1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
/*******************************************************************************************
*
* raylib [core] example - custom frame control
*
* NOTE: WARNING: This is an example for advanced 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()
*
* Example originally created with raylib 4.0, last time updated with raylib 4.0
*
* 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) 2021-2024 Ramon Santamaria (@raysan5)
*
********************************************************************************************/
#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 - 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), (int)position - 40, GetScreenHeight()/2 - 100, 20, MAROON);
DrawText(TextFormat("PosX: %03.0f", position), (int)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);
currentTime = GetTime();
deltaTime = (float)(currentTime - previousTime);
}
}
else deltaTime = (float)updateDrawTime; // Framerate could be variable
previousTime = currentTime;
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}
|
