我的程序是这样的,获取桌面图像,传到内存DC,在内存DC中取出图像,生成纹理(或其他处理操作,比如融合),进行纹理贴图。
我开始的时候写了两个小程序,一个是获取桌面图像并显示,已经成功;一个是从桌面的绝对路径载入一幅位图,并用于纹理贴图,也成功了。
现在想把两个程序合起来,不用从硬盘读取的位图贴图,改用从DC获取的位图贴图。但是程序运行效果就是贴出的图灰蒙蒙的白色。经过我自己的实验,发现如果放位图的指针地址里没有东西的话,就会出现这种效果。
说明我根本没从内存DC中将位图取出来,大神们快看看,这个改怎么解决,已经三天了,实在没招了。
glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT );
GLfloat ctrlpoints[4][4][3] = {
{{-2.5,-3, 0.0},{-2,-1.5,0.0},
{2,-1.5,0.0},{2.5,-3,0.0}},
{{-3,-1.5,0.0},{-2,-0.3,0.0},
{2,-0.3,0.0},{3,-1.5,0.0}},
{{-3.5,0.0,0.0},{-2,0.9,0.0},
{2,0.9,0.0},{3.5,0.0,0.0}},
{{-4,1.5,0.0},{-2,2.1,0.0},
{2,2.1,0.0},{4,1.5,0.0}}
};
GLfloat texpts[2][2][2] = {{{0.0, 0.0}, {1.0, 0.0}},
{{0.0, 1.0}, {1.0, 1.0}}};
glMap2f(GL_MAP2_VERTEX_3,0,1,3,4,0,1,12,4,&ctrlpoints[0][0][0]);
glMap2f(GL_MAP2_TEXTURE_COORD_2, 0, 1, 2, 2,
0, 1, 4, 2, &texpts[0][0][0]);
glEnable(GL_MAP2_TEXTURE_COORD_2);
glEnable(GL_MAP2_VERTEX_3);
glMapGrid2f(20,0.0,1.0,20,0.0,1.0);
glColor3f (0.0f, 0.0f, 0.0f);
//makeImage();
RECT rcView;
GetClientRect(&rcView);
CDC *deskDC = CDC::FromHandle(::GetDC(NULL));//获取当前DC
CDC memDC;
memDC.CreateCompatibleDC(deskDC);//创建兼容DC
CBitmap pDeskBmp ;
CBitmap *pOldBmp;
UINT uDeskBmpWidth = ::GetSystemMetrics(SM_CXSCREEN);//屏幕宽度
UINT uDeskBmpHeight = ::GetSystemMetrics(SM_CYSCREEN);//屏幕高度
pDeskBmp.CreateCompatibleBitmap(deskDC, uDeskBmpWidth, uDeskBmpHeight);//创建兼容位图
pOldBmp = memDC.SelectObject(&pDeskBmp);//将兼容位图选入创建的DC中
memDC.BitBlt(0, 0, uDeskBmpWidth, uDeskBmpHeight, deskDC, 0, 0, SRCCOPY);//将屏幕图像复制到内存DC中
BITMAP bmp;
pDeskBmp.GetBitmap(&bmp);
bmp.bmBits=(char*)malloc((bmp.bmWidth)*(bmp.bmHeight)*(bmp.bmBitsPixel));
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
//glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, imageWidth, imageHeight, 0,
// GL_BGR_EXT, GL_UNSIGNED_BYTE, data);
gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB, bmp.bmWidth, bmp.bmHeight,
GL_BGR_EXT, GL_UNSIGNED_BYTE, bmp.bmBits);//
glEnable(GL_TEXTURE_2D);
glEvalMesh2(GL_LINE, 0, 20, 0, 20);
glFlush();