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)); }