// Gradient.cpp: implementation of the CGradient class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "Gradient.h"
#include "math.h"


CGradient::CGradient()
{
}

CGradient::~CGradient()
{
}

void CGradient::HorizontalGradient(CDC* pDC, LPRECT lpRect, COLORREF sColor, COLORREF eColor, BOOL bGamma, double gamma)
{
	// Gradient params
	int width = lpRect->right - lpRect->left - 1;
	int height = lpRect->bottom - lpRect->top - 1;

	// Draw gradient
	HBRUSH hBrush = NULL;
	double percent;
	unsigned char red, green, blue;
	COLORREF color;
	RECT rect;
	for (int i=0; i<width-1; i++)
	{
		// Gradient color percent
		percent = 1 - (double)i / (double)(width-2);

		// Gradient color
		red = (unsigned char)(GetRValue(sColor)*percent) + (unsigned char)(GetRValue(eColor)*(1-percent));
		green = (unsigned char)(GetGValue(sColor)*percent) + (unsigned char)(GetGValue(eColor)*(1-percent));
		blue = (unsigned char)(GetBValue(sColor)*percent) + (unsigned char)(GetBValue(eColor)*(1-percent));
		if (bGamma)
		{
			red = (unsigned char)(pow((double)red/255.0, gamma) * 255);
			green = (unsigned char)(pow((double)green/255.0, gamma) * 255);
			blue = (unsigned char)(pow((double)blue/255.0, gamma) * 255);
		}
		color = RGB(red, green, blue);

		// Gradient
		rect.left = lpRect->left + i + 1;
		rect.top = lpRect->top + 1;
		rect.right = rect.left + 1;
		rect.bottom = lpRect->bottom - 1;
		pDC->FillSolidRect(&rect, color);
	}
}

void CGradient::VerticalGradient(CDC* pDC, LPRECT lpRect, COLORREF sColor, COLORREF eColor, BOOL bGamma, double gamma)
{
	// Gradient params
	int width = lpRect->right - lpRect->left - 1;
	int height = lpRect->bottom - lpRect->top - 1;

	// Draw gradient
	HBRUSH hBrush = NULL;
	double percent;
	unsigned char red, green, blue;
	COLORREF color;
	RECT rect;
	for (int i=0; i<height-1; i++)
	{
		// Gradient color percent
		percent = 1 - (double)i / (double)(height-2);

		// Gradient color
		red = (unsigned char)(GetRValue(sColor)*percent) + (unsigned char)(GetRValue(eColor)*(1-percent));
		green = (unsigned char)(GetGValue(sColor)*percent) + (unsigned char)(GetGValue(eColor)*(1-percent));
		blue = (unsigned char)(GetBValue(sColor)*percent) + (unsigned char)(GetBValue(eColor)*(1-percent));
		if (bGamma)
		{
			red = (unsigned char)(pow((double)red/255.0, gamma) * 255);
			green = (unsigned char)(pow((double)green/255.0, gamma) * 255);
			blue = (unsigned char)(pow((double)blue/255.0, gamma) * 255);
		}
		color = RGB(red, green, blue);

		// Gradient
		rect.left = lpRect->left + 1;
		rect.top = lpRect->top + i + 1;
		rect.right = lpRect->right - 1;
		rect.bottom = rect.top + 1;
		pDC->FillSolidRect(&rect, color);
	}
}

void CGradient::HorizontalGradient(CDC* pDC, HRGN hRgn, COLORREF sColor, COLORREF eColor, BOOL bGamma, double gamma)
{
	RECT rgnRect;
	GetRgnBox(hRgn, &rgnRect);

	// Gradient params
	int width = rgnRect.right - rgnRect.left - 1;
	int height = rgnRect.bottom - rgnRect.top - 1;

	// Draw gradient
	HBRUSH hBrush = NULL;
	unsigned char red, green, blue;
	COLORREF color;
	int startY, endY;
	RECT rect;
	bool foundStart, foundEnd;
	double rrate = (GetRValue(sColor)-GetRValue(eColor))*1.0/width;
	double grate = (GetGValue(sColor)-GetGValue(eColor))*1.0/width;
	double brate = (GetBValue(sColor)-GetBValue(eColor))*1.0/width;
	unsigned char sred = GetRValue(sColor);
	unsigned char sgreen = GetGValue(sColor);
	unsigned char sblue = GetBValue(sColor);

	for (int i=0; i<width; i=i+2)
	{
		// Gradient color
		red = sred + (unsigned char)(rrate*i);
		green = sgreen + (unsigned char)(grate*i);
		blue = sblue + (unsigned char)(brate*i);
		color = RGB(red, green, blue);

		endY = rgnRect.top;
		while (endY<=rgnRect.bottom)
		{
			foundStart = foundEnd = false;

			// Top offset
			startY = endY;
			while (startY<=rgnRect.bottom)
			{
				if ( PtInRegion(hRgn, rgnRect.left+i, startY) )
				{
					foundStart = true;
					break;
				}
				else
					startY++;
			}

			// Bottom offset
			endY = startY;
			while (endY<=rgnRect.bottom)
			{
				if ( !PtInRegion(hRgn, rgnRect.left+i, endY) )
				{
					foundEnd = true;
					break;
				}
				else
					endY++;
			}

			if (foundStart && foundEnd)
			{
				// Gradient rectangle
				rect.left = rgnRect.left + i;
				rect.top = startY;
				rect.right = rect.left + 2;
				rect.bottom = endY;
				pDC->FillSolidRect(&rect, color);
			}
		}
	}
}


void CGradient::VerticalGradient(CDC* pDC, HRGN hRgn, COLORREF sColor, COLORREF eColor, BOOL bGamma, double gamma)
{
	RECT rgnRect;
	GetRgnBox(hRgn, &rgnRect);

	// Gradient params
	int width = rgnRect.right - rgnRect.left - 1;
	int height = rgnRect.bottom - rgnRect.top - 1;

	// Draw gradient
	HBRUSH hBrush = NULL;
	double percent;
	unsigned char red, green, blue;
	COLORREF color;
	int startX, endX;
	RECT rect;
	bool foundStart, foundEnd;

	double rrate = (GetRValue(sColor)-GetRValue(eColor))*1.0/height;
	double grate = (GetGValue(sColor)-GetGValue(eColor))*1.0/height;
	double brate = (GetBValue(sColor)-GetBValue(eColor))*1.0/height;
	unsigned char sred = GetRValue(sColor);
	unsigned char sgreen = GetGValue(sColor);
	unsigned char sblue = GetBValue(sColor);

	for (int i=0; i<height; i=i+2)
	{
		// Gradient color percent
		percent = 1 - (double)i / (double)(height);

		// Gradient color
		red = sred + (unsigned char)(rrate*i);
		green = sgreen + (unsigned char)(grate*i);
		blue = sblue + (unsigned char)(brate*i);
		color = RGB(red, green, blue);

		endX = rgnRect.left;
		while (endX<=rgnRect.right)
		{
			foundStart = foundEnd = false;

			// Left offset
			startX = endX;
			while (startX<=rgnRect.right)
			{
				if ( PtInRegion(hRgn, startX, rgnRect.top+i) )
				{
					foundStart = true;
					break;
				}
				
				startX++;
			}

			// Right offset
			endX = startX;
			while (endX<=rgnRect.right)
			{
				if ( !PtInRegion(hRgn, endX, rgnRect.top+i) )
				{
					foundEnd = true;
					break;
				}
				
				endX++;
			}

			if (foundStart && foundEnd)
			{
				// Gradient rectangle
				rect.left = startX;
				rect.top = rgnRect.top + i;
				rect.right = endX;
				rect.bottom = rect.top + 2;
				pDC->FillSolidRect(&rect, color);
			}
		}
	}
}