15.如何建立一个灰度级图标
HICON CreateGrayscaleIcon(HICON hIcon)
{
HICON hGrayIcon = NULL;
HDC hMainDC = NULL,
hMemDC1 = NULL,
hMemDC2 = NULL;
BITMAP bmp;
HBITMAP hOldBmp1 = NULL,
hOldBmp2 = NULL;
ICONINFO csII, csGrayII;
BOOL bRetValue = FALSE;
bRetValue = ::GetIconInfo(hIcon, &csII);
if (bRetValue == FALSE) return NULL;
hMainDC = ::GetDC(m_hWnd);
hMemDC1 = ::CreateCompatibleDC(hMainDC);
hMemDC2 = ::CreateCompatibleDC(hMainDC);
if (hMainDC == NULL ||
hMemDC1 == NULL ||
hMemDC2 == NULL)
return NULL;
if (::GetObject(csII.hbmColor,
sizeof(BITMAP), &
amp;bmp))
{
csGrayII.hbmColor =
::CreateBitmap(csII.xHotspot*2,
csII.yHotspot*2,
bmp.bmPlanes,
bmp.bmBitsPixel,
NULL);
if (csGrayII.hbmColor)
{
hOldBmp1 =
(HBITMAP)::SelectObject(hMemDC1,
csII.hbmColor);
hOldBmp2 =
(HBITMAP)::SelectObject(hMemDC2,
csGrayII.hbmColor);
::BitBlt(hMemDC2, 0, 0, csII.xHotspot*2,
csII.yHotspot*2, hMemDC1, 0, 0,
SRCCOPY);
DWORD dwLoopY = 0, dwLoopX = 0;
COLORREF crPixel = 0;
BYTE byNewPixel = 0;
for (dwLoopY = 0; dwLoopY < csII.yHotspot*2; dwLoopY++)
{
for (dwLoopX = 0; dwLoopX < csII.xHotspot*2; dwLoopX++)
{
crPixel = ::GetPixel(hMemDC2, dwLoopX, dwLoopY);
byNewPixel = (BYTE)((GetRValue(crPixel) * 0.299) +
(GetGValue(crPixel) * 0.587) +
(GetBValue(crPixel) * 0.114));
if (crPixel) ::SetPixel(hMemDC2,
dwLoopX,
dwLoopY,
RGB(byNewPixel,
byNewPixel,
byNewPixel));
} // for
} // for
::SelectObject(hMemDC1, hOldBmp1);
::SelectObject(hMemDC2, hOldBmp2);
csGrayII.hbmMask = csII.hbmMask;
csGrayII.fIcon = TRUE;
hGrayIcon = ::CreateIconIndirect(&#38;csGrayII);
} // if
::DeleteObject(csGrayII.hbmColor);
//::DeleteObject(csGrayII.hbmMask);
} // if
::DeleteObject(csII.hbmColor);
::DeleteObject(csII.hbmMask);
::DeleteDC(hMemDC1);
::DeleteDC(hMemDC2);
::ReleaseDC(m_hWnd, hMainDC);
return hGrayIcon;
} |
16.如何按指定角度旋转显示内存位图(用法和BitBlt类似)
void RotBlt(HDC destDC, int srcx1, int srcy1, int srcx2, int srcy2,
HDC srcDC , int destx1, int desty1 ,int thetaInDegrees ,DWORD mode)
{
double theta = thetaInDegrees * (3.14159/180);
//原图像原始大小
int width = srcx2 - srcx1;
int height = srcy2 - srcy1;
//原图像中心点
int centreX = int(float(srcx2 + srcx1)/2);
int centreY = int(float(srcy2 + srcy1)/2);
//判断出图像可以沿任意方向旋转的矩形框
if(width>height)height = width;
else
width = height;
HDC memDC = CreateCompatibleDC(destDC);
HBITMAP memBmp = CreateCompatibleBitmap(destDC, width, height);
HBITMAP obmp = (HBITMAP) SelectObject(memDC, memBmp);
//内存DC新在中心点
int newCentre = int(float(width)/2);
//开始旋转
for(int x = srcx1; x<=srcx2; x++)
for(int y = srcy1; y<=srcy2; y++)
{
COLORREF col = GetPixel(srcDC,x,y);
int newX = int((x-centreX)*sin(theta)+(y-centreY)*cos(theta));
int newY = int((x-centreX)*cos(theta)-(y-centreY)*sin(theta));
SetPixel(memDC , newX + newCentre, newY + newCentre, col);
}
//复制到目标DC上
BitBlt(destDC, destx1, desty1, width, height, memDC, 0,0,mode);
//释放内存
SelectObject(memDC, obmp);
DeleteDC(memDC);
DeleteObject(memBmp);
} |
用法:
RotBlt(dc, 0,0,150,150,memDC,200,0, 45, SRCCOPY); |
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