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MyGUI_GeometryUtility.cpp
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1 /*
2 * This source file is part of MyGUI. For the latest info, see http://mygui.info/
3 * Distributed under the MIT License
4 * (See accompanying file COPYING.MIT or copy at http://opensource.org/licenses/MIT)
5 */
6
7 #include "MyGUI_Precompiled.h"
8 #include "MyGUI_GeometryUtility.h"
9
10 namespace MyGUI
11 {
12
13 namespace geometry_utility
14 {
15
16 VectorFloatPoint cropPolygon(FloatPoint* _baseVerticiesPos, size_t _size, const IntCoord& _cropRectangle)
17 {
18 VectorFloatPoint resultVerticiesPos;
19 resultVerticiesPos.resize(_size);
20 for (size_t i = 0; i < _size; ++i)
21 {
22 resultVerticiesPos[i] = _baseVerticiesPos[i];
23 }
24
25 cropPolygonSide(resultVerticiesPos, _cropRectangle.left, Left);
26 cropPolygonSide(resultVerticiesPos, _cropRectangle.right(), Right);
27 cropPolygonSide(resultVerticiesPos, _cropRectangle.top, Top);
28 cropPolygonSide(resultVerticiesPos, _cropRectangle.bottom(), Bottom);
29
30 return resultVerticiesPos;
31 }
32
33 void cropPolygonSide(VectorFloatPoint& _verticies, int _sideCoord, Side _side)
34 {
35 VectorFloatPoint newVerticies;
36 int invert = (_side == Right || _side == Bottom) ? -1 : 1;
37 for (size_t i = 0; i < _verticies.size(); ++i)
38 {
39 FloatPoint& v0 = _verticies[i];
40 FloatPoint& v1 = _verticies[(i + 1) % _verticies.size()];
41 switch (_side)
42 {
43 case Left:
44 case Right:
45 // both inside
46 if (invert * v0.left >= invert * _sideCoord && invert * v1.left >= invert * _sideCoord)
47 newVerticies.push_back(v0);
48 // intersect side (1st vertex in)
49 else if (invert * v0.left >= invert * _sideCoord && invert * v1.left < invert * _sideCoord)
50 {
51 newVerticies.push_back(v0);
52 float c = (v0.left - _sideCoord) / (_sideCoord - v1.left);
53 newVerticies.push_back(FloatPoint((float)_sideCoord, (v0.top + c * v1.top) / (c + 1)));
54 }
55 // intersect side (2nd vertex in)
56 else if (invert * v0.left <= invert * _sideCoord && invert * v1.left > invert * _sideCoord)
57 {
58 float c = (v0.left - _sideCoord) / (_sideCoord - v1.left);
59 newVerticies.push_back(FloatPoint((float)_sideCoord, (v0.top + c * v1.top) / (c + 1)));
60 }
61 // else don't add any verticies
62 break;
63 case Top:
64 case Bottom:
65 // both inside
66 if (invert * v0.top >= invert * _sideCoord && invert * v1.top >= invert * _sideCoord)
67 newVerticies.push_back(v0);
68 // intersect side (1st vertex in)
69 else if (invert * v0.top >= invert * _sideCoord && invert * v1.top < invert * _sideCoord)
70 {
71 newVerticies.push_back(v0);
72 float c = (v0.top - _sideCoord) / (_sideCoord - v1.top);
73 newVerticies.push_back(FloatPoint((v0.left + c * v1.left) / (c + 1), (float)_sideCoord));
74 }
75 // intersect side (2nd vertex in)
76 else if (invert * v0.top <= invert * _sideCoord && invert * v1.top > invert * _sideCoord)
77 {
78 float c = (v0.top - _sideCoord) / (_sideCoord - v1.top);
79 newVerticies.push_back(FloatPoint((v0.left + c * v1.left) / (c + 1), (float)_sideCoord));
80 }
81 // else don't add any verticies
82 break;
83 }
84 }
85
86 _verticies = newVerticies;
87 }
88
89 FloatPoint getPositionInsideRect(const FloatPoint& _point, const FloatPoint& _corner0, const FloatPoint& _corner1, const FloatPoint& _corner2)
90 {
91 FloatPoint result;
92
93 FloatPoint point = _point - _corner0;
94 FloatPoint dirX = _corner1 - _corner0;
95 FloatPoint dirY = _corner2 - _corner0;
96
97 float div = dirX.left * dirY.top - dirX.top * dirY.left;
98 if (div == 0.0f)
99 return FloatPoint();
100 return FloatPoint(
101 (point.top * dirX.left - point.left * dirX.top) / div,
102 (point.left * dirY.top - point.top * dirY.left) / div);
103 }
104
105 FloatPoint getUVFromPositionInsideRect(const FloatPoint& _point, const FloatPoint& _v0, const FloatPoint& _v1, const FloatPoint& _baseUV)
106 {
107 return FloatPoint(
108 _baseUV.left + _point.left * _v0.left + _point.top * _v1.left,
109 _baseUV.top + _point.left * _v0.top + _point.top * _v1.top);
110 }
111
112 } // namespace geometry_utility
113
114 } // namespace MyGUI
MyGUI::types::TCoord< int >
MyGUI::geometry_utility::Left
Definition: MyGUI_GeometryUtility.h:21
MyGUI::geometry_utility::getPositionInsideRect
FloatPoint getPositionInsideRect(const FloatPoint &_point, const FloatPoint &_corner0, const FloatPoint &_corner1, const FloatPoint &_corner2)
Definition: MyGUI_GeometryUtility.cpp:89
MyGUI::types::TPoint< float >
MyGUI::geometry_utility::cropPolygon
VectorFloatPoint cropPolygon(FloatPoint *_baseVerticiesPos, size_t _size, const IntCoord &_cropRectangle)
Definition: MyGUI_GeometryUtility.cpp:16
MyGUI_Precompiled.h
MyGUI::geometry_utility::Bottom
Definition: MyGUI_GeometryUtility.h:21
MyGUI::geometry_utility::Side
Side
Definition: MyGUI_GeometryUtility.h:21
MyGUI_GeometryUtility.h
MyGUI::types::TPoint::top
T top
Definition: MyGUI_TPoint.h:21
MyGUI::geometry_utility::Right
Definition: MyGUI_GeometryUtility.h:21
MyGUI::VectorFloatPoint
std::vector< FloatPoint > VectorFloatPoint
Definition: MyGUI_GeometryUtility.h:15
MyGUI::types::TCoord::top
T top
Definition: MyGUI_TCoord.h:23
MyGUI::geometry_utility::getUVFromPositionInsideRect
FloatPoint getUVFromPositionInsideRect(const FloatPoint &_point, const FloatPoint &_v0, const FloatPoint &_v1, const FloatPoint &_baseUV)
Definition: MyGUI_GeometryUtility.cpp:105
MyGUI
Definition: MyGUI_ActionController.h:14
MyGUI::types::TPoint::left
T left
Definition: MyGUI_TPoint.h:20
MyGUI::types::TCoord::right
T right() const
Definition: MyGUI_TCoord.h:150
MyGUI::geometry_utility::cropPolygonSide
void cropPolygonSide(VectorFloatPoint &_verticies, int _sideCoord, Side _side)
Definition: MyGUI_GeometryUtility.cpp:33
MyGUI::types::TCoord::bottom
T bottom() const
Definition: MyGUI_TCoord.h:155
MyGUI::FloatPoint
types::TPoint< float > FloatPoint
Definition: MyGUI_Types.h:27
MyGUI::geometry_utility::Top
Definition: MyGUI_GeometryUtility.h:21
MyGUI::types::TCoord::left
T left
Definition: MyGUI_TCoord.h:22