Windows 内存绘图导出RGB

ゞ浴缸里的玫瑰 2022-08-09 06:49 11阅读 0赞

Windows 内存绘图导出RGB

1,      MFC 创建内存绘图显示设备

1）

CDC MemDC;  
    		CBitmap MemBitmap; 
    		CRect rect;
    		m_gl.GetClientRect(rect);
    		CDC *pDc = m_gl.GetDC();
    		MemDC.CreateCompatibleDC(pDc); 
    		 
    		MemBitmap.CreateCompatibleBitmap(pDc, rect.Width(), rect.Height());
    	 
    		 
    		CBitmap *pOldBit = MemDC.SelectObject(&MemBitmap);

2）获取内存数据，窗口兼容的CDC一般是32位深度，RGBA格式

BITMAP bitmap;
    		LONG size = ::GetObject(MemBitmap, sizeof(BITMAP),&bitmap);
    		DWORD dwSize = bitmap.bmHeight * bitmap.bmWidthBytes;
    		unsigned char * ptr = new unsigned char[dwSize];
    		MemBitmap.GetBitmapBits(dwSize, ptr);

2,Win32

HDC hDC = ::GetDC(m_windowWnd);
        HDC hDCMem;
        HBITMAP hBmpMem, hPreBmp;
        /* 创建双缓冲区 */
        // 创建与当前DC兼容的内存DC
        hDCMem = CreateCompatibleDC(hDC);
        // 创建一块指定大小的位图
    //hBmpMem = ::CreateBitmap(iWidth, iHeight, 1, 32, pBmpData); hBmpMem = CreateCompatibleBitmap(hDC, 64, 64); // 将该位图选入到内存DC中，默认是全黑色的 hPreBmp = (HBITMAP)::SelectObject(hDCMem, hBmpMem);

HBITMAP hbmp = hBmpMem;
    
    
        if(!::GetObject(hbmp, sizeof(BITMAP), (LPBYTE)&bmptemp))
            return 0;
    
    
        BYTE imgSize = bmptemp.bmBitsPixel / 8; //兼容24bit和32bit位图
        BITMAPINFO bi = { 0 };
        bi.bmiHeader.biSize = sizeof(bi.bmiHeader);
        bi.bmiHeader.biWidth = bmptemp.bmWidth;
        bi.bmiHeader.biHeight = bmptemp.bmHeight;
        bi.bmiHeader.biPlanes = 1;
        bi.bmiHeader.biBitCount = bmptemp.bmBitsPixel;
        bi.bmiHeader.biCompression = BI_RGB;
        bi.bmiHeader.biSizeImage = bmptemp.bmWidth * imgSize * bmptemp.bmHeight;
        bi.bmiHeader.biClrUsed = 0;
        bi.bmiHeader.biClrImportant = 0;
        // 获取位图数据
        BYTE* lpvBits = new BYTE[bi.bmiHeader.biSizeImage];
        ::ZeroMemory(lpvBits, bi.bmiHeader.biSizeImage);
    if(!::GetDIBits(hDCMem, hBmpMem, 0, bmptemp.bmHeight, lpvBits, &bi, DIB_RGB_COLORS)) {
            delete[] lpvBits;
            lpvBits = NULL;
        }

3,GDI，以上两种方法背景默认黑色，可是设置填充掩码颜色，实现透明效果

<span style="background-color: rgb(255, 255, 255); font-family: Arial, Helvetica, sans-serif;"></span><pre name="code" class="html">Bitmap bmp(bitmap.bmWidth, bitmap.bmHeight, PixelFormat32bppARGB);
    		Graphics GDIplusObj(&bmp);
    		Color aa(200, 200, 200, 0);
    		Color bb = aa;	Pen pen(aa, 3);
    		// 	aa.MakeARGB(100, 255, 0, 0);
    		SolidBrush brush(bb);
    		SolidBrush brush2(Color(100,255, 0, 0));
    		GDIplusObj.FillRectangle(&brush2, 100, 100, 100, 100);
    Graphics GDIplusObj2(m_gl.GetDC()->GetSafeHdc()); 
    GDIplusObj2.DrawImage(&bmp, Rect(0, 0, rect.Width(), rect.Height()));
    //获取内存数据
    //将Bitmap中的图像数据Buffer导出//用GDI的GetDIBits方法，用GDI+的LockBits方法