OpenShot Library | libopenshot  0.2.4
Point.h
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1 /**
2  * @file
3  * @brief Header file for Point class
4  * @author Jonathan Thomas <jonathan@openshot.org>
5  *
6  * @ref License
7  */
8 
9 /* LICENSE
10  *
11  * Copyright (c) 2008-2019 OpenShot Studios, LLC
12  * <http://www.openshotstudios.com/>. This file is part of
13  * OpenShot Library (libopenshot), an open-source project dedicated to
14  * delivering high quality video editing and animation solutions to the
15  * world. For more information visit <http://www.openshot.org/>.
16  *
17  * OpenShot Library (libopenshot) is free software: you can redistribute it
18  * and/or modify it under the terms of the GNU Lesser General Public License
19  * as published by the Free Software Foundation, either version 3 of the
20  * License, or (at your option) any later version.
21  *
22  * OpenShot Library (libopenshot) is distributed in the hope that it will be
23  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25  * GNU Lesser General Public License for more details.
26  *
27  * You should have received a copy of the GNU Lesser General Public License
28  * along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
29  */
30 
31 #ifndef OPENSHOT_POINT_H
32 #define OPENSHOT_POINT_H
33 
34 #include "Coordinate.h"
35 #include "Exceptions.h"
36 #include "Json.h"
37 
38 namespace openshot
39 {
40  /**
41  * @brief This controls how a Keyframe uses this point to interpolate between two points.
42  *
43  * Bezier is a smooth curve. Linear is a straight line. Constant is a jump from the
44  * previous point to this one.
45  */
47  BEZIER, ///< Bezier curves are quadratic curves, which create a smooth curve.
48  LINEAR, ///< Linear curves are angular, straight lines between two points.
49  CONSTANT ///< Constant curves jump from their previous position to a new one (with no interpolation).
50  };
51 
52  /**
53  * @brief When BEZIER interpolation is used, the point's left and right handles are used
54  * to influence the direction of the curve.
55  *
56  * AUTO will try and adjust the handles automatically, to achieve the smoothest curves.
57  * MANUAL will leave the handles alone, making it the responsibility of the user to set them.
58  */
59  enum HandleType {
60  AUTO, ///< Automatically adjust the handles to achieve the smoothest curve
61  MANUAL ///< Do not automatically adjust handles (set them manually)
62  };
63 
64  /**
65  * @brief A Point is the basic building block of a key-frame curve.
66  *
67  * Points have a primary coordinate and a left and right handle coordinate.
68  * The handles are used to influence the direction of the curve as it
69  * moves between the primary coordinate and the next primary coordinate when the
70  * interpolation mode is BEZIER. When using LINEAR or CONSTANT, the handles are
71  * ignored.
72  *
73  * Please see the following <b>Example Code</b>:
74  * \code
75  * Coordinate c1(3,9);
76  * Point p1(c1, BEZIER);
77  * assert(c1.X == 3);
78  * assert(c1.Y == 9);
79  *
80  * \endcode
81  */
82  class Point {
83  public:
84  Coordinate co; ///< This is the primary coordinate
85  Coordinate handle_left; ///< This is the left handle coordinate (in percentages from 0 to 1)
86  Coordinate handle_right; ///< This is the right handle coordinate (in percentages from 0 to 1)
87  InterpolationType interpolation; ///< This is the interpolation mode
88  HandleType handle_type; ///< This is the handle mode
89 
90  /// Default constructor (defaults to 1,0)
91  Point();
92 
93  /// Constructor which creates a single coordinate at X=1
94  Point(float y);
95 
96  /// Constructor which also creates a Point and sets the X and Y of the Point.
97  Point(float x, float y);
98 
99  /// Constructor which also creates a Point and sets the X,Y, and interpolation of the Point.
100  Point(float x, float y, InterpolationType interpolation);
101 
102  /// Constructor which takes a coordinate
103  Point(Coordinate co);
104 
105  /// Constructor which takes a coordinate and interpolation mode
106  Point(Coordinate co, InterpolationType interpolation);
107 
108  /// Constructor which takes a coordinate, interpolation mode, and handle type
109  Point(Coordinate co, InterpolationType interpolation, HandleType handle_type);
110 
111  /// Set the left and right handles to a percent of the primary coordinate (0 to 1)
112  /// Defaults to a smooth curve (Ease in and out)
113  void Initialize_Handles();
114 
115  /// Set the left handle to a percent of the primary coordinate (0 to 1)
116  void Initialize_LeftHandle(float x, float y);
117 
118  /// Set the right handle to a percent of the primary coordinate (0 to 1)
119  void Initialize_RightHandle(float x, float y);
120 
121  /// Get and Set JSON methods
122  std::string Json(); ///< Generate JSON string of this object
123  Json::Value JsonValue(); ///< Generate Json::JsonValue for this object
124  void SetJson(std::string value); ///< Load JSON string into this object
125  void SetJsonValue(Json::Value root); ///< Load Json::JsonValue into this object
126 
127  };
128 
129 }
130 
131 #endif
void Initialize_LeftHandle(float x, float y)
Set the left handle to a percent of the primary coordinate (0 to 1)
Definition: Point.cpp:100
Json::Value JsonValue()
Generate Json::JsonValue for this object.
Definition: Point.cpp:118
This class represents a Cartesian coordinate (X, Y) used in the Keyframe animation system...
Definition: Coordinate.h:55
Bezier curves are quadratic curves, which create a smooth curve.
Definition: Point.h:47
void SetJson(std::string value)
Load JSON string into this object.
Definition: Point.cpp:135
InterpolationType interpolation
This is the interpolation mode.
Definition: Point.h:87
Coordinate handle_right
This is the right handle coordinate (in percentages from 0 to 1)
Definition: Point.h:86
void Initialize_RightHandle(float x, float y)
Set the right handle to a percent of the primary coordinate (0 to 1)
Definition: Point.cpp:105
Coordinate handle_left
This is the left handle coordinate (in percentages from 0 to 1)
Definition: Point.h:85
A Point is the basic building block of a key-frame curve.
Definition: Point.h:82
HandleType handle_type
This is the handle mode.
Definition: Point.h:88
Do not automatically adjust handles (set them manually)
Definition: Point.h:61
Header file for all Exception classes.
std::string Json()
Get and Set JSON methods.
Definition: Point.cpp:111
Header file for JSON class.
HandleType
When BEZIER interpolation is used, the point&#39;s left and right handles are used to influence the direc...
Definition: Point.h:59
Point()
Default constructor (defaults to 1,0)
Definition: Point.cpp:37
Automatically adjust the handles to achieve the smoothest curve.
Definition: Point.h:60
InterpolationType
This controls how a Keyframe uses this point to interpolate between two points.
Definition: Point.h:46
This namespace is the default namespace for all code in the openshot library.
Linear curves are angular, straight lines between two points.
Definition: Point.h:48
Coordinate co
This is the primary coordinate.
Definition: Point.h:84
Header file for Coordinate class.
void SetJsonValue(Json::Value root)
Load Json::JsonValue into this object.
Definition: Point.cpp:164
void Initialize_Handles()
Definition: Point.cpp:93
Constant curves jump from their previous position to a new one (with no interpolation).
Definition: Point.h:49