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
131
132
133
134
135
|
/*******************************************************************************************
*
* raylib example - particles trail blending
*
* This example has been created using raylib 1.3 (www.raylib.com)
* raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
* Copyright (c) 2015 Ramon Santamaria (@raysan5)
*
********************************************************************************************/
#include "raylib.h"
#define MAX_PARTICLES 200
// Particle structure with basic data
typedef struct {
Vector2 position;
Color color;
float alpha;
float size;
float rotation;
bool active; // NOTE: Use it to activate/deactive particle
} Particle;
int main()
{
// Initialization
//--------------------------------------------------------------------------------------
int screenWidth = 800;
int screenHeight = 450;
InitWindow(screenWidth, screenHeight, "raylib [textures] example - particles trail blending");
// Particles pool, reuse them!
Particle mouseTail[MAX_PARTICLES];
// Initialize particles
for (int i = 0; i < MAX_PARTICLES; i++)
{
mouseTail[i].position = (Vector2){ 0, 0 };
mouseTail[i].color = (Color){ GetRandomValue(0, 255), GetRandomValue(0, 255), GetRandomValue(0, 255), 255 };
mouseTail[i].alpha = 1.0f;
mouseTail[i].size = (float)GetRandomValue(1, 30)/20.0f;
mouseTail[i].rotation = GetRandomValue(0, 360);
mouseTail[i].active = false;
}
float gravity = 3.0f;
Texture2D smoke = LoadTexture("resources/smoke.png");
int blending = BLEND_ALPHA;
SetTargetFPS(60);
//--------------------------------------------------------------------------------------
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
{
// Update
//----------------------------------------------------------------------------------
// Activate one particle every frame and Update active particles
// NOTE: Particles initial position should be mouse position when activated
// NOTE: Particles fall down with gravity and rotation... and disappear after 2 seconds (alpha = 0)
// NOTE: When a particle disappears, active = false and it can be reused.
for (int i = 0; i < MAX_PARTICLES; i++)
{
if (!mouseTail[i].active)
{
mouseTail[i].active = true;
mouseTail[i].alpha = 1.0f;
mouseTail[i].position = GetMousePosition();
i = MAX_PARTICLES;
}
}
for (int i = 0; i < MAX_PARTICLES; i++)
{
if (mouseTail[i].active)
{
mouseTail[i].position.y += gravity;
mouseTail[i].alpha -= 0.01f;
if (mouseTail[i].alpha <= 0.0f) mouseTail[i].active = false;
mouseTail[i].rotation += 5.0f;
}
}
if (IsKeyPressed(KEY_SPACE))
{
if (blending == BLEND_ALPHA) blending = BLEND_ADDITIVE;
else blending = BLEND_ALPHA;
}
//----------------------------------------------------------------------------------
// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
ClearBackground(DARKGRAY);
BeginBlendMode(blending);
// Draw active particles
for (int i = 0; i < MAX_PARTICLES; i++)
{
if (mouseTail[i].active) DrawTexturePro(smoke, (Rectangle){ 0, 0, smoke.width, smoke.height },
(Rectangle){ mouseTail[i].position.x, mouseTail[i].position.y, smoke.width*mouseTail[i].size, smoke.height*mouseTail[i].size },
(Vector2){ smoke.width*mouseTail[i].size/2, smoke.height*mouseTail[i].size/2 }, mouseTail[i].rotation,
Fade(mouseTail[i].color, mouseTail[i].alpha));
}
EndBlendMode();
DrawText("PRESS SPACE to CHANGE BLENDING MODE", 180, 20, 20, BLACK);
if (blending == BLEND_ALPHA) DrawText("ALPHA BLENDING", 290, screenHeight - 40, 20, BLACK);
else DrawText("ADDITIVE BLENDING", 280, screenHeight - 40, 20, RAYWHITE);
EndDrawing();
//----------------------------------------------------------------------------------
}
// De-Initialization
//--------------------------------------------------------------------------------------
UnloadTexture(smoke);
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}
|
