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/*******************************************************************************************
*
* raylib [core] example - custom frame control
*
* WARNING: This is an example for advance users willing to have full control over
* the frame processes. By default, EndDrawing() calls the following processes:
* 1. Draw remaining batch data: rlDrawRenderBatchActive()
* 2. SwapScreenBuffer()
* 3. Frame time control: WaitTime()
* 4. PollInputEvents()
*
* To avoid steps 2, 3 and 4, flag SUPPORT_CUSTOM_FRAME_CONTROL can be enabled in
* config.h (it requires recompiling raylib). This way those steps are up to the user.
*
* Note that enabling this flag invalidates some functions:
* - GetFrameTime()
* - SetTargetFPS()
* - GetFPS()
*
* This example has been created using raylib 3.8 (www.raylib.com)
* raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
* Copyright (c) 2021 Ramon Santamaria (@raysan5)
*
********************************************************************************************/
#include "raylib.h"
int main(void)
{
// Initialization
//--------------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;
InitWindow(screenWidth, screenHeight, "raylib [core] example - custom frame control");
// Custom timming variables
double previousTime = GetTime(); // Previous time measure
double currentTime = 0.0; // Current time measure
double updateDrawTime = 0.0; // Update + Draw time
double waitTime = 0.0; // Wait time (if target fps required)
float deltaTime = 0.0f; // Frame time (Update + Draw + Wait time)
float timeCounter = 0.0f; // Accumulative time counter (seconds)
float position = 0.0f; // Circle position
bool pause = false; // Pause control flag
int targetFPS = 60; // Our initial target fps
//--------------------------------------------------------------------------------------
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
{
// Update
//----------------------------------------------------------------------------------
PollInputEvents(); // Poll input events (SUPPORT_CUSTOM_FRAME_CONTROL)
if (IsKeyPressed(KEY_SPACE)) pause = !pause;
if (IsKeyPressed(KEY_UP)) targetFPS += 20;
else if (IsKeyPressed(KEY_DOWN)) targetFPS -= 20;
if (targetFPS < 0) targetFPS = 0;
if (!pause)
{
position += 200*deltaTime; // We move at 200 pixels per second
if (position >= GetScreenWidth()) position = 0;
timeCounter += deltaTime; // We count time (seconds)
}
//----------------------------------------------------------------------------------
// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
ClearBackground(RAYWHITE);
for (int i = 0; i < GetScreenWidth()/200; i++) DrawRectangle(200*i, 0, 1, GetScreenHeight(), SKYBLUE);
DrawCircle((int)position, GetScreenHeight()/2 - 25, 50, RED);
DrawText(TextFormat("%03.0f ms", timeCounter*1000.0f), position - 40, GetScreenHeight()/2 - 100, 20, MAROON);
DrawText(TextFormat("PosX: %03.0f", position), position - 50, GetScreenHeight()/2 + 40, 20, BLACK);
DrawText("Circle is moving at a constant 200 pixels/sec,\nindependently of the frame rate.", 10, 10, 20, DARKGRAY);
DrawText("PRESS SPACE to PAUSE MOVEMENT", 10, GetScreenHeight() - 60, 20, GRAY);
DrawText("PRESS UP | DOWN to CHANGE TARGET FPS", 10, GetScreenHeight() - 30, 20, GRAY);
DrawText(TextFormat("TARGET FPS: %i", targetFPS), GetScreenWidth() - 220, 10, 20, LIME);
DrawText(TextFormat("CURRENT FPS: %i", (int)(1.0f/deltaTime)), GetScreenWidth() - 220, 40, 20, GREEN);
EndDrawing();
// NOTE: In case raylib is configured to SUPPORT_CUSTOM_FRAME_CONTROL,
// Events polling, screen buffer swap and frame time control must be managed by the user
SwapScreenBuffer(); // Flip the back buffer to screen (front buffer)
currentTime = GetTime();
updateDrawTime = currentTime - previousTime;
if (targetFPS > 0) // We want a fixed frame rate
{
waitTime = (1.0f/(float)targetFPS) - updateDrawTime;
if (waitTime > 0.0)
{
WaitTime((float)waitTime*1000.0f);
currentTime = GetTime();
deltaTime = (float)(currentTime - previousTime);
}
}
else deltaTime = updateDrawTime; // Framerate could be variable
previousTime = currentTime;
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}
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