我有一个应用程序,它以一种相当简单的方式使用 OpenGL 来渲染纹理 QUADS。
它在本地运行时工作正常,但在远程运行(Microsoft 远程桌面)时,它会显示空白的白色窗口。
我想知道我所做的一些配置是否是直接原因,或者它是否是更基本的东西,只能通过另一种方法解决,比如使用显示列表或类似的东西。
我的代码如下。我像这样初始化上下文:
void InitWindow(HWND *hWnd, HDC *hDC, HGLRC *hRC)
{
*hDC = GetDC(*hWnd);
// set the pixel format for the DC
PIXELFORMATDESCRIPTOR pfd;
ZeroMemory(&pfd, sizeof(pfd));
pfd.nSize = sizeof(pfd);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL |
PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 24;
// pfd.cRedBits = 8;
// pfd.cGreenBits = 8;
// pfd.cBlueBits = 8;
pfd.cAlphaBits = 0;
pfd.cDepthBits = 0;
pfd.iLayerType = PFD_MAIN_PLANE;
int format = ChoosePixelFormat(*hDC, &pfd);
SetPixelFormat(*hDC, format, &pfd);
// create and enable the render context (RC)
*hRC = wglCreateContext(*hDC);
// make current context current
wglMakeCurrent(*hDC, *hRC);
}
并像这样绘制到屏幕上:
int Render(HWND hWnd, Raster* raster)
{
Size RasterSize = raster->GetSize();
HDC hDC = NULL;
HGLRC hRC = NULL;
// acquire DC, HGLRC for the window & make current
InitWindow(&hWnd, &hDC, &hRC);
GLenum raster_pixel_format = GL_BGRA_EXT;
GLint internal_format = GL_RGBA;
if (s_ClearBeforeDraw)
{
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClear(GL_COLOR_BUFFER_BIT);
}
GLuint texture;
// allocate a texture name
glGenTextures(1, &texture);
glBindTexture (GL_TEXTURE_2D, texture);
glPixelStorei (GL_UNPACK_ALIGNMENT, 1);
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_LINEAR);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glTexImage2D (GL_TEXTURE_2D, 0, internal_format,
RasterSize.width, RasterSize.height,
0, raster_pixel_format, GL_UNSIGNED_BYTE,
raster->GetData());
glBindTexture(GL_TEXTURE_2D, texture);
RECT wndRect;
::GetClientRect(hWnd, &wndRect);
GLsizei wndWidth = wndRect.right;
GLsizei wndHeight = wndRect.bottom;
glEnable(GL_TEXTURE_2D);
// this is usually stated in window coordinates,
// but since we know the raster gets its size from
// the window - we can use raster coordinates
glViewport(0, 0, RasterSize.width, RasterSize.height);
glBegin( GL_QUADS );
glTexCoord2d(0.0,0.0); glVertex2d(-1.0,+1.0);
glTexCoord2d(1.0,0.0); glVertex2d(+1.0,+1.0);
glTexCoord2d(1.0,1.0); glVertex2d(+1.0,-1.0);
glTexCoord2d(0.0,1.0); glVertex2d(-1.0,-1.0);
glEnd();
glDisable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, 0);
glDeleteTextures(1, &texture);
SwapBuffers(hDC);
wglMakeCurrent(NULL, NULL);
// Release the context handles if they aren't cached
wglDeleteContext(hRC);
ReleaseDC(hWnd, hDC);
return SUCCESS;
}