Source: core/sceneObjs/LineObjMixin.js

  1. /*
  2.  * Copyright 2024 The Ray Optics Simulation authors and contributors
  3.  *
  4.  * Licensed under the Apache License, Version 2.0 (the "License");
  5.  * you may not use this file except in compliance with the License.
  6.  * You may obtain a copy of the License at
  7.  *
  8.  *     http://www.apache.org/licenses/LICENSE-2.0
  9.  *
  10.  * Unless required by applicable law or agreed to in writing, software
  11.  * distributed under the License is distributed on an "AS IS" BASIS,
  12.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13.  * See the License for the specific language governing permissions and
  14.  * limitations under the License.
  15.  */
  17. import geometry from '../geometry.js';
  18. import BaseSceneObj from './BaseSceneObj.js';
  20. /**
  21.  * The mixin for the scene objects that are defined by a line segment.
  22.  * @template {typeof BaseSceneObj} T
  23.  * @param {T} Base 
  24.  * @returns {T}
  25.  */
  26. const LineObjMixin = Base => class extends Base {
  28.   move(diffX, diffY) {
  29.     // Move the first point
  30.     this.p1.x = this.p1.x + diffX;
  31.     this.p1.y = this.p1.y + diffY;
  32.     // Move the second point
  33.     this.p2.x = this.p2.x + diffX;
  34.     this.p2.y = this.p2.y + diffY;
  35.   }
  36.   
  37.   onConstructMouseDown(mouse, ctrl, shift) {
  38.     if (!this.constructionPoint) {
  39.       // Initialize the construction stage.
  40.       this.constructionPoint = mouse.getPosSnappedToGrid();
  41.       this.p1 = this.constructionPoint;
  42.       this.p2 = this.constructionPoint;
  43.     }
  44.     if (shift) {
  45.       this.p2 = mouse.getPosSnappedToDirection(this.constructionPoint, [{ x: 1, y: 0 }, { x: 0, y: 1 }, { x: 1, y: 1 }, { x: 1, y: -1 }]);
  46.     } else {
  47.       this.p2 = mouse.getPosSnappedToGrid();
  48.     }
  49.   }
  51.   onConstructMouseMove(mouse, ctrl, shift) {
  52.     if (shift) {
  53.       this.p2 = mouse.getPosSnappedToDirection(this.constructionPoint, [{ x: 1, y: 0 }, { x: 0, y: 1 }, { x: 1, y: 1 }, { x: 1, y: -1 }]);
  54.     } else {
  55.       this.p2 = mouse.getPosSnappedToGrid();
  56.     }
  58.     this.p1 = ctrl ? geometry.point(2 * this.constructionPoint.x - this.p2.x, 2 * this.constructionPoint.y - this.p2.y) : this.constructionPoint;
  59.   }
  61.   onConstructMouseUp(mouse, ctrl, shift) {
  62.     if (!mouse.snapsOnPoint(this.p1)) {
  63.       delete this.constructionPoint;
  64.       return {
  65.         isDone: true
  66.       };
  67.     }
  68.   }
  70.   checkMouseOver(mouse) {
  71.     let dragContext = {};
  72.     if (mouse.isOnPoint(this.p1) && geometry.distanceSquared(mouse.pos, this.p1) <= geometry.distanceSquared(mouse.pos, this.p2)) {
  73.       dragContext.part = 1;
  74.       dragContext.targetPoint = geometry.point(this.p1.x, this.p1.y);
  75.       return dragContext;
  76.     }
  77.     if (mouse.isOnPoint(this.p2)) {
  78.       dragContext.part = 2;
  79.       dragContext.targetPoint = geometry.point(this.p2.x, this.p2.y);
  80.       return dragContext;
  81.     }
  82.     if (mouse.isOnSegment(this)) {
  83.       const mousePos = mouse.getPosSnappedToGrid();
  84.       dragContext.part = 0;
  85.       dragContext.mousePos0 = mousePos; // Mouse position when the user starts dragging
  86.       dragContext.mousePos1 = mousePos; // Mouse position at the last moment during dragging
  87.       dragContext.snapContext = {};
  88.       return dragContext;
  89.     }
  90.   }
  92.   onDrag(mouse, dragContext, ctrl, shift) {
  93.     var basePoint;
  94.     if (dragContext.part == 1) {
  95.       // Dragging the first endpoint Dragging the first endpoint
  96.       basePoint = ctrl ? geometry.segmentMidpoint(dragContext.originalObj) : dragContext.originalObj.p2;
  98.       this.p1 = shift ? mouse.getPosSnappedToDirection(basePoint, [{ x: 1, y: 0 }, { x: 0, y: 1 }, { x: 1, y: 1 }, { x: 1, y: -1 }, { x: (dragContext.originalObj.p2.x - dragContext.originalObj.p1.x), y: (dragContext.originalObj.p2.y - dragContext.originalObj.p1.y) }]) : mouse.getPosSnappedToGrid();
  99.       this.p2 = ctrl ? geometry.point(2 * basePoint.x - this.p1.x, 2 * basePoint.y - this.p1.y) : basePoint;
  100.     }
  101.     if (dragContext.part == 2) {
  102.       // Dragging the second endpoint Dragging the second endpoint
  103.       basePoint = ctrl ? geometry.segmentMidpoint(dragContext.originalObj) : dragContext.originalObj.p1;
  105.       this.p2 = shift ? mouse.getPosSnappedToDirection(basePoint, [{ x: 1, y: 0 }, { x: 0, y: 1 }, { x: 1, y: 1 }, { x: 1, y: -1 }, { x: (dragContext.originalObj.p2.x - dragContext.originalObj.p1.x), y: (dragContext.originalObj.p2.y - dragContext.originalObj.p1.y) }]) : mouse.getPosSnappedToGrid();
  106.       this.p1 = ctrl ? geometry.point(2 * basePoint.x - this.p2.x, 2 * basePoint.y - this.p2.y) : basePoint;
  107.     }
  108.     if (dragContext.part == 0) {
  109.       // Dragging the entire line
  111.       if (shift) {
  112.         var mousePos = mouse.getPosSnappedToDirection(dragContext.mousePos0, [{ x: 1, y: 0 }, { x: 0, y: 1 }, { x: (dragContext.originalObj.p2.x - dragContext.originalObj.p1.x), y: (dragContext.originalObj.p2.y - dragContext.originalObj.p1.y) }, { x: (dragContext.originalObj.p2.y - dragContext.originalObj.p1.y), y: -(dragContext.originalObj.p2.x - dragContext.originalObj.p1.x) }], dragContext.snapContext);
  113.       } else {
  114.         var mousePos = mouse.getPosSnappedToGrid();
  115.         dragContext.snapContext = {}; // Unlock the dragging direction when the user release the shift key
  116.       }
  118.       var mouseDiffX = dragContext.mousePos1.x - mousePos.x; // The X difference between the mouse position now and at the previous moment
  119.       var mouseDiffY = dragContext.mousePos1.y - mousePos.y; // The Y difference between the mouse position now and at the previous moment The Y difference between the mouse position now and at the previous moment
  120.       // Move the first point
  121.       this.p1.x = this.p1.x - mouseDiffX;
  122.       this.p1.y = this.p1.y - mouseDiffY;
  123.       // Move the second point
  124.       this.p2.x = this.p2.x - mouseDiffX;
  125.       this.p2.y = this.p2.y - mouseDiffY;
  126.       // Update the mouse position
  127.       dragContext.mousePos1 = mousePos;
  128.     }
  129.   }
  131.   /**
  132.    * Check if a ray intersects the line segment.
  133.    * In the child class, this can be called from the `checkRayIntersects` method.
  134.    * @param {Ray} ray - The ray.
  135.    * @returns {Point} The intersection point, or null if there is no intersection.
  136.    */
  137.   checkRayIntersectsShape(ray) {
  138.     var rp_temp = geometry.linesIntersection(geometry.line(ray.p1, ray.p2), geometry.line(this.p1, this.p2));
  140.     if (geometry.intersectionIsOnSegment(rp_temp, this) && geometry.intersectionIsOnRay(rp_temp, ray)) {
  141.       return rp_temp;
  142.     } else {
  143.       return null;
  144.     }
  145.   }
  146. };
  148. export default LineObjMixin;