init

assets/shaders/rain.frag

@@ -0,0 +1,15 @@
+#version 450 core
+#include "common.glsl"
+// Thin, slightly bright streak lit by the overcast sky. Premultiplied alpha.
+
+in vec2 vLocal;
+in float vAlpha;
+layout(location = 0) out vec4 fragColor;
+
+void main() {
+    float across = 1.0 - abs(vLocal.x);
+    float along = (1.0 - vLocal.y) * smoothstep(0.0, 0.15, vLocal.y + 0.05);  // bright head, fading tail
+    float a = across * across * along * vAlpha * 0.6;
+    vec3 c = hemiAmbient(vec3(0.0, 1.0, 0.0)) * 2.0 + uSunColor.rgb * uSunDir.w * 0.2;
+    fragColor = vec4(c * a, a);
+}