Files
excalidraw/packages/excalidraw/renderer/helpers.ts
zsviczian 320af405e9 fix: move elementCenterPoint from common/src/utils.ts to element/src/bounds.ts (#9647)
move elementCenterPoint from utils to bounds.ts
2025-06-14 12:49:22 +02:00

430 lines
13 KiB
TypeScript

import { THEME, THEME_FILTER } from "@excalidraw/common";
import { FIXED_BINDING_DISTANCE } from "@excalidraw/element";
import { getDiamondPoints } from "@excalidraw/element";
import { elementCenterPoint, getCornerRadius } from "@excalidraw/element";
import {
curve,
curveCatmullRomCubicApproxPoints,
curveCatmullRomQuadraticApproxPoints,
curveOffsetPoints,
type GlobalPoint,
offsetPointsForQuadraticBezier,
pointFrom,
pointRotateRads,
} from "@excalidraw/math";
import type {
ElementsMap,
ExcalidrawDiamondElement,
ExcalidrawRectanguloidElement,
} from "@excalidraw/element/types";
import type { StaticCanvasRenderConfig } from "../scene/types";
import type { AppState, StaticCanvasAppState } from "../types";
export const fillCircle = (
context: CanvasRenderingContext2D,
cx: number,
cy: number,
radius: number,
stroke: boolean,
fill = true,
) => {
context.beginPath();
context.arc(cx, cy, radius, 0, Math.PI * 2);
if (fill) {
context.fill();
}
if (stroke) {
context.stroke();
}
};
export const getNormalizedCanvasDimensions = (
canvas: HTMLCanvasElement,
scale: number,
): [number, number] => {
// When doing calculations based on canvas width we should used normalized one
return [canvas.width / scale, canvas.height / scale];
};
export const bootstrapCanvas = ({
canvas,
scale,
normalizedWidth,
normalizedHeight,
theme,
isExporting,
viewBackgroundColor,
}: {
canvas: HTMLCanvasElement;
scale: number;
normalizedWidth: number;
normalizedHeight: number;
theme?: AppState["theme"];
isExporting?: StaticCanvasRenderConfig["isExporting"];
viewBackgroundColor?: StaticCanvasAppState["viewBackgroundColor"];
}): CanvasRenderingContext2D => {
const context = canvas.getContext("2d")!;
context.setTransform(1, 0, 0, 1, 0, 0);
context.scale(scale, scale);
if (isExporting && theme === THEME.DARK) {
context.filter = THEME_FILTER;
}
// Paint background
if (typeof viewBackgroundColor === "string") {
const hasTransparence =
viewBackgroundColor === "transparent" ||
viewBackgroundColor.length === 5 || // #RGBA
viewBackgroundColor.length === 9 || // #RRGGBBA
/(hsla|rgba)\(/.test(viewBackgroundColor);
if (hasTransparence) {
context.clearRect(0, 0, normalizedWidth, normalizedHeight);
}
context.save();
context.fillStyle = viewBackgroundColor;
context.fillRect(0, 0, normalizedWidth, normalizedHeight);
context.restore();
} else {
context.clearRect(0, 0, normalizedWidth, normalizedHeight);
}
return context;
};
function drawCatmullRomQuadraticApprox(
ctx: CanvasRenderingContext2D,
points: GlobalPoint[],
tension = 0.5,
) {
const pointSets = curveCatmullRomQuadraticApproxPoints(points, tension);
if (pointSets) {
for (let i = 0; i < pointSets.length - 1; i++) {
const [[cpX, cpY], [p2X, p2Y]] = pointSets[i];
ctx.quadraticCurveTo(cpX, cpY, p2X, p2Y);
}
}
}
function drawCatmullRomCubicApprox(
ctx: CanvasRenderingContext2D,
points: GlobalPoint[],
tension = 0.5,
) {
const pointSets = curveCatmullRomCubicApproxPoints(points, tension);
if (pointSets) {
for (let i = 0; i < pointSets.length; i++) {
const [[cp1x, cp1y], [cp2x, cp2y], [x, y]] = pointSets[i];
ctx.bezierCurveTo(cp1x, cp1y, cp2x, cp2y, x, y);
}
}
}
export const drawHighlightForRectWithRotation = (
context: CanvasRenderingContext2D,
element: ExcalidrawRectanguloidElement,
elementsMap: ElementsMap,
padding: number,
) => {
const [x, y] = pointRotateRads(
pointFrom<GlobalPoint>(element.x, element.y),
elementCenterPoint(element, elementsMap),
element.angle,
);
context.save();
context.translate(x, y);
context.rotate(element.angle);
let radius = getCornerRadius(
Math.min(element.width, element.height),
element,
);
if (radius === 0) {
radius = 0.01;
}
context.beginPath();
{
const topLeftApprox = offsetPointsForQuadraticBezier(
pointFrom(0, 0 + radius),
pointFrom(0, 0),
pointFrom(0 + radius, 0),
padding,
);
const topRightApprox = offsetPointsForQuadraticBezier(
pointFrom(element.width - radius, 0),
pointFrom(element.width, 0),
pointFrom(element.width, radius),
padding,
);
const bottomRightApprox = offsetPointsForQuadraticBezier(
pointFrom(element.width, element.height - radius),
pointFrom(element.width, element.height),
pointFrom(element.width - radius, element.height),
padding,
);
const bottomLeftApprox = offsetPointsForQuadraticBezier(
pointFrom(radius, element.height),
pointFrom(0, element.height),
pointFrom(0, element.height - radius),
padding,
);
context.moveTo(
topLeftApprox[topLeftApprox.length - 1][0],
topLeftApprox[topLeftApprox.length - 1][1],
);
context.lineTo(topRightApprox[0][0], topRightApprox[0][1]);
drawCatmullRomQuadraticApprox(context, topRightApprox);
context.lineTo(bottomRightApprox[0][0], bottomRightApprox[0][1]);
drawCatmullRomQuadraticApprox(context, bottomRightApprox);
context.lineTo(bottomLeftApprox[0][0], bottomLeftApprox[0][1]);
drawCatmullRomQuadraticApprox(context, bottomLeftApprox);
context.lineTo(topLeftApprox[0][0], topLeftApprox[0][1]);
drawCatmullRomQuadraticApprox(context, topLeftApprox);
}
// Counter-clockwise for the cutout in the middle. We need to have an "inverse
// mask" on a filled shape for the diamond highlight, because stroking creates
// sharp inset edges on line joins < 90 degrees.
{
const topLeftApprox = offsetPointsForQuadraticBezier(
pointFrom(0 + radius, 0),
pointFrom(0, 0),
pointFrom(0, 0 + radius),
-FIXED_BINDING_DISTANCE,
);
const topRightApprox = offsetPointsForQuadraticBezier(
pointFrom(element.width, radius),
pointFrom(element.width, 0),
pointFrom(element.width - radius, 0),
-FIXED_BINDING_DISTANCE,
);
const bottomRightApprox = offsetPointsForQuadraticBezier(
pointFrom(element.width - radius, element.height),
pointFrom(element.width, element.height),
pointFrom(element.width, element.height - radius),
-FIXED_BINDING_DISTANCE,
);
const bottomLeftApprox = offsetPointsForQuadraticBezier(
pointFrom(0, element.height - radius),
pointFrom(0, element.height),
pointFrom(radius, element.height),
-FIXED_BINDING_DISTANCE,
);
context.moveTo(
topLeftApprox[topLeftApprox.length - 1][0],
topLeftApprox[topLeftApprox.length - 1][1],
);
context.lineTo(bottomLeftApprox[0][0], bottomLeftApprox[0][1]);
drawCatmullRomQuadraticApprox(context, bottomLeftApprox);
context.lineTo(bottomRightApprox[0][0], bottomRightApprox[0][1]);
drawCatmullRomQuadraticApprox(context, bottomRightApprox);
context.lineTo(topRightApprox[0][0], topRightApprox[0][1]);
drawCatmullRomQuadraticApprox(context, topRightApprox);
context.lineTo(topLeftApprox[0][0], topLeftApprox[0][1]);
drawCatmullRomQuadraticApprox(context, topLeftApprox);
}
context.closePath();
context.fill();
context.restore();
};
export const strokeEllipseWithRotation = (
context: CanvasRenderingContext2D,
width: number,
height: number,
cx: number,
cy: number,
angle: number,
) => {
context.beginPath();
context.ellipse(cx, cy, width / 2, height / 2, angle, 0, Math.PI * 2);
context.stroke();
};
export const strokeRectWithRotation = (
context: CanvasRenderingContext2D,
x: number,
y: number,
width: number,
height: number,
cx: number,
cy: number,
angle: number,
fill: boolean = false,
/** should account for zoom */
radius: number = 0,
) => {
context.save();
context.translate(cx, cy);
context.rotate(angle);
if (fill) {
context.fillRect(x - cx, y - cy, width, height);
}
if (radius && context.roundRect) {
context.beginPath();
context.roundRect(x - cx, y - cy, width, height, radius);
context.stroke();
context.closePath();
} else {
context.strokeRect(x - cx, y - cy, width, height);
}
context.restore();
};
export const drawHighlightForDiamondWithRotation = (
context: CanvasRenderingContext2D,
padding: number,
element: ExcalidrawDiamondElement,
elementsMap: ElementsMap,
) => {
const [x, y] = pointRotateRads(
pointFrom<GlobalPoint>(element.x, element.y),
elementCenterPoint(element, elementsMap),
element.angle,
);
context.save();
context.translate(x, y);
context.rotate(element.angle);
{
context.beginPath();
const [topX, topY, rightX, rightY, bottomX, bottomY, leftX, leftY] =
getDiamondPoints(element);
const verticalRadius = element.roundness
? getCornerRadius(Math.abs(topX - leftX), element)
: (topX - leftX) * 0.01;
const horizontalRadius = element.roundness
? getCornerRadius(Math.abs(rightY - topY), element)
: (rightY - topY) * 0.01;
const topApprox = curveOffsetPoints(
curve(
pointFrom(topX - verticalRadius, topY + horizontalRadius),
pointFrom(topX, topY),
pointFrom(topX, topY),
pointFrom(topX + verticalRadius, topY + horizontalRadius),
),
padding,
);
const rightApprox = curveOffsetPoints(
curve(
pointFrom(rightX - verticalRadius, rightY - horizontalRadius),
pointFrom(rightX, rightY),
pointFrom(rightX, rightY),
pointFrom(rightX - verticalRadius, rightY + horizontalRadius),
),
padding,
);
const bottomApprox = curveOffsetPoints(
curve(
pointFrom(bottomX + verticalRadius, bottomY - horizontalRadius),
pointFrom(bottomX, bottomY),
pointFrom(bottomX, bottomY),
pointFrom(bottomX - verticalRadius, bottomY - horizontalRadius),
),
padding,
);
const leftApprox = curveOffsetPoints(
curve(
pointFrom(leftX + verticalRadius, leftY + horizontalRadius),
pointFrom(leftX, leftY),
pointFrom(leftX, leftY),
pointFrom(leftX + verticalRadius, leftY - horizontalRadius),
),
padding,
);
context.moveTo(
topApprox[topApprox.length - 1][0],
topApprox[topApprox.length - 1][1],
);
context.lineTo(rightApprox[1][0], rightApprox[1][1]);
drawCatmullRomCubicApprox(context, rightApprox);
context.lineTo(bottomApprox[1][0], bottomApprox[1][1]);
drawCatmullRomCubicApprox(context, bottomApprox);
context.lineTo(leftApprox[1][0], leftApprox[1][1]);
drawCatmullRomCubicApprox(context, leftApprox);
context.lineTo(topApprox[1][0], topApprox[1][1]);
drawCatmullRomCubicApprox(context, topApprox);
}
// Counter-clockwise for the cutout in the middle. We need to have an "inverse
// mask" on a filled shape for the diamond highlight, because stroking creates
// sharp inset edges on line joins < 90 degrees.
{
const [topX, topY, rightX, rightY, bottomX, bottomY, leftX, leftY] =
getDiamondPoints(element);
const verticalRadius = element.roundness
? getCornerRadius(Math.abs(topX - leftX), element)
: (topX - leftX) * 0.01;
const horizontalRadius = element.roundness
? getCornerRadius(Math.abs(rightY - topY), element)
: (rightY - topY) * 0.01;
const topApprox = curveOffsetPoints(
curve(
pointFrom(topX + verticalRadius, topY + horizontalRadius),
pointFrom(topX, topY),
pointFrom(topX, topY),
pointFrom(topX - verticalRadius, topY + horizontalRadius),
),
-FIXED_BINDING_DISTANCE,
);
const rightApprox = curveOffsetPoints(
curve(
pointFrom(rightX - verticalRadius, rightY + horizontalRadius),
pointFrom(rightX, rightY),
pointFrom(rightX, rightY),
pointFrom(rightX - verticalRadius, rightY - horizontalRadius),
),
-FIXED_BINDING_DISTANCE,
);
const bottomApprox = curveOffsetPoints(
curve(
pointFrom(bottomX - verticalRadius, bottomY - horizontalRadius),
pointFrom(bottomX, bottomY),
pointFrom(bottomX, bottomY),
pointFrom(bottomX + verticalRadius, bottomY - horizontalRadius),
),
-FIXED_BINDING_DISTANCE,
);
const leftApprox = curveOffsetPoints(
curve(
pointFrom(leftX + verticalRadius, leftY - horizontalRadius),
pointFrom(leftX, leftY),
pointFrom(leftX, leftY),
pointFrom(leftX + verticalRadius, leftY + horizontalRadius),
),
-FIXED_BINDING_DISTANCE,
);
context.moveTo(
topApprox[topApprox.length - 1][0],
topApprox[topApprox.length - 1][1],
);
context.lineTo(leftApprox[1][0], leftApprox[1][1]);
drawCatmullRomCubicApprox(context, leftApprox);
context.lineTo(bottomApprox[1][0], bottomApprox[1][1]);
drawCatmullRomCubicApprox(context, bottomApprox);
context.lineTo(rightApprox[1][0], rightApprox[1][1]);
drawCatmullRomCubicApprox(context, rightApprox);
context.lineTo(topApprox[1][0], topApprox[1][1]);
drawCatmullRomCubicApprox(context, topApprox);
}
context.closePath();
context.fill();
context.restore();
};