🚚 Move shader code to GLSL files

resources/shaders/energize-b-declarations.glsl

@@ -0,0 +1,66 @@
+// Inject some common shader snippets. It is only possible to include glsl files from the
+// "common" directory. Also, the files in the "common" directory are not allowed to
+// include any further files.
+#include "common/uniforms.glsl"
+#include "common/noise.glsl"
+#include "common/edgeMask.glsl"
+
+uniform vec3 uColor;
+uniform float uScale;
+
+const float SHOWER_TIME  = 0.3;
+const float SHOWER_WIDTH = 0.3;
+const float STREAK_TIME  = 0.6;
+const float EDGE_FADE    = 50;
+
+// This method returns four values:
+//  result.x: A mask for the particles which lead the shower.
+//  result.y: A mask for the streaks which follow the shower particles.
+//  result.z: A mask for the final "atom" particles.
+//  result.w: The opacity of the fading window.
+vec4 getMasks() {
+  float showerProgress = uProgress / SHOWER_TIME;
+  float streakProgress = clamp((uProgress - SHOWER_TIME) / STREAK_TIME, 0, 1);
+  float fadeProgress   = clamp((uProgress - SHOWER_TIME) / (1.0 - SHOWER_TIME), 0, 1);
+
+  // Gradient from top to bottom.
+  float t = cogl_tex_coord_in[0].t;
+
+  // A smooth gradient which moves to the bottom within the showerProgress.
+  float showerMask =
+    smoothstep(1, 0, abs(showerProgress - t - SHOWER_WIDTH) / SHOWER_WIDTH);
+
+  // This is 1 above the streak mask.
+  float streakMask = (showerProgress - t - SHOWER_WIDTH) > 0 ? 1 : 0;
+
+  // Compute mask for the "atom" particles.
+  float atomMask = getRelativeEdgeMask(0.2);
+  atomMask       = max(0, atomMask - showerMask);
+  atomMask *= streakMask;
+  atomMask *= sqrt(1 - fadeProgress * fadeProgress);
+
+  // Make some particles visible in the streaks.
+  showerMask += 0.05 * streakMask;
+
+  // Add shower mask to streak mask.
+  streakMask = max(streakMask, showerMask);
+
+  // Fade-out the masks at the window edges.
+  float edgeFade = getAbsoluteEdgeMask(EDGE_FADE);
+  streakMask *= edgeFade;
+  showerMask *= edgeFade;
+
+  // Fade-out the masks from top to bottom.
+  float fade = smoothstep(0.0, 1.0, 1.0 + t - 2.0 * streakProgress);
+  streakMask *= fade;
+  showerMask *= fade;
+
+  // Compute fading window opacity.
+  float windowMask = pow(1.0 - fadeProgress, 2.0);
+
+  if (uForOpening) {
+    windowMask = 1.0 - windowMask;
+  }
+
+  return vec4(showerMask, streakMask, atomMask, windowMask);
+}