├── processingShaderHelloWorld
    ├── data
    │   ├── screenshot.png
    │   └── myShader.frag
    └── processingShaderHelloWorld.pde
└── README.md


/processingShaderHelloWorld/data/screenshot.png:
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https://raw.githubusercontent.com/golanlevin/ProcessingShader/HEAD/processingShaderHelloWorld/data/screenshot.png


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/processingShaderHelloWorld/data/myShader.frag:
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 1 | #ifdef GL_ES
 2 | precision mediump float;
 3 | #endif
 4 | 
 5 | #define PROCESSING_COLOR_SHADER
 6 | 
 7 | uniform vec2  u_resolution;
 8 | uniform vec2  u_mouse;
 9 | uniform bool  u_button;
10 | uniform float u_time;
11 | 
12 | void main() {
13 |     vec2 uv = gl_FragCoord.st/u_resolution;
14 | 
15 |     float r = (u_button) ? uv.x : 1.0-uv.x;
16 |     float g = u_mouse.x / u_resolution.x;
17 |     float b = 0.5 + 0.5 * sin(u_time + 30.0*uv.y);
18 | 
19 |     gl_FragColor = vec4(r,g,b, 1.0);
20 | }


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/README.md:
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 1 | "Hello World" example for GLSL shaders in Processing v.3.4.
 2 | 
 3 | Golan Levin, October 2018
 4 | 
 5 | --
 6 | 
 7 | More resources for programming GLSL shaders in Processing: 
 8 | * [The Book of Shaders, by Patricio Gonzalez Vivo and Jen Lowe](https://thebookofshaders.com/)
 9 | * [Processing Shader Tutorial, by Andres Colubri](https://processing.org/tutorials/pshader/)
10 | * [Gene Kogan, Processing Shader Examples](https://github.com/genekogan/Processing-Shader-Examples/)
11 | * [Florian Bruggisser, Processing PostFX shaders](https://github.com/cansik/processing-postfx)
12 | 
13 | ![screenshot](processingShaderHelloWorld/data/screenshot.png)
14 | 


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/processingShaderHelloWorld/processingShaderHelloWorld.pde:
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 1 | // Simple "Hello World" example for shaders in Processing v.3.4.
 2 | // Golan Levin, October 2018
 3 | 
 4 | PShader myShader;
 5 | 
 6 | void setup() {
 7 |   size(540, 720, OPENGL);
 8 |   myShader = loadShader("myShader.frag");
 9 | }
10 | 
11 | void draw() {
12 |   background(0);
13 | 
14 |   myShader.set("u_resolution", float(width), float(height));
15 |   myShader.set("u_mouse", float(mouseX), float(mouseY));
16 |   myShader.set("u_time", ((float)millis()/1000.0));
17 |   myShader.set("u_button", mousePressed); 
18 | 
19 |   noStroke();
20 |   shader(myShader);
21 |   rect(0, 0, width, height);
22 | }
23 | 
24 | 
25 | /*
26 | // Here's what the shader code should look like. 
27 | // It should be stored in the file: data/myShader.frag
28 | 
29 | #ifdef GL_ES
30 | precision mediump float;
31 | #endif
32 | 
33 | #define PROCESSING_COLOR_SHADER
34 | 
35 | uniform vec2  u_resolution;
36 | uniform vec2  u_mouse;
37 | uniform bool  u_button;
38 | uniform float u_time;
39 | 
40 | void main() {
41 |     vec2 uv = gl_FragCoord.st/u_resolution;
42 | 
43 |     float r = (u_button) ? uv.x : 1.0-uv.x;
44 |     float g = u_mouse.x / u_resolution.x;
45 |     float b = 0.5 + 0.5 * sin(u_time + 30.0*uv.y);
46 | 
47 |     gl_FragColor = vec4(r,g,b, 1.0);
48 | }
49 | */
50 | 
51 | 
52 | // More resources for programming GLSL shaders in Processing: 
53 | // The Book of Shaders, by Patricio Gonzalez Vivo and Jen Lowe
54 | //    https://thebookofshaders.com/
55 | // Shaders (Processing Shader Tutorial), by Andres Colubri
56 | //    https://processing.org/tutorials/pshader/
57 | // Gene Kogan, Processing Shader Examples: 
58 | //    https://github.com/genekogan/Processing-Shader-Examples/
59 | // Florian Bruggisser, Processing PostFX shaders
60 | //    https://github.com/cansik/processing-postfx
61 | 


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