Add hexagons

src/drawables/shapes/hexagon-factory.ts

@@ -0,0 +1,69 @@
+import { mat2d, vec2, vec3, vec4 } from 'gl-matrix';
+import { codeForColorAccess } from '../../helper/code-for-color-access';
+import { DrawableDescriptor } from '../drawable-descriptor';
+import { EmptyDrawable } from '../empty-drawable';
+
+/**
+ * @category Drawable
+ */
+class HexagonBase extends EmptyDrawable {
+  constructor(public center: vec2, public radius: number) {
+    super();
+  }
+}
+
+/**
+ * @category Drawable
+ */
+export const HexagonFactory = (color: vec3 | vec4 | number): typeof HexagonBase => {
+  class Hexagon extends HexagonBase {
+    public static descriptor: DrawableDescriptor = {
+      sdf: {
+        shader: `
+            uniform vec2 hexagonCenters[HEXAGON_COUNT];
+            uniform float hexagonSize[HEXAGON_COUNT];
+  
+            float hexagonMinDistance(vec2 target, out vec4 color) {
+              color = ${codeForColorAccess(color)};
+              float minDistance = 1000.0;
+              for (int i = 0; i < HEXAGON_COUNT; i++) {
+                const vec3 k = vec3(-0.866025404,0.5,0.577350269);
+                float r = hexagonSize[i];
+                vec2 p = abs(target - hexagonCenters[i]);
+                float cosa = 0.8660;
+                float sina = 0.5;
+                p = vec2(cosa * p.x - sina * p.y, sina * p.x + cosa * p.y);
+                p -= 2.0*min(dot(k.xy,p),0.0)*k.xy;
+                p -= vec2(clamp(p.x, -k.z*r, k.z*r), r);
+                float dist = length(p)*sign(p.y);
+                minDistance = min(minDistance, dist);
+              }
+  
+              return minDistance;
+            }
+          `,
+        distanceFunctionName: 'hexagonMinDistance',
+      },
+      propertyUniformMapping: {
+        center: 'hexagonCenters',
+        radius: 'hexagonSize',
+      },
+      uniformCountMacroName: 'HEXAGON_COUNT',
+      shaderCombinationSteps: [0, 1, 2, 3, 8, 16],
+      empty: new Hexagon(vec2.create(), 0),
+    };
+
+    public minDistance(target: vec2): number {
+      return vec2.dist(this.center, target) - this.radius;
+    }
+
+    protected getObjectToSerialize(transform2d: mat2d, transform1d: number): any {
+      return {
+        center: vec2.transformMat2d(vec2.create(), this.center, transform2d),
+        radius: this.radius * transform1d,
+      };
+    }
+  }
+
+  return Hexagon;
+};

src/main.ts

@@ -33,6 +33,7 @@ export * from './drawables/drawable-descriptor';
 export * from './drawables/lights/circle-light';
 export * from './drawables/lights/flashlight';
 export * from './drawables/shapes/circle-factory';
+export * from './drawables/shapes/hexagon-factory';
 export * from './drawables/shapes/colorful-circle';
 export * from './drawables/shapes/droplet-factory';
 export * from './drawables/shapes/inverted-tunnel-factory';