🚚 Move fire shader to its own file

2021-12-22 05:40:42 +01:00
parent e32b11a010
commit 3149371a04
5 changed files with 212 additions and 141 deletions
@@ -0,0 +1,102 @@
+//////////////////////////////////////////////////////////////////////////////////////////
+//          )                                                   (                       //
+//       ( /(   (  (               )    (       (  (  (         )\ )    (  (            //
+//       )\()) ))\ )(   (         (     )\ )    )\))( )\  (    (()/( (  )\))(  (        //
+//      ((_)\ /((_|()\  )\ )      )\  '(()/(   ((_)()((_) )\ )  ((_)))\((_)()\ )\       //
+//      | |(_|_))( ((_)_(_/(    _((_))  )(_))  _(()((_|_)_(_/(  _| |((_)(()((_|(_)      //
+//      | '_ \ || | '_| ' \))  | '  \()| || |  \ V  V / | ' \)) _` / _ \ V  V (_-<      //
+//      |_.__/\_,_|_| |_||_|   |_|_|_|  \_, |   \_/\_/|_|_||_|\__,_\___/\_/\_//__/      //
+//                                 |__/                                                 //
+//                       Copyright (c) 2021 Simon Schneegans                            //
+//          Released under the GPLv3 or later. See LICENSE file for details.            //
+//////////////////////////////////////////////////////////////////////////////////////////
+
+'use strict';
+
+function standardUniforms() {
+  return `
+  uniform sampler2D uTexture;
+  uniform float     uProgress;
+  uniform float     uTime;
+  uniform int       uSizeX;
+  uniform int       uSizeY;
+  `;
+}
+
+// The noise implementation is from https://www.shadertoy.com/view/3tcBzH
+// (CC-BY-NC-SA).
+function noise() {
+  return `
+  float rand(vec2 co) {
+    return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
+  }
+
+  float hermite(float t) {
+    return t * t * (3.0 - 2.0 * t);
+  }
+
+  float noiseImpl(vec2 co, float frequency) {
+    vec2 v = vec2(co.x * frequency, co.y * frequency);
+
+    float ix1 = floor(v.x);
+    float iy1 = floor(v.y);
+    float ix2 = floor(v.x + 1.0);
+    float iy2 = floor(v.y + 1.0);
+
+    float fx = hermite(fract(v.x));
+    float fy = hermite(fract(v.y));
+
+    float fade1 = mix(rand(vec2(ix1, iy1)), rand(vec2(ix2, iy1)), fx);
+    float fade2 = mix(rand(vec2(ix1, iy2)), rand(vec2(ix2, iy2)), fx);
+
+    return mix(fade1, fade2, fy);
+  }
+
+  float perlinNoise(vec2 co, float freq, int steps, float persistence) {
+    float value = 0.0;
+    float ampl = 1.0;
+    float sum = 0.0;
+
+    for(int i=0 ; i<steps ; i++) {
+      sum += ampl;
+      value += noiseImpl(co, freq) * ampl;
+      freq *= 2.0;
+      ampl *= persistence;
+    }
+
+    return value / sum;
+  }
+  `;
+}
+
+function effectMask() {
+  return `
+  vec2 effectMask(float hideTime, float fadeWidth, float edgeFadeWidth) {
+    float burnProgress      = clamp(uProgress/hideTime, 0, 1);
+    float afterBurnProgress = clamp((uProgress-hideTime)/(1-hideTime), 0, 1);
+
+    // Gradient from top to bottom.
+    float t = cogl_tex_coord_in[0].t * (1 - fadeWidth);
+
+    // Visible part of the window. Gradually dissolves towards the bottom.
+    float windowMask = 1 - clamp((burnProgress - t) / fadeWidth, 0, 1);
+
+    // Gradient from top burning window.
+    float effectMask = clamp(t*(1-windowMask)/burnProgress, 0, 1);
+
+    // Fade-out when the window burned down.
+    if (uProgress > hideTime) {
+      effectMask *= mix(1, 1-t, afterBurnProgress) * pow(1-afterBurnProgress, 2);
+    }
+
+    // Fade at window borders.
+    vec2 pos = cogl_tex_coord_in[0].st * vec2(uSizeX, uSizeY);
+    effectMask *= clamp(pos.x / edgeFadeWidth, 0, 1);
+    effectMask *= clamp(pos.y / edgeFadeWidth, 0, 1);
+    effectMask *= clamp((uSizeX - pos.x) / edgeFadeWidth, 0, 1);
+    effectMask *= clamp((uSizeY - pos.y) / edgeFadeWidth, 0, 1);
+
+    return vec2(windowMask, effectMask);
+  }
+  `;
+}