[DX9] Vsync Lag

Armion · 2010-08-21T16:10:34

Hi guys,Before i get to the question i need to clarify some things. I'm a novice so don't be too harsh on me if i make some stupid mistake :) Also English is not my native language :)I spent the last two days trying to understand the extreme input lag(or at least i thought so at first) i get when using vsync (D3DPRESENT_INTERVAL_DEFAULT or D3DPRESENT_INTERVAL_ONE) or when having low fps(in the case below 240fps) in my simple 3d application. I read a lot of articles and posts in different forums and reached a conclusion that it's kind of normal because the specifics or vsync and buffering. Still i'm not sure that that much lag is normal. To be more precise it's not exactly input lag - more like something to do with presentation lag. I'm reading the book of Frank Luna about DirectX 9.0, so i modified the source of chapter one to show you what i mean. It's pretty basic stuff, but is perfect for demonstration. The idea is simple - you move the mouse around the window and a mouse texture is drawn at the current position of the mouse every frame... The two cursors should overlap perfectly... Or at least i want it to be that way, but it isn't. The DirectX drawn mouse always lags behind the Windows cursor and it's quite annoying for me. One more important thing - i'm using Windows 7 and disabling Aero almost fixes the problem. I don't have a Windows XP PC to test there. I was planning on doing a simple DirectX GUI Library to use in my future education projects, but when i came across this problem i just wonder what will dragging look like... I remember seeing some commercial games behave the same way with vsync enabled - can't recall any names at the moment. Still, the majority of them don't behave that way. I just don't believe that you have to render at least 240 frames for smooth feeling even if you don't have vsync enabled.To be honest i tried some solutions, but none of them gave me satisfactory results except disabling Aero - but i don't think that's the solution(I'm still interested why is that working at all). I also tried decreasing render ahead and even disabling it completely - still no improvement. I'm posting the source as i don't see an option for attaching files.FILENAME: d3dUtility.h//////////////////////////////////////////////////////////////////////////////////////////////////// // File: d3dUtility.h// // Author: Frank Luna (C) All Rights Reserved//// System: AMD Athlon 1800+ XP, 512 DDR, Geforce 3, Windows XP, MSVC++ 7.0 //// Desc: Provides utility functions for simplifying common tasks.// //////////////////////////////////////////////////////////////////////////////////////////////////#ifndef __d3dUtilityH__#define __d3dUtilityH__#include <d3dx9.h>#include <string>namespace d3d{ bool InitD3D( HINSTANCE hInstance, // [in] Application instance. int width, int height, // [in] Backbuffer dimensions. bool windowed, // [in] Windowed (true)or full screen (false). D3DDEVTYPE deviceType, // [in] HAL or REF IDirect3DDevice9** device);// [out]The created device. int EnterMsgLoop( bool (*ptr_display)(float timeDelta)); LRESULT CALLBACK WndProc( HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam); static HWND handle; HWND GetHandle(); template<class T> void Release(T t) { if( t ) { t->Release(); t = 0; } } template<class T> void Delete(T t) { if( t ) { delete t; t = 0; } }}#endif // __d3dUtilityH__FILENAME: d3dUtility.cpp//////////////////////////////////////////////////////////////////////////////////////////////////// // File: d3dUtility.cpp// // Author: Frank Luna (C) All Rights Reserved//// System: AMD Athlon 1800+ XP, 512 DDR, Geforce 3, Windows XP, MSVC++ 7.0 //// Desc: Provides utility functions for simplifying common tasks.// //////////////////////////////////////////////////////////////////////////////////////////////////#include "d3dUtility.h"bool d3d::InitD3D( HINSTANCE hInstance, int width, int height, bool windowed, D3DDEVTYPE deviceType, IDirect3DDevice9** device){ // // Create the main application window. // WNDCLASS wc; wc.style = CS_HREDRAW | CS_VREDRAW; wc.lpfnWndProc = (WNDPROC)d3d::WndProc; wc.cbClsExtra = 0; wc.cbWndExtra = 0; wc.hInstance = hInstance; wc.hIcon = LoadIcon(0, IDI_APPLICATION); wc.hCursor = LoadCursor(0, IDC_ARROW); wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH); wc.lpszMenuName = 0; wc.lpszClassName = "Direct3D9App"; if( !RegisterClass(&wc) ) { ::MessageBox(0, "RegisterClass() - FAILED", 0, 0); return false; } HWND hwnd = 0; DWORD styles = WS_CAPTION | WS_SYSMENU | WS_EX_TRANSPARENT; RECT screenRect = {300, 300, 300 + width, 300 + height}; AdjustWindowRect(&screenRect, styles, false); hwnd = ::CreateWindow("Direct3D9App", "Direct3D9App", WS_CAPTION | WS_SYSMENU | WS_EX_TRANSPARENT, screenRect.left, screenRect.top, screenRect.right - screenRect.left, screenRect.bottom - screenRect.top, 0 /*parent hwnd*/, 0 /* menu */, hInstance, 0 /*extra*/); if( !hwnd ) { ::MessageBox(0, "CreateWindow() - FAILED", 0, 0); return false; } handle = hwnd; ::ShowWindow(hwnd, SW_SHOW); ::UpdateWindow(hwnd); // // Init D3D: // HRESULT hr = 0; // Step 1: Create the IDirect3D9 object. IDirect3D9* d3d9 = 0; d3d9 = Direct3DCreate9(D3D_SDK_VERSION); if( !d3d9 ) { ::MessageBox(0, "Direct3DCreate9() - FAILED", 0, 0); return false; } // Step 2: Check for hardware vp. D3DCAPS9 caps; d3d9->GetDeviceCaps(D3DADAPTER_DEFAULT, deviceType, &caps); int vp = 0; if( caps.DevCaps & D3DDEVCAPS_HWTRANSFORMANDLIGHT ) vp = D3DCREATE_HARDWARE_VERTEXPROCESSING; else vp = D3DCREATE_SOFTWARE_VERTEXPROCESSING; // Step 3: Fill out the D3DPRESENT_PARAMETERS structure. D3DPRESENT_PARAMETERS d3dpp; d3dpp.BackBufferWidth = width; d3dpp.BackBufferHeight = height; d3dpp.BackBufferFormat = D3DFMT_A8R8G8B8; d3dpp.BackBufferCount = 1; d3dpp.MultiSampleType = D3DMULTISAMPLE_NONE; d3dpp.MultiSampleQuality = 0; d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD; d3dpp.hDeviceWindow = hwnd; d3dpp.Windowed = windowed; d3dpp.EnableAutoDepthStencil = true; d3dpp.AutoDepthStencilFormat = D3DFMT_D24S8; d3dpp.Flags = 0; d3dpp.FullScreen_RefreshRateInHz = D3DPRESENT_RATE_DEFAULT; d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_ONE; // Step 4: Create the device. hr = d3d9->CreateDevice( D3DADAPTER_DEFAULT, // primary adapter deviceType, // device type hwnd, // window associated with device vp, // vertex processing &d3dpp, // present parameters device); // return created device if( FAILED(hr) ) { // try again using a 16-bit depth buffer d3dpp.AutoDepthStencilFormat = D3DFMT_D16; hr = d3d9->CreateDevice( D3DADAPTER_DEFAULT, deviceType, hwnd, vp, &d3dpp, device); if( FAILED(hr) ) { d3d9->Release(); // done with d3d9 object ::MessageBox(0, "CreateDevice() - FAILED", 0, 0); return false; } } d3d9->Release(); // done with d3d9 object return true;}HWND d3d::GetHandle(){ return handle;}int d3d::EnterMsgLoop( bool (*ptr_display)(float timeDelta) ){ MSG msg; ::ZeroMemory(&msg, sizeof(MSG)); static float lastTime = (float)timeGetTime(); while(msg.message != WM_QUIT) { if(::PeekMessage(&msg, 0, 0, 0, PM_REMOVE)) { ::TranslateMessage(&msg); ::DispatchMessage(&msg); } else { float currTime = (float)timeGetTime(); float timeDelta = (currTime - lastTime); ptr_display(timeDelta); lastTime = currTime; } } return msg.wParam;}FILENAME: d3dinit.cpp//////////////////////////////////////////////////////////////////////////////////////////////////// // File: d3dinit.cpp// // Author: Frank Luna (C) All Rights Reserved//// System: AMD Athlon 1800+ XP, 512 DDR, Geforce 3, Windows XP, MSVC++ 7.0 //// Desc: Demonstrates how to initialize Direct3D, how to use the book's framework// functions, and how to clear the screen to black. Note that the Direct3D// initialization code is in the d3dUtility.h/.cpp files.// //////////////////////////////////////////////////////////////////////////////////////////////////#include "d3dUtility.h"//// Globals//IDirect3DDevice9* Device = 0;LPDIRECT3DTEXTURE9 texture = 0;LPD3DXSPRITE sprite = 0; //// Framework Functions//bool Setup(){ // Nothing to setup in this sample. HRESULT r1 = D3DXCreateTextureFromFile(Device, "C:\\Users\\Armion\\Desktop\\cursor.png", &texture); HRESULT r2 = D3DXCreateSprite(Device, &sprite); return true;}void Cleanup(){ // Nothing to cleanup in this sample. texture->Release(); sprite->Release();}bool Display(float timeDelta){ if( Device ) // Only use Device methods if we have a valid device. { // Instruct the device to set each pixel on the back buffer black - // D3DCLEAR_TARGET: 0x00000000 (black) - and to set each pixel on // the depth buffer to a value of 1.0 - D3DCLEAR_ZBUFFER: 1.0f. static float totalTime = 0; static int frames = 0; totalTime += timeDelta; frames++; HWND handle = d3d::GetHandle(); if (totalTime > 1000) { char strFrames[10]; itoa(frames, strFrames, 10); char strFps[16]; strcpy(strFps, "FPS: "); strcat(strFps, strFrames); frames = 0; totalTime -= 1000; ::SetWindowTextA(handle, strFps); } Device->Clear(0, 0, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0x00000000, 1.0f, 0); Device->BeginScene(); POINT coords; ::GetCursorPos(&coords); ::ScreenToClient(handle, &coords); RECT client; GetClientRect(handle, &client); D3DXVECTOR3 pos(coords.x, coords.y, 0); sprite->Begin(D3DXSPRITE_ALPHABLEND); HRESULT test = sprite->Draw(texture, 0, 0, &pos, 0xFFFFFFFF); sprite->End(); //::SetWindowText(hwnd, Device->EndScene(); // Swap the back and front buffers. Device->Present(0, 0, 0, 0); } return true;}//// WndProc//LRESULT CALLBACK d3d::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam){ switch( msg ) { case WM_DESTROY: ::PostQuitMessage(0); break; case WM_KEYDOWN: if( wParam == VK_ESCAPE ) ::DestroyWindow(hwnd); break; } return ::DefWindowProc(hwnd, msg, wParam, lParam);}//// WinMain//int WINAPI WinMain(HINSTANCE hinstance, HINSTANCE prevInstance, PSTR cmdLine, int showCmd){ if(!d3d::InitD3D(hinstance, 640, 480, true, D3DDEVTYPE_HAL, &Device)) { ::MessageBox(0, "InitD3D() - FAILED", 0, 0); return 0; } if(!Setup()) { ::MessageBox(0, "Setup() - FAILED", 0, 0); return 0; } d3d::EnterMsgLoop( Display ); Cleanup(); Device->Release(); return 0;}Thanks in advance :)

Graphics and GPU Programming Programming

Started by Armion August 19, 2010 02:47 PM

12 comments, last by Armion 13 years, 8 months ago

Matias Goldberg

9,637

August 21, 2010 12:58 PM

Quote:Original post by Armion
@Matias Goldberg: Hmm... I will test if there is any error in my arguments when creating the fullscreen. Could this be related to the Ex version of interfaces and calls(IDirect3DDevice9Ex, PresentEx())?

I don't think so.
The problem is basically when the device doesn't like the arguments for the backbuffer format you passed for the actual resolution you end up using (i.e. wrong refresh rate or bpp colour).

Quote:Original post by Armion
I don't think low fps is the problem - getting more than 4000 with D3DPRESENT_INTERVAL_IMMEDIATE - my app is just rendering its own cursor below the real one.(Unreal Tournament, Battlefield 2 Bad Company)

Oh I see, I thought this problem appeared when you were low on fps with VSync enabled.

Quote:Original post by Armion
- limiting your fps to one or two below the refresh rate - let's say 58fps for 60Hz refresh rate... And it works like a charm. Can someone explain to me this STRANGE behavior?

Well, I'm not sure if I get what exactly you're doing, but seems you're clamping the FPS through the CPU. I can only guess with +60fps present() takes time inside the driver, while having 58-59fps makes present() returns almost immediately except for occasional nano- or milliseconds delay to synchronize with the monitor's refresh; which makes your timing response somehow more accurate. I'm only guessing

There's something I don't understand though about how you're rendering the cursor.
If I understand correctly, you're letting the window's default cursor to show on top of the in window, and at the same time you're drawing a quad with your own cursor. Then use a function like GetCursorPos() to draw it in the same position the hardware cursor should be?
How exactly are you doing this?

Twitter: @matiasgoldberg

Distant Souls ? Alliance AirWar ? My Free Royalty-Free Music Library

Armion

272

Author

August 21, 2010 02:49 PM

Hi Matias :)

As you can see in the source code above i fill my D3DPRESENT_PARAMETERS structure with the following code:

D3DPRESENT_PARAMETERS d3dpp;	d3dpp.BackBufferWidth            = width;	d3dpp.BackBufferHeight           = height;	d3dpp.BackBufferFormat           = D3DFMT_A8R8G8B8;	d3dpp.BackBufferCount            = 1;	d3dpp.MultiSampleType            = D3DMULTISAMPLE_NONE;	d3dpp.MultiSampleQuality         = 0;	d3dpp.SwapEffect                 = D3DSWAPEFFECT_DISCARD; 	d3dpp.hDeviceWindow              = hwnd;	d3dpp.Windowed                   = windowed;	d3dpp.EnableAutoDepthStencil     = true; 	d3dpp.AutoDepthStencilFormat     = D3DFMT_D24S8;	d3dpp.Flags                      = 0;	d3dpp.FullScreen_RefreshRateInHz = D3DPRESENT_RATE_DEFAULT;	d3dpp.PresentationInterval       = D3DPRESENT_INTERVAL_ONE;

What part of it could be the problem? Checking the created device with PIX the only strange thing i see is that Windowed is set to true if we have specified fullscreen. Still i guess this interesting thing is happening because of the internal workings of PIX - even if i force Windowed to false Pix still tells me that Windowed is false. So i can't really see what could be messing with my application for i-don't-know-how-much-time. I tried playing with the settings and the once that gave me problems didn't return S_OK when creating the device so even if i wanted i couldn't use them.

For your next assumption - yes, clamping the FPS through CPU remedies the problem in fullscreen. Windowed mode still lags but it's not as bad as before.

As for how i'm rendering the cursor:
The windows cursor is on. Additionally that's what i'm doing in my render procedure:

// This source is almost the same as the in the book of Frank Luna,// called Introduction to 3D Game Programming With DirectX 9.0// For complete source code see my first post - 3rd code fileDevice->Clear(some parameters);Device->BeginScene();//Get the current cursor position according to screen coordinates//Render a texture representing a second cursor in that exact placeDevice->EndScene();Device->Present(0, 0, 0, 0);

No matter how i think about it in the worst case scenario the difference in the position should be at most 1/60 of the second. I don't see how the difference in time between moment 2 and 3 can be more that.
moment 1: Present() at retrace period
moment 2: Render cursor
moment 3: Present() at retrace period

And still the drawn cursor is lagging behind...

Matias Goldberg

9,637

August 21, 2010 03:57 PM

About the fullscreen <-> Win7 issue, seems we can discard that as a problem.

But regarding my questions with mouse cursor, you haven't answered anything meaningful.
For example you say:

Quote:It's only polling the cursor position

You said you're not using WM_CURSOR, ok, then HOW are you polling the cursor? What function? GetMouseCursorPos? Are you using DirectInput?

Twitter: @matiasgoldberg

Distant Souls ? Alliance AirWar ? My Free Royalty-Free Music Library

Armion

272

Author

August 21, 2010 04:10 PM

I'm sorry i've misunderstood you :) Here is the code you asked for:

		POINT coords;	::GetCursorPos(&coords);	::ScreenToClient(handle, &coords);	RECT client;	GetClientRect(handle, &client); 	// This works correctly for windowed	D3DXVECTOR3 pos(coords.x, coords.y, 0);	sprite->Begin(D3DXSPRITE_ALPHABLEND);	HRESULT test = sprite->Draw(texture, 0, 0, &pos, 0xFFFFFFFF);	sprite->End();

[Edited by - Armion on August 21, 2010 5:10:59 PM]

[DX9] Vsync Lag

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