🚚 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 +1,101 @@
+//////////////////////////////////////////////////////////////////////////////////////////
+//          )                                                   (                       //
+//       ( /(   (  (               )    (       (  (  (         )\ )    (  (            //
+//       )\()) ))\ )(   (         (     )\ )    )\))( )\  (    (()/( (  )\))(  (        //
+//      ((_)\ /((_|()\  )\ )      )\  '(()/(   ((_)()((_) )\ )  ((_)))\((_)()\ )\       //
+//      | |(_|_))( ((_)_(_/(    _((_))  )(_))  _(()((_|_)_(_/(  _| |((_)(()((_|(_)      //
+//      | '_ \ || | '_| ' \))  | '  \()| || |  \ V  V / | ' \)) _` / _ \ V  V (_-<      //
+//      |_.__/\_,_|_| |_||_|   |_|_|_|  \_, |   \_/\_/|_|_||_|\__,_\___/\_/\_//__/      //
+//                                 |__/                                                 //
+//                       Copyright (c) 2021 Simon Schneegans                            //
+//          Released under the GPLv3 or later. See LICENSE file for details.            //
+//////////////////////////////////////////////////////////////////////////////////////////
+
+'use strict';
+
+const {Clutter, GObject} = imports.gi;
+
+const ExtensionUtils = imports.misc.extensionUtils;
+const Me             = imports.misc.extensionUtils.getCurrentExtension();
+const shaderSnippets = Me.imports.src.extension.shaderSnippets;
+
+//////////////////////////////////////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////////////////////////
+
+var FireShader = GObject.registerClass({Properties: {}, Signals: {}},
+                                       class FireShader extends Clutter.ShaderEffect {
+  _init(settings) {
+    super._init({shader_type: Clutter.ShaderType.FRAGMENT_SHADER});
+
+    // Load the gradient values from the settings. We directly inject the values in the
+    // GLSL code below. The shader is compiled once for each window-closing anyways. In
+    // the future, we my want to prevent this frequent recompilations of shaders,
+    // though.
+    const gradient = [];
+    for (let i = 1; i <= 5; i++) {
+      const color = Clutter.Color.from_string(settings.get_string('fire-color-' + i))[1];
+      gradient.push(`vec4(${color.red / 255}, ${color.green / 255}, ${
+          color.blue / 255}, ${color.alpha / 255})`);
+    }
+
+
+    this.set_shader_source(`
+      ${shaderSnippets.standardUniforms()}
+      ${shaderSnippets.noise()}
+      ${shaderSnippets.effectMask()}
+
+      // These may be configurable in the future.
+      const float EDGE_FADE  = 70;
+      const float FADE_WIDTH = 0.1;
+      const float HIDE_TIME  = 0.2;
+      const vec2  FIRE_SCALE = vec2(400, 600) * ${settings.get_double('flame-scale')};
+      const float FIRE_SPEED = ${settings.get_double('flame-movement-speed')};
+
+      vec4 getFireColor(float v) {
+        const float steps[5] = float[](0.0, 0.2, 0.35, 0.5, 0.8);
+        const vec4 colors[5] = vec4[](
+          ${gradient[0]},
+          ${gradient[1]},
+          ${gradient[2]},
+          ${gradient[3]},
+          ${gradient[4]}
+        );
+
+        if (v < steps[0]) {
+          return colors[0];
+        }
+
+        for (int i=0; i<4; ++i) {
+          if (v <= steps[i+1]) {
+            return mix(colors[i], colors[i+1], vec4(v -
+            steps[i])/(steps[i+1]-steps[i]));
+          }
+        }
+
+        return colors[4];
+      }
+
+      void main(void) {
+
+        // Get a noise value.
+        vec2 uv = cogl_tex_coord_in[0].st * vec2(uSizeX, uSizeY) / FIRE_SCALE;
+        uv.y += uTime * FIRE_SPEED;
+        float noise = perlinNoise(uv, 10.0, 5, 0.5);
+
+        // Modulate noise by mask.
+        vec2 effectMask = effectMask(HIDE_TIME, FADE_WIDTH, EDGE_FADE);
+        noise *= effectMask.y;
+
+        // Map noise value to color.
+        vec4 fire = getFireColor(noise);
+        fire.rgb *= fire.a;
+
+        // Get window texture.
+        cogl_color_out = texture2D(uTexture, cogl_tex_coord_in[0].st) * effectMask.x;
+
+        // Add fire.
+        cogl_color_out += fire;
+      }
+    `);
+  };
+});