/*******************************************************************************************
|
|
*
|
|
* raylib [core] example - delta time
|
|
*
|
|
* Example complexity rating: [★☆☆☆] 1/4
|
|
*
|
|
* Example originally created with raylib 5.5
|
|
*
|
|
* Example contributed by Robin (@RobinsAviary) and reviewed by Ramon Santamaria (@raysan5)
|
|
*
|
|
* Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
|
|
* BSD-like license that allows static linking with closed source software
|
|
*
|
|
* Copyright (c) 2025-2025 Robin (@RobinsAviary)
|
|
*
|
|
********************************************************************************************/
|
|
|
|
#include "raylib.h"
|
|
|
|
//------------------------------------------------------------------------------------
|
|
// Program main entry point
|
|
//------------------------------------------------------------------------------------
|
|
int main(void)
|
|
{
|
|
// Initialization
|
|
//--------------------------------------------------------------------------------------
|
|
const int screenWidth = 800;
|
|
const int screenHeight = 450;
|
|
|
|
InitWindow(screenWidth, screenHeight, "raylib [core] example - delta time");
|
|
|
|
int currentFps = 60;
|
|
|
|
// Store the position for the both of the circles
|
|
Vector2 deltaCircle = {0, screenHeight / 3.0f};
|
|
Vector2 frameCircle = {0, screenHeight * (2.0f/3.0f)};
|
|
|
|
// The speed applied to both circles
|
|
const float speed = 10.0;
|
|
const float circleRadius = 32;
|
|
|
|
SetTargetFPS(currentFps);
|
|
//--------------------------------------------------------------------------------------
|
|
|
|
// Main game loop
|
|
while (!WindowShouldClose()) // Detect window close button or ESC key
|
|
{
|
|
// Update
|
|
//----------------------------------------------
|
|
if (IsKeyPressed(KEY_R)) // Reset both circles' positions when you press R
|
|
{
|
|
deltaCircle.x = 0;
|
|
frameCircle.x = 0;
|
|
}
|
|
|
|
// Adjust the FPS target based on the mouse wheel
|
|
float mouseWheel = GetMouseWheelMove();
|
|
if (mouseWheel != 0)
|
|
{
|
|
currentFps += (int)mouseWheel;
|
|
SetTargetFPS(currentFps);
|
|
}
|
|
|
|
// GetFrameTime() returns the time it took to draw the last frame, in seconds (usually called delta time)
|
|
// Uses the delta time to make the circle look like it's moving at a "consistent" speed regardless of FPS
|
|
|
|
// Multiply by 6.0 (an arbitrary value) in order to make the speed visually closer to the other circle (at 60 fps), for comparison
|
|
deltaCircle.x += GetFrameTime() * 6.0f * speed;
|
|
// This circle can move faster or slower visually depending on the FPS
|
|
frameCircle.x += .1f * speed;
|
|
|
|
// If either circle is off the screen, reset it back to the start
|
|
if (deltaCircle.x > screenWidth)
|
|
{
|
|
deltaCircle.x = 0;
|
|
}
|
|
|
|
if (frameCircle.x > screenWidth)
|
|
{
|
|
frameCircle.x = 0;
|
|
}
|
|
|
|
// Draw
|
|
//----------------------------------------------------------------------------------
|
|
BeginDrawing();
|
|
|
|
ClearBackground(RAYWHITE);
|
|
|
|
// Draw both circles to the screen
|
|
DrawCircleV(deltaCircle, circleRadius, RED);
|
|
DrawCircleV(frameCircle, circleRadius, BLUE);
|
|
|
|
// Determine what help text to show depending on the current FPS target
|
|
const char* fpsText;
|
|
|
|
if (currentFps <= 0)
|
|
{
|
|
if (currentFps < 0)
|
|
{
|
|
// Clamp values below 0
|
|
currentFps = 0;
|
|
}
|
|
|
|
// Special text for when the FPS target is set to 0 or less, which makes it unlimited
|
|
fpsText = TextFormat("fps: unlimited (%i)", GetFPS());
|
|
}
|
|
else
|
|
{
|
|
fpsText = TextFormat("fps: %i (target: %i)", GetFPS(), currentFps);
|
|
}
|
|
|
|
// Draw the help text
|
|
DrawText(fpsText, 10, 10, 20, DARKGRAY);
|
|
DrawText(TextFormat("frame time: %02.02f ms", GetFrameTime()), 10, 30, 20, DARKGRAY);
|
|
DrawText("use the scroll wheel to change the fps limit, r to reset", 10, 50, 20, DARKGRAY);
|
|
|
|
// Draw the text above the circles
|
|
DrawText("x += GetFrameTime() * speed", 10, 90, 20, RED);
|
|
DrawText("x += speed", 10, 240, 20, BLUE);
|
|
|
|
EndDrawing();
|
|
//----------------------------------------------------------------------------------
|
|
}
|
|
|
|
// De-Initialization
|
|
//--------------------------------------------------------------------------------------
|
|
CloseWindow(); // Close window and OpenGL context
|
|
//--------------------------------------------------------------------------------------
|
|
|
|
return 0;
|
|
}
|