// Copyright 2014 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "../../../include/fxge/fx_ge.h"
//#define _SKIA_SUPPORT_
#if defined(_SKIA_SUPPORT_)
#include "../../../include/fxcodec/fx_codec.h"
#include "SkBlitter.h"
#include "fx_skia_blitter_new.h"
	// We use our own renderer here to make it simple
	void CFX_SkiaRenderer::blitAntiH(int x, int y, const SkAlpha antialias[], const int16_t runs[])
	{
		FXSYS_assert(m_Alpha);
		if (m_pOriDevice == NULL && composite_span == NULL) return;
		if (y < m_ClipBox.top || y >= m_ClipBox.bottom) return;
		while (1)
		{
			int width = runs[0];
			SkASSERT(width >= 0);
			if (width <= 0) 
				return;
			unsigned aa = antialias[0];
			if (aa)
				(this->*composite_span)(m_pDestScan, m_pOriScan, 0, x, width, y, aa, m_ClipBox.top, m_ClipBox.left, m_ClipBox.right, m_pClipScan, m_pDestExtraAlphaScan);
			runs += width;
			antialias += width;
			x += width;
		}
	}

	void CFX_SkiaRenderer::blitH(int x, int y, int width)
	{
		FXSYS_assert(m_Alpha && width);
		if (y < m_ClipBox.top || y >= m_ClipBox.bottom) return;
		(this->*composite_span)(m_pDestScan, m_pOriScan, 0, x, width, y, 255, m_ClipBox.top, m_ClipBox.left, m_ClipBox.right, m_pClipScan, m_pDestExtraAlphaScan);
	}

	void CFX_SkiaRenderer::blitV(int x, int y, int height, SkAlpha alpha)
	{
		FXSYS_assert(m_Alpha && alpha);
		if (alpha == 255) {
			this->blitRect(x, y, 1, height);
		} else {
			int16_t runs[2];
			runs[0] = 1;
			runs[1] = 0;
			while (--height >= 0) {
				if (y >= m_ClipBox.bottom)
					return;
				this->blitAntiH(x, y ++, &alpha, runs);
			}
		}
	}
	void CFX_SkiaRenderer::blitRect(int x, int y, int width, int height)
	{
		FXSYS_assert(m_Alpha && width);
		while (--height >= 0){
			if (y >= m_ClipBox.bottom)
				return;
			blitH(x, y ++, width);
		}
	}

	void CFX_SkiaRenderer::blitAntiRect(int x, int y, int width, int height,
                             SkAlpha leftAlpha, SkAlpha rightAlpha) 
	{
		blitV(x++, y, height, leftAlpha);
		if (width > 0) {
			blitRect(x, y, width, height);
			x += width;
		}
		blitV(x, y, height, rightAlpha);
	}
	/*---------------------------------------------------------------------------------------------------*/
	void CFX_SkiaRenderer::CompositeSpan1bpp_0(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_bRgbByteOrder);
		ASSERT(!m_pDevice->IsCmykImage());
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left/8;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start/8;

		int index = 0;
		if (m_pDevice->GetPalette() == NULL) 
			index = ((FX_BYTE)m_Color == 0xff) ? 1 : 0;
		else {
			for (int i = 0; i < 2; i ++)
				if (FXARGB_TODIB(m_pDevice->GetPalette()[i]) == m_Color) 
					index = i;
		} 
		FX_LPBYTE dest_scan1 = dest_scan;
		int src_alpha = m_Alpha * cover_scan / 255;
		for (int col = col_start; col < col_end; col ++) {
			if (src_alpha) {
				if (!index)
					*dest_scan1 &= ~(1 << (7 - (col+span_left)%8));
				else
					*dest_scan1|= 1 << (7 - (col+span_left)%8);
			} 
			dest_scan1 = dest_scan+(span_left%8+col-col_start+1)/8;
		}
	}
	void CFX_SkiaRenderer::CompositeSpan1bpp_4(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_bRgbByteOrder);
		ASSERT(!m_pDevice->IsCmykImage());
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left/8;
		clip_scan = (FX_BYTE*)m_pClipMask->GetScanline(span_top-clip_top) - clip_left + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start/8;

		int index = 0;
		if (m_pDevice->GetPalette() == NULL) 
			index = ((FX_BYTE)m_Color == 0xff) ? 1 : 0;
		else {
			for (int i = 0; i < 2; i ++)
				if (FXARGB_TODIB(m_pDevice->GetPalette()[i]) == m_Color) 
					index = i;
		} 
		FX_LPBYTE dest_scan1 = dest_scan;
		int src_alpha = m_Alpha * cover_scan / 255;
		for (int col = col_start; col < col_end; col ++) {
			int src_alpha1 = src_alpha * clip_scan[col] / 255;
			if (src_alpha1) {
				if (!index)
					*dest_scan1 &= ~(1 << (7 - (col+span_left)%8));
				else
					*dest_scan1|= 1 << (7 - (col+span_left)%8);
			} 
			dest_scan1 = dest_scan+(span_left%8+col-col_start+1)/8;
		}
	}
	/*-----------------------------------------------------------------------------------------------------*/
	void CFX_SkiaRenderer::CompositeSpanGray_2(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_pDevice->IsCmykImage());
		ASSERT(!m_bRgbByteOrder);
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start;
		if (cover_scan == 255 && m_Alpha == 255) {
			FXSYS_memset32(dest_scan, FXARGB_MAKE(m_Gray, m_Gray, m_Gray, m_Gray), col_end - col_start);
			return;
		}
		int src_alpha = m_Alpha * cover_scan / 255;
		for (int col = col_start; col < col_end; col ++) {
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Gray, src_alpha);
			dest_scan++;
		}
	}
	void CFX_SkiaRenderer::CompositeSpanGray_3(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_pDevice->IsCmykImage());
		ASSERT(!m_bRgbByteOrder);
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left;
		ori_scan  = (FX_BYTE*)m_pOriDevice->GetScanline(span_top) + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start;
		ori_scan += col_start;
		if (m_Alpha == 255 && cover_scan == 255) {
			FXSYS_memset32(dest_scan, FXARGB_MAKE(m_Gray, m_Gray, m_Gray, m_Gray), col_end - col_start);
		} else {
			int src_alpha = m_Alpha;
#if 1
			for (int col = col_start; col < col_end; col ++) {
				int gray = FXDIB_ALPHA_MERGE(*ori_scan++, m_Gray, src_alpha);
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, gray, cover_scan);
				dest_scan ++;
			}
#else
			if (m_bFullCover) {
				if (src_alpha == 255) {
					FXSYS_memset(dest_scan, FXARGB_MAKE(m_Gray, m_Gray, m_Gray, m_Gray), col_end - col_start);
					return;
				}
				for (int col = col_start; col < col_end; col ++)
					*dest_scan = FXDIB_ALPHA_MERGE(*ori_scan++, m_Gray, src_alpha);
			} else {
				for (int col = col_start; col < col_end; col ++) {
					int gray = FXDIB_ALPHA_MERGE(*ori_scan++, m_Gray, src_alpha);
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, gray, cover_scan);
					dest_scan++;
				}
			}
#endif
		}
	}

	void CFX_SkiaRenderer::CompositeSpanGray_6(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_bRgbByteOrder);
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left;
		clip_scan = (FX_BYTE*)m_pClipMask->GetScanline(span_top-clip_top) - clip_left + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start;
		int src_alpha = m_Alpha * cover_scan / 255;
		for (int col = col_start; col < col_end; col ++) {
			int src_alpha1 = src_alpha * clip_scan[col] / 255;
			if (!src_alpha1) {
				dest_scan ++;
				continue;
			}
			if (src_alpha1 == 255)
				*dest_scan++ = m_Gray;
			else {
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Gray, src_alpha1);
				dest_scan ++;
			}
		}	
	}

	void CFX_SkiaRenderer::CompositeSpanGray_7(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_pDevice->IsCmykImage());
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left;
		ori_scan  = (FX_BYTE*)m_pOriDevice->GetScanline(span_top) + span_left;
		clip_scan = (FX_BYTE*)m_pClipMask->GetScanline(span_top-clip_top) - clip_left + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start;
		ori_scan += col_start;
#if 1
		for (int col = col_start; col < col_end; col ++) {
			int src_alpha = m_Alpha * clip_scan[col] / 255;
			if (src_alpha == 255 && cover_scan == 255) {
				*dest_scan++ = m_Gray;
				ori_scan++;
				continue;
			}
			int gray = FXDIB_ALPHA_MERGE(*ori_scan++, m_Gray, src_alpha);
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, gray, cover_scan);
			dest_scan++;
		}

#else
		if (m_bFullCover) {
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha = m_Alpha * clip_scan[col] / 255;
				if (!src_alpha) {
					dest_scan++;
					ori_scan++;
					continue;
				}
				if (src_alpha == 255){
					*dest_scan++ = m_Gray;
					ori_scan++;
					continue;
				}
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Gray, src_alpha);
			}
		} else {
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha = m_Alpha * clip_scan[col] / 255;
				if (src_alpha == 255 && cover_scan == 255) {
					*dest_scan++ = m_Gray;
					ori_scan++;
					continue;
				}
				int gray = FXDIB_ALPHA_MERGE(*ori_scan++, m_Gray, src_alpha);
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, gray, cover_scan);
				dest_scan++;
			}
		}
#endif
	}
	/*--------------------------------------------------------------------------------------------------*/

	void CFX_SkiaRenderer::CompositeSpanARGB_2(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + (span_left<<2);
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start<<2;
		if (m_Alpha == 255 && cover_scan == 255) {
			FXSYS_memset32(dest_scan, m_Color, (col_end - col_start)<<2);
			return;
		}
		int src_alpha;
#if 0
		if (m_bFullCover) {
			if (m_Alpha == 255) {
				FXSYS_memset32(dest_scan, m_Color, (col_end - col_start)<<2);
				return;
			}
		}
		else 
#endif
			src_alpha = m_Alpha * cover_scan / 255;
		for (int col = col_start; col < col_end; col ++) {
			// Dest format: Argb
			// calculate destination alpha (it's union of source and dest alpha)
			if (dest_scan[3] == 0) {
				dest_scan[3] = src_alpha;
				*dest_scan++ = m_Blue;
				*dest_scan++ = m_Green;
				*dest_scan = m_Red;
				dest_scan += 2; 
				continue;
			}
			FX_BYTE dest_alpha = dest_scan[3] + src_alpha - dest_scan[3] * src_alpha / 255;
			dest_scan[3] = dest_alpha;
			int alpha_ratio = src_alpha*255/dest_alpha;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
			dest_scan += 2;
		}
	}

	void CFX_SkiaRenderer::CompositeSpanARGB_3(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_pDevice->IsCmykImage());
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + (span_left<<2);
		//ori_scan  = (FX_BYTE*)m_pOriDevice->GetScanline(span_top) + (span_left<<2);
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start << 2;
		//ori_scan += col_start << 2;

		if (m_Alpha == 255 && cover_scan == 255){
			FXSYS_memset32(dest_scan, m_Color, (col_end - col_start)<<2);
			return;
		}		
		if (cover_scan == 255) {
			int dst_color = (0x00ffffff&m_Color)|(m_Alpha<<24);
			FXSYS_memset32(dest_scan, dst_color, (col_end - col_start)<<2);
			return;
		}
		// Do not need origin bitmap, because of merge in pure transparent background
		int src_alpha_covered = m_Alpha * cover_scan / 255;
		for (int col = col_start; col < col_end; col ++) 
		{
			// shortcut
			if (dest_scan[3] == 0) {
				dest_scan[3] = src_alpha_covered;
				*dest_scan ++ = m_Blue;
				*dest_scan ++ = m_Green;
				*dest_scan = m_Red;
				dest_scan += 2; 
				continue;
			}
			// We should do alpha transition and color transition
			// alpha fg          color fg
			// alpha bg          color bg
			// alpha cover       color cover
			dest_scan[3] = FXDIB_ALPHA_MERGE(dest_scan[3], m_Alpha, cover_scan);
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, cover_scan);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, cover_scan);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, cover_scan);
			dest_scan += 2;
		}
	}
	void CFX_SkiaRenderer::CompositeSpanARGB_6(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + (span_left<<2);
		clip_scan = (FX_BYTE*)m_pClipMask->GetScanline(span_top-clip_top) - clip_left + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start << 2;
#if 1
		int src_alpha = m_Alpha * cover_scan / 255; 
		for (int col = col_start; col < col_end; col ++) {
			int src_alpha1 = src_alpha* clip_scan[col] / 255;
			if (!src_alpha1) {
				dest_scan += 4;
				continue;
			}
			if (src_alpha1 == 255) {
				*(FX_DWORD*)dest_scan = m_Color;
				dest_scan += 4;
			} else {
				// Dest format: Argb
				// calculate destination alpha (it's union of source and dest alpha)
				if (dest_scan[3] == 0) {
					dest_scan[3] = src_alpha1;
					*dest_scan++ = m_Blue;
					*dest_scan++ = m_Green;
					*dest_scan = m_Red;
					dest_scan += 2; 
					continue;
				}
				FX_BYTE dest_alpha = dest_scan[3] + src_alpha1 - dest_scan[3] * src_alpha1 / 255;
				dest_scan[3] = dest_alpha;
				int alpha_ratio = src_alpha1*255/dest_alpha;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
				dest_scan += 2;
			}
		}
#else
		if (m_bFullCover) {
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha = m_Alpha * clip_scan[col] / 255;
				if (!src_alpha) {
					dest_scan += 4;
					continue;
				}
				if (src_alpha == 255){
					*(FX_DWORD*)dest_scan = m_Color;
					dest_scan += 4;
					continue;
				} else {
					// Dest format: Argb
					// calculate destination alpha (it's union of source and dest alpha)
					if (dest_scan[3] == 0) {
						dest_scan[3] = src_alpha;
						*dest_scan++ = m_Blue;
						*dest_scan++ = m_Green;
						*dest_scan = m_Red;
						dest_scan += 2; 
						continue;
					}
					FX_BYTE dest_alpha = dest_scan[3] + src_alpha - dest_scan[3] * src_alpha / 255;
					dest_scan[3] = dest_alpha;
					int alpha_ratio = src_alpha*255/dest_alpha;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
					dest_scan += 2;
				}
			}
		} else {
			int src_alpha = m_Alpha * cover_scan / 255; 
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha1 = src_alpha* clip_scan[col] / 255;
				if (!src_alpha1) {
					dest_scan += 4;
					continue;
				}
				if (src_alpha1 == 255) {
					*(FX_DWORD*)dest_scan = m_Color;
					dest_scan += 4;
				} else {
					// Dest format: Argb
					// calculate destination alpha (it's union of source and dest alpha)
					if (dest_scan[3] == 0) {
						dest_scan[3] = src_alpha1;
						*dest_scan++ = m_Blue;
						*dest_scan++ = m_Green;
						*dest_scan = m_Red;
						dest_scan += 2; 
						continue;
					}
					FX_BYTE dest_alpha = dest_scan[3] + src_alpha1 - dest_scan[3] * src_alpha1 / 255;
					dest_scan[3] = dest_alpha;
					int alpha_ratio = src_alpha1*255/dest_alpha;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
					dest_scan += 2;
				}
			}
		}
#endif
	}

	void CFX_SkiaRenderer::CompositeSpanARGB_7(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_pDevice->IsCmykImage());
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + (span_left<<2);
		//ori_scan  = (FX_BYTE*)m_pOriDevice->GetScanline(span_top) + (span_left<<2);
		clip_scan = (FX_BYTE*)m_pClipMask->GetScanline(span_top-clip_top) - clip_left + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start << 2;
		//ori_scan += col_start << 2;
		// Do not need origin bitmap, because of merge in pure transparent background
		for (int col = col_start; col < col_end; col ++) 
		{
			int src_alpha = m_Alpha * clip_scan[col] / 255;
			int src_alpha_covered = src_alpha * cover_scan / 255;
			// shortcut
			if (src_alpha_covered == 0){
				dest_scan += 4;
				continue;
			}
			// shortcut
			if (cover_scan == 255 || dest_scan[3] == 0)
			{
				// origin alpha always zero, just get src alpha
				dest_scan[3] = src_alpha_covered;
				*dest_scan ++ = m_Blue;
				*dest_scan ++ = m_Green;
				*dest_scan = m_Red;
				dest_scan += 2; 
				continue;
			}
			// We should do alpha transition and color transition
			// alpha fg          color fg
			// alpha bg          color bg
			// alpha cover       color cover
			dest_scan[3] = FXDIB_ALPHA_MERGE(dest_scan[3], src_alpha, cover_scan);
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, cover_scan);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, cover_scan);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, cover_scan);
			dest_scan += 2;
		}
	}
	
	/*-----------------------------------------------------------------------------------------------------------*/
	void CFX_SkiaRenderer::CompositeSpanRGB32_2(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + (span_left<<2);
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += (col_start << 2);
		if (m_Alpha == 255 && cover_scan == 255) {
			FXSYS_memset32(dest_scan, m_Color, (col_end - col_start)<<2);
			return;
		}
		int src_alpha;
#if 0
		if (m_bFullCover)
			src_alpha = m_Alpha;
		else 
#endif
			src_alpha = m_Alpha * cover_scan / 255;
		for (int col = col_start; col < col_end; col ++) {
			// Dest format:  Rgb32
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, src_alpha);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, src_alpha);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, src_alpha);
			dest_scan += 2;
		}
	}
	void CFX_SkiaRenderer::CompositeSpanRGB32_3(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + (span_left<<2);
		ori_scan  = (FX_BYTE*)m_pOriDevice->GetScanline(span_top) + (span_left<<2);
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start << 2;
		ori_scan += col_start << 2;
		if (m_Alpha == 255 && cover_scan == 255) {
			FXSYS_memset32(dest_scan, m_Color, (col_end - col_start)<<2);
			return;
		}
		int src_alpha = m_Alpha;
		for (int col = col_start; col < col_end; col ++) {
#if 0
			if (m_bFullCover) {
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Blue, src_alpha);
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Green, src_alpha);
				*dest_scan = FXDIB_ALPHA_MERGE(*ori_scan, m_Red, src_alpha);
				dest_scan += 2; ori_scan += 2;
				continue;
			}
#endif
			int b = FXDIB_ALPHA_MERGE(*ori_scan++, m_Blue, src_alpha);
			int g = FXDIB_ALPHA_MERGE(*ori_scan++, m_Green, src_alpha);
			int r = FXDIB_ALPHA_MERGE(*ori_scan, m_Red, src_alpha);
			ori_scan += 2;
			*dest_scan = FXDIB_ALPHA_MERGE( *dest_scan, b, cover_scan);
 			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, g, cover_scan);
 			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, r, cover_scan);
			dest_scan += 2;
		}
	}
	void CFX_SkiaRenderer::CompositeSpanRGB32_6(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + (span_left<<2);
		clip_scan = (FX_BYTE*)m_pClipMask->GetScanline(span_top-clip_top) - clip_left + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start << 2;
#if 1
		int src_alpha = m_Alpha * cover_scan / 255;
		for (int col = col_start; col < col_end; col ++) {
			int src_alpha1 = src_alpha * clip_scan[col] / 255;
			if (!src_alpha1) {
				dest_scan += 4;
				continue;
			}
			if (src_alpha1 == 255) {
				*(FX_DWORD*)dest_scan = m_Color;
				dest_scan += 4;
			} else {
				// Dest format: Rgb or Rgb32
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, src_alpha1);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, src_alpha1);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, src_alpha1);
				dest_scan += 2;
			}				
		}
#else
		if (m_bFullCover) {
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha = m_Alpha * clip_scan[col] / 255;
				if (!src_alpha) {
					dest_scan += 4;
					continue;
				}
				if (src_alpha == 255) {
					*(FX_DWORD*)dest_scan = m_Color;
					dest_scan += 4;
				} else {
					// Dest format: Rgb or Rgb32
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, src_alpha);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, src_alpha);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, src_alpha);
					dest_scan += 2;
				}
			}
		} else {
			// Rgb32
			int src_alpha = m_Alpha * cover_scan / 255;
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha1 = src_alpha * clip_scan[col] / 255;
				if (!src_alpha1) {
					dest_scan += 4;
					continue;
				}
				if (src_alpha1 == 255) {
					*(FX_DWORD*)dest_scan = m_Color;
					dest_scan += 4;
				} else {
					// Dest format: Rgb or Rgb32
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, src_alpha1);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, src_alpha1);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, src_alpha1);
					dest_scan += 2;
				}				
			}
		}			
#endif
	}
	void CFX_SkiaRenderer::CompositeSpanRGB32_7(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_pDevice->IsCmykImage());
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + (span_left<<2);
		ori_scan  = (FX_BYTE*)m_pOriDevice->GetScanline(span_top) + (span_left<<2);
		clip_scan = (FX_BYTE*)m_pClipMask->GetScanline(span_top-clip_top) - clip_left + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start << 2;
		ori_scan += col_start << 2;
#if 1
		for (int col = col_start; col < col_end; col ++) {
			int src_alpha = m_Alpha * clip_scan[col] / 255;
			if (src_alpha == 255 && cover_scan == 255) {
				*(FX_DWORD*)dest_scan = m_Color;
				dest_scan += 4;
				ori_scan += 4;
				continue;
			}
			int b = FXDIB_ALPHA_MERGE(*ori_scan++, m_Blue, src_alpha);
			int g = FXDIB_ALPHA_MERGE(*ori_scan++, m_Green, src_alpha);
			int r = FXDIB_ALPHA_MERGE(*ori_scan, m_Red, src_alpha);
			ori_scan += 2;
			*dest_scan = FXDIB_ALPHA_MERGE( *dest_scan, b, cover_scan);
 			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, g, cover_scan);
 			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, r, cover_scan);
			dest_scan += 2;
		}
#else
		if (m_bFullCover) {
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha = m_Alpha * clip_scan[col] / 255;
				if (!src_alpha) {
					*(FX_DWORD*)dest_scan = *(FX_DWORD*)ori_scan;
					dest_scan += 4;
					ori_scan += 4;
					continue;
				}
				if (src_alpha == 255) {
					*(FX_DWORD*)dest_scan = m_Color;
					dest_scan += 4;
					ori_scan += 4;
					continue;
				}
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Blue, src_alpha);
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Green, src_alpha);
				*dest_scan = FXDIB_ALPHA_MERGE(*ori_scan, m_Red, src_alpha);
				dest_scan += 2; ori_scan += 2;
			}			
		} else {
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha = m_Alpha * clip_scan[col] / 255;
				if (src_alpha == 255 && cover_scan == 255) {
					*(FX_DWORD*)dest_scan = m_Color;
					dest_scan += 4;
					ori_scan += 4;
					continue;
				}
				int b = FXDIB_ALPHA_MERGE(*ori_scan++, m_Blue, src_alpha);
				int g = FXDIB_ALPHA_MERGE(*ori_scan++, m_Green, src_alpha);
				int r = FXDIB_ALPHA_MERGE(*ori_scan, m_Red, src_alpha);
				ori_scan += 2;
				*dest_scan = FXDIB_ALPHA_MERGE( *dest_scan, b, cover_scan);
 				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, g, cover_scan);
 				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, r, cover_scan);
				dest_scan += 2;
			}
		}
#endif
	}
	/*-----------------------------------------------------------------------------------------------------*/
	void CFX_SkiaRenderer::CompositeSpanRGB24_2(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left + (span_left<<1);
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += (col_start<<1)+col_start;
		int src_alpha;
#if 0
		if (m_bFullCover)
			src_alpha = m_Alpha;
		else 
#endif
			src_alpha = m_Alpha * cover_scan / 255;
		if (src_alpha == 255) {
			for (int col = col_start; col < col_end; col ++) {
				*dest_scan++ = m_Blue;
				*dest_scan++ = m_Green;
				*dest_scan++ = m_Red;
			}
			return;
		}
		for (int col = col_start; col < col_end; col ++) {
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, src_alpha);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, src_alpha);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, src_alpha);
			dest_scan ++;
		}
	}
	void CFX_SkiaRenderer::CompositeSpanRGB24_3(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_pDevice->IsCmykImage());
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left + (span_left<<1);
		ori_scan  = (FX_BYTE*)m_pOriDevice->GetScanline(span_top) + span_left + (span_left<<1);
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += (col_start<<1) + col_start;
		ori_scan += (col_start<<1) + col_start;
		if (m_Alpha == 255&&cover_scan == 255) {
			for (int col = col_start; col < col_end; col ++) {
				*dest_scan ++ = m_Blue;
 				*dest_scan ++ = m_Green;
				*dest_scan ++ = m_Red;
			}
			return;
		}
		for (int col = col_start; col < col_end; col ++) {
#if 0
			if (m_bFullCover) {
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Blue, m_Alpha);
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Green, m_Alpha);
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Red, m_Alpha);
				continue;
			}
#endif
			int b = FXDIB_ALPHA_MERGE(*ori_scan++, m_Blue, m_Alpha);
			int g = FXDIB_ALPHA_MERGE(*ori_scan++, m_Green, m_Alpha);
			int r = FXDIB_ALPHA_MERGE(*ori_scan++, m_Red, m_Alpha);
			*dest_scan = FXDIB_ALPHA_MERGE( *dest_scan, b, cover_scan);
 			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, g, cover_scan);
 			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, r, cover_scan);
			dest_scan ++;
		}
	}
	void CFX_SkiaRenderer::CompositeSpanRGB24_6(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left+(span_left<<1);
		clip_scan = (FX_BYTE*)m_pClipMask->GetScanline(span_top-clip_top) - clip_left + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start + (col_start << 1);
#if 1
		int src_alpha = m_Alpha * cover_scan /255;
		for (int col = col_start; col < col_end; col ++) {
			int src_alpha1 = src_alpha * clip_scan[col] / 255;	
			if (!src_alpha1) {
				dest_scan += 3;
				continue;
			}
			if (src_alpha1 == 255) {
				*dest_scan++ = m_Blue;
				*dest_scan++ = m_Green;
				*dest_scan++ = m_Red;
			} else {
				// Dest format: Rgb
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, src_alpha1);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, src_alpha1);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, src_alpha1);
				dest_scan ++;
			}
		}
#else
		if (m_bFullCover) {
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha = m_Alpha * clip_scan[col] / 255;	
				if (!src_alpha) {
					dest_scan += 3;
					continue;
				}
				if (src_alpha == 255) {
					*dest_scan++ = m_Blue;
					*dest_scan++ = m_Green;
					*dest_scan++ = m_Red;
				} else {
					// Dest format: Rgb
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, src_alpha);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, src_alpha);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, src_alpha);
					dest_scan ++;
				}
			}
		} else {
			int src_alpha = m_Alpha * cover_scan /255;
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha1 = src_alpha * clip_scan[col] / 255;	
				if (!src_alpha1) {
					dest_scan += 3;
					continue;
				}
				if (src_alpha1 == 255) {
					*dest_scan++ = m_Blue;
					*dest_scan++ = m_Green;
					*dest_scan++ = m_Red;
				} else {
					// Dest format: Rgb
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, src_alpha1);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, src_alpha1);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, src_alpha1);
					dest_scan ++;
				}
			}
		}
#endif
	}
	void CFX_SkiaRenderer::CompositeSpanRGB24_7(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_pDevice->IsCmykImage());
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left+(span_left<<1);
		ori_scan  = (FX_BYTE*)m_pOriDevice->GetScanline(span_top) + span_left+(span_left<<1);
		clip_scan = (FX_BYTE*)m_pClipMask->GetScanline(span_top-clip_top) - clip_left + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start + (col_start<<1);
		ori_scan += col_start + (col_start<<1);
#if 1
		for (int col = col_start; col < col_end; col ++) {
			int src_alpha = m_Alpha * clip_scan[col] / 255;
			if (src_alpha == 255 && cover_scan == 255) {
				*dest_scan++ = m_Blue;
				*dest_scan++ = m_Green;
				*dest_scan++ = m_Red;
				ori_scan += 3;
				continue;
			}
			int b = FXDIB_ALPHA_MERGE(*ori_scan++, m_Blue, src_alpha);
			int g = FXDIB_ALPHA_MERGE(*ori_scan++, m_Green, src_alpha);
			int r = FXDIB_ALPHA_MERGE(*ori_scan++, m_Red, src_alpha);
			*dest_scan = FXDIB_ALPHA_MERGE( *dest_scan, b, cover_scan);
 			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, g, cover_scan);
 			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, r, cover_scan);
			dest_scan ++;
		}
#else
		if (m_bFullCover) { 
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha = m_Alpha * clip_scan[col] / 255;
				if (!src_alpha){
					*dest_scan++ = *ori_scan++;
					*dest_scan++ = *ori_scan++;
					*dest_scan++ = *ori_scan++;
					continue;
				}
				if (src_alpha == 255){
					*dest_scan++ = m_Blue;
					*dest_scan++ = m_Green;
					*dest_scan++ = m_Red;
					ori_scan += 3;
					continue;
				}
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Blue, src_alpha);
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Green, src_alpha);
				*dest_scan++ = FXDIB_ALPHA_MERGE(*ori_scan++, m_Red, src_alpha);
			}
		} else {
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha = m_Alpha * clip_scan[col] / 255;
				if (src_alpha == 255 && cover_scan == 255) {
					*dest_scan++ = m_Blue;
					*dest_scan++ = m_Green;
					*dest_scan++ = m_Red;
					ori_scan += 3;
					continue;
				}
				int b = FXDIB_ALPHA_MERGE(*ori_scan++, m_Blue, src_alpha);
				int g = FXDIB_ALPHA_MERGE(*ori_scan++, m_Green, src_alpha);
				int r = FXDIB_ALPHA_MERGE(*ori_scan++, m_Red, src_alpha);
				*dest_scan = FXDIB_ALPHA_MERGE( *dest_scan, b, cover_scan);
 				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, g, cover_scan);
 				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, r, cover_scan);
				dest_scan ++;
			}
		}
#endif
	}
	void CFX_SkiaRenderer::CompositeSpanRGB24_10(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left+(span_left<<1);
		dest_extra_alpha_scan =  (FX_BYTE*)m_pDevice->m_pAlphaMask->GetScanline(span_top)+span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start+(col_start<<1);
#if 1
		if (m_Alpha == 255 && cover_scan == 255) {
			for (int col = col_start; col < col_end; col ++) {
				*dest_scan++ = (FX_BYTE)m_Blue;
				*dest_scan++ = (FX_BYTE)m_Green;
				*dest_scan++ = (FX_BYTE)m_Red;
				*dest_extra_alpha_scan++ = 255;
			}
			return;
		}
		int src_alpha = m_Alpha * cover_scan / 255;
		for (int col = col_start; col < col_end; col ++) {
			// Dest format: Rgba
			// calculate destination alpha (it's union of source and dest alpha)
			FX_BYTE dest_alpha = (*dest_extra_alpha_scan) + src_alpha - 
								(*dest_extra_alpha_scan) * src_alpha / 255;
			*dest_extra_alpha_scan++ = dest_alpha;
			int alpha_ratio = src_alpha*255/dest_alpha;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
			dest_scan ++;
			*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
			dest_scan ++;			
		}
#else
		if (m_bFullCover) {
			if (m_Alpha == 255) {
				for (int col = col_start; col < col_end; col ++) {
					*dest_scan++ = (FX_BYTE)m_Blue;
					*dest_scan++ = (FX_BYTE)m_Green;
					*dest_scan++ = (FX_BYTE)m_Red;
					*dest_extra_alpha_scan++ = 255;
				}
				return;
			}
			for (int col = col_start; col < col_end; col ++) {
				// Dest format: Rgba
				// calculate destination alpha (it's union of source and dest alpha)
				FX_BYTE dest_alpha = (*dest_extra_alpha_scan) + m_Alpha - 
									(*dest_extra_alpha_scan) * m_Alpha / 255;
				*dest_extra_alpha_scan++ = dest_alpha;
				int alpha_ratio = m_Alpha*255/dest_alpha;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
				dest_scan ++;
			}
		} else {
			if (m_Alpha == 255 && cover_scan == 255) {
				for (int col = col_start; col < col_end; col ++) {
					*dest_scan++ = (FX_BYTE)m_Blue;
					*dest_scan++ = (FX_BYTE)m_Green;
					*dest_scan++ = (FX_BYTE)m_Red;
					*dest_extra_alpha_scan++ = 255;
				}
				return;
			}
			int src_alpha = m_Alpha * cover_scan / 255;
			for (int col = col_start; col < col_end; col ++) {
				// Dest format: Rgba
				// calculate destination alpha (it's union of source and dest alpha)
				FX_BYTE dest_alpha = (*dest_extra_alpha_scan) + src_alpha - 
									(*dest_extra_alpha_scan) * src_alpha / 255;
				*dest_extra_alpha_scan++ = dest_alpha;
				int alpha_ratio = src_alpha*255/dest_alpha;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
				dest_scan ++;			
			}
		}
#endif
	}
	void CFX_SkiaRenderer::CompositeSpanRGB24_14(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		dest_scan = (FX_BYTE*)m_pDevice->GetScanline(span_top) + span_left+(span_left<<1);
		dest_extra_alpha_scan =  (FX_BYTE*)m_pDevice->m_pAlphaMask->GetScanline(span_top)+span_left;
		clip_scan = (FX_BYTE*)m_pClipMask->GetScanline(span_top-clip_top) - clip_left + span_left;
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start + (col_start << 1);
#if 1
		int src_alpha = m_Alpha * cover_scan / 255;
		for (int col = col_start; col < col_end; col ++) {
			int src_alpha1 = src_alpha * clip_scan[col] / 255;
			if (!src_alpha1) {
				dest_extra_alpha_scan++;
				dest_scan += 3;
				continue;
			}				
			if (src_alpha1 == 255) {
				*dest_scan++ = (FX_BYTE)m_Blue;
				*dest_scan++ = (FX_BYTE)m_Green;
				*dest_scan++ = (FX_BYTE)m_Red;
				*dest_extra_alpha_scan++ = (FX_BYTE)m_Alpha;
			} else {
				// Dest format: Rgba
				// calculate destination alpha (it's union of source and dest alpha)
				FX_BYTE dest_alpha = (*dest_extra_alpha_scan) + src_alpha1 - 
									(*dest_extra_alpha_scan) * src_alpha1 / 255;
				*dest_extra_alpha_scan++ = dest_alpha;
				int alpha_ratio = src_alpha1*255/dest_alpha;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
				dest_scan ++;
				*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
				dest_scan ++;
			}
		}
#else
		if (m_bFullCover) {
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha = m_Alpha * clip_scan[col] / 255;
				if (!src_alpha) {
					dest_extra_alpha_scan++;
					dest_scan += 3;
					continue;
				}
				if (src_alpha == 255) {
					*dest_scan++ = (FX_BYTE)m_Blue;
					*dest_scan++ = (FX_BYTE)m_Green;
					*dest_scan++ = (FX_BYTE)m_Red;
					*dest_extra_alpha_scan++ = (FX_BYTE)m_Alpha;
				} else {
					// Dest format: Rgba
					// calculate destination alpha (it's union of source and dest alpha)
					FX_BYTE dest_alpha = (*dest_extra_alpha_scan) + src_alpha - 
										(*dest_extra_alpha_scan) * src_alpha / 255;
					*dest_extra_alpha_scan++ = dest_alpha;
					int alpha_ratio = src_alpha*255/dest_alpha;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
					dest_scan ++;
				}
			}
		} else {
			int src_alpha = m_Alpha * cover_scan / 255;
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha1 = m_Alpha * cover_scan * clip_scan[col] / 255;
				if (!src_alpha1) {
					dest_extra_alpha_scan++;
					dest_scan += 3;
					continue;
				}				
				if (src_alpha1 == 255) {
					*dest_scan++ = (FX_BYTE)m_Blue;
					*dest_scan++ = (FX_BYTE)m_Green;
					*dest_scan++ = (FX_BYTE)m_Red;
					*dest_extra_alpha_scan++ = (FX_BYTE)m_Alpha;
				} else {
					// Dest format: Rgba
					// calculate destination alpha (it's union of source and dest alpha)
					FX_BYTE dest_alpha = (*dest_extra_alpha_scan) + src_alpha1 - 
										(*dest_extra_alpha_scan) * src_alpha1 / 255;
					*dest_extra_alpha_scan++ = dest_alpha;
					int alpha_ratio = src_alpha1*255/dest_alpha;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
					dest_scan ++;
					*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
					dest_scan ++;
				}
			}
		}
#endif
	}
	/*-----------------------------------------------------------------------------------------------------*/

	// A general alpha merge function (with clipping mask). Cmyka/Cmyk device.
	void CFX_SkiaRenderer::CompositeSpanCMYK(FX_LPBYTE dest_scan, FX_LPBYTE ori_scan,int Bpp,
			int span_left, int span_len, int span_top, FX_BYTE cover_scan, 
			int clip_top, int clip_left, int clip_right, FX_LPBYTE clip_scan, 
			FX_LPBYTE dest_extra_alpha_scan)
	{
		ASSERT(!m_bRgbByteOrder);
		// Cmyk(a)
		int col_start = span_left < clip_left ? clip_left - span_left : 0;
		int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
		if (col_end < col_start) return; // do nothing.
		dest_scan += col_start * 4;
		Bpp; // for avoid compile warning.
		
		if (dest_extra_alpha_scan) {
			// CMYKa
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha;
				if (m_bFullCover) {
					if (clip_scan)
						src_alpha = m_Alpha * clip_scan[col] / 255;
					else
						src_alpha = m_Alpha;
				} else {
					if (clip_scan)
						src_alpha = m_Alpha * cover_scan * clip_scan[col] / 255 / 255;
					else
						src_alpha = m_Alpha * cover_scan / 255;
				}
				
				if (src_alpha) {
					if (src_alpha == 255) {
						*(FX_CMYK*)dest_scan = m_Color;
						*dest_extra_alpha_scan = (FX_BYTE)m_Alpha;
					} else {
						// Dest format: Cmyka
						// calculate destination alpha (it's union of source and dest alpha)
						FX_BYTE dest_alpha = (*dest_extra_alpha_scan) + src_alpha - 
							(*dest_extra_alpha_scan) * src_alpha / 255;
						*dest_extra_alpha_scan++ = dest_alpha;
						int alpha_ratio = src_alpha*255/dest_alpha;
						*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, alpha_ratio);
						dest_scan ++;
						*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, alpha_ratio);
						dest_scan ++;
						*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, alpha_ratio);
						dest_scan ++;
						*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Gray, alpha_ratio);
						dest_scan ++;
						continue;
					}
				}
				dest_extra_alpha_scan++;
				dest_scan += 4;
			}
		} else {
			// CMYK
			for (int col = col_start; col < col_end; col ++) {
				int src_alpha;
				if (clip_scan)
					src_alpha = m_Alpha * cover_scan * clip_scan[col] / 255 / 255;
				else
					src_alpha = m_Alpha * cover_scan / 255;
				
				if (src_alpha) {
					if (src_alpha == 255) {
						*(FX_CMYK*)dest_scan = m_Color;
					} else {
						// Dest format: cmyk
						*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Red, src_alpha);
						dest_scan ++;
						*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Green, src_alpha);
						dest_scan ++;
						*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Blue, src_alpha);
						dest_scan ++;
						*dest_scan = FXDIB_ALPHA_MERGE(*dest_scan, m_Gray, src_alpha);
						dest_scan ++;
						continue;
					}
				}
				dest_scan += 4;
			}
		}
	}

   
	
	//--------------------------------------------------------------------
	FX_BOOL CFX_SkiaRenderer::Init(CFX_DIBitmap* pDevice, CFX_DIBitmap* pOriDevice, const CFX_ClipRgn* pClipRgn, FX_DWORD color, FX_BOOL bFullCover, FX_BOOL bRgbByteOrder, 
		int alpha_flag, void* pIccTransform) //The alpha flag must be fill_flag if exist.
	{
		m_pDevice = pDevice;
		m_pClipRgn = pClipRgn;
		m_bRgbByteOrder = bRgbByteOrder;
		m_pOriDevice = pOriDevice;
		m_pDestScan = NULL;
		m_pDestExtraAlphaScan = NULL;
		m_pOriScan = NULL;
		m_pClipScan = NULL;
		composite_span = NULL;
		if (m_pClipRgn)
			m_ClipBox = m_pClipRgn->GetBox();
		else {
			m_ClipBox.left = m_ClipBox.top = 0;
			m_ClipBox.right = m_pDevice->GetWidth();
			m_ClipBox.bottom = m_pDevice->GetHeight();
		}
		m_pClipMask = NULL;
		if (m_pClipRgn && m_pClipRgn->GetType() == CFX_ClipRgn::MaskF)
		{
			m_pClipMask = m_pClipRgn->GetMask();
			m_pClipScan = m_pClipMask->GetBuffer();
		}
		if (m_pDevice->m_pAlphaMask)
			m_pDestExtraAlphaScan = m_pDevice->m_pAlphaMask->GetBuffer();
		if (m_pOriDevice)
			m_pOriScan = m_pOriDevice->GetBuffer();
		m_pDestScan = m_pDevice->GetBuffer();
		
		m_bFullCover = bFullCover;
		
		FX_BOOL bObjectCMYK = FXGETFLAG_COLORTYPE(alpha_flag);
		FX_BOOL bDeviceCMYK = pDevice->IsCmykImage();

		m_Alpha = bObjectCMYK ? FXGETFLAG_ALPHA_FILL(alpha_flag) : FXARGB_A(color);

		ICodec_IccModule* pIccModule = NULL;
		// No lcms engine, we skip the transform
		if (!CFX_GEModule::Get()->GetCodecModule() || !CFX_GEModule::Get()->GetCodecModule()->GetIccModule()) 
			pIccTransform = NULL;
		else
			pIccModule = CFX_GEModule::Get()->GetCodecModule()->GetIccModule();
		
		if (m_pDevice->GetBPP() == 8) { // Gray(a) device
			ASSERT(!m_bRgbByteOrder);
			if (m_pDevice->IsAlphaMask()) {
				//Alpha Mask
				m_Gray = 255;
			} else {
				//Gray(a) device
				if (pIccTransform) {
					FX_BYTE gray;
					color = bObjectCMYK ? FXCMYK_TODIB(color) : FXARGB_TODIB(color);
					pIccModule->TranslateScanline(pIccTransform, &gray, (FX_LPCBYTE)&color, 1);
					m_Gray = gray;
				} else {
					if (bObjectCMYK) {
						FX_BYTE r, g, b;
						AdobeCMYK_to_sRGB1(FXSYS_GetCValue(color), FXSYS_GetMValue(color), FXSYS_GetYValue(color), FXSYS_GetKValue(color), 
							r, g, b);
						m_Gray = FXRGB2GRAY(r, g, b);
					} else {
						m_Gray = FXRGB2GRAY(FXARGB_R(color), FXARGB_G(color), FXARGB_B(color));
					}
				}
			}
		} else {
			if (bDeviceCMYK) { // Cmyk(a) Device
				ASSERT(!m_bRgbByteOrder);
				//TODO... opt for cmyk
				composite_span = &CFX_SkiaRenderer::CompositeSpanCMYK;
				if (bObjectCMYK) { 
					m_Color = FXCMYK_TODIB(color);
					if (pIccTransform)
						pIccModule->TranslateScanline(pIccTransform, (FX_LPBYTE)&m_Color, (FX_LPCBYTE)&m_Color, 1);
				} else { // Object RGB
					if (!pIccTransform)
						return FALSE;
					color = FXARGB_TODIB(color);
					pIccModule->TranslateScanline(pIccTransform, (FX_LPBYTE)&m_Color, (FX_LPCBYTE)&color, 1);
				}
				m_Red	= ((FX_LPBYTE)&m_Color)[0];
				m_Green = ((FX_LPBYTE)&m_Color)[1];
				m_Blue	= ((FX_LPBYTE)&m_Color)[2];
				m_Gray	= ((FX_LPBYTE)&m_Color)[3];
				return TRUE;
			} else { 
				if (pIccTransform) {
					color = bObjectCMYK ? FXCMYK_TODIB(color) : FXARGB_TODIB(color);
					pIccModule->TranslateScanline(pIccTransform, (FX_LPBYTE)&m_Color, (FX_LPCBYTE)&color, 1);
					((FX_LPBYTE)&m_Color)[3] = m_Alpha;
					m_Red = ((FX_LPBYTE)&m_Color)[2];
					m_Green = ((FX_LPBYTE)&m_Color)[1];
					m_Blue = ((FX_LPBYTE)&m_Color)[0];
					// Need Johnson to improvement it.
					if (m_bRgbByteOrder) {
						// swap
						m_Red = ((FX_LPBYTE)&m_Color)[0];
						m_Blue = ((FX_LPBYTE)&m_Color)[2];
						m_Color = FXARGB_TODIB(m_Color);
						m_Color = FXARGB_TOBGRORDERDIB(m_Color);
					}
				} else {
					if (bObjectCMYK) {
						FX_BYTE r, g, b;
						AdobeCMYK_to_sRGB1(FXSYS_GetCValue(color), FXSYS_GetMValue(color), FXSYS_GetYValue(color), FXSYS_GetKValue(color), 
							r, g, b);
						m_Color = FXARGB_MAKE(m_Alpha, r, g, b);
						if (m_bRgbByteOrder){
							m_Color = FXARGB_TOBGRORDERDIB(m_Color);
							m_Red = b; m_Green = g; m_Blue = r;//
						}else {
							m_Color = FXARGB_TODIB(m_Color);
							m_Red = r; m_Green = g; m_Blue = b;//
						}
					} else {
						if (m_bRgbByteOrder){
							m_Color = FXARGB_TOBGRORDERDIB(color);
							ArgbDecode(color, m_Alpha, m_Blue, m_Green, m_Red); //
						}else {
							m_Color = FXARGB_TODIB(color);
							ArgbDecode(color, m_Alpha, m_Red, m_Green, m_Blue); 
						}					
					}
				}	
			}
		}
		// Get palette transparency selector
		m_ProcessFilter = (m_pOriDevice? 1 : 0)	/* has Ori Device flag */
						+ (m_pDevice->GetBPP() >= 8 ? 2 : 0)	/* bpp flag */			
						+ (m_pClipMask? 4 : 0)					/* has clip region flag */
						+ (m_pDevice->m_pAlphaMask? 8 : 0);		/* has Alpha Mask chanel flag */
		switch(m_ProcessFilter) {
			case 0:
				composite_span = &CFX_SkiaRenderer::CompositeSpan1bpp_0;
				break;
			case 2:
				{
					if (m_pDevice->GetBPP() == 8)
						composite_span = &CFX_SkiaRenderer::CompositeSpanGray_2;
					else if (m_pDevice->GetBPP() == 24)
						composite_span = &CFX_SkiaRenderer::CompositeSpanRGB24_2;
					else
						composite_span = m_pDevice->HasAlpha()?&CFX_SkiaRenderer::CompositeSpanARGB_2 : &CFX_SkiaRenderer::CompositeSpanRGB32_2;
				}
				break;
			case 3:
				{
					if (m_pDevice->GetBPP() == 8)
						composite_span = &CFX_SkiaRenderer::CompositeSpanGray_3;
					else if (m_pDevice->GetBPP() == 24)
						composite_span = &CFX_SkiaRenderer::CompositeSpanRGB24_3;
					else 
						composite_span = m_pDevice->HasAlpha()?&CFX_SkiaRenderer::CompositeSpanARGB_3 : &CFX_SkiaRenderer::CompositeSpanRGB32_3;
				}
				break;
			case 4:
				composite_span = &CFX_SkiaRenderer::CompositeSpan1bpp_4;
				break;
			case 6:
				{
					if (m_pDevice->GetBPP() == 8)
						composite_span = &CFX_SkiaRenderer::CompositeSpanGray_6;
					else if (m_pDevice->GetBPP() == 24)
						composite_span = &CFX_SkiaRenderer::CompositeSpanRGB24_6;
					else 
						composite_span = m_pDevice->HasAlpha()?&CFX_SkiaRenderer::CompositeSpanARGB_6 : &CFX_SkiaRenderer::CompositeSpanRGB32_6;
				}
				break;
			case 7:
				{
					if (m_pDevice->GetBPP() == 8)
						composite_span = &CFX_SkiaRenderer::CompositeSpanGray_7;
					else if (m_pDevice->GetBPP() == 24)
						composite_span = &CFX_SkiaRenderer::CompositeSpanRGB24_7;
					else 
						composite_span = m_pDevice->HasAlpha()?&CFX_SkiaRenderer::CompositeSpanARGB_7 : &CFX_SkiaRenderer::CompositeSpanRGB32_7;
				}
				break;
			case 1:
			case 5:
			case 8:
			case 9:
			case 11:
			case 12:
			case 13:
			case 15:
				//TODO...
				break;
			case 10:
				composite_span = &CFX_SkiaRenderer::CompositeSpanRGB24_10;
				break;
			case 14:
				composite_span = &CFX_SkiaRenderer::CompositeSpanRGB24_14;
				break;
		}
		if (composite_span == NULL)
			return FALSE;
		return TRUE;
	}

	/*----------------------------------------------------------------------------------------------------*/
	void CFX_SkiaA8Renderer::blitAntiH(int x, int y, const SkAlpha antialias[], const int16_t runs[])
	{
		FXSYS_assert(m_pDevice);
		int dst_y = y - m_Top;
		if (dst_y < 0 || dst_y >=  m_pDevice->GetHeight())
			return;
		
		FX_LPBYTE dest_scan = m_pDevice->GetBuffer() + m_pDevice->GetPitch() * dst_y;
		FX_LPBYTE dest_pos = dest_scan;
		while (1)
		{
			if (x >= m_dstWidth) 
				return;
			int width = runs[0];
			SkASSERT(width >= 0);
			if (width <= 0) 
				return;
			unsigned aa = antialias[0];
			if (aa) {
				int col_start = x < m_Left ? 0 : x - m_Left;
				int col_end = x + width;
				col_end = col_end < m_dstWidth ? col_end - m_Left: m_pDevice->GetWidth();
				int result = col_end - col_start;
				if (result > 0) {
					dest_pos = dest_scan + col_start;
					if (result >= 4)
						FXSYS_memset32(dest_pos, FXARGB_MAKE(aa, aa, aa, aa),result);
					else
						FXSYS_memset(dest_pos,aa,result);
				}				
			}	
			runs += width;
			antialias += width;
			x += width;
		}
	}
	void CFX_SkiaA8Renderer::blitH(int x, int y, int width)
	{
		FXSYS_assert(m_pDevice);
		int dst_y = y - m_Top;
		if (dst_y < 0 || dst_y >=  m_pDevice->GetHeight())
			return;
		if (x >= m_dstWidth) 
			return;
		FX_LPBYTE dest_scan = m_pDevice->GetBuffer() + m_pDevice->GetPitch() * dst_y;
		int col_start = x < m_Left ? 0 : x - m_Left;
		int col_end = x + width;
		col_end = col_end < m_dstWidth ? col_end - m_Left: m_pDevice->GetWidth();
		int result = col_end - col_start;
		if (result > 0) {
			FX_BYTE* dest_pos = dest_scan + col_start;
			if (result >= 4)
				FXSYS_memset32(dest_pos, 0xffffffff,result);
			else
				FXSYS_memset(dest_pos,255,result);
		}
	}
	void CFX_SkiaA8Renderer::blitV(int x, int y, int height, SkAlpha alpha)
	{
		FXSYS_assert(alpha);
		if (alpha == 255) {
			this->blitRect(x, y, 1, height);
		} else {
			int16_t runs[2];
			runs[0] = 1;
			runs[1] = 0;
			while (--height >= 0) {
				if (y >= m_dstHeight)
					return;
				this->blitAntiH(x, y ++, &alpha, runs);
			}
		}
	}
	void CFX_SkiaA8Renderer::blitRect(int x, int y, int width, int height)
	{
		FXSYS_assert(m_pDevice);
		while (--height >= 0) {
			if (y >= m_dstHeight)
				return;
			blitH(x , y ++, width);
		}
	}

	void CFX_SkiaA8Renderer::blitAntiRect(int x, int y, int width, int height,
                             SkAlpha leftAlpha, SkAlpha rightAlpha) 
	{
		blitV(x++, y, height, leftAlpha);
		if (width > 0) {
			blitRect(x, y, width, height);
			x += width;
		}
		blitV(x, y, height, rightAlpha);
	}

	FX_BOOL CFX_SkiaA8Renderer::Init(CFX_DIBitmap* pDevice, int Left, int Top)
	{
		m_pDevice = pDevice;
		m_Left = Left;
		m_Top = Top;
		if (pDevice){
			m_dstWidth = m_Left + pDevice->GetWidth();
			m_dstHeight = m_Top + pDevice->GetHeight();
		}
		return TRUE;
	}
#endif