GLSL Toy

This is discontinued

GLSL Toy is a ShaderToy clone meant with more freedoms.

1. Runs natively ⚡
2. Works as a live background 🖼️ (Linux only)
3. Can execute any other code along with GLSL shaders 🤯

Usage

1. Install dependencies
   • GL, GLFW, GLEW, X11
   • make, cc (for compiling)
   • libpng (for metablobs)
2. Compile (with make)

   $ make

3. Run

   ./glsl metablobs

Eye Candy

TODO

• (bring back) compute shader support
• frame buffer to access previous frame
• remove all my debug statements
• cleanup and normalize errors
• add more examples

Making Shaders

Each shader project is stored independently in a folder.

shader.glsl

Here is an example:

// shader.glsl
#version 330 core

out vec4 FragColor;

uniform vec2 resolution;
uniform float time;
uniform vec3 mouse;

void main() {

    // Normalized pixel coordinates (from 0 to 1)
    vec2 uv = (vec2(mouse) + vec2(gl_FragCoord)) / resolution;

    // Varying pixel color
    vec3 color;
	color = vec3(uv, 1) * vec3(1, 1, 1) * 0.5 * sin(time) + 0.5;

    // Output to screen
    FragColor = vec4(color, 1.0);

}

Usefull data such as the cursor position can be imported using uniform, here are the default available, a custom tick.so can add or remove these:

• vec2 resolution - Screen size
• float time - Time (s) since start
• vec3 mouse - Mouse x, y and btn

Makefile

The Makefile is responsible for compiling any CPU code to an SO file called tick.so. Although the projects here use c, theoretically any language can be used as long as they export the right tokens.

Here is an example:

# Makefile
tick.so: tick.c
	cc tick.c -o tick.so -shared -lm -lglfw -lGLEW -lGL -O4 -fPIC

// tick.c
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <stdlib.h>

float x, y;
float xv, yv;

void init(GLFWwindow* window, GLuint shader, int w, int h) {
	// Optional
	// Called on first frame
	x = rand() / (float)RAND_MAX * w;
	y = rand() / (float)RAND_MAX * h;
	xv = 2;
	yv = 2;
}

void tick(GLFWwindow* window, GLuint shader, int w, int h) {
	// Optional
	// Called every frame
	x += xv;
	y += yv;
	if (x < 0) {
		x = 0;
		xv = 2;
	} else if (x > w) {
		x = w;
		xv = -2
	}
	if (y < 0) {
		y = 0;
		yv = 2;
	} else if (y > h) {
		y = h;
		yv = -2;
	}
	// Push data to GPU
	glUniform2f(glGetUniformLocation(shader, "pos"), x, y);
}