the alignment, as I assume you're using images that are a power of 2. Didn't notice you posted in the NeHe forum or I would have told you this in the first place

Edited by - Quantum on February 8, 2001 12:41:05 AM

got a problem:
i got layer declared as AUX_RGBImageRec layer[3];
and i loaded up the 0th element

glPrint("Size: %2.0f, %2.0f", (float)layer[0].sizeX, (float)layer[0].sizeY); 

works, i''m using nehe''s bitmap text btw

but when i do BYTE a = (BYTE)(layer[0].data[0]);
it crashes
y does it crash?

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nm, i got it working
just changed it to 3*(XPos + YPos * TextureImage.sizeX) and it worked
thanks


thuned

life is unfair, take advantage of it.
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