// ----------------------------------------------------------------------
// color_conv.c
// 21.02.2005, Jens Ahrensfeld
// ----------------------------------------------------------------------
#include <string.h>
#include <math.h>
#include "color_conv.h"
#include "colortypes.h"
#include "mutil.h"

// ----------------------------------------------------------------------
void rgb2hsv(color_vector_t *pRGB, color_vector_t *pHSV, int len)
{
	int i;
	double *rgb, *hsv, v_min, v_max, diff_max, diff_max_r, diff_r, diff_g, diff_b;

	for (i=0; i < len; i++)
	{
		rgb = (double*)&pRGB[i];
		hsv = (double*)&pHSV[i];

		v_min = smin(rgb[0], rgb[1]);
		v_min = smin(v_min, rgb[2]);

		v_max = smax(rgb[0], rgb[1]);
		v_max = smax(v_max, rgb[2]);

		diff_max = v_max - v_min;

		hsv[2] = v_max;

		if (diff_max == 0)
		{
			hsv[0] = diff_max;
			hsv[1] = diff_max;
		}
		else
		{
			diff_max_r = 1.0/diff_max;
			hsv[1] = diff_max/v_max;

			diff_r = (((v_max - rgb[0])*(1.0/6)) + (0.5*diff_max))*diff_max_r;
			diff_g = (((v_max - rgb[1])*(1.0/6)) + (0.5*diff_max))*diff_max_r;
			diff_b = (((v_max - rgb[2])*(1.0/6)) + (0.5*diff_max))*diff_max_r;

			if (rgb[0] == v_max)
			{
				hsv[0] = diff_b - diff_g;
			}
			else
			{
				if (rgb[1] == v_max)
				{
					hsv[0] = 1.0/3 + diff_r - diff_b;
				}
				else
				{
					if (rgb[2] == v_max)
					{
						hsv[0] = 2.0/3 + diff_g - diff_r;
					}
				}
			}

			if (hsv[0] < 0)
				hsv[0] += 1;

			if (hsv[0] > 1.0)
				hsv[0] -= 1;

		}
	}
}

// ----------------------------------------------------------------------
void hsv2rgb(color_vector_t *pHSV, color_vector_t *pRGB, int len)
{
	int i, j;
	double h, t1, t2, t3, *rgb, *hsv;

	for (i=0; i < len; i++)
	{
		rgb = (double*)&pRGB[i];
		hsv = (double*)&pHSV[i];

		if (hsv[1] == 0)
		{
			rgb[0] = hsv[2];
			rgb[1] = hsv[2];
			rgb[2] = hsv[2];

			continue;
		}

		h = hsv[0] * 6;
		j = (int)h;
		t1 = hsv[2]*(1 - hsv[1]);
		t2 = hsv[2]*(1 - hsv[1]*(h-(double)j));
		t3 = hsv[2]*(1 - hsv[1]*(1-(h-(double)j)));

		switch(j)
		{
			case 0:
			rgb[0] = hsv[2];
			rgb[1] = t3;
			rgb[2] = t1;
			break;

			case 1:
			rgb[0] = t2;
			rgb[1] = hsv[2];
			rgb[2] = t1;
			break;

			case 2:
			rgb[0] = t1;
			rgb[1] = hsv[2];
			rgb[2] = t3;
			break;

			case 3:
			rgb[0] = t1;
			rgb[1] = t2;
			rgb[2] = hsv[2];
			break;

			case 4:
			rgb[0] = t3;
			rgb[1] = t1;
			rgb[2] = hsv[2];
			break;

			default:
			rgb[0] = hsv[2];
			rgb[1] = t1;
			rgb[2] = t2;
			break;
		}
	}
}

// ----------------------------------------------------------------------
void rgb2hsl(color_vector_t *pRGB, color_vector_t *pHSL, int len)
{
	int i;
	double *rgb, *hsl, v_min, v_max, diff_max, diff_max_r, diff_r, diff_g, diff_b;

	for (i=0; i < len; i++)
	{
		rgb = (double*)&pRGB[i];
		hsl = (double*)&pHSL[i];

		v_min = smin(rgb[0], rgb[1]);
		v_min = smin(v_min, rgb[2]);

		v_max = smax(rgb[0], rgb[1]);
		v_max = smax(v_max, rgb[2]);

		diff_max = v_max - v_min;

		hsl[2] = (v_max + v_min)/2;

		if (diff_max == 0)
		{
			hsl[0] = diff_max;
			hsl[1] = diff_max;
		}
		else
		{
			diff_max_r = 1.0/diff_max;

			if(hsl[2] < 0.5)
			{
				hsl[1] = diff_max/(v_max + v_min);
			}
			else
			{
				hsl[1] = diff_max/(2 - v_max - v_min);
			}

			diff_r = (((v_max - rgb[0])*(1.0/6)) + (0.5*diff_max))*diff_max_r;
			diff_g = (((v_max - rgb[1])*(1.0/6)) + (0.5*diff_max))*diff_max_r;
			diff_b = (((v_max - rgb[2])*(1.0/6)) + (0.5*diff_max))*diff_max_r;

			if (rgb[0] == v_max)
			{
				hsl[0] = diff_b - diff_g;
			}
			else
			{
				if (rgb[1] == v_max)
				{
					hsl[0] = 1.0/3 + diff_r - diff_b;
				}
				else
				{
					if (rgb[2] == v_max)
					{
						hsl[0] = 2.0/3 + diff_g - diff_r;
					}
				}
			}

			if (hsl[0] < 0)
				hsl[0] += 1;

			if (hsl[0] > 1.0)
				hsl[0] -= 1;

		}
	}
}

// ----------------------------------------------------------------------
inline double Hue_2_RGB(double v1, double v2, double vH)             //Function Hue_2_RGB
{
	if (vH < 0)
		vH += 1;
	if (vH > 1)
		vH -= 1;

	if ((6*vH) < 1)
		return v1 + (v2 - v1)*6*vH;

	if ((2*vH) < 1)
		return v2;

	if ((3*vH) < 2)
		return v1 + (v2 - v1)*((2.0/3) - vH)*6;

	return v1;
}

// ----------------------------------------------------------------------
void hsl2rgb(color_vector_t *pHSL, color_vector_t *pRGB, int len)
{
	int i, j;
	double h, t1, t2, t3, *rgb, *hsl;

	for (i=0; i < len; i++)
	{
		rgb = (double*)&pRGB[i];
		hsl = (double*)&pHSL[i];

		if (hsl[1] == 0)
		{
			rgb[0] = hsl[2];
			rgb[1] = hsl[2];
			rgb[2] = hsl[2];

			continue;
		}

		if(hsl[2] < 0.5)
		{
			t2 = hsl[2]*(1 + hsl[1]);
		}
		else
		{
			t2 = (hsl[2] + hsl[1]) - hsl[2]*hsl[1];
		}

		t1 = 2*hsl[2] - t2;

		rgb[0] = Hue_2_RGB(t1, t2, hsl[0] + 1.0/3);
		rgb[1] = Hue_2_RGB(t1, t2, hsl[0]);
		rgb[2] = Hue_2_RGB(t1, t2, hsl[0] - 1.0/3);
	}
}

// ----------------------------------------------------------------------
void rgb2xyz(double **ppRGB, double **ppXYZ, int len)
{
	int i, j;
	double rgb[3];
	double *pRGB, *pXYZ;

	for (i=0; i < len; i++)
	{
		pRGB = ((double*)ppRGB[i]);
		pXYZ = ((double*)ppXYZ[i]);

		for (j=0; j < 3; j++)
		{
			if (pRGB[j] > 0.04045)
			{
				rgb[j] = pow((pRGB[j]+0.055)/1.055,2.4);
			}
			else
			{
				rgb[j] = 1.0/12.92 * pRGB[j];
			}

			rgb[j] *= K_XYZ;

		}

		// Observer = 2°, Illuminant = D65
		pXYZ[0] = 0.412453*rgb[0] + 0.357580*rgb[1] + 0.180423*rgb[2];
		pXYZ[1] = 0.212671*rgb[0] + 0.715160*rgb[1] + 0.072169*rgb[2];
		pXYZ[2] = 0.019334*rgb[0] + 0.119193*rgb[1] + 0.950227*rgb[2];

	}
}

// ----------------------------------------------------------------------
void xyz2rgb(double **ppXYZ, double **ppRGB, int len)
{
	int i, j;
	double xyz[3];
	double *pRGB, *pXYZ;

	for (i=0; i < len; i++)
	{
		pRGB = ((double*)ppRGB[i]);
		pXYZ = ((double*)ppXYZ[i]);

		for (j=0; j < 3; j++)
		{
			xyz[j] = 1.0/K_XYZ * pXYZ[j];
		}

		// Observer = 2°, Illuminant = D65
		pRGB[0] =  3.240479*xyz[0] - 1.537150*xyz[1] - 0.498535*xyz[2];
		pRGB[1] = -0.969256*xyz[0] + 1.875992*xyz[1] + 0.041556*xyz[2];
		pRGB[2] =  0.055648*xyz[0] - 0.204043*xyz[1] + 1.057311*xyz[2];

		for (j=0; j < 3; j++)
		{
			if (pRGB[j] > 0.0031308)
			{
				pRGB[j] = 1.055 * pow(pRGB[j],1.0/2.4) - 0.055;
			}
			else
			{
				pRGB[j] = 12.92 * pRGB[j];
			}
		}
	}
}

// ----------------------------------------------------------------------
void xyz2lab(double **ppXYZ, double **ppLAB, double *pRef, int len)
{
	int i, j;
	double xyz[3] = {0};
	double *pLAB, *pXYZ;

	for (i=0; i < len; i++)
	{
		pXYZ = ((double*)ppXYZ[i]);
		pLAB = ((double*)ppLAB[i]);

		for (j=0; j < 3; j++)
		{
			xyz[j] = pXYZ[j] / pRef[j];
		}

		for (j=0; j < 3; j++)
		{
			if (xyz[j] > 0.008856)
			{
				xyz[j] = pow(xyz[j],1.0/3.0);
			}
			else
			{
				xyz[j] = 7.787*xyz[j] + 16.0/116.0;
			}

		}

		pLAB[0] = 116.0*xyz[1] - 16;
		pLAB[1] = 500.0*(xyz[0] - xyz[1]);
		pLAB[2] = 200.0*(xyz[1] - xyz[2]);

	}
}

// ----------------------------------------------------------------------
void lab2xyz(double **ppLAB, double **ppXYZ, double *pRef, int len)
{
	int i, j;
	double xyz[3], xyz3;
	double *pLAB, *pXYZ;

	for (i=0; i < len; i++)
	{
		pXYZ = ((double*)ppXYZ[i]);
		pLAB = ((double*)ppLAB[i]);

		xyz[1] = 1.0/116.0*(pLAB[0] + 16);
		xyz[0] = 1.0/500.0*pLAB[1] + xyz[1];
		xyz[2] = xyz[1] - 1.0/200.0*pLAB[2];

		for (j=0; j < 3; j++)
		{
			xyz3 = pow(xyz[j],3.0);
			if (xyz3 > 0.008856)
			{
				xyz[j] = xyz3;
			}
			else
			{
				xyz[j] =  1.0/7.787*(xyz[j] - 16.0/116);
			}
		}

		for (j=0; j < 3; j++)
		{
			pXYZ[j] = xyz[j] *pRef[j];
		}

	}
}

// ----------------------------------------------------------------------
void tristimulus(double *pRef, unsigned illuminant_type, unsigned observer_type)
{
	double ref[3] = {K_XYZ*0.95047, K_XYZ*1.0, K_XYZ*1.08883};

	if(observer_type == OBS_TYPE_2DEG)
	{

		switch (illuminant_type)
		{
			case ILLU_TYPE_A:
			case ILLU_TYPE_INCANDESCENT:
				pRef[0] = K_XYZ*1.09850;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*0.35585;
			break;

			case ILLU_TYPE_C:
				pRef[0] = K_XYZ*0.98074;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*1.18232;
			break;

			case ILLU_TYPE_D50:
				pRef[0] = K_XYZ*0.96422;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*0.82521;
			break;

			case ILLU_TYPE_D55:
				pRef[0] = K_XYZ*0.95682;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*0.92149;
			break;

			case ILLU_TYPE_D65:
			case ILLU_TYPE_DAYLIGHT:
				pRef[0] = K_XYZ*0.95047;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*1.08883;
			break;

			case ILLU_TYPE_D75:
				pRef[0] = K_XYZ*0.94972;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*1.22638;
			break;

			case ILLU_TYPE_F2:
			case ILLU_TYPE_FLUORESCENT:
				pRef[0] = K_XYZ*0.99187;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*0.67395;
			break;

			case ILLU_TYPE_F7:
				pRef[0] = K_XYZ*0.95044;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*1.08755;
			break;

			case ILLU_TYPE_F11:
				pRef[0] = K_XYZ*1.00966;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*0.64370;
			break;

			default:
				memcpy(pRef, ref, 3*sizeof(double));
			break;
		}
	}

	if(observer_type == OBS_TYPE_10DEG)
	{

		switch (illuminant_type)
		{
			case ILLU_TYPE_A:
			case ILLU_TYPE_INCANDESCENT:
				pRef[0] = K_XYZ*1.11144;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*0.35200;
			break;

			case ILLU_TYPE_C:
				pRef[0] = K_XYZ*0.97285;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*1.16145;
			break;

			case ILLU_TYPE_D50:
				pRef[0] = K_XYZ*0.96720;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*0.81427;
			break;

			case ILLU_TYPE_D55:
				pRef[0] = K_XYZ*0.95799;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*0.90926;
			break;

			case ILLU_TYPE_D65:
			case ILLU_TYPE_DAYLIGHT:
				pRef[0] = K_XYZ*0.94811;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*1.07304;
			break;

			case ILLU_TYPE_D75:
				pRef[0] = K_XYZ*0.94416;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*1.20641;
			break;

			case ILLU_TYPE_F2:
			case ILLU_TYPE_FLUORESCENT:
				pRef[0] = K_XYZ*1.03280;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*0.69026;
			break;

			case ILLU_TYPE_F7:
				pRef[0] = K_XYZ*0.95792;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*1.07687;
			break;

			case ILLU_TYPE_F11:
				pRef[0] = K_XYZ*1.03866;
				pRef[1] = K_XYZ*1.0;
				pRef[2] = K_XYZ*0.65627;
			break;

			default:
				memcpy(pRef, ref, 3*sizeof(double));
			break;
		}
	}
}

void rgb2rgb(double **ppSrc, double **ppDst, int len)
{
	int i, j;
	double *pSrc, *pDst;

	for (i=0; i < len; i++)
	{
		pSrc = ((double*)ppSrc[i]);
		pDst = ((double*)ppDst[i]);

		for (j=0; j < 3; j++)
		{
			pDst[j] = pSrc[j];
		}

	}
}