D2D : how to create a steady frame timing without tearing ?

[Roger Cabo]

Hi everyone,

In the past I used the simple VSYNC or Vsync Address $387?! <-- but do not remember exactly.. but that does not work in windows since decades.
But how to get a fixed FPS timing?

Let's say I want to have 15,30,60,90,120,140,240?
+ How I get the current FPS setting from the Monitor vis API?
+ And we implement this to the d2dLib?

This doesn't work unfortunately!

Function GetMonitorRefreshRate() As Integer
 
 Dim devMode As DEVMODE
 
 Declare Function EnumDisplaySettings Lib "user32" Alias "EnumDisplaySettingsA" (ByVal lpszDeviceName As Long, ByVal iModeNum As Long, ByRef lpDevMode As DEVMODE) As Boolean
 
 devMode.dmSize = Len(DEVMODE)
 If EnumDisplaySettings(0, ENUM_CURRENT_SETTINGS, devMode) Then
   MsgBox devMode.dmDisplayFrequency
   GetMonitorRefreshRate = devMode.dmDisplayFrequency
 Else
   GetMonitorRefreshRate = -1 ' Fehlerfall
 End If
End Function

Type DEVMODE
 dmDeviceName As String * 32
 dmSpecVersion As Integer
 dmDriverVersion As Integer
 dmSize As Integer
 dmDriverExtra As Integer
 dmFields As Long
 dmOrientation As Integer
 dmPaperSize As Integer
 dmPaperLength As Integer
 dmPaperWidth As Integer
 dmScale As Integer
 dmCopies As Integer
 dmDefaultSource As Integer
 dmPrintQuality As Integer
 dmColor As Integer
 dmDuplex As Integer
 dmYResolution As Integer
 dmTTOption As Integer
 dmCollate As Integer
 dmFormName As String * 32
 dmUnusedPadding As Integer
 dmBitsPerPel As Integer
 dmPelsWidth As Long
 dmPelsHeight As Long
 dmDisplayFlags As Long
 dmDisplayFrequency As Long
End Type

How is D2EndDraw configured? DXGI_PRESENT_SYNC_INTERVAL ?

Would this be a common solution?

Dim TargetFrameRateMs# = 1000/60 // ... 60FPS anyhow from the current Monitor
Dim t#
Do
  t#= Timer // Timer high precision
  D2BeginDraw(win1RT);
  D2Clear(D2C_ForestGreen);
  ... Draw
  D2EndDraw();
  t# = timer- t#
  Sleep(TargetFrameRateMs# - t#)
  DoEvents  or PEEKEVENT ?        // <---- ??
Loop Until anything

And how to calculate the Timer.DeltaTime for fixed timing animation?


I think that's important to know

[Roger Cabo]

Get Screen Refresh Rate

MsgBox GetScreenDeviceRefreshRate

Function GetScreenDeviceRefreshRate() As Integer
 Const VERTREFRESH = 116
 Dim hdc%
 hdc = GetDC(0)
 If hdc
   Dim RR% = GetDeviceCaps(hdc, VERTREFRESH)
   ~ReleaseDC(0, hdc)
   Return RR%
 Else
   Return -1
 End If
End Function



[scalion]

The port was 986 ( $3DA)

When i wrote some 16 bits programme under windows 3.11 that's worked, but now it cause an error:

Privileged-Instruction(I/O Ports for NT)
Exception: 0xc0000096

the orignal code (I found it in my archives) :

PROCEDURE VSYNC
 REPEAT
 UNTIL AND(INP(PORT 986),8)
RETURN

Also, i found a code to determine the frequency (source : www.compuphase.com/vretrace.htm#BASIC):

Global Int freq, hdc
hdc = GetDC(Null)
freq = GetDeviceCaps(hdc, VREFRESH)
Void ReleaseDC(Null, hdc)
Message freq


[Roger Cabo]

Dec 24, 2023 21:45:49 GMT 1 scalion said:

The port was 986 ( $3DA)

When i wrote some 16 bits programme under windows 3.11 that's worked, but now it cause an error:

Privileged-Instruction(I/O Ports for NT)
Exception: 0xc0000096

the orignal code (I found it in my archives) :

PROCEDURE VSYNC
 REPEAT
 UNTIL AND(INP(PORT 986),8)
RETURN

Also, i found a code to determine the frequency (source : www.compuphase.com/vretrace.htm#BASIC):

Global Int freq, hdc
hdc = GetDC(Null)
freq = GetDeviceCaps(hdc, VREFRESH)
Void ReleaseDC(Null, hdc)
Message freq


Yes cool! There is any reason why you should not call ReleaseDC(Null, hdc) if hdc = 0.
But I must have a look at this.

I think I have a good solution to create a steady frame timing. I will post soon..

[Roger Cabo]

My initial objective was to enable the main program to pause for approximately 1ms. Unfortunately, Sleep(1) does not achieve this; it results in a delay of about 15ms, which is far too lengthy for precise timing control.
It's important to note that we are discussing GB32 and the goal of achieving a ~1ms wait without overloading the CPU. Certainly, you can use the following code:

Dim t# = Timer
Dim Check# = t#
While Timer - t# < 0.001
   PeekEvent
Wend
MsgBox Timer - Check#

This will allow for a 1ms wait each time, but it leads to extreme power usage and high CPU load.


Interestingly, the subsequent code exhibits an unusual behavior, resulting in a sleep duration of almost exactly 1ms. When you move the mouse while this code is running, the timer indicates a delay of about 1ms.

OpenW # 1, 0, 0, 500, 500
FontSize = 20
Do
 Dim t# = Timer
 Sleep
 t = Timer - t
 Print AT(1, 2); "Move your mouse"
 Print AT(1, 2); (t) * 1000; "       "
 DoEvents
Loop Until MouseK || Me Is Nothing


At the moment, I am facing a challenge with this issue unfortunately!

TimerQ:
The GfaWinX library incorporates a millisecond precision timer. However, I'm unsure how to effectively utilize the TimerQ for pausing the main program for X milliseconds.
When I initiate TimerQ with an 8ms wait time, I also need to wait for TimerQ in the main GB32 thread. Unfortunately, this leads to significant power consumption as well through the Wait Code in GB32

______________________________________

My current solution to ran 60FPS like the monitor frequency well is:

OpenW 1, 0, 0, Screen.x, Screen.y, ~15
Set Win1RT = D2GetRT(Win_1.hWnd)  // <-------------


It's important to use the .hwnd of the Form or Win_X in D2GetRT(...). Otherwise D2D will not sync the redraw to the current display device.
D2DSteadyFrameTime.G32 (3.76 KB)

(If you have a better idea about whats going on in this case, please post!)


____________________________________________________________________________________

But this does NOT explain how you can target 30fps while your render time is variable between eg. 8ms and 23ms, and your monitor is running at 60fps.

[Roger Cabo]

Thank you. I try it.

Unity 3D required 5 or 6 years to implement a stable frame timing and a correct
DeltaTime. 🤭


The deal ist to create the best visual experience in a game with moving backgrounds and animations. You're D2D screen should run smooth on any animations or scrolling.👁️👁️

All this permanent visual glitches hiccups and jerks frame stutterings are terrible.

[(X)]

Observations:
If we try to paint a graphic at a given frame rate of 30 fps, to a new position according to a time based linear motion formula, we expect to see a smooth motion. We do not. We see 90% to 95% smooth motion and about 5% to 10% motion pause and jumps.

Hypotheses:
1) It could be that the computer is skipping frames and then jumping to the next frame.
2) It could be that the calculation of the next position is incorrect.

I will investigate along these lines.

[(X)]

I am not sure this is exactly what you are looking for but this little demo seems to at least move forms and update graphics without stuttering.

As usual here is a YT vid...

youtu.be/bR0FAeI4xHk

Attachments:

Demo TimerQ ms precision.G32 (101.54 KB)

[Roger Cabo]

Yes I c! :-)

[Roger Cabo]

Dec 30, 2023 1:57:46 GMT 1 (X) said:

I am not sure this is exactly what you are looking for but this little demo seems to at least move forms and update graphics without stuttering.

Some time ago you provided a D2D demos and use normal graphics commands and pass them into D2D.. (I Think!
But I didn't find this code or thread..

Do you remember this small project? Perhaps I'm completely wrong.

[(X)]

Dec 31, 2023 0:21:49 GMT 1 Roger Cabo said:

Dec 30, 2023 1:57:46 GMT 1 (X) said:

I am not sure this is exactly what you are looking for but this little demo seems to at least move forms and update graphics without stuttering.

Some time ago you provided a D2D demos and use normal graphics commands and pass them into D2D.. (I Think! :)
But I didn't find this code or thread..

Do you remember this small project? Perhaps I'm completely wrong.

"Normal graphic commands to D2D"

Old demo? Nothing come to mind. Sometimes it is just as quick to start fresh.  

What normal graphic command do you want to send to D2D?

(I can guess that you want to change pixels in a D2D graphic based on another post you made.)

Perhaps scalion has the wider experience in this so far.

It's always fun to experiment, but, it seems you want to do things very fast, which means OpenGL and other Frameworks capable of calling on GPUs to draw graphics.