SDL  2.0
SDL_rect.h
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 
22 /**
23  * \file SDL_rect.h
24  *
25  * Header file for SDL_rect definition and management functions.
26  */
27 
28 #ifndef SDL_rect_h_
29 #define SDL_rect_h_
30 
31 #include "SDL_stdinc.h"
32 #include "SDL_error.h"
33 #include "SDL_pixels.h"
34 #include "SDL_rwops.h"
35 
36 #include "begin_code.h"
37 /* Set up for C function definitions, even when using C++ */
38 #ifdef __cplusplus
39 extern "C" {
40 #endif
41 
42 /**
43  * The structure that defines a point (integer)
44  *
45  * \sa SDL_EnclosePoints
46  * \sa SDL_PointInRect
47  */
48 typedef struct SDL_Point
49 {
50  int x;
51  int y;
52 } SDL_Point;
53 
54 /**
55  * The structure that defines a point (floating point)
56  *
57  * \sa SDL_EnclosePoints
58  * \sa SDL_PointInRect
59  */
60 typedef struct SDL_FPoint
61 {
62  float x;
63  float y;
64 } SDL_FPoint;
65 
66 
67 /**
68  * A rectangle, with the origin at the upper left (integer).
69  *
70  * \sa SDL_RectEmpty
71  * \sa SDL_RectEquals
72  * \sa SDL_HasIntersection
73  * \sa SDL_IntersectRect
74  * \sa SDL_UnionRect
75  * \sa SDL_EnclosePoints
76  */
77 typedef struct SDL_Rect
78 {
79  int x, y;
80  int w, h;
81 } SDL_Rect;
82 
83 
84 /**
85  * A rectangle, with the origin at the upper left (floating point).
86  */
87 typedef struct SDL_FRect
88 {
89  float x;
90  float y;
91  float w;
92  float h;
93 } SDL_FRect;
94 
95 
96 /**
97  * Returns true if point resides inside a rectangle.
98  */
100 {
101  return ( (p->x >= r->x) && (p->x < (r->x + r->w)) &&
102  (p->y >= r->y) && (p->y < (r->y + r->h)) ) ? SDL_TRUE : SDL_FALSE;
103 }
104 
105 /**
106  * Returns true if the rectangle has no area.
107  */
109 {
110  return ((!r) || (r->w <= 0) || (r->h <= 0)) ? SDL_TRUE : SDL_FALSE;
111 }
112 
113 /**
114  * Returns true if the two rectangles are equal.
115  */
117 {
118  return (a && b && (a->x == b->x) && (a->y == b->y) &&
119  (a->w == b->w) && (a->h == b->h)) ? SDL_TRUE : SDL_FALSE;
120 }
121 
122 /**
123  * Determine whether two rectangles intersect.
124  *
125  * If either pointer is NULL the function will return SDL_FALSE.
126  *
127  * \param A an SDL_Rect structure representing the first rectangle
128  * \param B an SDL_Rect structure representing the second rectangle
129  * \returns SDL_TRUE if there is an intersection, SDL_FALSE otherwise.
130  *
131  * \since This function is available since SDL 2.0.0.
132  *
133  * \sa SDL_IntersectRect
134  */
135 extern DECLSPEC SDL_bool SDLCALL SDL_HasIntersection(const SDL_Rect * A,
136  const SDL_Rect * B);
137 
138 /**
139  * Calculate the intersection of two rectangles.
140  *
141  * If `result` is NULL then this function will return SDL_FALSE.
142  *
143  * \param A an SDL_Rect structure representing the first rectangle
144  * \param B an SDL_Rect structure representing the second rectangle
145  * \param result an SDL_Rect structure filled in with the intersection of
146  * rectangles `A` and `B`
147  * \returns SDL_TRUE if there is an intersection, SDL_FALSE otherwise.
148  *
149  * \since This function is available since SDL 2.0.0.
150  *
151  * \sa SDL_HasIntersection
152  */
153 extern DECLSPEC SDL_bool SDLCALL SDL_IntersectRect(const SDL_Rect * A,
154  const SDL_Rect * B,
155  SDL_Rect * result);
156 
157 /**
158  * Calculate the union of two rectangles.
159  *
160  * \param A an SDL_Rect structure representing the first rectangle
161  * \param B an SDL_Rect structure representing the second rectangle
162  * \param result an SDL_Rect structure filled in with the union of rectangles
163  * `A` and `B`
164  */
165 extern DECLSPEC void SDLCALL SDL_UnionRect(const SDL_Rect * A,
166  const SDL_Rect * B,
167  SDL_Rect * result);
168 
169 /**
170  * Calculate a minimal rectangle enclosing a set of points.
171  *
172  * If `clip` is not NULL then only points inside of the clipping rectangle are
173  * considered.
174  *
175  * \param points an array of SDL_Point structures representing points to be
176  * enclosed
177  * \param count the number of structures in the `points` array
178  * \param clip an SDL_Rect used for clipping or NULL to enclose all points
179  * \param result an SDL_Rect structure filled in with the minimal enclosing
180  * rectangle
181  * \returns SDL_TRUE if any points were enclosed or SDL_FALSE if all the
182  * points were outside of the clipping rectangle.
183  */
184 extern DECLSPEC SDL_bool SDLCALL SDL_EnclosePoints(const SDL_Point * points,
185  int count,
186  const SDL_Rect * clip,
187  SDL_Rect * result);
188 
189 /**
190  * Calculate the intersection of a rectangle and line segment.
191  *
192  * This function is used to clip a line segment to a rectangle. A line segment
193  * contained entirely within the rectangle or that does not intersect will
194  * remain unchanged. A line segment that crosses the rectangle at either or
195  * both ends will be clipped to the boundary of the rectangle and the new
196  * coordinates saved in `X1`, `Y1`, `X2`, and/or `Y2` as necessary.
197  *
198  * \param rect an SDL_Rect structure representing the rectangle to intersect
199  * \param X1 a pointer to the starting X-coordinate of the line
200  * \param Y1 a pointer to the starting Y-coordinate of the line
201  * \param X2 a pointer to the ending X-coordinate of the line
202  * \param Y2 a pointer to the ending Y-coordinate of the line
203  * \returns SDL_TRUE if there is an intersection, SDL_FALSE otherwise.
204  */
205 extern DECLSPEC SDL_bool SDLCALL SDL_IntersectRectAndLine(const SDL_Rect *
206  rect, int *X1,
207  int *Y1, int *X2,
208  int *Y2);
209 
210 /* Ends C function definitions when using C++ */
211 #ifdef __cplusplus
212 }
213 #endif
214 #include "close_code.h"
215 
216 #endif /* SDL_rect_h_ */
217 
218 /* vi: set ts=4 sw=4 expandtab: */
float w
Definition: SDL_rect.h:91
SDL_FORCE_INLINE SDL_bool SDL_RectEquals(const SDL_Rect *a, const SDL_Rect *b)
Definition: SDL_rect.h:116
SDL_bool
Definition: SDL_stdinc.h:167
SDL_FORCE_INLINE SDL_bool SDL_PointInRect(const SDL_Point *p, const SDL_Rect *r)
Definition: SDL_rect.h:99
SDL_FORCE_INLINE SDL_bool SDL_RectEmpty(const SDL_Rect *r)
Definition: SDL_rect.h:108
float y
Definition: SDL_rect.h:90
#define SDL_FORCE_INLINE
Definition: begin_code.h:143
SDL_bool SDL_IntersectRectAndLine(const SDL_Rect *rect, int *X1, int *Y1, int *X2, int *Y2)
int x
Definition: SDL_rect.h:50
int y
Definition: SDL_rect.h:51
SDL_bool SDL_IntersectRect(const SDL_Rect *A, const SDL_Rect *B, SDL_Rect *result)
SDL_bool SDL_EnclosePoints(const SDL_Point *points, int count, const SDL_Rect *clip, SDL_Rect *result)
SDL_bool SDL_HasIntersection(const SDL_Rect *A, const SDL_Rect *B)
int x
Definition: SDL_rect.h:79
int w
Definition: SDL_rect.h:80
float h
Definition: SDL_rect.h:92
int h
Definition: SDL_rect.h:80
float x
Definition: SDL_rect.h:89
void SDL_UnionRect(const SDL_Rect *A, const SDL_Rect *B, SDL_Rect *result)
int y
Definition: SDL_rect.h:79
float x
Definition: SDL_rect.h:62
float y
Definition: SDL_rect.h:63