mirror of
https://github.com/Pomax/BezierInfo-2.git
synced 2025-09-25 15:49:06 +02:00
535 lines
10 KiB
JavaScript
535 lines
10 KiB
JavaScript
import { enrich } from "../lib/enrich.js";
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import { Bezier } from "./types/bezier.js";
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import { Vector } from "./types/vector.js";
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import { Shape } from "./util/shape.js";
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import { Matrix } from "./util/matrix.js";
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import { BaseAPI } from "./base-api.js";
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const MOUSE_PRECISION_ZONE = 5;
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const TOUCH_PRECISION_ZONE = 30;
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let CURRENT_HUE = 0;
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/**
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* Our Graphics API, which is the "public" side of the API.
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*/
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class GraphicsAPI extends BaseAPI {
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static get constants() {
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return [
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`POINTER`,
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`HAND`,
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`PI`,
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`TAU`,
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`POLYGON`,
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`CURVE`,
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`BEZIER`,
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`CENTER`,
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`LEFT`,
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`RIGHT`,
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];
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}
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draw() {
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CURRENT_HUE = 0;
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super.draw();
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}
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get PI() {
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return 3.14159265358979;
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}
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get TAU() {
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return 6.28318530717958;
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}
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get POINTER() {
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return `default`;
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}
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get HAND() {
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return `pointer`;
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}
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get POLYGON() {
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return Shape.POLYGON;
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}
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get CURVE() {
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return Shape.CURVE;
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}
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get BEZIER() {
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return Shape.BEZIER;
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}
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get CENTER() {
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return `center`;
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}
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get LEFT() {
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return `left`;
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}
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get RIGHT() {
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return `right`;
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}
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onMouseDown(evt) {
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super.onMouseDown(evt);
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const cdist = evt.targetTouches
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? TOUCH_PRECISION_ZONE
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: MOUSE_PRECISION_ZONE;
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for (let i = 0, e = this.movable.length, p, d; i < e; i++) {
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p = this.movable[i];
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d = new Vector(p).dist(this.cursor);
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if (d <= cdist) {
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this.currentPoint = p;
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break;
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}
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}
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}
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onMouseMove(evt) {
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super.onMouseMove(evt);
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if (this.currentPoint) {
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this.currentPoint.x = this.cursor.x;
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this.currentPoint.y = this.cursor.y;
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} else {
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for (let i = 0, e = this.movable.length, p; i < e; i++) {
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p = this.movable[i];
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if (new Vector(p).dist(this.cursor) <= 5) {
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this.setCursor(this.HAND);
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return; // NOTE: this is a return, not a break.
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}
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}
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this.setCursor(this.POINTER);
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}
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}
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onMouseUp(evt) {
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super.onMouseUp(evt);
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this.currentPoint = undefined;
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}
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resetMovable(points) {
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this.movable.splice(0, this.movable.length);
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if (points) this.setMovable(points);
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}
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setMovable(points) {
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points.forEach((p) => this.movable.push(p));
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}
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/**
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* transforms: translate
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*/
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translate(x, y) {
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this.ctx.translate(x, y);
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}
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/**
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* transforms: rotate
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*/
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rotate(angle) {
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this.ctx.rotate(angle);
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}
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/**
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* transforms: scale
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*/
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scale(x, y) {
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y = y ? y : x; // NOTE: this turns y=0 into y=x, which is fine. Scaling by 0 is really silly =)
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this.ctx.scale(x, y);
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}
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/**
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* transforms: screen to world
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*/
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screenToWorld(x, y) {
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if (y === undefined) {
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y = x.y;
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x = x.x;
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}
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let M = this.ctx.getTransform().invertSelf();
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let ret = {
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x: x * M.a + y * M.c + M.e,
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y: x * M.b + y * M.d + M.f,
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};
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return ret;
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}
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/**
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* transforms: world to screen
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*/
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worldToScreen(x, y) {
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if (y === undefined) {
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y = x.y;
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x = x.x;
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}
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let M = this.ctx.getTransform();
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let ret = {
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x: x * M.a + y * M.c + M.e,
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y: x * M.b + y * M.d + M.f,
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};
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return ret;
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}
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/**
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* transforms: reset
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*/
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resetTransform() {
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this.ctx.resetTransform();
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}
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/**
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* custom element scoped querySelector
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*/
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find(qs) {
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if (!this.element) return false;
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return enrich(this.element.querySelector(qs));
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}
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/**
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* custom element scoped querySelectorAll
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*/
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findAll(qs) {
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if (!this.element) return false;
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return Array.from(this.element.querySelectorAll(qs)).map((e) => enrich(e));
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}
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/**
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* Set a (CSS) border on the canvas
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*/
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setBorder(width = 1, color = `black`) {
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if (width === false) {
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this.canvas.style.border = `none`;
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} else {
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this.canvas.style.border = `${width}px solid ${color}`;
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}
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}
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/**
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* Set the cursor type while the cursor is over the canvas
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*/
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setCursor(type) {
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this.canvas.style.cursor = type;
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}
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/**
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* Get a random color
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*/
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randomColor(a = 1.0) {
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CURRENT_HUE = (CURRENT_HUE + 73) % 360;
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return `hsla(${CURRENT_HUE},50%,50%,${a})`;
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}
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/**
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* Set the context fillStyle
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*/
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setFill(color) {
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if (color === false) color = `transparent`;
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this.ctx.fillStyle = color;
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}
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/**
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* Convenience alias
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*/
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noFill() {
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this.setFill(false);
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}
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/**
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* Set the context strokeStyle
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*/
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setStroke(color) {
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if (color === false) color = `transparent`;
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this.ctx.strokeStyle = color;
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}
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/**
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* Convenience alias
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*/
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noStroke() {
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this.setStroke(false);
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}
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/**
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* Set the context lineWidth
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*/
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setWidth(width) {
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this.ctx.lineWidth = `${width}px`;
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}
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/**
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* Reset the canvas bitmap to a uniform color.
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*/
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clear(color = `white`) {
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this.ctx.cacheStyle();
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this.resetTransform();
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this.ctx.fillStyle = color;
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this.ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);
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this.ctx.restoreStyle();
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}
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/**
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* Draw a Point (or {x,y,z?} conformant) object on the canvas
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*/
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point(x, y) {
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this.circle(x, y, 5);
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}
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/**
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* Draw a line between two Points
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*/
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line(x1, y1, x2, y2) {
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this.ctx.beginPath();
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this.ctx.moveTo(x1, y1);
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this.ctx.lineTo(x2, y2);
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this.ctx.stroke();
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}
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/**
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* Draw a circle around a Point
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*/
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circle(x, y, r) {
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this.ctx.beginPath();
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this.ctx.arc(x, y, r, 0, this.TAU);
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this.ctx.fill();
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this.ctx.stroke();
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}
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/**
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* Draw text on the canvas
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*/
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text(str, x, y, alignment) {
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if (y === undefined) {
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y = x.y;
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x = x.x;
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}
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const ctx = this.ctx;
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if (alignment) {
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ctx.cacheStyle();
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ctx.textAlign = alignment;
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}
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this.ctx.fillText(str, x, y);
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if (alignment) ctx.restoreStyle();
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}
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/**
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* Draw a rectangle start with {p} in the upper left
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*/
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rect(x, y, w, h) {
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this.ctx.fillRect(x, y, w, h);
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this.ctx.strokeRect(x, y, w, h);
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}
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/**
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* Draw a function plot from [start] to [end] in [steps] steps.
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* Returns the plot shape so that it can be cached for redrawing.
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*/
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plot(fn, start = 0, end = 1, steps = 24) {
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const ctx = this.ctx;
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ctx.cacheStyle();
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ctx.fillStyle = `transparent`;
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const interval = end - start;
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this.start();
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for (let i = 0, e = steps - 1, v; i < steps; i++) {
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v = fn(start + (interval * i) / e);
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this.vertex(v.x, v.y);
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}
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this.end();
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ctx.restoreStyle();
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return this.currentShape;
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}
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/**
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* A signal for starting a complex shape
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*/
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start(type) {
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this.currentShape = new Shape(type || this.POLYGON);
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}
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/**
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* A signal for starting a new segment of a complex shape
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*/
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segment(type, factor) {
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this.currentShape.addSegment(type, factor);
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}
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/**
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* Add a plain point to the current shape
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*/
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vertex(x, y) {
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this.currentShape.vertex({ x, y });
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}
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/**
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* Draw a previously created shape
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*/
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drawShape(shape) {
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this.currentShape = shape;
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this.end();
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}
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/**
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* A signal to draw the current complex shape
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*/
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end() {
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this.ctx.beginPath();
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let { x, y } = this.currentShape.first;
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this.ctx.moveTo(x, y);
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this.currentShape.segments.forEach((s) =>
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this[`draw${s.type}`](s.points, s.factor)
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);
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this.ctx.fill();
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this.ctx.stroke();
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}
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/**
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* Polygon draw function
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*/
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drawPolygon(points) {
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points.forEach((p) => this.ctx.lineTo(p.x, p.y));
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}
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/**
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* Curve draw function, which draws a CR curve as a series of Beziers
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*/
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drawCatmullRom(points, f) {
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// invent a virtual first and last point
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const f0 = points[0],
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f1 = points[1],
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fn = f0.reflect(f1),
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l1 = points[points.length - 2],
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l0 = points[points.length - 1],
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ln = l0.reflect(l1),
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cpoints = [fn, ...points, ln];
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// four point sliding window over the segment
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for (let i = 0, e = cpoints.length - 3; i < e; i++) {
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let [c1, c2, c3, c4] = cpoints.slice(i, i + 4);
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let p2 = {
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x: c2.x + (c3.x - c1.x) / (6 * f),
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y: c2.y + (c3.y - c1.y) / (6 * f),
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};
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let p3 = {
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x: c3.x - (c4.x - c2.x) / (6 * f),
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y: c3.y - (c4.y - c2.y) / (6 * f),
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};
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this.ctx.bezierCurveTo(p2.x, p2.y, p3.x, p3.y, c3.x, c3.y);
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}
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}
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/**
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* Curve draw function, which assumes Bezier coordinates
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*/
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drawBezier(points) {
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for (let i = 0, e = points.length; i < e; i += 3) {
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let [p1, p2, p3] = points.slice(i, i + 3);
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this.ctx.bezierCurveTo(p1.x, p1.y, p2.x, p2.y, p3.x, p3.y);
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}
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}
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/**
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* Yield a snapshot of the current shape.
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*/
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save() {
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return this.currentShape;
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}
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/**
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* convenient grid drawing function
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*/
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drawGrid(division = 20) {
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for (let x = (division / 2) | 0; x < this.width; x += division) {
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this.line({ x, y: 0 }, { x, y: this.height });
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}
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for (let y = (division / 2) | 0; y < this.height; y += division) {
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this.line({ x: 0, y }, { x: this.width, y });
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}
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}
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/**
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* convenient axis drawing function
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*
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* api.drawAxes(pad, "t",0,1, "S","0%","100%");
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*
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*/
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drawAxes(hlabel, hs, he, vlabel, vs, ve, w, h) {
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h = h || this.height;
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w = w || this.width;
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this.line(0, 0, w, 0);
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this.line(0, 0, 0, h);
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const hpos = 0 - 5;
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this.text(`${hlabel} →`, this.width / 2, hpos, this.CENTER);
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this.text(hs, 0, hpos, this.CENTER);
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this.text(he, w, hpos, this.CENTER);
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const vpos = -10;
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this.text(`${vlabel}\n↓`, vpos, this.height / 2, this.RIGHT);
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this.text(vs, vpos, 0 + 5, this.RIGHT);
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this.text(ve, vpos, h, this.RIGHT);
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}
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/**
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* math functions
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*/
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floor(v) {
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return Math.floor(v);
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}
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ceil(v) {
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return Math.ceil(v);
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}
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round(v) {
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return Math.round(v);
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}
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random(v = 1) {
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return Math.random() * v;
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}
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abs(v) {
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return Math.abs(v);
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}
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sin(v) {
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return Math.sin(v);
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}
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cos(v) {
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return Math.cos(v);
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}
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tan(v) {
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return Math.tan(v);
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}
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sqrt(v) {
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return Math.sqrt(v);
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}
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atan2(dy, dx) {
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return Math.atan2(dy, dx);
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}
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pow(v, p) {
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return Math.pow(v, p);
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}
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map(v, s, e, ns, ne, constrain = false) {
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const i1 = e - s,
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i2 = ne - ns,
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p = v - s;
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let r = ns + (p * i2) / i1;
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if (constrain) return this.constrain(r, ns, ne);
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return r;
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}
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constrain(v, s, e) {
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return v < s ? s : v > e ? e : v;
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}
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}
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export { GraphicsAPI, Bezier, Vector, Matrix };
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