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pathfinder/demo2/pathfinder.ts

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// pathfinder/demo2/pathfinder.ts
//
// Copyright © 2018 The Pathfinder Project Developers.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
import COVER_VERTEX_SHADER_SOURCE from "./cover.vs.glsl";
import COVER_FRAGMENT_SHADER_SOURCE from "./cover.fs.glsl";
import STENCIL_VERTEX_SHADER_SOURCE from "./stencil.vs.glsl";
import STENCIL_FRAGMENT_SHADER_SOURCE from "./stencil.fs.glsl";
import SVG from "../resources/svg/Ghostscript_Tiger.svg";
const SVGPath: (path: string) => SVGPath = require('svgpath');
const parseColor: (color: string) => any = require('parse-color');
const SVG_NS: string = "http://www.w3.org/2000/svg";
const TILE_SIZE: number = 16.0;
const STENCIL_FRAMEBUFFER_SIZE: number = TILE_SIZE * 64;
const GLOBAL_OFFSET: Point2D = {x: 200.0, y: 150.0};
const QUAD_VERTEX_POSITIONS: Uint8Array = new Uint8Array([
0, 0,
1, 0,
1, 1,
0, 1,
]);
interface SVGPath {
abs(): SVGPath;
translate(x: number, y: number): SVGPath;
iterate(f: (segment: string[], index: number, x: number, y: number) => string[][] | void):
SVGPath;
}
interface Point2D {
x: number;
y: number;
}
interface Size2D {
width: number;
height: number;
}
interface Rect {
origin: Point2D;
size: Size2D;
}
interface Vector3D {
x: number;
y: number;
z: number;
}
interface Color {
r: number;
g: number;
b: number;
a: number;
}
type Edge = 'left' | 'top' | 'right' | 'bottom';
class App {
private canvas: HTMLCanvasElement;
private svg: XMLDocument;
private gl: WebGL2RenderingContext;
private stencilTexture: WebGLTexture;
private stencilFramebuffer: WebGLFramebuffer;
private coverProgram:
Program<'FramebufferSize' | 'TileSize' | 'StencilTexture' | 'StencilTextureSize',
'TessCoord' | 'TileOrigin' | 'TileIndex' | 'Color'>;
private stencilProgram: Program<'FramebufferSize' | 'TileSize',
'TessCoord' | 'From' | 'To' | 'TileIndex'>;
private quadVertexBuffer: WebGLBuffer;
private stencilVertexPositionsBuffer: WebGLBuffer;
private stencilVertexTileIndicesBuffer: WebGLBuffer;
private stencilVertexArray: WebGLVertexArrayObject;
private coverVertexBuffer: WebGLBuffer;
private coverVertexArray: WebGLVertexArrayObject;
constructor(svg: XMLDocument) {
this.canvas = staticCast(document.getElementById('canvas'), HTMLCanvasElement);
this.svg = svg;
const gl = unwrapNull(this.canvas.getContext('webgl2', {antialias: false}));
this.gl = gl;
gl.getExtension('EXT_color_buffer_float');
this.stencilTexture = unwrapNull(gl.createTexture());
gl.bindTexture(gl.TEXTURE_2D, this.stencilTexture);
gl.texImage2D(gl.TEXTURE_2D,
0,
gl.R16F,
STENCIL_FRAMEBUFFER_SIZE,
STENCIL_FRAMEBUFFER_SIZE,
0,
gl.RED,
gl.HALF_FLOAT,
null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
this.stencilFramebuffer = unwrapNull(gl.createFramebuffer());
gl.bindFramebuffer(gl.FRAMEBUFFER, this.stencilFramebuffer);
gl.framebufferTexture2D(gl.FRAMEBUFFER,
gl.COLOR_ATTACHMENT0,
gl.TEXTURE_2D,
this.stencilTexture,
0);
if (gl.checkFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE)
throw new Error("Stencil framebuffer incomplete!");
const coverProgram = new Program(gl,
COVER_VERTEX_SHADER_SOURCE,
COVER_FRAGMENT_SHADER_SOURCE,
[
'FramebufferSize',
'TileSize',
'StencilTexture',
'StencilTextureSize'
],
['TessCoord', 'TileOrigin', 'TileIndex', 'Color']);
this.coverProgram = coverProgram;
const stencilProgram = new Program(gl,
STENCIL_VERTEX_SHADER_SOURCE,
STENCIL_FRAGMENT_SHADER_SOURCE,
['FramebufferSize', 'TileSize'],
['TessCoord', 'From', 'To', 'TileIndex']);
this.stencilProgram = stencilProgram;
// Initialize quad VBO.
this.quadVertexBuffer = unwrapNull(gl.createBuffer());
gl.bindBuffer(gl.ARRAY_BUFFER, this.quadVertexBuffer);
gl.bufferData(gl.ARRAY_BUFFER, QUAD_VERTEX_POSITIONS, gl.STATIC_DRAW);
// Initialize stencil VBOs.
this.stencilVertexPositionsBuffer = unwrapNull(gl.createBuffer());
this.stencilVertexTileIndicesBuffer = unwrapNull(gl.createBuffer());
// Initialize stencil VAO.
this.stencilVertexArray = unwrapNull(gl.createVertexArray());
gl.bindVertexArray(this.stencilVertexArray);
gl.useProgram(this.stencilProgram.program);
gl.bindBuffer(gl.ARRAY_BUFFER, this.quadVertexBuffer);
gl.vertexAttribPointer(stencilProgram.attributes.TessCoord,
2,
gl.UNSIGNED_BYTE,
false,
0,
0);
gl.bindBuffer(gl.ARRAY_BUFFER, this.stencilVertexPositionsBuffer);
gl.vertexAttribPointer(stencilProgram.attributes.From, 2, gl.FLOAT, false, 16, 0);
gl.vertexAttribDivisor(stencilProgram.attributes.From, 1);
gl.vertexAttribPointer(stencilProgram.attributes.To, 2, gl.FLOAT, false, 16, 8);
gl.vertexAttribDivisor(stencilProgram.attributes.To, 1);
gl.bindBuffer(gl.ARRAY_BUFFER, this.stencilVertexTileIndicesBuffer);
gl.vertexAttribIPointer(stencilProgram.attributes.TileIndex,
1,
gl.UNSIGNED_SHORT,
0,
0);
gl.vertexAttribDivisor(stencilProgram.attributes.TileIndex, 1);
gl.enableVertexAttribArray(stencilProgram.attributes.TessCoord);
gl.enableVertexAttribArray(stencilProgram.attributes.From);
gl.enableVertexAttribArray(stencilProgram.attributes.To);
gl.enableVertexAttribArray(stencilProgram.attributes.TileIndex);
// Initialize cover VBO.
this.coverVertexBuffer = unwrapNull(gl.createBuffer());
// Initialize cover VAO.
this.coverVertexArray = unwrapNull(gl.createVertexArray());
gl.bindVertexArray(this.coverVertexArray);
gl.useProgram(this.coverProgram.program);
gl.bindBuffer(gl.ARRAY_BUFFER, this.quadVertexBuffer);
gl.vertexAttribPointer(coverProgram.attributes.TessCoord,
2,
gl.UNSIGNED_BYTE,
false,
0,
0);
gl.bindBuffer(gl.ARRAY_BUFFER, this.coverVertexBuffer);
gl.vertexAttribPointer(coverProgram.attributes.TileOrigin, 2, gl.SHORT, false, 10, 0);
gl.vertexAttribDivisor(coverProgram.attributes.TileOrigin, 1);
gl.vertexAttribIPointer(coverProgram.attributes.TileIndex, 1, gl.UNSIGNED_SHORT, 10, 4);
gl.vertexAttribDivisor(coverProgram.attributes.TileIndex, 1);
gl.vertexAttribPointer(coverProgram.attributes.Color, 4, gl.UNSIGNED_BYTE, true, 10, 6);
gl.vertexAttribDivisor(coverProgram.attributes.Color, 1);
gl.enableVertexAttribArray(coverProgram.attributes.TessCoord);
gl.enableVertexAttribArray(coverProgram.attributes.TileOrigin);
gl.enableVertexAttribArray(coverProgram.attributes.TileIndex);
gl.enableVertexAttribArray(coverProgram.attributes.Color);
// TODO(pcwalton)
}
run(): void {
const gl = this.gl, canvas = this.canvas;
const scene = new Scene(this.svg);
console.log(scene.tiles.length, "tiles");
// Construct stencil VBOs.
let primitives = 0;
const stencilVertexPositions: number[] = [], stencilVertexTileIndices: number[] = [];
for (let tileIndex = 0; tileIndex < scene.tiles.length; tileIndex++) {
const tile = scene.tiles[tileIndex];
let firstPoint = {x: 0.0, y: 0.0}, lastPoint = {x: 0.0, y: 0.0};
tile.path.iterate(segment => {
let point;
if (segment[0] === 'Z') {
point = firstPoint;
} else {
point = {
x: parseFloat(segment[segment.length - 2]) - tile.origin.x,
y: parseFloat(segment[segment.length - 1]) - tile.origin.y,
};
}
if (!(point.x > -1.0))
throw new Error("x too low");
if (!(point.y > -1.0))
throw new Error("y too low");
if (!(point.x < TILE_SIZE + 1.0))
throw new Error("x too high:" + point.x);
if (!(point.y < TILE_SIZE + 1.0))
throw new Error("y too high");
if (segment[0] === 'M') {
firstPoint = point;
} else {
stencilVertexPositions.push(lastPoint.x, lastPoint.y, point.x, point.y);
stencilVertexTileIndices.push(tileIndex);
primitives++;
}
lastPoint = point;
});
}
console.log(stencilVertexPositions);
// Populate the stencil VBOs.
gl.bindBuffer(gl.ARRAY_BUFFER, this.stencilVertexPositionsBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(stencilVertexPositions), gl.STATIC_DRAW);
gl.bindBuffer(gl.ARRAY_BUFFER, this.stencilVertexTileIndicesBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Uint16Array(stencilVertexTileIndices), gl.STATIC_DRAW);
// Stencil.
gl.bindFramebuffer(gl.FRAMEBUFFER, this.stencilFramebuffer);
gl.viewport(0, 0, STENCIL_FRAMEBUFFER_SIZE, STENCIL_FRAMEBUFFER_SIZE);
gl.clearColor(0.0, 0.0, 0.0, 0.0);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.bindVertexArray(this.stencilVertexArray);
gl.useProgram(this.stencilProgram.program);
gl.uniform2f(this.stencilProgram.uniforms.FramebufferSize,
STENCIL_FRAMEBUFFER_SIZE,
STENCIL_FRAMEBUFFER_SIZE);
gl.uniform2f(this.stencilProgram.uniforms.TileSize, TILE_SIZE, TILE_SIZE);
gl.blendEquation(gl.FUNC_ADD);
gl.blendFunc(gl.ONE, gl.ONE);
gl.enable(gl.BLEND);
gl.drawArraysInstanced(gl.TRIANGLE_FAN, 0, 4, primitives);
gl.disable(gl.BLEND);
// Populate the cover VBO.
const coverVertexBufferData = new Int16Array(scene.tiles.length * 5);
for (let tileIndex = 0; tileIndex < scene.tiles.length; tileIndex++) {
const tile = scene.tiles[tileIndex];
const color = scene.pathColors[tile.pathIndex];
coverVertexBufferData[tileIndex * 5 + 0] = Math.floor(tile.origin.x);
coverVertexBufferData[tileIndex * 5 + 1] = Math.floor(tile.origin.y);
coverVertexBufferData[tileIndex * 5 + 2] = tileIndex;
coverVertexBufferData[tileIndex * 5 + 3] = color.r | (color.g << 8);
coverVertexBufferData[tileIndex * 5 + 4] = color.b | (color.a << 8);
}
gl.bindBuffer(gl.ARRAY_BUFFER, this.coverVertexBuffer);
gl.bufferData(gl.ARRAY_BUFFER, coverVertexBufferData, gl.DYNAMIC_DRAW);
console.log(coverVertexBufferData);
// Cover.
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
const framebufferSize = {width: canvas.width, height: canvas.height};
gl.viewport(0, 0, framebufferSize.width, framebufferSize.height);
gl.clearColor(1.0, 1.0, 1.0, 1.0);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.bindVertexArray(this.coverVertexArray);
gl.useProgram(this.coverProgram.program);
gl.uniform2f(this.coverProgram.uniforms.FramebufferSize,
framebufferSize.width,
framebufferSize.height);
gl.uniform2f(this.coverProgram.uniforms.TileSize, TILE_SIZE, TILE_SIZE);
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, this.stencilTexture);
gl.uniform1i(this.coverProgram.uniforms.StencilTexture, 0);
gl.uniform2f(this.coverProgram.uniforms.StencilTextureSize,
STENCIL_FRAMEBUFFER_SIZE,
STENCIL_FRAMEBUFFER_SIZE);
gl.blendEquation(gl.FUNC_ADD);
gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
gl.enable(gl.BLEND);
gl.drawArraysInstanced(gl.TRIANGLE_FAN, 0, 4, scene.tiles.length);
gl.disable(gl.BLEND);
}
}
class Scene {
tiles: Tile[];
pathColors: Color[];
constructor(svg: XMLDocument) {
const svgElement = unwrapNull(svg.documentElement).cloneNode(true);
document.body.appendChild(svgElement);
const pathElements = Array.from(document.getElementsByTagName('path'));
const tiles: Tile[] = [], pathColors = [];
for (let pathElementIndex = 0;
pathElementIndex < pathElements.length;
pathElementIndex++) {
const pathElement = pathElements[pathElementIndex];
const style = window.getComputedStyle(pathElement);
let paint: string;
if (style.fill != null && style.fill !== 'none') {
paint = style.fill;
/*} else if (style.stroke != null && style.stroke !== 'none') {
paint = style.stroke;*/
} else {
pathColors.push({r: 0, g: 0, b: 0, a: 0});
continue;
}
const color = parseColor(paint).rgba;
pathColors.push({
r: color[0],
g: color[1],
b: color[2],
a: Math.round(color[3] * 255.),
});
let path =
SVGPath(unwrapNull(pathElement.getAttribute('d'))).translate(GLOBAL_OFFSET.x,
GLOBAL_OFFSET.y);
path = canonicalizePath(path);
const boundingRect = this.boundingRectOfPath(path);
/*console.log("path " + pathElementIndex, path.toString(), ":",
boundingRect.origin.x,
boundingRect.origin.y,
boundingRect.size.width,
boundingRect.size.height);*/
let y = boundingRect.origin.y - boundingRect.origin.y % TILE_SIZE;
while (true) {
let x = boundingRect.origin.x - boundingRect.origin.x % TILE_SIZE;
while (true) {
const tileBounds = {
origin: {x, y},
size: {width: TILE_SIZE, height: TILE_SIZE},
};
const tilePath = this.clipPathToRect(path, tileBounds);
if (tilePath.toString().length > 0)
tiles.push(new Tile(pathElementIndex, tilePath, tileBounds.origin));
if (x >= boundingRect.origin.x + boundingRect.size.width)
break;
x += TILE_SIZE;
}
if (y >= boundingRect.origin.y + boundingRect.size.height)
break;
y += TILE_SIZE;
}
}
/*
for (const tile of tiles) {
const newSVG = staticCast(document.createElementNS(SVG_NS, 'svg'), SVGElement);
newSVG.setAttribute('class', "tile");
newSVG.style.left = (GLOBAL_OFFSET.x + tile.origin.x) + "px";
newSVG.style.top = (GLOBAL_OFFSET.y + tile.origin.y) + "px";
newSVG.style.width = TILE_SIZE + "px";
newSVG.style.height = TILE_SIZE + "px";
const newPath = document.createElementNS(SVG_NS, 'path');
newPath.setAttribute('d',
tile.path
.translate(-tile.origin.x, -tile.origin.y)
.toString());
const color = pathColors[tile.pathIndex];
newPath.setAttribute('fill',
"rgba(" + color.r + "," + color.g + "," + color.b + "," +
(color.a / 255.0));
newSVG.appendChild(newPath);
document.body.appendChild(newSVG);
}*/
document.body.removeChild(svgElement);
this.tiles = tiles;
this.pathColors = pathColors;
}
private boundingRectOfPath(path: SVGPath): Rect {
let minX: number | null = null, minY: number | null = null;
let maxX: number | null = null, maxY: number | null = null;
path.iterate(segment => {
for (let i = 1; i < segment.length; i += 2) {
const x = parseFloat(segment[i]), y = parseFloat(segment[i + 1]);
minX = minX == null ? x : Math.min(minX, x);
minY = minY == null ? y : Math.min(minY, y);
maxX = maxX == null ? x : Math.max(maxX, x);
maxY = maxY == null ? y : Math.max(maxY, y);
//console.log("x", x, "y", y, "maxX", maxX, "maxY", maxY, "segment", segment);
}
});
if (minX == null || minY == null || maxX == null || maxY == null)
return {origin: {x: 0, y: 0}, size: {width: 0, height: 0}};
return {origin: {x: minX, y: minY}, size: {width: maxX - minX, height: maxY - minY}};
}
private clipPathToRect(path: SVGPath, tileBounds: Rect): SVGPath {
path = this.clipPathToEdge('left', tileBounds.origin.x, path);
path = this.clipPathToEdge('top', tileBounds.origin.y, path);
path = this.clipPathToEdge('right', tileBounds.origin.x + tileBounds.size.width, path);
path = this.clipPathToEdge('bottom', tileBounds.origin.y + tileBounds.size.height, path);
return path;
}
private clipPathToEdge(edge: Edge, edgePos: number, input: SVGPath): SVGPath {
let pathStart: Point2D | null = null, from = {x: 0, y: 0}, firstPoint = false;
let output: string[][] = [];
input.iterate(segment => {
const event = segment[0];
let to;
switch (event) {
case 'M':
from = {
x: parseFloat(segment[segment.length - 2]),
y: parseFloat(segment[segment.length - 1]),
};
pathStart = from;
firstPoint = true;
return;
case 'Z':
if (pathStart == null)
return;
to = pathStart;
break;
default:
to = {
x: parseFloat(segment[segment.length - 2]),
y: parseFloat(segment[segment.length - 1]),
};
break;
}
if (this.pointIsInside(edge, edgePos, to)) {
if (!this.pointIsInside(edge, edgePos, from)) {
this.addLine(this.computeLineIntersection(edge, edgePos, from, to),
output,
firstPoint);
firstPoint = false;
}
this.addLine(to, output, firstPoint);
firstPoint = false;
} else if (this.pointIsInside(edge, edgePos, from)) {
this.addLine(this.computeLineIntersection(edge, edgePos, from, to),
output,
firstPoint);
firstPoint = false;
}
from = to;
if (event === 'Z') {
output.push(['Z']);
pathStart = null;
}
});
return SVGPath(output.map(segment => segment.join(" ")).join(" "));
}
private addLine(to: Point2D, output: string[][], firstPoint: boolean) {
if (firstPoint)
output.push(['M', "" + to.x, "" + to.y]);
else
output.push(['L', "" + to.x, "" + to.y]);
}
private pointIsInside(edge: Edge, edgePos: number, point: Point2D): boolean {
switch (edge) {
case 'left': return point.x >= edgePos;
case 'top': return point.y >= edgePos;
case 'right': return point.x <= edgePos;
case 'bottom': return point.y <= edgePos;
}
}
private computeLineIntersection(edge: Edge,
edgePos: number,
startPoint: Point2D,
endpoint: Point2D):
Point2D {
const start = {x: startPoint.x, y: startPoint.y, z: 1.0};
const end = {x: endpoint.x, y: endpoint.y, z: 1.0};
let edgeVector: Vector3D;
switch (edge) {
case 'left':
case 'right':
edgeVector = {x: 1.0, y: 0.0, z: -edgePos};
break;
default:
edgeVector = {x: 0.0, y: 1.0, z: -edgePos};
break;
}
const intersection = cross(cross(start, end), edgeVector);
return {x: intersection.x / intersection.z, y: intersection.y / intersection.z};
}
}
class Tile {
pathIndex: number;
path: SVGPath;
origin: Point2D;
constructor(pathIndex: number, path: SVGPath, origin: Point2D) {
this.pathIndex = pathIndex;
this.path = path;
this.origin = origin;
}
}
class Program<U extends string, A extends string> {
program: WebGLProgram;
uniforms: {[key in U]: WebGLUniformLocation};
attributes: {[key in A]: number};
private vertexShader: WebGLShader;
private fragmentShader: WebGLShader;
constructor(gl: WebGL2RenderingContext,
vertexShaderSource: string,
fragmentShaderSource: string,
uniformNames: U[],
attributeNames: A[]) {
this.vertexShader = unwrapNull(gl.createShader(gl.VERTEX_SHADER));
gl.shaderSource(this.vertexShader, vertexShaderSource);
gl.compileShader(this.vertexShader);
if (!gl.getShaderParameter(this.vertexShader, gl.COMPILE_STATUS)) {
console.error(gl.getShaderInfoLog(this.vertexShader));
throw new Error("Vertex shader compilation failed!");
}
this.fragmentShader = unwrapNull(gl.createShader(gl.FRAGMENT_SHADER));
gl.shaderSource(this.fragmentShader, fragmentShaderSource);
gl.compileShader(this.fragmentShader);
if (!gl.getShaderParameter(this.fragmentShader, gl.COMPILE_STATUS)) {
console.error(gl.getShaderInfoLog(this.fragmentShader));
throw new Error("Fragment shader compilation failed!");
}
this.program = unwrapNull(gl.createProgram());
gl.attachShader(this.program, this.vertexShader);
gl.attachShader(this.program, this.fragmentShader);
gl.linkProgram(this.program);
if (!gl.getProgramParameter(this.program, gl.LINK_STATUS)) {
console.error(gl.getProgramInfoLog(this.program));
throw new Error("Program linking failed!");
}
const uniforms: {[key in U]?: WebGLUniformLocation} = {};
for (const uniformName of uniformNames) {
uniforms[uniformName] = unwrapNull(gl.getUniformLocation(this.program,
"u" + uniformName));
}
this.uniforms = uniforms as {[key in U]: WebGLUniformLocation};
const attributes: {[key in A]?: number} = {};
for (const attributeName of attributeNames) {
attributes[attributeName] = unwrapNull(gl.getAttribLocation(this.program,
"a" + attributeName));
}
this.attributes = attributes as {[key in A]: number};
}
}
function canonicalizePath(path: SVGPath): SVGPath {
return path.abs().iterate(segment => {
if (segment[0] === 'H')
return [['L', segment[1], '0']];
if (segment[0] === 'V')
return [['L', '0', segment[1]]];
return [segment];
});
}
function cross(a: Vector3D, b: Vector3D): Vector3D {
return {
x: a.y*b.z - a.z*b.y,
y: a.z*b.x - a.x*b.z,
z: a.x*b.y - a.y*b.x,
};
}
function main(): void {
window.fetch(SVG).then(svg => {
svg.text().then(svgText => {
const svg = staticCast((new DOMParser).parseFromString(svgText, 'image/svg+xml'),
XMLDocument);
try {
new App(svg).run();
} catch (e) {
console.error("error", e, e.stack);
}
});
});
}
document.addEventListener('DOMContentLoaded', () => main(), false);
function staticCast<T>(value: any, constructor: { new(...args: any[]): T }): T {
if (!(value instanceof constructor))
throw new Error("Invalid dynamic cast");
return value;
}
function unwrapNull<T>(value: T | null): T {
if (value == null)
throw new Error("Unexpected null");
return value;
}
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