DirectInput Limiting Movement

[chronozphere]

Glad i could help

[lordzero]

can you show your code about frequency?

using this without interval dont will use 100% of CPU?

[Memphis]

bringing back a dead post to save creating a new thread. again similar problem only i was working on a new 3d engine.

i've been working on it for a long time, but only noticed this problem due to the fps changing.

vars:

[code=delphi]
iMoveSpeed: Single = 1;
iFrameRate: Cardinal; //obviously the fps
[/code]

[code=delphi]
if (buffer[DIK_A] and $80) <> 0 then begin
Cam.x := Cam.x + cos(Cam.RotX + PI/2) * (iMoveSpeed / iFrameRate);
Cam.z := Cam.z + sin(Cam.RotX + PI/2) * (iMoveSpeed / iFrameRate);
end else if (buffer[DIK_D] and $80) <> 0 then begin
Cam.x := Cam.x + cos(Cam.RotX - PI/2) * (iMoveSpeed / iFrameRate);
Cam.z := Cam.z + sin(Cam.RotX - PI/2) * (iMoveSpeed / iFrameRate);
end;

if (buffer[DIK_W] and $80) <> 0 then begin
Cam.x := Cam.x + cos(Cam.RotX) * (iMoveSpeed / iFrameRate);
Cam.y := Cam.y - cos(Cam.RotY + PI/2) * (iMoveSpeed / iFrameRate);
Cam.z := Cam.z + sin(Cam.RotX) * (iMoveSpeed / iFrameRate);
end else if (buffer[DIK_S] and $80) <> 0 then begin
Cam.x := Cam.x - cos(Cam.RotX) * (iMoveSpeed / iFrameRate);
Cam.y := Cam.y + cos(Cam.RotY + PI/2) * (iMoveSpeed / iFrameRate);
Cam.z := Cam.z - sin(Cam.RotX) * (iMoveSpeed / iFrameRate);
end;
[/code]

this works for moving around, however depending on framerate, it goes faster or slower.. i cant figure out how to keep it steady, note i use queryperformance for my counter/fps calculation.

thanks in advance.

;MM;

[JSoftware]

My guess is that you only update iFrameRate every second or so I would do it like this:

[pascal]
iMoveSpeed: single = 1; //Units/second
fDeltaTime: single; //fraction of second

LastTick, Tick: Cardinal; //Just use GetTickCount. It's precise enough and you don't get problems with changing frequencies
[/pascal]

Every frame before calculating positions do:
[pascal]
Tick := GetTickCount;
fDeltaTime := (Tick-LastTick)/1000;
LastTick := Tick;
[/pascal]

[pascal]
if (buffer[DIK_A] and $80) <> 0 then begin
Cam.x := Cam.x + cos(Cam.RotX + PI/2) * (iMoveSpeed * fDeltaTime);
Cam.z := Cam.z + sin(Cam.RotX + PI/2) * (iMoveSpeed * fDeltaTime);
end else if (buffer[DIK_D] and $80) <> 0 then begin
Cam.x := Cam.x + cos(Cam.RotX - PI/2) * (iMoveSpeed * fDeltaTime);
Cam.z := Cam.z + sin(Cam.RotX - PI/2) * (iMoveSpeed * fDeltaTime);
end;

if (buffer[DIK_W] and $80) <> 0 then begin
Cam.x := Cam.x + cos(Cam.RotX) * (iMoveSpeed * fDeltaTime);
Cam.y := Cam.y - cos(Cam.RotY + PI/2) * (iMoveSpeed * fDeltaTime);
Cam.z := Cam.z + sin(Cam.RotX) * (iMoveSpeed * fDeltaTime);
end else if (buffer[DIK_S] and $80) <> 0 then begin
Cam.x := Cam.x - cos(Cam.RotX) * (iMoveSpeed * fDeltaTime);
Cam.y := Cam.y + cos(Cam.RotY + PI/2) * (iMoveSpeed * fDeltaTime);
Cam.z := Cam.z - sin(Cam.RotX) * (iMoveSpeed * fDeltaTime);
end;
[/pascal]

[Memphis]

yes you were right my problem was my performance counter. thanks.

i will keep gettickcount in mind, i however am still using query counter, the problem was how i was doing it, adding the delta time was the solution

F_DeltaTime := (F_ThisTime - F_LastTime) / 1000;


thanks again jsoftware