openRNDR code for https://imgur.com/gallery/pyhAILS

ColorRadials.kt

package org.ygl.openrndr.demos

import org.openrndr.Application
import org.openrndr.application
import org.openrndr.draw.shadeStyle
import org.openrndr.extra.compositor.compose
import org.openrndr.extra.compositor.draw
import org.openrndr.extra.compositor.post
import org.openrndr.extra.fx.blur.ZoomBlur
import org.openrndr.ffmpeg.ScreenRecorder
import org.ygl.openrndr.utils.colorMapBufferTextureFromStrings
import org.ygl.openrndr.utils.doubleArrayBufferTexture
import org.ygl.openrndr.utils.shaderColorMap
import java.io.File
import kotlin.random.Random

private const val WIDTH = 920
private const val HEIGHT = 920
private const val TOTAL_FRAMES = 360 * 4
private const val RECORDING = true

fun main() = application {

    configure {
        width = WIDTH
        height = HEIGHT
    }

    program {

        var time = 0.0
        val rays = 48
        val rng = Random(6)
        val colors = listOf(
                "233041","4979a1","8674a3","e88873","ffd6b4"
        )
        val colorBufferTexture = colorMapBufferTextureFromStrings(colors)
        val offsets = doubleArrayBufferTexture(List(rays) { rng.nextDouble() })
        val noiseFragShader = Application::class.java.getResource("/shaders/simplexNoise2D.glsl").readText()

        val composite = compose {
            draw {
                drawer.shadeStyle = shadeStyle {
                    fragmentPreamble = shaderColorMap(colors.size) + noiseFragShader +
                        """
                            float cubicPulse(float c, float w, float x) {
                                x = abs(x - c);
                                if (x > w) return 0.0;
                                x /= w;
                                return 1.0 - x * x * (3.0 - 2.0 * x);
                            }
                        """.trimIndent()

                    fragmentTransform = """
                        const float PI = 3.14159265359;
                        vec2 pos = vec2(c_boundsPosition.x - 0.5, 1 - c_boundsPosition.y - 0.5);
                        float d = length(pos);
                        
                        float dist = mix(sqrt(d), 0.2 / d, smoothstep(0.0, 0.2, d));
                        
                        float noiseAngle = 2 * PI * (dist + p_time);
                        vec2 noiseInput = vec2(
                            0.4 * cos(noiseAngle),
                            0.4 * sin(noiseAngle)
                        );
                        float noiseValue = 0.1 * snoise(noiseInput);
                        
                        float angle = 0.5 + 0.5 * (atan(pos.y, pos.x) / PI);
                        float phase = fract(angle + noiseValue);
                        
                        int colorIndex = int(phase * p_rays);
                        vec4 color = getColor(texelFetch(p_offsets, colorIndex).r);
                        
                        color *= smoothstep(0.0, 0.04, d);
                        color += (-0.05 + 0.1 * cubicPulse(0.5, 0.5, fract(angle + 0.25)));
                        color *= clamp(0.55 + cubicPulse(0.5, 0.5, fract(angle + 0.25)), 0, 1);
                        
                        x_fill = color;
                        
                    """.trimIndent()
                    parameter("time", (2 * time))
                    parameter("colorMap", colorBufferTexture)
                    parameter("offsets", offsets)
                    parameter("rays", rays)
                }
                drawer.rectangle(drawer.bounds)
            }
        }

        if (RECORDING) {
            extend(ScreenRecorder()) {
                outputFile = "video/ColorRadials.mp4"
                frameRate = 60
                frameClock = true
            }
        }

        extend {
            time = ((frameCount - 1) % TOTAL_FRAMES) / TOTAL_FRAMES.toDouble()
            composite.draw(drawer)

            if (RECORDING) {
                if (frameCount >= TOTAL_FRAMES) {
                    application.exit()
                }
            }
        }
    }
}