#include <stdio.h>
#include <math.h>
#include <mdiwin/main.hpp>
#include <mdiwin/shear.hpp>

HGLOBAL Shear::performShear(WORD &width,WORD &height,double hFraction,double gFraction,UHUGE *lpImage)
{
	POINT workPoint;
	HGLOBAL hGlobalImage;
	HGLOBAL hGlobalSource;
	UHUGE *ptrSource;
	UHUGE *ptrImage;
	double tempxPoint;
	double tempyPoint;
	double tempFraction;

	mSourceWidth=width;
	mSourceHeight=height;
	mxSourceHalf=mSourceWidth/2;
	mySourceHalf=mSourceHeight/2;
	calculateDimensions(width,height,hFraction,gFraction);
	hGlobalSource=Main::upsideDown(width,height,lpImage);
	ptrSource=(UHUGE*)::GlobalLock(hGlobalSource);
  hGlobalImage=::GlobalAlloc(GMEM_FIXED,(LONG)mDestWidth*(LONG)mDestHeight);
	ptrImage=(UHUGE *)::GlobalLock(hGlobalImage);
	Main::hmemset(ptrImage,0,(LONG)mDestWidth*(LONG)mDestHeight);
	for(int row=0;row<mSourceHeight;row++)
	{
		 for(int col=0;col<mSourceWidth;col++)
		 {
		   setPoint(col,row,workPoint);
			 cartesianPoint(workPoint);
			 tempFraction=hFraction*(double)workPoint.y;
			 if(tempFraction)tempFraction+=(tempFraction<0.00?-0.50:0.459);
			 tempxPoint=((double)workPoint.x+tempFraction);
			 if(tempxPoint)tempxPoint+=(tempxPoint<0.00?-0.50:0.459);
			 tempFraction=gFraction*(double)workPoint.x;
			 if(tempFraction)tempFraction+=(tempFraction<0.00?-0.50:0.459);
			 tempyPoint=(tempFraction+(double)workPoint.y);
			 if(tempyPoint)tempyPoint+=(tempyPoint<0.00?-0.50:0.459);
			 setPoint(tempxPoint,tempyPoint,workPoint);
			 imagePoint(workPoint);
			 *(ptrImage+((LONG)workPoint.y*(LONG)mDestWidth)+(LONG)workPoint.x)=
			 *(ptrSource+((LONG)row*(LONG)mSourceWidth)+(LONG)col);
		 }
	}


	::GlobalUnlock(hGlobalSource);
	::GlobalFree(hGlobalSource);
	hGlobalSource=Main::upsideDown(mDestWidth,mDestHeight,ptrImage);
	::GlobalUnlock(hGlobalImage);
	::GlobalFree(hGlobalImage);
	width=mDestWidth;
	height=mDestHeight;
	return hGlobalSource;
}

void Shear::calculateDimensions(WORD width,WORD height,double xFactor,double yFactor)
{
	POINT maxPoint;
	POINT minPoint;
	double tempPoint;
	int maxx;
	int minx;
	int maxy;
	int miny;

	if(xFactor<0)
	{
		setPoint(0,0,minPoint);
		setPoint(width-1,height-1,maxPoint);
  }
	else
	{
		setPoint(0,width-1,minPoint);
		setPoint(width-1,0,maxPoint);
	}
	cartesianPoint(minPoint);
	cartesianPoint(maxPoint);
	tempPoint=xFactor*(double)maxPoint.y;
	if(tempPoint)tempPoint+=(tempPoint<0?-.5:.459);
	tempPoint+=(double)maxPoint.x;
	if(tempPoint)tempPoint+=(tempPoint<0?-.5:.459);
	maxx=tempPoint;
	tempPoint=xFactor*(double)minPoint.y;
	if(tempPoint)tempPoint+=(tempPoint<0?-.5:.459);
	tempPoint+=(double)minPoint.x;
	if(tempPoint)tempPoint+=(tempPoint<0?-.5:.459);
	minx=tempPoint;
	if(yFactor<0)
	{
		setPoint(width-1,height-1,minPoint);
		setPoint(0,0,maxPoint);
	}
	else
	{
		setPoint(0,height-1,minPoint);
		setPoint(width-1,0,maxPoint);
	}
	cartesianPoint(minPoint);
	cartesianPoint(maxPoint);
	tempPoint=yFactor*(double)minPoint.x;
	if(tempPoint)tempPoint+=(tempPoint<0?-.5:.459);
	tempPoint+=(double)minPoint.y;
	if(tempPoint)tempPoint+=(tempPoint<0?-.5:.459);
	miny=tempPoint;
	tempPoint=yFactor*(double)maxPoint.x;
	if(tempPoint)tempPoint+=(tempPoint<0?-.5:.459);
	tempPoint+=(double)maxPoint.y;
	if(tempPoint)tempPoint+=(tempPoint<0?-.5:.459);
	maxy=tempPoint;
	mDestWidth=::abs(maxx)+::abs(minx)+1;
	mDestHeight=::abs(maxy)+::abs(miny)+1;
	mxDestHalf=::abs(minx);
}