time_system.h File Reference

Manages time-related functionality for frame rate independence and timing. More...

#include <SDL.h>

Go to the source code of this file.

Classes
struct	TimeSystem
	Structure to handle time-related functionality. More...

Typedefs
typedef struct TimeSystem	TimeSystem
	Structure to handle time-related functionality.

Functions
void	Time_PreUpdate ()
	[PreUpdate] Updates the time system values
void	Time_UpdateFPS ()
	[Utility] Updates the FPS counter
void	Time_SetTimeScale (float scale)
	[Utility] Sets the time scale.
void	Time_ResetTotalTime ()
	[Utility] Resets the total time elapsed in the program.

Variables
const TimeSystem *const	Time
	Global read-only time system pointer for other modules.

Detailed Description

Manages time-related functionality for frame rate independence and timing.

The time system struct is used to keep track of the program's time, delta time, and time scale. Time delta is the time between the current frame and the previous frame. It's super useful for making sure that the game runs at the same speed on different fps.

Usage Examples

Usage in updating the position of an object that's moving up with the speed of 5 units per second.

It is quite tempting to move an object something like this:

// This line is called every frame
object.y -= 5; // btw in SDL reducing y moves the object up

Since this is called every frame, the speed will be 5 units/frame. Which causes the speed to be dependent on the frame rate.

To make the speed independent of the frame rate, we can use the delta time like this:

// This line is called every frame
object.y -= 5 * Time->deltaTimeSeconds; // Do this instead!

This way, the object will move up 5 units per second regardless of the frame rate.

Author

Mango

Date

2025-01-03

Typedef Documentation

TimeSystem

typedef struct TimeSystem TimeSystem

Structure to handle time-related functionality.

Function Documentation

Time_PreUpdate()

void Time_PreUpdate

(

)

[PreUpdate] Updates the time system values

Called at the beginning of each frame to calculate delta time and other time-related metrics. Caps deltaTime to prevent spiral of death if the game freezes temporarily.

Time_ResetTotalTime()

void Time_ResetTotalTime

(

)

[Utility] Resets the total time elapsed in the program.

Zeroes out the accumulated program time, useful for timing specific operations or resetting game timers.

Time_SetTimeScale()

void Time_SetTimeScale

(

float

scale

)

[Utility] Sets the time scale.

Adjusts the game's time scale, which can speed up or slow down the entire game. A value of 1.0 is normal speed, while 2.0 would be double speed and 0.5 would be half speed.

Parameters

scale

The scale to set the time to.

Time_UpdateFPS()

void Time_UpdateFPS

(

)

[Utility] Updates the FPS counter

Calculates average FPS over different time scales to monitor performance metrics for the game.

Variable Documentation

Time

const TimeSystem* const Time

extern

Global read-only time system pointer for other modules.