62 lines
1.9 KiB
TypeScript
62 lines
1.9 KiB
TypeScript
import { mat2d, vec2, vec3, vec4 } from 'gl-matrix';
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import { codeForColorAccess } from '../../helper/code-for-color-access';
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import { DrawableDescriptor } from '../drawable-descriptor';
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import { EmptyDrawable } from '../empty-drawable';
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/**
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* @category Drawable
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*/
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class MetaCircleBase extends EmptyDrawable {
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constructor(public center: vec2, public radius: number) {
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super();
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}
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}
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/**
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* @category Drawable
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*/
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export const MetaCircleFactory = (color: vec3 | vec4 | number): typeof MetaCircleBase => {
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class MetaCircle extends MetaCircleBase {
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public static descriptor: DrawableDescriptor = {
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sdf: {
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shader: `
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uniform vec2 metaCircleCenters[META_CIRCLE_COUNT];
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uniform float metaCircleRadii[META_CIRCLE_COUNT];
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const float k = 32.0;
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float metaCircleMinDistance(vec2 target, out vec4 color) {
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color = ${codeForColorAccess(color)};
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float res = 0.0;
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for (int i = 0; i < META_CIRCLE_COUNT; i++) {
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float dist = distance(metaCircleCenters[i], target) - metaCircleRadii[i];
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res += exp2(-k * dist);
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}
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return -log2(res) / k;
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}
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`,
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distanceFunctionName: 'metaCircleMinDistance',
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},
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propertyUniformMapping: {
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center: 'metaCircleCenters',
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radius: 'metaCircleRadii',
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},
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uniformCountMacroName: 'META_CIRCLE_COUNT',
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shaderCombinationSteps: [0, 1, 2, 3, 8, 16],
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empty: new MetaCircle(vec2.create(), 0),
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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 * 2;
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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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return MetaCircle;
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};
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