Doomsday Engine

From line 399:
void GL_GetColorPaletteRGB(DGLuint id, DGLubyte rgb³, ushort idx) {
if(id != 0 && id - 1 < numColorPalettes) {
const gl_colorpalette_t* pal = &colorPalettes[id-1];

if(idx >= pal->num)
            VERBOSE(
            Con_Message("GL_GetColorPaletteRGB: Warning, color idx %u " 
                        "out of range in palette %u.\n", idx, id))

idx = MINMAX_OF(0, idx, pal->num) * 3;
        rgb[CR] = pal->data[idx];
        rgb[CG] = pal->data[idx + 1];
        rgb[CB] = pal->data[idx + 2];
    }
}
elsewhere:
#define MINMAX_OF(a, x, b)  ((x) < (a)? (a) : (x) > (b)? (b) : (x))

The ConMessage says that an idx equal to or greater than pal->num is invalid. But the MINMAX_OF macro limits idx to pal->num, INCLUSIVE.
Say pal->num is 5. Based on the code, that means pal->num is [15]. If you pass an idx of 6 to the function, it tells you that it's out of range. But then it goes right ahead and tries to get pal->data¹⁵, pal->data¹⁶ and pal->data¹⁷ anyway. Perhaps it should be MINMAX_OF(0, idx, (pal->num - 1)) * 3 instead?

Labels: OpenGL Renderer