sdf-2d/src/drawables/shapes/meta-circle-factory.ts

73 lines
2.1 KiB
TypeScript

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';
import { numberToGlslFloat } from '../../helper/number-to-glsl-float';
/**
* @category Drawable
*/
class MetaCircleBase extends EmptyDrawable {
constructor(
public center: vec2,
public radius: number
) {
super();
}
}
let _id = 0;
/**
* @category Drawable
*/
export const MetaCircleFactory = (
color: vec3 | vec4 | number,
k = 32
): typeof MetaCircleBase => {
class MetaCircle extends MetaCircleBase {
public static descriptor: DrawableDescriptor = {
sdf: {
shader: `
uniform vec2 metaCircleCenters${_id}[META_CIRCLE_COUNT${_id}];
uniform float metaCircleRadii${_id}[META_CIRCLE_COUNT${_id}];
float metaCircleMinDistance${_id}(vec2 target, out vec4 color) {
const float k = ${numberToGlslFloat(k)};
color = ${codeForColorAccess(color)};
float res = 0.0;
for (int i = 0; i < META_CIRCLE_COUNT${_id}; i++) {
float dist = distance(metaCircleCenters${_id}[i], target) - metaCircleRadii${_id}[i];
res += exp2(-k * dist);
}
return -log2(res) / k;
}
`,
distanceFunctionName: `metaCircleMinDistance${_id}`,
},
propertyUniformMapping: {
center: `metaCircleCenters${_id}`,
radius: `metaCircleRadii${_id}`,
},
uniformCountMacroName: `META_CIRCLE_COUNT${_id}`,
shaderCombinationSteps: [0, 1, 2, 3, 8, 16],
empty: new MetaCircle(vec2.create(), 0),
};
public minDistance(target: vec2): number {
return vec2.dist(this.center, target) - this.radius * 2;
}
protected getObjectToSerialize(transform2d: mat2d, transform1d: number): any {
return {
center: vec2.transformMat2d(vec2.create(), this.center, transform2d),
radius: this.radius * transform1d,
};
}
}
_id++;
return MetaCircle;
};