我们有一个应用程序,在其中我们同时使用GDI和OpenGL来绘制到同一个HWND上,但是是互斥的。
例如:
- 首先我们处于2D模式,因此我们使用GDI进行绘制。 - 然后我们切换到3D模式,使用OpenGL进行绘制。 - 然后我们切换回2D模式,并使用GDI对其进行绘制。
当切换到3D模式时,我们只需为该HWND创建一个OpenGL上下文,然后就可以使用OpenGL进行绘制。当切换回2D模式时,我们只需销毁OpenGL上下文,然后就可以使用GDI对HWND进行绘制。
这在最近一直很有效。然而,在Windows 10上,对于某些NVidia显卡,如果驱动程序比382.05更新,那么这种方法就不再起作用了。在这种情况下,当我们删除OpenGL上下文并使用GDI对HWND进行绘制时,窗口仍然显示OpenGL的最后内容。
我已经检查了所有可用的像素格式。所有都有同样的问题。
我们是否做错了什么,或者这是一个NVidia的bug?您是否看到解决方案/解决方法?
有可能与NVidia + Intel双GPU设置有关,但至少有一个反例。我们得到反馈的卡片如下:
未重现:
- GTX 980M,单一GPU - GTX 1060,单一GPU
已重现:
- GTX 1060(Forceware 397.31)+ Intel HD Graphics 630 - Quadro M3000M(Forceware 387.95)+ Intel HD Graphics P530 - Qudrao K110M + Intel HD 4600 - Quadro P3000 + Intel HD 630 - Quadro M4000(Forceware 385.90),单一GPU
不可能在OpenGL中绘制2D内容或反之亦然。此外,该应用程序对性能非常敏感,因此不能将2D内容绘制到离屏GDI图像中,以便将其作为OpenGL四边形进行绘制。销毁和重新创建HWND也不是一个选择。
下面是一个示例应用程序,可复现该问题。默认情况下,应用程序显示带有一些文本的蓝色背景。在OpenGL模式下,会显示旋转的三角形。空格键用于在模式之间切换。
例如:
- 首先我们处于2D模式,因此我们使用GDI进行绘制。 - 然后我们切换到3D模式,使用OpenGL进行绘制。 - 然后我们切换回2D模式,并使用GDI对其进行绘制。
当切换到3D模式时,我们只需为该HWND创建一个OpenGL上下文,然后就可以使用OpenGL进行绘制。当切换回2D模式时,我们只需销毁OpenGL上下文,然后就可以使用GDI对HWND进行绘制。
这在最近一直很有效。然而,在Windows 10上,对于某些NVidia显卡,如果驱动程序比382.05更新,那么这种方法就不再起作用了。在这种情况下,当我们删除OpenGL上下文并使用GDI对HWND进行绘制时,窗口仍然显示OpenGL的最后内容。
我已经检查了所有可用的像素格式。所有都有同样的问题。
我们是否做错了什么,或者这是一个NVidia的bug?您是否看到解决方案/解决方法?
有可能与NVidia + Intel双GPU设置有关,但至少有一个反例。我们得到反馈的卡片如下:
未重现:
- GTX 980M,单一GPU - GTX 1060,单一GPU
已重现:
- GTX 1060(Forceware 397.31)+ Intel HD Graphics 630 - Quadro M3000M(Forceware 387.95)+ Intel HD Graphics P530 - Qudrao K110M + Intel HD 4600 - Quadro P3000 + Intel HD 630 - Quadro M4000(Forceware 385.90),单一GPU
不可能在OpenGL中绘制2D内容或反之亦然。此外,该应用程序对性能非常敏感,因此不能将2D内容绘制到离屏GDI图像中,以便将其作为OpenGL四边形进行绘制。销毁和重新创建HWND也不是一个选择。
下面是一个示例应用程序,可复现该问题。默认情况下,应用程序显示带有一些文本的蓝色背景。在OpenGL模式下,会显示旋转的三角形。空格键用于在模式之间切换。
#include <windows.h>
#include <GL/gl.h>
#include <iostream>
#pragma comment( lib, "OpenGL32.lib" )
HWND s_hwnd = 0;
HDC s_hdc = 0;
HGLRC s_hglrc = 0;
bool s_quit = false;
static HGLRC createContext(HWND hwnd, HDC hdc)
{
PIXELFORMATDESCRIPTOR pfd;
memset(&pfd, 0, sizeof(pfd));
pfd.nSize = sizeof(pfd);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL |
PFD_GENERIC_ACCELERATED /*| PFD_DOUBLEBUFFER*/;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 32;
int pf = ChoosePixelFormat(hdc, &pfd);
SetPixelFormat(hdc, pf, &pfd);
return wglCreateContext(hdc);
}
static void display()
{
if (s_hglrc)
{
/* rotate a triangle around */
glClear(GL_COLOR_BUFFER_BIT);
glRotatef(1.0f, 0.0f, 0.0f, 1.0f);
glBegin(GL_TRIANGLES);
glIndexi(1);
glColor3f(1.0f, 0.0f, 0.0f);
glVertex2f(0.0f, 0.8f);
glIndexi(2);
glColor3f(0.0f, 1.0f, 0.0f);
glVertex2f(-0.8f, -0.8f);
glIndexi(3);
glColor3f(0.0f, 0.0f, 1.0f);
glVertex2f(0.8f, -0.8f);
glEnd();
glFlush();
SwapBuffers(s_hdc);
}
else
{
HBRUSH brush = CreateSolidBrush(RGB(0, 0, 255));
RECT rect;
GetClientRect(s_hwnd, &rect);
FillRect(s_hdc, &rect, brush);
DeleteObject(brush);
DrawText(s_hdc, L"This is GDI", -1, &rect, DT_CENTER | DT_VCENTER | DT_SINGLELINE);
GdiFlush();
}
}
static void toggle_between_GDI_and_OpenGL()
{
if (!s_hglrc)
{
s_hglrc = createContext(s_hwnd, s_hdc);
wglMakeCurrent(s_hdc, s_hglrc);
std::cout << "Renderer: " << glGetString(GL_RENDERER) << std::endl;
}
else
{
wglMakeCurrent(NULL, NULL);
wglDeleteContext(s_hglrc);
s_hglrc = 0;
}
}
LONG WINAPI WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg) {
case WM_ERASEBKGND:
return 0;
case WM_PAINT:
display();
PAINTSTRUCT ps;
BeginPaint(hWnd, &ps);
EndPaint(hWnd, &ps);
return 0;
case WM_TIMER:
display();
return 0;
case WM_SIZE:
glViewport(0, 0, LOWORD(lParam), HIWORD(lParam));
PostMessage(hWnd, WM_PAINT, 0, 0);
return 0;
case WM_CHAR:
switch (wParam) {
case 27: /* ESC key */
s_quit = true;
break;
case ' ':
toggle_between_GDI_and_OpenGL();
PostMessage(hWnd, WM_PAINT, 0, 0);
break;
}
return 0;
case WM_CLOSE:
s_quit = true;
return 0;
case WM_QUIT:
s_quit = true;
return 0;
}
return (LONG)DefWindowProc(hWnd, uMsg, wParam, lParam);
}
static HWND CreateOpenGLWindow()
{
HWND hWnd;
WNDCLASS wc;
static HINSTANCE hInstance = 0;
/* only register the window class once - use hInstance as a flag. */
if (!hInstance) {
hInstance = GetModuleHandle(NULL);
wc.style = CS_OWNDC;
wc.lpfnWndProc = (WNDPROC)WindowProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_WINLOGO);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = NULL;
wc.lpszMenuName = NULL;
wc.lpszClassName = L"OpenGL";
if (!RegisterClass(&wc)) {
MessageBox(NULL, L"RegisterClass() failed: Cannot register window class.", L"Error", MB_OK);
return NULL;
}
}
hWnd = CreateWindow(L"OpenGL", L"GDI / OpenGL switching", WS_OVERLAPPEDWINDOW |
WS_CLIPSIBLINGS | WS_CLIPCHILDREN,
0, 0, 256, 256, NULL, NULL, hInstance, NULL);
if (hWnd == NULL) {
MessageBox(NULL, L"CreateWindow() failed: Cannot create a window.",
L"Error", MB_OK);
return NULL;
}
return hWnd;
}
void executeApplication()
{
s_hwnd = CreateOpenGLWindow();
if (s_hwnd == NULL)
exit(1);
s_hdc = GetDC(s_hwnd);
//toggle_between_GDI_and_OpenGL(); // initialize OpenGL
ShowWindow(s_hwnd, SW_SHOW);
UpdateWindow(s_hwnd);
SetTimer(s_hwnd, 1, 50, NULL);
while (1) {
MSG msg;
while (PeekMessage(&msg, s_hwnd, 0, 0, PM_NOREMOVE)) {
if (!s_quit && GetMessage(&msg, s_hwnd, 0, 0)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
else {
goto quit;
}
}
if (s_quit)
goto quit;
}
quit:
wglMakeCurrent(NULL, NULL);
if (s_hglrc)
toggle_between_GDI_and_OpenGL(); // uninitialize OpenGL
DestroyWindow(s_hwnd);
DeleteDC(s_hdc);
}
int APIENTRY WinMain(HINSTANCE hCurrentInst, HINSTANCE hPreviousInst, LPSTR lpszCmdLine, int nCmdShow)
{
executeApplication();
return 0;
}
int main()
{
executeApplication();
return 0;
}
更新: @Ripi2 和 @datenwolf 建议,一旦为窗口设置了一个没有PFD_SUPPORT_GDI
标志的像素格式,就不允许切换回 GDI。以下是来自SetPixelFormat文档的摘录:
对窗口设置像素格式多次可能会给窗口管理器和多线程应用程序带来重大的复杂性,因此不允许这样做。
这是一个明确的迹象,他们是正确的。
更新 2: 我曾经说过重新创建 HWND 不是一个选项。但是重新思考后,这似乎是我最容易的解决方案。
代码:
#include <windows.h>
#include <GL/gl.h>
#include <iostream>
#pragma comment( lib, "OpenGL32.lib" )
HWND s_mainWnd = 0;
HWND s_childWnd = 0;
HGLRC s_hglrc = 0;
bool s_isOpenGLMode = false;
bool s_quit = false;
static HWND CreateChildWindow(HWND hWndParent);
static HGLRC createContext(HWND hwnd, HDC hdc)
{
PIXELFORMATDESCRIPTOR pfd;
memset(&pfd, 0, sizeof(pfd));
pfd.nSize = sizeof(pfd);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL |
PFD_GENERIC_ACCELERATED /*| PFD_DOUBLEBUFFER*/;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 32;
int pf = ChoosePixelFormat(hdc, &pfd);
SetPixelFormat(hdc, pf, &pfd);
return wglCreateContext(hdc);
}
static void display()
{
HDC hdc = GetDC(s_childWnd);
if (s_isOpenGLMode)
{
/* rotate a triangle around */
glClear(GL_COLOR_BUFFER_BIT);
glRotatef(1.0f, 0.0f, 0.0f, 1.0f);
glBegin(GL_TRIANGLES);
glIndexi(1);
glColor3f(1.0f, 0.0f, 0.0f);
glVertex2f(0.0f, 0.8f);
glIndexi(2);
glColor3f(0.0f, 1.0f, 0.0f);
glVertex2f(-0.8f, -0.8f);
glIndexi(3);
glColor3f(0.0f, 0.0f, 1.0f);
glVertex2f(0.8f, -0.8f);
glEnd();
glFlush();
SwapBuffers(hdc);
}
else
{
HBRUSH brush = CreateSolidBrush(RGB(0, 0, 255));
RECT rect;
GetClientRect(s_childWnd, &rect);
FillRect(hdc, &rect, brush);
DeleteObject(brush);
DrawText(hdc, L"This is GDI", -1, &rect, DT_CENTER | DT_VCENTER | DT_SINGLELINE);
GdiFlush();
}
DeleteDC(hdc);
}
static void toggle_between_GDI_and_OpenGL()
{
if (!s_isOpenGLMode)
{
DestroyWindow(s_childWnd);
s_childWnd = CreateChildWindow(s_mainWnd);
ShowWindow(s_childWnd, SW_SHOW);
HDC hdc = GetDC(s_childWnd);
s_hglrc = createContext(s_childWnd, hdc);
wglMakeCurrent(hdc, s_hglrc);
DeleteDC(hdc);
std::cout << "Renderer: " << glGetString(GL_RENDERER) << std::endl;
RECT rect;
GetClientRect(s_childWnd, &rect);
glViewport(0, 0, max(rect.left, rect.right), max(rect.top, rect.bottom));
}
else
{
if (s_hglrc)
{
wglMakeCurrent(NULL, NULL);
wglDeleteContext(s_hglrc);
s_hglrc = 0;
}
DestroyWindow(s_childWnd);
s_childWnd = CreateChildWindow(s_mainWnd);
ShowWindow(s_childWnd, SW_SHOW);
}
s_isOpenGLMode = !s_isOpenGLMode;
}
LONG WINAPI WindowProc_MainWnd(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg) {
case WM_TIMER:
display();
return 0;
case WM_CHAR:
switch (wParam) {
case 27: /* ESC key */
s_quit = true;
break;
case ' ':
toggle_between_GDI_and_OpenGL();
PostMessage(hWnd, WM_PAINT, 0, 0);
break;
}
return 0;
case WM_CLOSE:
case WM_QUIT:
s_quit = true;
return 0;
case WM_SIZE:
if (s_childWnd)
MoveWindow(s_childWnd, 0, 0, LOWORD(lParam), HIWORD(lParam), TRUE);
break;
}
return (LONG)DefWindowProc(hWnd, uMsg, wParam, lParam);
}
LONG WINAPI WindowProc_ChildWnd(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg) {
case WM_ERASEBKGND:
return 0;
case WM_PAINT:
display();
PAINTSTRUCT ps;
BeginPaint(hWnd, &ps);
EndPaint(hWnd, &ps);
return 0;
case WM_SIZE:
if (s_hglrc && s_isOpenGLMode)
glViewport(0, 0, LOWORD(lParam), HIWORD(lParam));
PostMessage(hWnd, WM_PAINT, 0, 0);
return 0;
}
return (LONG)DefWindowProc(hWnd, uMsg, wParam, lParam);
}
static HWND CreateMainWindow()
{
static HINSTANCE hInstance = 0;
if (!hInstance)
{
hInstance = GetModuleHandle(NULL);
WNDCLASS wc;
wc.style = CS_VREDRAW | CS_HREDRAW;
wc.lpfnWndProc = (WNDPROC)WindowProc_MainWnd;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_WINLOGO);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = NULL;
wc.lpszMenuName = NULL;
wc.lpszClassName = L"MainWindow";
if (!RegisterClass(&wc)) {
MessageBox(NULL, L"RegisterClass() failed: Cannot register window class.", L"Error", MB_OK);
return NULL;
}
}
HWND hWnd = CreateWindow(L"MainWindow", L"GDI / OpenGL switching", WS_OVERLAPPEDWINDOW |
WS_CLIPSIBLINGS | WS_CLIPCHILDREN,
300, 300, 256, 256, NULL, NULL, hInstance, NULL);
if (hWnd == NULL) {
MessageBox(NULL, L"CreateWindow() failed: Cannot create a window.",
L"Error", MB_OK);
return NULL;
}
return hWnd;
}
static HWND CreateChildWindow(HWND hWndParent)
{
static HINSTANCE hInstance = 0;
/* only register the window class once - use hInstance as a flag. */
if (!hInstance)
{
hInstance = GetModuleHandle(NULL);
WNDCLASS wc;
wc.style = CS_OWNDC;
wc.lpfnWndProc = (WNDPROC)WindowProc_ChildWnd;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_WINLOGO);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = NULL;
wc.lpszMenuName = NULL;
wc.lpszClassName = L"ChildWindow";
if (!RegisterClass(&wc)) {
MessageBox(NULL, L"RegisterClass() failed: Cannot register window class.", L"Error", MB_OK);
return NULL;
}
}
RECT rect;
GetClientRect(hWndParent, &rect);
HWND hWnd = CreateWindow(L"ChildWindow", L"ChildWindow", WS_CHILD,
0, 0, max(rect.left, rect.right), max(rect.top, rect.bottom), hWndParent, NULL, hInstance, NULL);
if (hWnd == NULL) {
MessageBox(NULL, L"CreateWindow() failed: Cannot create a window.",
L"Error", MB_OK);
return NULL;
}
return hWnd;
}
void executeApplication()
{
s_mainWnd = CreateMainWindow();
if (s_mainWnd == NULL)
exit(1);
s_childWnd = CreateChildWindow(s_mainWnd);
//toggle_between_GDI_and_OpenGL(); // initialize OpenGL
ShowWindow(s_mainWnd, SW_SHOW);
ShowWindow(s_childWnd, SW_SHOW);
UpdateWindow(s_mainWnd);
UpdateWindow(s_childWnd);
SetTimer(s_mainWnd, 1, 50, NULL);
while (1) {
MSG msg;
while (PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE)) {
if (!s_quit && GetMessage(&msg, NULL, 0, 0)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
else {
goto quit;
}
}
if (s_quit)
goto quit;
}
quit:
if (s_hglrc)
{
wglMakeCurrent(NULL, NULL);
wglDeleteContext(s_hglrc);
}
DestroyWindow(s_childWnd);
DestroyWindow(s_mainWnd);
}
int APIENTRY WinMain(HINSTANCE hCurrentInst, HINSTANCE hPreviousInst, LPSTR lpszCmdLine, int nCmdShow)
{
executeApplication();
return 0;
}
int main()
{
executeApplication();
return 0;
}
glReadPixels
并将其作为位图在GDI中使用与将GDI作为四边形传递给GPU的性能,并加以比较。 - Ripi2