All files / src/components/world SceneSlopePreview.tsx

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
import React, { useCallback, useEffect, useRef, useState } from "react";
import { SlopePreview } from "store/features/editor/editorState";
import styled from "styled-components";
 
const TILE_SIZE = 8;
 
const Canvas = styled.canvas`
  position: absolute;
  top: 0;
  left: 0;
`;
 
interface SceneSlopePreviewProps {
  width: number;
  height: number;
  slopePreview: SlopePreview;
}
 
const SceneSlopePreview = ({
  width,
  height,
  slopePreview,
}: SceneSlopePreviewProps) => {
  const canvas = useRef<HTMLCanvasElement>(null);
  const { startX, startY, endX, endY, slopeIncline } = slopePreview;
  const [offset, setOffset] = useState(slopePreview.offset);
 
  const onKeyDown = useCallback((e: KeyboardEvent) => {
    Iif (!(e.target instanceof HTMLElement)) return;
    Iif (e.target.nodeName !== "BODY") {
      return;
    }
    Iif (e.shiftKey) {
      setOffset(true);
    }
  }, []);
 
  const onKeyUp = useCallback((e: KeyboardEvent) => {
    Iif (!(e.target instanceof HTMLElement)) return;
    Iif (e.target.nodeName !== "BODY") {
      return;
    }
    Iif (!e.shiftKey) {
      setOffset(false);
    }
  }, []);
 
  // Keyboard handlers
  useEffect(() => {
    window.addEventListener("keydown", onKeyDown);
    window.addEventListener("keyup", onKeyUp);
    return () => {
      window.removeEventListener("keydown", onKeyDown);
      window.removeEventListener("keyup", onKeyUp);
    };
  }, [onKeyDown, onKeyUp]);
 
  useEffect(() => {
    Iif (canvas.current) {
      // eslint-disable-next-line no-self-assign
      canvas.current.width = canvas.current.width; // Clear canvas
      const ctx = canvas.current.getContext("2d");
 
      Iif (!ctx) return;
 
      ctx.strokeStyle = "rgba(0,0,255,0.6)";
 
      let lineStartX = 0;
      let lineStartY = 0;
      let lineEndX = 0;
      let lineEndY = 0;
 
      const diffX = endX - startX;
      const diffY = endY - startY;
      const signX = Math.sign(diffX);
      const signY = Math.sign(diffY);
 
      if (endX < startX) {
        lineStartX = (startX + 1) * TILE_SIZE;
        lineEndX = (endX + 1) * TILE_SIZE;
      } else {
        lineStartX = startX * TILE_SIZE;
        lineEndX = endX * TILE_SIZE;
      }
 
      if (endY < startY) {
        lineStartY = (startY + 1) * TILE_SIZE;
        lineEndY = (endY + 1) * TILE_SIZE;
      } else {
        lineStartY = startY * TILE_SIZE;
        lineEndY = endY * TILE_SIZE;
      }
 
      Iif (slopeIncline === "shallow" && offset) {
        lineStartY += signY * 0.5 * TILE_SIZE;
        lineEndY += signY * 0.5 * TILE_SIZE;
      }
      Iif (slopeIncline === "steep" && offset) {
        lineStartX += signX * 0.5 * TILE_SIZE;
        lineEndX += signX * 0.5 * TILE_SIZE;
      }
 
      Iif (
        lineStartY === lineEndY &&
        // Drag left to right for top collision
        // Drag right to left for bottom collision
        // Shift to toggle
        ((lineStartX > lineEndX && !offset) ||
          (lineStartX <= lineEndX && offset))
      ) {
        // Bottom collision
        ctx.strokeStyle = "rgba(255,250,40,0.6)";
        lineStartY += TILE_SIZE - 1;
        lineEndY += TILE_SIZE - 1;
      }
      if (
        lineStartX === lineEndX &&
        // Drag top to bottom for left collision
        // Drag bottom to top for right collision
        // Shift to toggle
        ((lineStartY > lineEndY && !offset) ||
          (lineStartY <= lineEndY && offset))
      ) {
        // Right collision
        ctx.strokeStyle = "rgba(40,250,250,0.6)";
        lineStartX += TILE_SIZE - 1;
        lineEndX += TILE_SIZE - 1;
      } else Iif (lineStartX === lineEndX) {
        // Left collision
        ctx.strokeStyle = "rgba(250,40,250,0.6)";
      }
 
      ctx.moveTo(lineStartX, lineStartY);
      ctx.lineTo(lineEndX, lineEndY);
      ctx.stroke();
    }
  }, [endX, endY, height, offset, slopeIncline, startX, startY, width]);
 
  return (
    <Canvas
      ref={canvas}
      width={width * TILE_SIZE}
      height={height * TILE_SIZE}
    />
  );
};
 
export default SceneSlopePreview;