Example of using GLSL shaders on the EYESY openFrameworks beta OS

An EYESY Shader Example.md

EYESY openFrameworks mode demonstrating the use of GLSL shaders.

Requirements/Usage:

• Install the EYESY_OS beta image from December 2021
• Connect to EYESY wifi editor, create a new folder, and place these three files in it
• You might also want to sync to ofEyesy commit 3991169 or newer. (It might work fine with original OS image or latest, but this is what my local repo is at currently.)

Video demo: https://vimeo.com/698406641

Lissajous plasma technique is inspired by the classic LoL Shield plasma demo.

fragment.glsl

// Lissajous Plasma Ramps

uniform vec2 resolution;
uniform float time;
uniform float knob1;
uniform float knob2;
uniform float knob3;
uniform float knob4;
uniform float knob5;

#define TAU 6.283184

vec3 hsv2rgb(vec3 c) {
  vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
  vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
  return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
}

void main(void)
{
    vec2 uv = (-1. + 2. * vec2(gl_FragCoord.x / resolution.x, gl_FragCoord.y / resolution.y)) *
        ((50. * knob1) + (8. * sin(time/33.))) + (16. * cos(time/73.));
    
    vec2 p1 = vec2(
        (sin(time/31.) + 4.) * (3.45 + 12. * knob2) - 40.,
        (sin(time/3.66) + 3.) * 7.5 + (2. * knob3 - 1.) * 47.
    );
    
    vec2 p2 = vec2(
        (sin(time/13.) + 3.) * (13.27 - 4. * knob2) - 41.,
        (sin(time/7.81) + 1.) * 16. * (1. - knob3) + 14.
    );
    
    float d1 = distance(uv, p1);
    float d2 = distance(uv, p2);
    
    float hueRange = .1 + knob5 * .38;
    float baseHue = (1. - knob4) * (1. - hueRange);
    
    gl_FragColor = vec4(
        hsv2rgb(vec3(
            baseHue + hueRange * abs(sin(TAU * mod(time, 72.) / 72. + sqrt(d1 * d2))),
            abs(.9 - .32 * abs(sin(sqrt(1. + (d1 + d2))))),
            abs(sin(sqrt(abs(1. - d1) * abs(4. - d2))))
        )),
        1.
    );
}

main.lua

require("eyesy")

modeTitle = "S - Lissajous Plasma Ramps"
modeExplain = "Demonstrate loading a shader in Eyesy ofLua, by Anagram/Dewb"

print(modeTitle)
print(modeExplain)

function script_path()
   local str = debug.getinfo(2, "S").source:sub(2)
   return str:match("(.*/)")
end

print(script_path())

function setup()
    w = of.getWidth()
    h = of.getHeight()
    time = 0
    
    k1s = knob1
    k2s = knob2
    k3s = knob3
    k4s = knob4
    k5s = knob5
    
    inLTexture = of.Texture()
    inRTexture = of.Texture()
    inLTexture:allocate(256, 1, 0x1903) -- of.GL_RED
    inRTexture:allocate(256, 1, 0x1903) -- of.GL_RED
    
    shader = of.Shader()
    shader:load(script_path() .. "vertex.glsl", script_path() .. "fragment.glsl", "")
end

function update()
    time = (time + of.getLastFrameTime()) % 3600.0
    
    -- basic knob smoothing
    k1s = (k1s + knob1) / 2
    k2s = (k2s + knob2) / 2
    k3s = (k3s + knob3) / 2
    k4s = (k4s + knob4) / 2
    k5s = (k5s + knob5) / 2
    
    -- need to enhance SWIG for loadData to convert table to float array?
    --inLTexture:loadData(inL, 256, 1, 0x1903) -- of.GL_RED
    --inRTexture:loadData(inR, 256, 1, 0x1903) -- of.GL_RED
end

function draw()
    shader:beginShader()
    shader:setUniform2f("resolution", w, h)
    shader:setUniform1f("time", time)
    shader:setUniform1f("knob1", k1s)
    shader:setUniform1f("knob2", k2s)
    shader:setUniform1f("knob3", k3s)
    shader:setUniform1f("knob4", k4s)
    shader:setUniform1f("knob5", k5s)
    of.drawRectangle(0, 0, w, h)
    shader:endShader()
end

function exit()
    print("script finished")        
end

vertex.glsl

// default vertex shader

attribute vec4 position;
uniform mat4 modelViewProjectionMatrix;

void main()
{
    gl_Position = modelViewProjectionMatrix * position;
}