🔧 Tweak effect

src/shaderSnippets.js

@@ -33,6 +33,24 @@ function standardUniforms() {
   `;
 }
 
+function math2D() {
+  return `
+  float distToLine(vec2 origin, vec2 direction, vec2 point) {
+    vec2 perpendicular = vec2(direction.y, -direction.x);
+    return abs(dot(normalize(perpendicular), origin - point));
+  }
+
+  float getWinding(vec2 a, vec2 b) {
+    return cross(vec3(a, 0.0), vec3(b, 0.0)).z;
+  }
+
+  vec2 rotate(vec2 a, float angle) {
+    return vec2(a.x * cos(angle) - a.y * sin(angle),
+                a.x * sin(angle) + a.y * cos(angle));
+  }
+  `;
+}
+
 // This method returns a mask which smoothly transitions towards zero when approaching
 // the window's borders. There is a variant which takes the transition area width in
 // pixels and one which takes this as a percentage.