Add plasma.glsl

plasma.glsl

@@ -0,0 +1,147 @@
+#ifdef GL_ES
+precision mediump float;
+#extension GL_OES_standard_derivatives : enable
+#endif
+
+uniform float time;
+uniform vec2 mouse;
+uniform vec2 resolution;
+
+
+// START ASHIMA
+
+//
+// Description : Array and textureless GLSL 2D/3D/4D simplex 
+//               noise functions.
+//      Author : Ian McEwan, Ashima Arts.
+//  Maintainer : ijm
+//     Lastmod : 20110822 (ijm)
+//     License : Copyright (C) 2011 Ashima Arts. All rights reserved.
+//               Distributed under the MIT License. See LICENSE file.
+//               https://github.com/ashima/webgl-noise
+// 
+
+vec3 mod289(vec3 x) {
+  return x - floor(x * (1.0 / 289.0)) * 289.0;
+}
+
+vec4 mod289(vec4 x) {
+  return x - floor(x * (1.0 / 289.0)) * 289.0;
+}
+
+vec4 permute(vec4 x) {
+     return mod289(((x*34.0)+1.0)*x);
+}
+
+vec4 taylorInvSqrt(vec4 r)
+{
+  return 1.79284291400159 - 0.85373472095314 * r;
+}
+
+float snoise(vec3 v)
+  { 
+  const vec2  C = vec2(1.0/6.0, 1.0/3.0) ;
+  const vec4  D = vec4(0.0, 0.5, 1.0, 2.0);
+
+// First corner
+  vec3 i  = floor(v + dot(v, C.yyy) );
+  vec3 x0 =   v - i + dot(i, C.xxx) ;
+
+// Other corners
+  vec3 g = step(x0.yzx, x0.xyz);
+  vec3 l = 1.0 - g;
+  vec3 i1 = min( g.xyz, l.zxy );
+  vec3 i2 = max( g.xyz, l.zxy );
+
+  //   x0 = x0 - 0.0 + 0.0 * C.xxx;
+  //   x1 = x0 - i1  + 1.0 * C.xxx;
+  //   x2 = x0 - i2  + 2.0 * C.xxx;
+  //   x3 = x0 - 1.0 + 3.0 * C.xxx;
+  vec3 x1 = x0 - i1 + C.xxx;
+  vec3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
+  vec3 x3 = x0 - D.yyy;      // -1.0+3.0*C.x = -0.5 = -D.y
+
+// Permutations
+  i = mod289(i); 
+  vec4 p = permute( permute( permute( 
+             i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
+           + i.y + vec4(0.0, i1.y, i2.y, 1.0 )) 
+           + i.x + vec4(0.0, i1.x, i2.x, 1.0 ));
+
+// Gradients: 7x7 points over a square, mapped onto an octahedron.
+// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
+  float n_ = 0.142857142857; // 1.0/7.0
+  vec3  ns = n_ * D.wyz - D.xzx;
+
+  vec4 j = p - 49.0 * floor(p * ns.z * ns.z);  //  mod(p,7*7)
+
+  vec4 x_ = floor(j * ns.z);
+  vec4 y_ = floor(j - 7.0 * x_ );    // mod(j,N)
+
+  vec4 x = x_ *ns.x + ns.yyyy;
+  vec4 y = y_ *ns.x + ns.yyyy;
+  vec4 h = 1.0 - abs(x) - abs(y);
+
+  vec4 b0 = vec4( x.xy, y.xy );
+  vec4 b1 = vec4( x.zw, y.zw );
+
+  //vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
+  //vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
+  vec4 s0 = floor(b0)*2.0 + 1.0;
+  vec4 s1 = floor(b1)*2.0 + 1.0;
+  vec4 sh = -step(h, vec4(0.0));
+
+  vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
+  vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;
+
+  vec3 p0 = vec3(a0.xy,h.x);
+  vec3 p1 = vec3(a0.zw,h.y);
+  vec3 p2 = vec3(a1.xy,h.z);
+  vec3 p3 = vec3(a1.zw,h.w);
+
+//Normalise gradients
+  vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
+  p0 *= norm.x;
+  p1 *= norm.y;
+  p2 *= norm.z;
+  p3 *= norm.w;
+
+// Mix final noise value
+  vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);
+  m = m * m;
+  return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1), 
+                                dot(p2,x2), dot(p3,x3) ) );
+  }
+
+// END ASHIMA
+
+vec3 rgb2hsv(vec3 c)
+{
+    vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+    vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
+    vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
+
+    float d = q.x - min(q.w, q.y);
+    float e = 1.0e-10;
+    return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
+}
+
+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 position = gl_FragCoord.xy / min(resolution.x, resolution.y);
+
+	const float scale = 0.5;
+	float x = position.x * scale;
+	float y = position.y * scale;
+	float t = time;
+
+	float hue = snoise(vec3(x, y, t));
+	vec3 rgb = hsv2rgb(vec3(hue, 1.0, 1.0));
+
+	gl_FragColor = vec4(rgb, 1.0);
+}