即使使用 DeltaTime，C++ Raylib 在不同 FPS 下也有不同的移动速度

Question

rigth now I try to make a small game with raylib and c++. Rigth now I only have a small cube and a plain window with the FPS in the corner. Becuase I doesnt wanted to use SetTargetFPS() I tried to implement deltaTime.

Rigth now I´m also calculating it and it works fine, when the FPS are stable, so for example: The cube moves at stable 200 FPS as fast as at stable 60 FPS, but when I get rid of SetTargetFPS(), so I have unstable FPS and the jump between 2000FPS and 1000FPS, The movement speed isn´t good.

I calculate the deltaTime so:

oldTime = newTime;
newTime = GetTime();
deltaTime = (newTime - oldTime) * 500;

That does also work and I have pretty similar numbers at the sma FPS.

And that is how I move things:

newPosX = posX + addX * deltaTime;

Does somebody know why this happens?

Thanks

Answer 1

I'm new to raylib but I believe the GetFrameTime() function is what you're looking for. This is the snippet in the cheat sheet :

float GetFrameTime(void);        // Returns time in seconds for last frame drawn