#include "trop.h"
#include "tpixelutils.h"

#define FLOOR(x) ((int)(x) > (x) ? (int)(x)-1 : (int)(x))

/*
inline bool isInFirstColor(const TDimensionD &dim,int x, int y,const TPointD &offset)
{
  int lx=dim.lx;
  int ly=dim.ly;
  int offX,offY;
  offX = offset.x>=0 ? (int)offset.x : (int)(lx-offset.x);
  offY = offset.y>=0 ? (int)offset.y : (int)(ly-offset.y);
  if ((( ((int)(offX+x))/lx + ((int)(offY+y))/ly )%2 ) == 0)
    return false;
  return true;
}
*/

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

namespace
{

template <typename PIXEL>
void do_checkBoard(TRasterPT<PIXEL> rout, const PIXEL &pix1, const PIXEL &pix2,
				   const TDimensionD &dim, const TPointD &offset)
{
	assert(dim.lx > 0);
	assert(dim.ly > 0);

	double freqX = 0.5 / dim.lx;
	double freqY = 0.5 / dim.ly;

	double phaseX = 0;
	if (offset.x >= 0) {
		double q = offset.x * freqX;
		phaseX = (q - floor(q));
	} else {
		double q = (-offset.x * freqX);
		phaseX = 1.0 - (q - floor(q));
	}

	double phaseY = 0;
	if (offset.y >= 0) {
		double q = offset.y * freqY;
		phaseY = (q - floor(q));
	} else {
		double q = (-offset.y * freqY);
		phaseY = 1.0 - (q - floor(q));
	}

	int lx = rout->getLx();
	int ly = rout->getLy();

	for (int y = 0; y < ly; y++) {
		double yy = 2.0 * (phaseY + y * freqY);
		int iy = FLOOR(yy);
		assert(iy == (int)floor(yy));
		rout->lock();
		PIXEL *pix = rout->pixels(y);
		for (int x = 0; x < lx; x++) {
			double xx = 2.0 * (phaseX + x * freqX);
			int ix = FLOOR(xx);
			assert(ix == (int)floor(xx));
			if ((ix ^ iy) & 1)
				*pix++ = pix1;
			else
				*pix++ = pix2;
		}
		rout->unlock();
	}
}

} //namespace

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

void TRop::checkBoard(TRasterP rout, const TPixel32 &pix1, const TPixel32 &pix2,
					  const TDimensionD &dim, const TPointD &offset)
{
	//assert(offset.x<=dim.lx && offset.y<=dim.ly);

	TRaster32P rout32 = rout;
	if (rout32)
		do_checkBoard<TPixel32>(rout32, pix1, pix2, dim, offset);
	else {
		TRaster64P rout64 = rout;
		if (rout64)
			do_checkBoard<TPixel64>(rout64, toPixel64(pix1), toPixel64(pix2), dim, offset);
		else
			throw TRopException("unsupported pixel type");
	}
}