🚚 Move shader code to GLSL files

resources/shaders/energize-a-declarations.glsl

@@ -0,0 +1,49 @@
+// 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 FADE_IN_TIME    = 0.3;
+const float FADE_OUT_TIME   = 0.6;
+const float HEART_FADE_TIME = 0.3;
+const float EDGE_FADE_WIDTH = 50;
+
+// This method returns two values:
+//  result.x: A mask for the particles.
+//  result.y: The opacity of the fading window.
+vec2 getMasks() {
+  float fadeInProgress  = clamp(uProgress / FADE_IN_TIME, 0, 1);
+  float fadeOutProgress = clamp((uProgress - FADE_IN_TIME) / FADE_OUT_TIME, 0, 1);
+  float heartProgress =
+    clamp((uProgress - (1.0 - HEART_FADE_TIME)) / HEART_FADE_TIME, 0, 1);
+
+  // Compute mask for the "atom" particles.
+  float dist     = length(cogl_tex_coord_in[0].st - 0.5) * 4.0;
+  float atomMask = smoothstep(0.0, 1.0, (fadeInProgress * 2.0 - dist + 1.0));
+  atomMask *= fadeInProgress;
+  atomMask *= smoothstep(1.0, 0.0, fadeOutProgress);
+
+  // Fade-out the masks at the window edges.
+  float edgeFade = getAbsoluteEdgeMask(EDGE_FADE_WIDTH);
+  atomMask *= edgeFade;
+
+  float heartMask = getRelativeEdgeMask(0.5);
+  heartMask       = 3.0 * pow(heartMask, 5);
+  heartMask *= fadeOutProgress;
+  heartMask *= 1.0 - heartProgress;
+  atomMask = clamp(heartMask + atomMask, 0, 1);
+
+  // Compute fading window opacity.
+  float windowMask = pow(1.0 - fadeOutProgress, 2.0);
+
+  if (uForOpening) {
+    windowMask = 1.0 - windowMask;
+  }
+
+  return vec2(atomMask, windowMask);
+}