51 lines
1.9 KiB
JavaScript
51 lines
1.9 KiB
JavaScript
import { Matrix, Vector } from '@doodle3d/cal';
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export function calculateGestureMatrix(positions, previousPositions, screenMatrix, { rotate, scale, pan }) {
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const matrix = screenMatrix.inverseMatrix();
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const screenCenter = positions[0].add(positions[1]).scale(0.5).applyMatrix(matrix);
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let gestureMatrix = new Matrix();
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if (pan) {
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const previousCenter = previousPositions[0].add(previousPositions[1]).scale(0.5);
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const center = positions[0].add(positions[1]).scale(0.5);
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const gesturePan = center.subtract(previousCenter).applyMatrix(matrix.normalize());
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gestureMatrix = gestureMatrix.translate(gesturePan.x, gesturePan.y);
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}
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if (scale) {
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const previousLength = previousPositions[0].distanceTo(previousPositions[1]);
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const length = positions[0].distanceTo(positions[1]);
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const gestureScale = length / previousLength;
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gestureMatrix = gestureMatrix.scaleAroundAbsolute(gestureScale, gestureScale, screenCenter);
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}
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if (rotate) {
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const previousAngle = previousPositions[1].subtract(previousPositions[0]).angle();
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const angle = positions[1].subtract(positions[0]).angle();
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const gestureRotation = angle - previousAngle;
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gestureMatrix = gestureMatrix.rotateAroundAbsolute(gestureRotation, screenCenter);
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}
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return gestureMatrix;
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}
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export function decomposeMatrix(matrix) {
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const { sx, sy, x, y, rotation } = matrix;
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return { position: new Vector(x, y), scale: new Vector(sx, sy), rotation };
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}
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export function calculatePointInImage(point, shapeData, screenMatrix) {
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const { width, height } = shapeData.imageData;
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const centerOffset = new Vector(width / 2, height / 2);
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const matrix = shapeData.transform.multiplyMatrix(screenMatrix).inverseMatrix();
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return point
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.applyMatrix(matrix)
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.add(centerOffset)
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.round();
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}
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export function isNegative(transform) {
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const negativeX = transform.sx > 0;
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const negativeY = transform.sy > 0;
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return !((negativeX && negativeY) || (!negativeX && !negativeY));
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}
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