49 lines
1.6 KiB
TypeScript
49 lines
1.6 KiB
TypeScript
import { mat2d, vec2 } from 'gl-matrix';
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import { Drawable } from '../drawable';
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import { DrawableDescriptor } from '../drawable-descriptor';
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export class Circle extends Drawable {
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public static descriptor: DrawableDescriptor = {
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sdf: {
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shader: `
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uniform struct {
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vec2 center;
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float radius;
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}[CIRCLE_COUNT] circles;
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void circleMinDistance(inout float minDistance, inout float color) {
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float myMinDistance = maxMinDistance;
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for (int i = 0; i < CIRCLE_COUNT; i++) {
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float dist = distance(circles[i].center, position) - circles[i].radius;
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myMinDistance = min(myMinDistance, dist);
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}
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minDistance = min(minDistance, myMinDistance);
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color = mix(2.0, color, step(
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distanceNdcPixelSize + SURFACE_OFFSET,
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myMinDistance
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));
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}
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`,
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distanceFunctionName: 'circleMinDistance',
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},
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uniformName: 'circles',
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uniformCountMacroName: 'CIRCLE_COUNT',
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shaderCombinationSteps: [0, 1, 2, 3, 16, 32],
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empty: new Circle(vec2.fromValues(0, 0), 0),
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};
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constructor(public center: vec2, public radius: number) {
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super();
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}
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public minDistance(target: vec2): number {
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return vec2.dist(this.center, target) - this.radius;
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}
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protected getObjectToSerialize(transform2d: mat2d, transform1d: number): any {
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return {
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center: vec2.transformMat2d(vec2.create(), this.center, transform2d),
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radius: this.radius * transform1d,
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};
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}
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}
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