🚚 Move shader code to GLSL files

resources/shaders/matrix.glsl

@@ -0,0 +1,32 @@
+vec2 coords = cogl_tex_coord_in[0].st;
+coords.y    = coords.y * (uOverShoot + 1.0) - uOverShoot * 0.5;
+
+// Get a cool matrix effect. See comments for those methods above.
+vec2 rainMask  = getRain(coords);
+float textMask = getText(coords);
+
+// Get the window texture.
+cogl_color_out = texture2D(uTexture, coords);
+
+// Shell.GLSLEffect uses straight alpha. So we have to convert from premultiplied.
+if (cogl_color_out.a > 0) {
+  cogl_color_out.rgb /= cogl_color_out.a;
+}
+
+// Fade the window according to the effect mask.
+cogl_color_out.a *= rainMask.y;
+
+// This is used to fade out the remaining trails in the end.
+float finalFade =
+  1 - clamp((uProgress - FINAL_FADE_START_TIME) / (1 - FINAL_FADE_START_TIME), 0, 1);
+float rainAlpha = finalFade * rainMask.x;
+
+// Add the matrix effect to the window.
+vec4 text =
+  vec4(mix(uTrailColor, uTipColor, min(1, pow(rainAlpha + 0.1, 4))), rainAlpha* textMask);
+cogl_color_out = alphaOver(cogl_color_out, text);
+
+// These are pretty useful for understanding how this works.
+// cogl_color_out = vec4(vec3(textMask), 1);
+// cogl_color_out = vec4(vec3(rainMask.x), 1);
+// cogl_color_out = vec4(vec3(rainMask.y), 1);