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分享cxImage Draw
请教CxImage中的Draw函数的参数pClipRect怎么用啊？我使用如下代码。lSenX lSenY 是屏幕中心，m_SmallIcons载入一张150X75的png图片，在不使用参数ClipRect的时候可以正常显示，一旦用上就无法显示，请问这是为什么呢
RECT ShowRect, ClipRect;
ClipRect.left = 45;
ClipRect.top = 30;
ClipRect.right = 60;
ClipRect.bottom = 45;
ShowRect.left = lSenX - 7;
ShowRect.top = lSenY - 7;
ShowRect.right = lSenX + 8;
ShowRect.bottom = lSenY + 8;
m_SmallIcons.Draw(dcMemery, ShowRect, &ClipRect);
DWORD avd = GetLastError();
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youyifang 2009-08-26
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这个ClipRect是来选择绘制区域的,如果你的showrect相对应的没有在clipRect区域,它是没发绘制出图像的.为空的时候,是用这个dcMemery所在的窗口区域来绘制.
yuan697 2009-08-26
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long CxImage::Draw(HDC hdc, long x, long y, long cx, long cy, RECT* pClipRect, bool bSmooth)
{
if((pDib==0)||(hdc==0)||(cx==0)||(cy==0)||(!info.bEnabled)) return 0;
if (cx < 0) cx = head.biWidth;
if (cy < 0) cy = head.biHeight;
bool bTransparent = info.nBkgndIndex >= 0;
bool bAlpha = pAlpha != 0;
//required for MM_ANISOTROPIC, MM_HIENGLISH, and similar modes [Greg Peatfield]
int hdc_Restore = ::SaveDC(hdc);
if (!hdc_Restore)
return 0;
#if !defined (_WIN32_WCE)
RECT mainbox; // (experimental)
if (pClipRect){
GetClipBox(hdc,&mainbox);
HRGN rgn = CreateRectRgnIndirect(pClipRect);
ExtSelectClipRgn(hdc,rgn,RGN_AND);
DeleteObject(rgn);
}
#endif
//find the smallest area to paint
RECT clipbox,paintbox;
GetClipBox(hdc,&clipbox);
paintbox.top = min(clipbox.bottom,max(clipbox.top,y));
paintbox.left = min(clipbox.right,max(clipbox.left,x));
paintbox.right = max(clipbox.left,min(clipbox.right,x+cx));
paintbox.bottom = max(clipbox.top,min(clipbox.bottom,y+cy));
long destw = paintbox.right - paintbox.left;
long desth = paintbox.bottom - paintbox.top;
if (!(bTransparent || bAlpha || info.bAlphaPaletteEnabled)){
if (cx==head.biWidth && cy==head.biHeight){ //NORMAL
#if !defined (_WIN32_WCE)
SetStretchBltMode(hdc,COLORONCOLOR);
#endif
SetDIBitsToDevice(hdc, x, y, cx, cy, 0, 0, 0, cy,
info.pImage,(BITMAPINFO*)pDib,DIB_RGB_COLORS);
} else { //STRETCH
//pixel informations
RGBQUAD c={0,0,0,0};
//Preparing Bitmap Info
BITMAPINFO bmInfo;
memset(&bmInfo.bmiHeader,0,sizeof(BITMAPINFOHEADER));
bmInfo.bmiHeader.biSize=sizeof(BITMAPINFOHEADER);
bmInfo.bmiHeader.biWidth=destw;
bmInfo.bmiHeader.biHeight=desth;
bmInfo.bmiHeader.biPlanes=1;
bmInfo.bmiHeader.biBitCount=24;
BYTE *pbase; //points to the final dib
BYTE *pdst; //current pixel from pbase
BYTE *ppix; //current pixel from image
//get the background
HDC TmpDC=CreateCompatibleDC(hdc);
HBITMAP TmpBmp=CreateDIBSection(hdc,&bmInfo,DIB_RGB_COLORS,(void**)&pbase,0,0);
HGDIOBJ TmpObj=SelectObject(TmpDC,TmpBmp);
if (pbase){
long xx,yy;
long sx,sy;
float dx,dy;
BYTE *psrc;
long ew = ((((24 * destw) + 31) / 32) * 4);
long ymax = paintbox.bottom;
long xmin = paintbox.left;
float fx=(float)head.biWidth/(float)cx;
float fy=(float)head.biHeight/(float)cy;
for(yy=0;yy<desth;yy++){
dy = head.biHeight-(ymax-yy-y)*fy;
sy = max(0L,(long)floor(dy));
psrc = info.pImage+sy*info.dwEffWidth;
pdst = pbase+yy*ew;
for(xx=0;xx<destw;xx++){
dx = (xx+xmin-x)*fx;
sx = max(0L,(long)floor(dx));
#if CXIMAGE_SUPPORT_INTERPOLATION
if (bSmooth){
if (fx > 1 && fy > 1) {
c = GetAreaColorInterpolated(dx - 0.5f, dy - 0.5f, fx, fy, CxImage::IM_BILINEAR, CxImage::OM_REPEAT);
} else {
c = GetPixelColorInterpolated(dx - 0.5f, dy - 0.5f, CxImage::IM_BILINEAR, CxImage::OM_REPEAT);
}
} else
#endif //CXIMAGE_SUPPORT_INTERPOLATION
{
if (head.biClrUsed){
c=GetPaletteColor(GetPixelIndex(sx,sy));
} else {
ppix = psrc + sx*3;
c.rgbBlue = *ppix++;
c.rgbGreen= *ppix++;
c.rgbRed = *ppix;
}
}
*pdst++=c.rgbBlue;
*pdst++=c.rgbGreen;
*pdst++=c.rgbRed;
}
}
}
//paint the image & cleanup
SetDIBitsToDevice(hdc,paintbox.left,paintbox.top,destw,desth,0,0,0,desth,pbase,&bmInfo,0);
DeleteObject(SelectObject(TmpDC,TmpObj));
DeleteDC(TmpDC);
}
} else { // draw image with transparent/alpha blending
//////////////////////////////////////////////////////////////////
//Alpha blend - Thanks to Florian Egel
//pixel informations
RGBQUAD c={0,0,0,0};
RGBQUAD ct = GetTransColor();
long* pc = (long*)&c;
long* pct= (long*)&ct;
long cit = GetTransIndex();
long ci = 0;
//Preparing Bitmap Info
BITMAPINFO bmInfo;
memset(&bmInfo.bmiHeader,0,sizeof(BITMAPINFOHEADER));
bmInfo.bmiHeader.biSize=sizeof(BITMAPINFOHEADER);
bmInfo.bmiHeader.biWidth=destw;
bmInfo.bmiHeader.biHeight=desth;
bmInfo.bmiHeader.biPlanes=1;
bmInfo.bmiHeader.biBitCount=24;
BYTE *pbase; //points to the final dib
BYTE *pdst; //current pixel from pbase
BYTE *ppix; //current pixel from image
//get the background
HDC TmpDC=CreateCompatibleDC(hdc);
HBITMAP TmpBmp=CreateDIBSection(hdc,&bmInfo,DIB_RGB_COLORS,(void**)&pbase,0,0);
HGDIOBJ TmpObj=SelectObject(TmpDC,TmpBmp);
BitBlt(TmpDC,0,0,destw,desth,hdc,paintbox.left,paintbox.top,SRCCOPY);
if (pbase){
long xx,yy,alphaoffset,ix,iy;
BYTE a,a1,*psrc;
long ew = ((((24 * destw) + 31) / 32) * 4);
long ymax = paintbox.bottom;
long xmin = paintbox.left;
if (cx!=head.biWidth || cy!=head.biHeight){
//STRETCH
float fx=(float)head.biWidth/(float)cx;
float fy=(float)head.biHeight/(float)cy;
float dx,dy;
long sx,sy;
for(yy=0;yy<desth;yy++){
dy = head.biHeight-(ymax-yy-y)*fy;
sy = max(0L,(long)floor(dy));
alphaoffset = sy*head.biWidth;
pdst = pbase + yy*ew;
psrc = info.pImage + sy*info.dwEffWidth;
for(xx=0;xx<destw;xx++){
dx = (xx+xmin-x)*fx;
sx = max(0L,(long)floor(dx));
if (bAlpha) a=pAlpha[alphaoffset+sx]; else a=255;
a =(BYTE)((a*(1+info.nAlphaMax))>>8);
if (head.biClrUsed){
ci = GetPixelIndex(sx,sy);
#if CXIMAGE_SUPPORT_INTERPOLATION
if (bSmooth){
if (fx > 1 && fy > 1) {
c = GetAreaColorInterpolated(dx - 0.5f, dy - 0.5f, fx, fy, CxImage::IM_BILINEAR, CxImage::OM_REPEAT);
} else {
c = GetPixelColorInterpolated(dx - 0.5f, dy - 0.5f, CxImage::IM_BILINEAR, CxImage::OM_REPEAT);
}
} else
#endif //CXIMAGE_SUPPORT_INTERPOLATION
{
c = GetPaletteColor(GetPixelIndex(sx,sy));
}
if (info.bAlphaPaletteEnabled){
a = (BYTE)((a*(1+c.rgbReserved))>>8);
}
} else {
#if CXIMAGE_SUPPORT_INTERPOLATION
if (bSmooth){
if (fx > 1 && fy > 1) {
c = GetAreaColorInterpolated(dx - 0.5f, dy - 0.5f, fx, fy, CxImage::IM_BILINEAR, CxImage::OM_REPEAT);
} else {
c = GetPixelColorInterpolated(dx - 0.5f, dy - 0.5f, CxImage::IM_BILINEAR, CxImage::OM_REPEAT);
}
} else
#endif //CXIMAGE_SUPPORT_INTERPOLATION
{
ppix = psrc + sx*3;
c.rgbBlue = *ppix++;
c.rgbGreen= *ppix++;
c.rgbRed = *ppix;
}
}
//if (*pc!=*pct || !bTransparent){
//if ((head.biClrUsed && ci!=cit) || ((!head.biClrUsed||bSmooth) && *pc!=*pct) || !bTransparent){
if ((head.biClrUsed && ci!=cit) || (!head.biClrUsed && *pc!=*pct) || !bTransparent){
// DJT, assume many pixels are fully transparent or opaque and thus avoid multiplication
if (a == 0) { // Transparent, retain dest
pdst+=3;
} else if (a == 255) { // opaque, ignore dest
*pdst++= c.rgbBlue;
*pdst++= c.rgbGreen;
*pdst++= c.rgbRed;
} else { // semi transparent
a1=(BYTE)~a;
*pdst++=(BYTE)((*pdst * a1 + a * c.rgbBlue)>>8);
*pdst++=(BYTE)((*pdst * a1 + a * c.rgbGreen)>>8);
*pdst++=(BYTE)((*pdst * a1 + a * c.rgbRed)>>8);
}
} else {
pdst+=3;
}
}
}
} else {
//NORMAL
iy=head.biHeight-ymax+y;
for(yy=0;yy<desth;yy++,iy++){
alphaoffset=iy*head.biWidth;
ix=xmin-x;
pdst=pbase+yy*ew;
ppix=info.pImage+iy*info.dwEffWidth+ix*3;
for(xx=0;xx<destw;xx++,ix++){
if (bAlpha) a=pAlpha[alphaoffset+ix]; else a=255;
a = (BYTE)((a*(1+info.nAlphaMax))>>8);
if (head.biClrUsed){
ci = GetPixelIndex(ix,iy);
c = GetPaletteColor((BYTE)ci);
if (info.bAlphaPaletteEnabled){
a = (BYTE)((a*(1+c.rgbReserved))>>8);
}
} else {
c.rgbBlue = *ppix++;
c.rgbGreen= *ppix++;
c.rgbRed = *ppix++;
}
//if (*pc!=*pct || !bTransparent){
if ((head.biClrUsed && ci!=cit) || (!head.biClrUsed && *pc!=*pct) || !bTransparent){
// DJT, assume many pixels are fully transparent or opaque and thus avoid multiplication
if (a == 0) { // Transparent, retain dest
pdst+=3;
} else if (a == 255) { // opaque, ignore dest
*pdst++= c.rgbBlue;
*pdst++= c.rgbGreen;
*pdst++= c.rgbRed;
} else { // semi transparent
a1=(BYTE)~a;
*pdst++=(BYTE)((*pdst * a1 + a * c.rgbBlue)>>8);
*pdst++=(BYTE)((*pdst * a1 + a * c.rgbGreen)>>8);
*pdst++=(BYTE)((*pdst * a1 + a * c.rgbRed)>>8);
}
} else {
pdst+=3;
}
}
}
}
}
//paint the image & cleanup
SetDIBitsToDevice(hdc,paintbox.left,paintbox.top,destw,desth,0,0,0,desth,pbase,&bmInfo,0);
DeleteObject(SelectObject(TmpDC,TmpObj));
DeleteDC(TmpDC);
}
#if !defined (_WIN32_WCE)
if (pClipRect){ // (experimental)
HRGN rgn = CreateRectRgnIndirect(&mainbox);
ExtSelectClipRgn(hdc,rgn,RGN_OR);
DeleteObject(rgn);
}
#endif
::RestoreDC(hdc,hdc_Restore);
return 1;
}
youyifang 2009-08-26
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把cximage的代码draw的代码帖上来看看
