C++ (Cpp) max3v Examples

Example #1

File: IrisBitmap.cpp Project: big-moon/Iris-2D-Project

void IrisBitmap::BitmapRGBtoHSL(const COLOR_RGB *rgb, COLOR_HSL *hsl)
{
    float h=0, s=0, l=0;
    // normalizes red-green-blue values
    float r = rgb->red/255.f;
    float g = rgb->green/255.f;
    float b = rgb->blue/255.f;
    float maxVal = max3v(r, g, b);
    float minVal = min3v(r, g, b);

    // hue

    if(maxVal == minVal)
    {
        h = 0; // undefined
    }

    else if(maxVal==r && g>=b)
    {
        h = 60.0f*(g-b)/(maxVal-minVal);
    }

    else if(maxVal==r && g<b)
    {
        h = 60.0f*(g-b)/(maxVal-minVal) + 360.0f;
    }

    else if(maxVal==g)
    {
        h = 60.0f*(b-r)/(maxVal-minVal) + 120.0f;
    }
    else if(maxVal==b)
    {
        h = 60.0f*(r-g)/(maxVal-minVal) + 240.0f;
    }

    // luminance
    l = (maxVal+minVal)/2.0f;
    // saturation

    if(l == 0 || maxVal == minVal)
    {
        s = 0;
    }

    else if(0<l && l<=0.5f)
    {
        s = (maxVal-minVal)/(maxVal+minVal);
    }
    else if(l>0.5f)
    {
        s = (maxVal-minVal)/(2 - (maxVal+minVal)); //(maxVal-minVal > 0)?
    }
    hsl->hue = (h>360)? 360 : ((h<0)?0:h);
    hsl->saturation = ((s>1)? 1 : ((s<0)?0:s))*100;
    hsl->luminance = ((l>1)? 1 : ((l<0)?0:l))*100;
}

Example #2

File: EasyTracer.c Project: hosea1008/LEPTON_STM32F4

//RGB转HSL
static void RGBtoHSL(const COLOR_RGB *Rgb, COLOR_HSL *Hsl)
{
    int h,s,l,maxVal,minVal,difVal;
	int r  = Rgb->red;
	int g  = Rgb->green;
    int b  = Rgb->blue;
	
	maxVal = max3v(r, g, b);
	minVal = min3v(r, g, b);
	
	difVal = maxVal-minVal;
	
	//计算亮度
    l = (maxVal+minVal)*240/255/2;
	
	if(maxVal == minVal)//若r=g=b
	{
		h = 0; 
		s = 0;
	}
	else
	{
		//计算色调
		if(maxVal==r)
		{
			if(g>=b)
				h = 40*(g-b)/(difVal);
			else
				h = 40*(g-b)/(difVal) + 240;
		}
		else if(maxVal==g)
			h = 40*(b-r)/(difVal) + 80;
		else if(maxVal==b)
			h = 40*(r-g)/(difVal) + 160;
		//计算饱和度
		if(l == 0)
			s = 0;
		else if(l<=120)
			s = (difVal)*240/(maxVal+minVal);
		else
			s = (difVal)*240/(511 - (maxVal+minVal));
	}
    Hsl->hue =        (unsigned char)(((h>240)? 240 : ((h<0)?0:h)));
    Hsl->saturation = (unsigned char)(((s>240)? 240 : ((s<0)?0:s)));
    Hsl->luminance =  (unsigned char)(((l>240)? 240 : ((l<0)?0:l)));
}