#include "tpixelutils.h"

namespace
{

enum { SUBSTITUTE,
	   PATTERNTYPE,
	   ADD,
	   SUBTRACT,
	   MULTIPLY,
	   LIGHTEN,
	   DARKEN };

typedef void (*func32)(TPixel32 &pixmask, const TPixel32 &pixtext, double v);
typedef void (*func64)(TPixel64 &pixmask, const TPixel64 &pixtext, double v);

//=======================================================================================

//  Pixel operations

//-----------------------------------------------------------------------------

//!Make \b pixout completely opaque if \b pixcomp is not fully transparent. This helps
//!in avoiding antialias merge problems when overing palette filtered masks with their
//!inverses.
template <class T>
inline void makeOpaque(T &pixout, const T &pixcomp, double v)
{
	if (pixcomp.m > 0) {
		double k = T::maxChannelValue / (double)pixout.m;
		pixout.r = troundp(k * pixout.r);
		pixout.g = troundp(k * pixout.g);
		pixout.b = troundp(k * pixout.b);
		pixout.m = T::maxChannelValue;
	}
}

//---------------------------------------------------------------------------------------

//!Copies \b pixin into \b pixout - while matte components are multiplied.
template <class T>
inline void substitute(T &pixout, const T &pixin, double v)
{
	double k = pixout.m / (double)T::maxChannelValue;
	pixout.r = k * pixin.r;
	pixout.g = k * pixin.g;
	pixout.b = k * pixin.b;
	pixout.m = k * pixin.m;
}

//---------------------------------------------------------------------------------------

//!Decrease \b pixout's rgb colors proportionally to \b pixin's value. The matte channel
//!is kept unaltered.
inline void pattern32(TPixel32 &pixout, const TPixel32 &pixin, double v)
{
	double val = TPixelGR8::from(pixin).value / 255.0;
	pixout.r = troundp(val * pixout.r);
	pixout.g = troundp(val * pixout.g);
	pixout.b = troundp(val * pixout.b);
}

inline void pattern64(TPixel64 &pixout, const TPixel64 &pixin, double v)
{
	double val = TPixelGR16::from(pixin).value / 65535.0;
	pixout.r = troundp(val * pixout.r);
	pixout.g = troundp(val * pixout.g);
	pixout.b = troundp(val * pixout.b);
}

//---------------------------------------------------------------------------------------

template <class T>
void textureAdd(T &pixout, const T &pixin, double v)
{
	if (pixin.m > 0) {
		TINT32 pixoutm = pixout.m;

		double k = T::maxChannelValue / (double)pixoutm;
		pixout.r = pixout.r * k;
		pixout.g = pixout.g * k;
		pixout.b = pixout.b * k;
		pixout.m = T::maxChannelValue;

		add(pixout, pixin, v);

		k = pixoutm / (double)T::maxChannelValue;
		pixout.r = pixout.r * k;
		pixout.g = pixout.g * k;
		pixout.b = pixout.b * k;
		pixout.m = pixoutm;
	}
}

//---------------------------------------------------------------------------------------

template <class T>
void textureSub(T &pixout, const T &pixin, double v)
{
	if (pixin.m > 0) {
		TINT32 pixoutm = pixout.m;

		double k = T::maxChannelValue / (double)pixoutm;
		pixout.r = pixout.r * k;
		pixout.g = pixout.g * k;
		pixout.b = pixout.b * k;
		pixout.m = T::maxChannelValue;

		sub(pixout, pixin, v);

		k = pixoutm / (double)T::maxChannelValue;
		pixout.r = pixout.r * k;
		pixout.g = pixout.g * k;
		pixout.b = pixout.b * k;
		pixout.m = pixoutm;
	}
}

//---------------------------------------------------------------------------------------

template <class T>
void textureMult(T &pixout, const T &pixin, double v)
{
	TINT32 pixoutm = pixout.m;

	double k = T::maxChannelValue / (double)pixoutm;
	pixout.r = pixout.r * k;
	pixout.g = pixout.g * k;
	pixout.b = pixout.b * k;
	pixout.m = T::maxChannelValue;

	mult(pixout, pixin, v);

	k = pixoutm / (double)T::maxChannelValue;
	pixout.r = pixout.r * k;
	pixout.g = pixout.g * k;
	pixout.b = pixout.b * k;
	pixout.m = pixoutm;
}

//---------------------------------------------------------------------------------------

template <class T>
void textureLighten(T &pixout, const T &pixin, double v)
{
	TINT32 pixoutm = pixout.m;

	double k = T::maxChannelValue / (double)pixoutm;
	pixout.r = pixout.r * k;
	pixout.g = pixout.g * k;
	pixout.b = pixout.b * k;
	pixout.m = T::maxChannelValue;

	lighten(pixout, pixin, v);

	k = pixoutm / (double)T::maxChannelValue;
	pixout.r = pixout.r * k;
	pixout.g = pixout.g * k;
	pixout.b = pixout.b * k;
	pixout.m = pixoutm;
}

//---------------------------------------------------------------------------------------

template <class T>
void textureDarken(T &pixout, const T &pixin, double v)
{
	TINT32 pixoutm = pixout.m;

	double k = T::maxChannelValue / (double)pixoutm;
	pixout.r = pixout.r * k;
	pixout.g = pixout.g * k;
	pixout.b = pixout.b * k;
	pixout.m = T::maxChannelValue;

	darken(pixout, pixin, v);

	k = pixoutm / (double)T::maxChannelValue;
	pixout.r = pixout.r * k;
	pixout.g = pixout.g * k;
	pixout.b = pixout.b * k;
	pixout.m = pixoutm;
}

//=======================================================================================

void myOver32(const TRaster32P &rasOut, const TRasterP &rasUp,
			  func32 func, double v)
{
	assert(rasOut->getSize() == rasUp->getSize());
	TRaster32P rasUp32 = rasUp;
	assert(rasUp32);
	for (int y = rasOut->getLy(); --y >= 0;) {
		TPixel32 *out_pix = rasOut->pixels(y);
		TPixel32 *const out_end = out_pix + rasOut->getLx();
		const TPixel32 *up_pix = rasUp32->pixels(y);
		for (; out_pix < out_end; ++out_pix, ++up_pix) {
			if (out_pix->m > 0)
				(*func)(*out_pix, *up_pix, v);
		}
	}
}

void myOver64(const TRaster64P &rasOut, const TRasterP &rasUp,
			  func64 func, double v)
{
	assert(rasOut->getSize() == rasUp->getSize());
	TRaster64P rasUp64 = rasUp;
	assert(rasUp64);
	for (int y = rasOut->getLy(); --y >= 0;) {
		TPixel64 *out_pix = rasOut->pixels(y);
		TPixel64 *const out_end = out_pix + rasOut->getLx();
		const TPixel64 *up_pix = rasUp64->pixels(y);
		for (; out_pix < out_end; ++out_pix, ++up_pix) {
			if (out_pix->m > 0)
				(*func)(*out_pix, *up_pix, v);
		}
	}
}
}