apix/Image_editor_example/image_editor_modules/curve.js
2025-11-29 22:08:42 +07:00

493 lines
16 KiB
JavaScript

import { clamp01 } from "./color.js";
const CHANNEL_COLORS = {
rgb: "#ffffff",
r: "#ff7070",
g: "#70ffa0",
b: "#72a0ff"
};
export class CurveEditor {
constructor({ canvas, channelButtons = [], resetButton, onChange, onCommit }) {
this.canvas = canvas;
this.ctx = canvas.getContext("2d");
this.channelButtons = channelButtons;
this.resetButton = resetButton;
this.onChange = onChange;
this.onCommit = onCommit;
this.channels = ["rgb", "r", "g", "b"];
this.activeChannel = "rgb";
this.curves = this.createDefaultCurves();
this.curveTangents = {};
this.channels.forEach(channel => (this.curveTangents[channel] = []));
this.luts = this.buildAllLUTs();
this.isDragging = false;
this.dragIndex = null;
this.curveDirty = false;
this.displayWidth = this.canvas.clientWidth || 240;
this.displayHeight = this.canvas.clientHeight || 240;
this.resizeObserver = null;
this.handleResize = this.handleResize.bind(this);
this.onPointerDown = this.onPointerDown.bind(this);
this.onPointerMove = this.onPointerMove.bind(this);
this.onPointerUp = this.onPointerUp.bind(this);
this.onDoubleClick = this.onDoubleClick.bind(this);
window.addEventListener("resize", this.handleResize);
this.canvas.addEventListener("mousedown", this.onPointerDown);
window.addEventListener("mousemove", this.onPointerMove);
window.addEventListener("mouseup", this.onPointerUp);
this.canvas.addEventListener("dblclick", this.onDoubleClick);
this.attachChannelButtons();
this.attachResetButton();
this.handleResize();
if (window.ResizeObserver) {
this.resizeObserver = new ResizeObserver(() => this.handleResize());
this.resizeObserver.observe(this.canvas);
}
this.draw();
}
destroy() {
this.resizeObserver?.disconnect();
window.removeEventListener("resize", this.handleResize);
this.canvas.removeEventListener("mousedown", this.onPointerDown);
window.removeEventListener("mousemove", this.onPointerMove);
window.removeEventListener("mouseup", this.onPointerUp);
this.canvas.removeEventListener("dblclick", this.onDoubleClick);
}
attachChannelButtons() {
this.channelButtons.forEach(btn => {
btn.addEventListener("click", () => {
const channel = btn.dataset.curveChannel;
if (channel && this.channels.includes(channel)) {
this.activeChannel = channel;
this.updateChannelButtons();
this.draw();
}
});
});
this.updateChannelButtons();
}
attachResetButton() {
if (!this.resetButton) return;
this.resetButton.addEventListener("click", () => {
this.resetChannel(this.activeChannel);
this.notifyChange();
this.notifyCommit();
});
}
updateChannelButtons() {
this.channelButtons.forEach(btn => {
const channel = btn.dataset.curveChannel;
btn.classList.toggle("active", channel === this.activeChannel);
});
}
handleResize() {
const rect = this.canvas.getBoundingClientRect();
const width = Math.max(1, rect.width || 240);
const height = Math.max(1, rect.height || 240);
this.displayWidth = width;
this.displayHeight = height;
const dpr = window.devicePixelRatio || 1;
this.canvas.width = width * dpr;
this.canvas.height = height * dpr;
this.ctx.setTransform(1, 0, 0, 1, 0, 0);
this.ctx.scale(dpr, dpr);
this.draw();
}
createDefaultCurve() {
return [
{ x: 0, y: 0 },
{ x: 1, y: 1 }
];
}
createDefaultCurves() {
return {
rgb: this.createDefaultCurve().map(p => ({ ...p })),
r: this.createDefaultCurve().map(p => ({ ...p })),
g: this.createDefaultCurve().map(p => ({ ...p })),
b: this.createDefaultCurve().map(p => ({ ...p }))
};
}
cloneCurves(source = this.curves) {
const clone = {};
this.channels.forEach(channel => {
clone[channel] = (source[channel] || this.createDefaultCurve()).map(p => ({ x: p.x, y: p.y }));
});
return clone;
}
setState(state) {
if (!state) return;
const incoming = this.cloneCurves(state.curves || {});
this.curves = incoming;
if (state.activeChannel && this.channels.includes(state.activeChannel)) {
this.activeChannel = state.activeChannel;
}
this.rebuildAllLUTs();
this.updateChannelButtons();
this.draw();
}
getState() {
return {
curves: this.cloneCurves(),
activeChannel: this.activeChannel
};
}
resetChannel(channel, emit = false) {
if (!this.channels.includes(channel)) return;
this.curves[channel] = this.createDefaultCurve().map(p => ({ ...p }));
this.rebuildChannelLUT(channel);
this.draw();
if (emit) {
this.notifyChange();
this.notifyCommit();
this.curveDirty = false;
}
}
resetAll(emit = true) {
this.channels.forEach(channel => {
this.curves[channel] = this.createDefaultCurve().map(p => ({ ...p }));
});
this.rebuildAllLUTs();
this.draw();
if (emit) {
this.notifyChange();
this.notifyCommit();
this.curveDirty = false;
}
}
hasAdjustments() {
return this.channels.some(channel => !this.isDefaultCurve(this.curves[channel]));
}
isDefaultCurve(curve) {
if (!curve || curve.length !== 2) return false;
const [start, end] = curve;
const epsilon = 0.0001;
return Math.abs(start.x) < epsilon && Math.abs(start.y) < epsilon &&
Math.abs(end.x - 1) < epsilon && Math.abs(end.y - 1) < epsilon;
}
notifyChange() {
this.onChange?.();
}
notifyCommit() {
this.onCommit?.();
}
getLUTPack() {
return {
rgb: this.isDefaultCurve(this.curves.rgb) ? null : this.luts.rgb,
r: this.isDefaultCurve(this.curves.r) ? null : this.luts.r,
g: this.isDefaultCurve(this.curves.g) ? null : this.luts.g,
b: this.isDefaultCurve(this.curves.b) ? null : this.luts.b,
hasAdjustments: this.hasAdjustments()
};
}
buildAllLUTs() {
const result = {};
this.channels.forEach(channel => {
const curve = this.curves[channel];
const tangents = this.computeTangents(curve);
this.curveTangents[channel] = tangents;
result[channel] = this.buildCurveLUT(curve, tangents);
});
return result;
}
rebuildAllLUTs() {
this.luts = this.buildAllLUTs();
}
rebuildChannelLUT(channel) {
const curve = this.curves[channel];
const tangents = this.computeTangents(curve);
this.curveTangents[channel] = tangents;
this.luts[channel] = this.buildCurveLUT(curve, tangents);
}
buildCurveLUT(curve, tangents = null) {
const curveTangents = tangents || this.computeTangents(curve);
const lut = new Uint8ClampedArray(256);
for (let i = 0; i < 256; i++) {
const pos = i / 255;
lut[i] = Math.round(clamp01(this.sampleSmoothCurve(curve, pos, curveTangents)) * 255);
}
return lut;
}
computeTangents(curve) {
const n = curve.length;
if (n < 2) return new Array(n).fill(0);
const tangents = new Array(n).fill(0);
const delta = new Array(n - 1).fill(0);
const dx = new Array(n - 1).fill(0);
for (let i = 0; i < n - 1; i++) {
dx[i] = Math.max(1e-6, curve[i + 1].x - curve[i].x);
delta[i] = (curve[i + 1].y - curve[i].y) / dx[i];
}
tangents[0] = delta[0];
tangents[n - 1] = delta[n - 2];
for (let i = 1; i < n - 1; i++) {
if (delta[i - 1] * delta[i] <= 0) {
tangents[i] = 0;
} else {
const w1 = 2 * dx[i] + dx[i - 1];
const w2 = dx[i] + 2 * dx[i - 1];
tangents[i] = (w1 + w2) / (w1 / delta[i - 1] + w2 / delta[i]);
}
}
for (let i = 0; i < n - 1; i++) {
if (Math.abs(delta[i]) < 1e-6) {
tangents[i] = 0;
tangents[i + 1] = 0;
} else {
let alpha = tangents[i] / delta[i];
let beta = tangents[i + 1] / delta[i];
const sum = alpha * alpha + beta * beta;
if (sum > 9) {
const tau = 3 / Math.sqrt(sum);
alpha *= tau;
beta *= tau;
tangents[i] = alpha * delta[i];
tangents[i + 1] = beta * delta[i];
}
}
}
return tangents;
}
sampleSmoothCurve(curve, t, tangents) {
if (!curve || curve.length === 0) return t;
const n = curve.length;
if (!tangents || tangents.length !== n) {
tangents = this.computeTangents(curve);
}
if (t <= curve[0].x) return curve[0].y;
if (t >= curve[n - 1].x) return curve[n - 1].y;
let idx = 1;
for (; idx < n; idx++) {
if (t <= curve[idx].x) break;
}
const p0 = curve[idx - 1];
const p1 = curve[idx];
const m0 = tangents[idx - 1] ?? 0;
const m1 = tangents[idx] ?? 0;
const span = p1.x - p0.x || 1e-6;
const u = (t - p0.x) / span;
const h00 = (2 * u ** 3) - (3 * u ** 2) + 1;
const h10 = u ** 3 - 2 * u ** 2 + u;
const h01 = (-2 * u ** 3) + (3 * u ** 2);
const h11 = u ** 3 - u ** 2;
const value = h00 * p0.y + h10 * span * m0 + h01 * p1.y + h11 * span * m1;
return clamp01(value);
}
getActiveCurve() {
return this.curves[this.activeChannel];
}
addPoint(x, y) {
const points = this.getActiveCurve();
let insertIndex = points.findIndex(point => x < point.x);
if (insertIndex === -1) {
points.push({ x, y });
insertIndex = points.length - 1;
} else {
points.splice(insertIndex, 0, { x, y });
}
this.rebuildChannelLUT(this.activeChannel);
this.draw();
this.curveDirty = true;
this.notifyChange();
return insertIndex;
}
updatePoint(index, x, y) {
const points = this.getActiveCurve();
const point = points[index];
if (!point) return;
const originalX = point.x;
const originalY = point.y;
if (index === 0) {
point.x = 0;
point.y = clamp01(y);
} else if (index === points.length - 1) {
point.x = 1;
point.y = clamp01(y);
} else {
const minX = points[index - 1].x + 0.01;
const maxX = points[index + 1].x - 0.01;
point.x = clamp01(Math.min(Math.max(x, minX), maxX));
point.y = clamp01(y);
}
if (Math.abs(originalX - point.x) < 0.0001 && Math.abs(originalY - point.y) < 0.0001) {
return;
}
this.rebuildChannelLUT(this.activeChannel);
this.draw();
this.curveDirty = true;
this.notifyChange();
}
removePoint(index) {
const points = this.getActiveCurve();
if (index <= 0 || index >= points.length - 1) return;
points.splice(index, 1);
this.rebuildChannelLUT(this.activeChannel);
this.draw();
this.notifyChange();
this.notifyCommit();
this.curveDirty = false;
}
getPointerPosition(event) {
const rect = this.canvas.getBoundingClientRect();
if (!rect.width || !rect.height) return null;
const x = clamp01((event.clientX - rect.left) / rect.width);
const y = clamp01(1 - (event.clientY - rect.top) / rect.height);
return { x, y };
}
findPointIndex(pos, threshold = 10) {
if (!pos) return -1;
const points = this.getActiveCurve();
const targetX = pos.x * this.displayWidth;
const targetY = (1 - pos.y) * this.displayHeight;
for (let i = 0; i < points.length; i++) {
const pt = points[i];
const px = pt.x * this.displayWidth;
const py = (1 - pt.y) * this.displayHeight;
const dist = Math.hypot(px - targetX, py - targetY);
if (dist <= threshold) return i;
}
return -1;
}
onPointerDown(event) {
if (event.button !== 0) return;
const pos = this.getPointerPosition(event);
if (!pos) return;
event.preventDefault();
let idx = this.findPointIndex(pos);
if (idx === -1) {
idx = this.addPoint(pos.x, pos.y);
}
this.dragIndex = idx;
this.isDragging = true;
this.updatePoint(idx, pos.x, pos.y);
}
onPointerMove(event) {
if (!this.isDragging || this.dragIndex === null) return;
const pos = this.getPointerPosition(event);
if (!pos) return;
event.preventDefault();
this.updatePoint(this.dragIndex, pos.x, pos.y);
}
onPointerUp() {
if (!this.isDragging) return;
this.isDragging = false;
this.dragIndex = null;
if (this.curveDirty) {
this.curveDirty = false;
this.notifyCommit();
}
}
onDoubleClick(event) {
const pos = this.getPointerPosition(event);
if (!pos) return;
const idx = this.findPointIndex(pos, 8);
if (idx > 0 && idx < this.getActiveCurve().length - 1) {
this.removePoint(idx);
}
}
getChannelColor() {
return CHANNEL_COLORS[this.activeChannel] || "#ffffff";
}
draw() {
if (!this.ctx) return;
const ctx = this.ctx;
const w = this.displayWidth;
const h = this.displayHeight;
ctx.clearRect(0, 0, w, h);
this.drawGrid(ctx, w, h);
this.drawCurve(ctx, w, h);
this.drawPoints(ctx, w, h);
}
drawGrid(ctx, w, h) {
ctx.fillStyle = "rgba(0,0,0,0.5)";
ctx.fillRect(0, 0, w, h);
ctx.strokeStyle = "rgba(255,255,255,0.08)";
ctx.lineWidth = 1;
for (let i = 1; i < 4; i++) {
const x = (w / 4) * i;
const y = (h / 4) * i;
ctx.beginPath();
ctx.moveTo(x, 0);
ctx.lineTo(x, h);
ctx.stroke();
ctx.beginPath();
ctx.moveTo(0, y);
ctx.lineTo(w, y);
ctx.stroke();
}
}
drawCurve(ctx, w, h) {
const points = this.getActiveCurve();
if (!points?.length) return;
const tangents = this.curveTangents[this.activeChannel] || this.computeTangents(points);
ctx.strokeStyle = this.getChannelColor();
ctx.lineWidth = 2;
ctx.beginPath();
const steps = 128;
for (let i = 0; i <= steps; i++) {
const t = i / steps;
const value = this.sampleSmoothCurve(points, t, tangents);
const x = t * w;
const y = (1 - value) * h;
if (i === 0) ctx.moveTo(x, y);
else ctx.lineTo(x, y);
}
ctx.stroke();
}
drawPoints(ctx, w, h) {
const points = this.getActiveCurve();
ctx.fillStyle = "#000";
ctx.lineWidth = 2;
ctx.strokeStyle = this.getChannelColor();
points.forEach(pt => {
const x = pt.x * w;
const y = (1 - pt.y) * h;
ctx.beginPath();
ctx.arc(x, y, 5, 0, Math.PI * 2);
ctx.fill();
ctx.stroke();
});
}
}