/*
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* Copyright 2010 ZXing authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import ResultPoint from '../../ResultPoint';
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import NotFoundException from '../../NotFoundException';
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/**
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* @author Mariusz Dąbrowski
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*/
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export default class CornerDetector {
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/**
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* @throws NotFoundException if image is too small to accommodate {@code initSize}
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*/
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constructor(image, initSize, x, y, targetMatrixSize) {
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this.image = image;
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this.height = image.getHeight();
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this.width = image.getWidth();
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const halfsize = initSize / 2;
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this.leftInit = x - halfsize;
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this.rightInit = x + halfsize;
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this.upInit = y - halfsize;
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this.downInit = y + halfsize;
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this.targetMatrixSize = targetMatrixSize * 2;
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if (this.upInit < 0 || this.leftInit < 0 || this.downInit >= this.height || this.rightInit >= this.width) {
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throw new NotFoundException();
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}
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}
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/**
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* @throws NotFoundException if no Data Matrix Code can be found
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*/
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detect() {
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let left = this.leftInit;
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let right = this.rightInit;
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let up = this.upInit;
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let down = this.downInit;
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let sizeExceeded = false;
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let aBlackPointFoundOnBorder = true;
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let atLeastOneBlackPointFoundOnBorder = false;
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let atLeastOneBlackPointFoundOnRight = false;
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let atLeastOneBlackPointFoundOnBottom = false;
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let atLeastOneBlackPointFoundOnLeft = false;
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let atLeastOneBlackPointFoundOnTop = false;
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while (aBlackPointFoundOnBorder) {
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aBlackPointFoundOnBorder = false;
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// .....
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// . |
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// .....
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let rightBorderNotWhite = true;
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while ((rightBorderNotWhite || !atLeastOneBlackPointFoundOnRight) && right < this.width) {
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rightBorderNotWhite = this.containsBlackPoint(up, down, right, false);
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if (rightBorderNotWhite) {
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right++;
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aBlackPointFoundOnBorder = true;
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atLeastOneBlackPointFoundOnRight = true;
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}
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else if (!atLeastOneBlackPointFoundOnRight) {
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right++;
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}
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}
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if (right >= this.width) {
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sizeExceeded = true;
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break;
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}
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// .....
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// . .
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// .___.
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let bottomBorderNotWhite = true;
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while ((bottomBorderNotWhite || !atLeastOneBlackPointFoundOnBottom) && down < this.height) {
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bottomBorderNotWhite = this.containsBlackPoint(left, right, down, true);
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if (bottomBorderNotWhite) {
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down++;
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aBlackPointFoundOnBorder = true;
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atLeastOneBlackPointFoundOnBottom = true;
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}
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else if (!atLeastOneBlackPointFoundOnBottom) {
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down++;
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}
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}
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if (down >= this.height) {
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sizeExceeded = true;
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break;
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}
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// .....
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// | .
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// .....
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let leftBorderNotWhite = true;
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while ((leftBorderNotWhite || !atLeastOneBlackPointFoundOnLeft) && left >= 0) {
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leftBorderNotWhite = this.containsBlackPoint(up, down, left, false);
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if (leftBorderNotWhite) {
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left--;
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aBlackPointFoundOnBorder = true;
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atLeastOneBlackPointFoundOnLeft = true;
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}
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else if (!atLeastOneBlackPointFoundOnLeft) {
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left--;
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}
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}
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if (left < 0) {
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sizeExceeded = true;
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break;
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}
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// .___.
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// . .
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// .....
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let topBorderNotWhite = true;
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while ((topBorderNotWhite || !atLeastOneBlackPointFoundOnTop) && up >= 0) {
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topBorderNotWhite = this.containsBlackPoint(left, right, up, true);
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if (topBorderNotWhite) {
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up--;
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aBlackPointFoundOnBorder = true;
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atLeastOneBlackPointFoundOnTop = true;
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}
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else if (!atLeastOneBlackPointFoundOnTop) {
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up--;
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}
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}
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if (up < 0) {
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sizeExceeded = true;
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break;
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}
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if (aBlackPointFoundOnBorder) {
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atLeastOneBlackPointFoundOnBorder = true;
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}
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}
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if (!sizeExceeded && atLeastOneBlackPointFoundOnBorder) {
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return this.findCorners(right, left, down, up);
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}
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else {
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throw new NotFoundException();
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}
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}
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findCorners(right, left, down, up) {
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//
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// A------------ ------------B
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// | | up | |
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// | -------|--------------|------- |
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// | | | | | |
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// | | | | | |
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// ------------AP BP------------
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// | |
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// | |
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// left | | right
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// | |
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// | |
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// ------------DP CP------------
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// | | | | | |
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// | | | down | | |
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// | -------|-------------|-------- |
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// | | | |
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// D-----------| |------------C
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//
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const width = right - left;
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const height = down - up;
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const sampler = 16 / this.targetMatrixSize;
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const sampler2 = 4 / this.targetMatrixSize;
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const deltaX = width * sampler2;
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const deltaY = height * sampler2;
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const areaWidth = deltaX + (right - left) * sampler;
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const areaHeight = deltaY + (down - up) * sampler;
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const a = new ResultPoint(left - deltaX, up - deltaY);
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const b = new ResultPoint(right + deltaX, up - deltaY);
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const c = new ResultPoint(right + deltaX, down + deltaY);
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const d = new ResultPoint(left - deltaX, down + deltaY);
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const ap = new ResultPoint(a.getX() + areaWidth, a.getY() + areaHeight);
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const bp = new ResultPoint(b.getX() - areaWidth, b.getY() + areaHeight);
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const cp = new ResultPoint(c.getX() - areaWidth, c.getY() - areaHeight);
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const dp = new ResultPoint(d.getX() + areaWidth, d.getY() - areaHeight);
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const topLeftCorner = this.getCornerFromArea(a.getX(), ap.getX(), a.getY(), ap.getY(), false, false);
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const topRightCorner = this.getCornerFromArea(bp.getX(), b.getX(), b.getY(), bp.getY(), true, false);
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const bottomRightCorner = this.getCornerFromArea(cp.getX(), c.getX(), cp.getY(), c.getY(), true, true);
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const bottomLeftCorner = this.getCornerFromArea(d.getX(), dp.getX(), dp.getY(), d.getY(), false, true);
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const xCorrection = (topRightCorner.getX() - topLeftCorner.getX()) / this.targetMatrixSize;
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const yCorrection = (bottomRightCorner.getY() - topRightCorner.getY()) / this.targetMatrixSize;
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const topLeftCornerCenter = new ResultPoint(topLeftCorner.getX() + xCorrection, topLeftCorner.getY() + yCorrection);
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const topRightCornerCenter = new ResultPoint(topRightCorner.getX() - xCorrection, topRightCorner.getY() + yCorrection);
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const bottomRightCornerCenter = new ResultPoint(bottomRightCorner.getX() - xCorrection, bottomRightCorner.getY() - yCorrection);
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const bottomLeftCornerCenter = new ResultPoint(bottomLeftCorner.getX() + xCorrection, bottomLeftCorner.getY() - yCorrection);
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const result = [topLeftCornerCenter, topRightCornerCenter, bottomRightCornerCenter, bottomLeftCornerCenter];
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return result;
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}
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getCornerFromArea(left, right, top, bottom, maximizeX, maximizeY) {
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let resX = maximizeX ? 0 : Number.MAX_VALUE;
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let resY = maximizeY ? 0 : Number.MAX_VALUE;
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for (let x = left; x < right; x++) {
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for (let y = top; y < bottom; y++) {
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if (x > 0 && y > 0 && x < this.image.getWidth() && y < this.image.getHeight()) {
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if (this.image.get(x, y)) {
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if (maximizeX) {
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if (x > resX) {
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resX = x;
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}
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}
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else {
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if (x < resX) {
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resX = x;
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}
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}
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if (maximizeY) {
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if (y > resY) {
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resY = y;
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}
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}
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else {
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if (y < resY) {
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resY = y;
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}
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}
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}
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}
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}
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}
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if (resX === 0 || resY === 0) {
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throw new NotFoundException();
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}
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else {
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return new ResultPoint(resX, resY);
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}
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}
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/**
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* Determines whether a segment contains a black point
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*
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* @param a min value of the scanned coordinate
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* @param b max value of the scanned coordinate
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* @param fixed value of fixed coordinate
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* @param horizontal set to true if scan must be horizontal, false if vertical
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* @return true if a black point has been found, else false.
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*/
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containsBlackPoint(a, b, fixed, horizontal) {
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if (horizontal) {
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for (let x = a; x <= b; x++) {
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if (this.image.get(x, fixed)) {
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return true;
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}
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}
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}
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else {
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for (let y = a; y <= b; y++) {
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if (this.image.get(fixed, y)) {
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return true;
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}
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}
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}
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return false;
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}
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}
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