GameProgrammerArt

Math

C/C++

pixeltype RGBtoHSV(pixeltype palette_color){
	//0.0f <= r <= 1.0f
	//0.0f <= g <= 1.0f
	//0.0f <= b <= 1.0f
    double r = (double)(RED_OF(palette_color));
    double g = (double)(GREEN_OF(palette_color));
    double b = (double)(BLUE_OF(palette_color));
    double max, min, h, s, l;

	if(r > g){
		max = r;
	}else{
		max = g;
	}
	if(b > max){
		max = b;
	}

	if(r < g){
		min = r;
	}else{
		min = g;
	}
	if(b < min){
		min = b;
	}

    if(max == min){
        h = 0.0f;
    }else if(max == r){
        h = ((60.0f * ((g - b) / (max - min)) + 360) % 360.0f);
    }else if(max == g){
        h = ((60.0f * ((b - r) / (max - min)) + 120));
    }else if(max == b){
        h = ((60.0f * ((r - g) / (max - min)) + 240));
    }

	l = (max + min) / 2.0f;

	if(max == min){
		s = 0;
	}else if(l <= 0.5f){
		s = ((max - min) / (2 * l));
	}else if(l > 0.5f){
		s = ((max - min) / (2 - (2 * l)));
	}

	//0.0f <= h <= 360.0f
	//0.0f <= s <= 1.0f
	//0.0f <= l <= 1.0f
    return HSL_OF(h, s, l);
}
}