DevIL PNG format for display in OpenGL

Question

I'm doing some pixel work in OpenGL, and all was going well until I had to load a PNG. I found a thing called 'DevIL', and followed an example I found. It does display something, but it's just kind of a random rainbow. I'm doing it right as far as I can tell; I output the data to a text file to check it. I tried some other libraries, but building them is a little beyond my capabilities. Here's my setup:

((In global scope))
unsigned char pixels[160000*3];
ILubyte * bytes  ;

((Main))
ilInit();

ilLoadImage( "test.png" ) ;

size = ilGetInteger( IL_IMAGE_SIZE_OF_DATA ) ;

bytes = ilGetData() ;

And here's my drawing routine:

//Color the screen all pretty
for(int i=0;i<160000*3;)
{   
    pixels[i] = a;
    i++;
    pixels[i] = b;
    i++;
    pixels[i] = c;
    i++;
}   

//Break the png
for( int i = 0 ; i < size;)
{
    if(bytes[i+3] != 255)
    {   i+=4;
            continue;   }

    pixels[i] = bytes[i];
    i++;
    pixels[i] = bytes[i];
    i++;
    pixels[i] = bytes[i];
    i++;
    i++;
}

glDrawPixels(
    400,
    300,
    GL_RGB,
    GL_UNSIGNED_BYTE,
    pixels
    );

I know the alignment is wrong; I'll fix that later. The problem is the colors are totally not right

P.S. I know you're supposed to use textured quads

Answer 1

PNG is a compressed format. Seems like ilGetData returns pointer to a compressed data. To get decoded image use ilCopyPixels.