Doodle3D-Core/src/utils/matrixUtils.js

51 lines
1.9 KiB
JavaScript
Raw Normal View History

2017-11-14 15:27:48 +01:00
import { Matrix, Vector } from 'cal';
export function calculateGestureMatrix(positions, previousPositions, screenMatrix, { rotate, scale, pan }) {
const matrix = screenMatrix.inverseMatrix();
const screenCenter = positions[0].add(positions[1]).scale(0.5).applyMatrix(matrix);
let gestureMatrix = new Matrix();
if (pan) {
const previousCenter = previousPositions[0].add(previousPositions[1]).scale(0.5);
const center = positions[0].add(positions[1]).scale(0.5);
const gesturePan = center.subtract(previousCenter).applyMatrix(matrix.normalize());
gestureMatrix = gestureMatrix.translate(gesturePan.x, gesturePan.y);
}
if (scale) {
const previousLength = previousPositions[0].distanceTo(previousPositions[1]);
const length = positions[0].distanceTo(positions[1]);
const gestureScale = length / previousLength;
gestureMatrix = gestureMatrix.scaleAroundAbsolute(gestureScale, gestureScale, screenCenter);
}
if (rotate) {
const previousAngle = previousPositions[1].subtract(previousPositions[0]).angle();
const angle = positions[1].subtract(positions[0]).angle();
const gestureRotation = angle - previousAngle;
gestureMatrix = gestureMatrix.rotateAroundAbsolute(gestureRotation, screenCenter);
}
return gestureMatrix;
}
export function decomposeMatrix(matrix) {
const { sx, sy, x, y, rotation } = matrix;
return { position: new Vector(x, y), scale: new Vector(sx, sy), rotation };
}
export function calculatePointInImage(point, shapeData, screenMatrix) {
const { width, height } = shapeData.imageData;
const centerOffset = new Vector(width / 2, height / 2);
const matrix = shapeData.transform.multiplyMatrix(screenMatrix).inverseMatrix();
return point
.applyMatrix(matrix)
.add(centerOffset)
.round();
}
export function isNegative(transform) {
const negativeX = transform.sx > 0;
const negativeY = transform.sy > 0;
return !((negativeX && negativeY) || (!negativeX && !negativeY));
}