我正在尝试构建一个OpenGL应用程序,即使主窗口被调整大小或移动,它也能够快速响应。我找到的最合理的解决方案是创建一个子窗口和一个消息泵,使用单独的线程来渲染OpenGL。在帧之间可以根据需要调整大小。主要的消息泵和窗口框架在主进程中运行。
它在某种程度上非常有效。窗口可以移动,使用菜单并调整大小,而不影响子窗口的帧率。但是,当调用SwapBuffers()时,一切都崩溃了。
以这种方式运行SwapBuffers()似乎是以软件模式运行的。它不再保持60 FPS以匹配我的显示器的VSync,在窗口大约为100x100时跳入数百个FPS,并在最大化到1920x1080时降至20 FPS。当在单个线程中运行时,一切似乎正常。
有一些问题我已经解决了。例如,当父母和孩子之间需要传递消息时,它会使整个应用程序停顿。覆盖WM_SETCURSOR并设置WS_EX_NOPARENTNOTIFY解决了这些问题。但是,我点击时它仍然偶尔会出现卡顿。
我希望我只是没有做正确的事情,有经验的OpenGL用户可以帮助我。我的初始化或清除可能存在问题,因为即使在关闭它后,它仍会干扰其他在我的PC上运行的OpenGL应用程序。
这是一个简化的测试案例,展示了我正在遇到的问题。它应该能够在任何现代Visual Studio中编译。
我一直在NVIDIA GeForce 8800 GTX上运行它,但我希望任何解决方案都能在现代卡上同样适用。
我尝试过其他方法,比如在主进程中将线程渲染到窗口中,但在调整大小期间我遇到了伪影甚至出现了几个蓝屏。我的应用程序将是跨平台的,因此DirectX不是一个选择。
它在某种程度上非常有效。窗口可以移动,使用菜单并调整大小,而不影响子窗口的帧率。但是,当调用SwapBuffers()时,一切都崩溃了。
以这种方式运行SwapBuffers()似乎是以软件模式运行的。它不再保持60 FPS以匹配我的显示器的VSync,在窗口大约为100x100时跳入数百个FPS,并在最大化到1920x1080时降至20 FPS。当在单个线程中运行时,一切似乎正常。
有一些问题我已经解决了。例如,当父母和孩子之间需要传递消息时,它会使整个应用程序停顿。覆盖WM_SETCURSOR并设置WS_EX_NOPARENTNOTIFY解决了这些问题。但是,我点击时它仍然偶尔会出现卡顿。
我希望我只是没有做正确的事情,有经验的OpenGL用户可以帮助我。我的初始化或清除可能存在问题,因为即使在关闭它后,它仍会干扰其他在我的PC上运行的OpenGL应用程序。
这是一个简化的测试案例,展示了我正在遇到的问题。它应该能够在任何现代Visual Studio中编译。
#include <windows.h>
#include <gl/gl.h>
#include <gl/glu.h>
#include <wchar.h>
#pragma comment(lib, "opengl32.lib")
typedef signed int s32;
typedef unsigned int u32;
typedef unsigned long long u64;
typedef float f32;
typedef double f64;
bool run = true;
// Window procedure for the main application window
LRESULT CALLBACK AppWindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
if (msg == WM_DESTROY && (GetWindowLong(hWnd, GWL_EXSTYLE) & WS_EX_APPWINDOW))
PostQuitMessage(0);
return DefWindowProc(hWnd, msg, wParam, lParam);
}
// Window procedure for the OpenGL rendering window
LRESULT CALLBACK RenderWindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
if (msg == WM_SETCURSOR)
{
SetCursor(LoadCursor(NULL, IDC_CROSS));
return TRUE;
}
if (msg == WM_SIZE)
glViewport(0, 0, LOWORD(lParam)-2, HIWORD(lParam)-2);
return AppWindowProc(hWnd, msg, wParam, lParam);
}
int WINAPI ThreadMain(HWND parent)
{
HINSTANCE hInstance = GetModuleHandle(0);
// Depending on if this is running as a child or a overlap window, set up the window styles
UINT ClassStyle, Style, ExStyle;
if (parent)
{
ClassStyle = 0;
Style = WS_CHILD;
ExStyle = WS_EX_NOPARENTNOTIFY;
} else {
ClassStyle = 0 | CS_VREDRAW | CS_HREDRAW;
Style = WS_OVERLAPPEDWINDOW;
ExStyle = WS_EX_APPWINDOW;
}
// Create the child window class
WNDCLASSEX wc = {0};
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = ClassStyle;
wc.hInstance = hInstance;
wc.lpfnWndProc = RenderWindowProc;
wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
wc.hIcon = LoadIcon(0, IDI_APPLICATION);
wc.hCursor = LoadCursor(0, IDC_ARROW);
wc.lpszClassName = L"OGLChild";
ATOM ClassAtom = RegisterClassEx(&wc);
// Create the child window
RECT r = {0, 0, 640, 480};
if (parent)
GetClientRect(parent, &r);
HWND WindowHandle = CreateWindowExW(ExStyle, (LPCTSTR)MAKELONG(ClassAtom, 0), 0, Style,
0, 0, r.right, r.bottom, parent, 0, hInstance, 0);
// Initialize OpenGL render context
PIXELFORMATDESCRIPTOR pfd = {0};
pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 32;
pfd.cDepthBits = 16;
pfd.iLayerType = PFD_MAIN_PLANE;
HDC DeviceContext = GetDC(WindowHandle);
int format = ChoosePixelFormat(DeviceContext, &pfd);
SetPixelFormat(DeviceContext, format, &pfd);
HGLRC RenderContext = wglCreateContext(DeviceContext);
wglMakeCurrent(DeviceContext, RenderContext);
ShowWindow(WindowHandle, SW_SHOW);
GetClientRect(WindowHandle, &r);
glViewport(0, 0, r.right, r.bottom);
// Set up an accurate clock
u64 start, now, last, frequency;
QueryPerformanceFrequency((LARGE_INTEGER*)&frequency);
QueryPerformanceCounter((LARGE_INTEGER*)&now);
start = last = now;
u32 frames = 0; // total frames this second
f64 nextFrameCount = 0; // next FPS update
f32 left = 0; // line position
MSG msg;
while (run)
{
while (PeekMessage(&msg, 0, 0, 0, PM_REMOVE))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
if (msg.message == WM_QUIT || msg.message == WM_DESTROY)
run = false;
}
// Update the clock
QueryPerformanceCounter((LARGE_INTEGER*)&now);
f64 clock = (f64)(now - start) / frequency;
f64 delta = (f64)(now - last) / frequency;
last = now;
// Render a line moving
glOrtho(0, 640, 480, 0, -1, 1);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glColor3f(1.0f, 1.0f, 0.0f);
left += (f32)(delta * 320.0f);
if (left > 640.0f)
left = 0;
glBegin(GL_LINES);
glVertex2f(0.0f, 0.0f);
glVertex2f(left, 480.0f);
glEnd();
SwapBuffers(DeviceContext);
// Resize as necessary
if (parent)
{
RECT pr, cr;
GetClientRect(parent, &pr);
GetClientRect(WindowHandle, &cr);
if (pr.right != cr.right || pr.bottom != cr.bottom)
MoveWindow(WindowHandle, 0, 0, pr.right, pr.bottom, FALSE);
}
// Update FPS counter
frames++;
if (clock > nextFrameCount)
{
WCHAR title[16] = {0};
_snwprintf_s(title, 16, 16, L"FPS: %u", frames);
SetWindowText(parent ? parent : WindowHandle, title);
nextFrameCount = clock + 1;
frames = 0;
}
Sleep(1);
}
// Cleanup OpenGL context
wglDeleteContext(RenderContext);
wglMakeCurrent(0,0);
ReleaseDC(WindowHandle, DeviceContext);
DestroyWindow(WindowHandle);
return 0;
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
int result = MessageBox(0, L"Would you like to run in threaded child mode?",
L"Threaded OpenGL Demo", MB_YESNOCANCEL | MB_ICONQUESTION);
if (result == IDNO)
return ThreadMain(0);
else if (result != IDYES)
return 0;
// Create the parent window class
WNDCLASSEX wc = {0};
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = 0;
wc.hInstance = hInstance;
wc.lpfnWndProc = (WNDPROC)AppWindowProc;
wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
wc.hIcon = LoadIcon(0, IDI_APPLICATION);
wc.hCursor = LoadCursor(0, IDC_ARROW);
wc.lpszClassName = L"OGLFrame";
ATOM ClassAtom = RegisterClassEx(&wc);
// Create the parent window
HWND WindowHandle = CreateWindowExW(WS_EX_APPWINDOW, (LPCTSTR)MAKELONG(ClassAtom, 0),
0, WS_OVERLAPPEDWINDOW | WS_CLIPCHILDREN,
0, 0, 640, 480, 0, 0, hInstance, 0);
ShowWindow(WindowHandle, SW_SHOW);
// Start the child thread
HANDLE thread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)&ThreadMain, (LPVOID)WindowHandle, 0, 0);
MSG msg;
while (run)
{
while (PeekMessage(&msg, 0, 0, 0, PM_REMOVE))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
if (msg.message == WM_QUIT)
run = false;
}
Sleep(100);
}
DestroyWindow(WindowHandle);
// Wait for the child thread to finish
WaitForSingleObject(thread, INFINITE);
ExitProcess(0);
return 0;
}
我一直在NVIDIA GeForce 8800 GTX上运行它,但我希望任何解决方案都能在现代卡上同样适用。
我尝试过其他方法,比如在主进程中将线程渲染到窗口中,但在调整大小期间我遇到了伪影甚至出现了几个蓝屏。我的应用程序将是跨平台的,因此DirectX不是一个选择。