1/* graphene-line-segment-private.h: Segments
2 *
3 * SPDX-License-Identifier: MIT
4 *
5 * Copyright 2014 Emmanuele Bassi
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
26#pragma once
27
28#include "graphene-point.h"
29
30typedef struct {
31 graphene_point_t start;
32 graphene_point_t end;
33} graphene_line_segment_t;
34
35static inline graphene_line_segment_t
36graphene_line_segment_init (const graphene_point_t *start,
37 const graphene_point_t *end)
38{
39 graphene_line_segment_t l;
40 l.start = *start;
41 l.end = *end;
42
43 return l;
44}
45
46static inline bool
47graphene_line_segment_points_on_same_side (graphene_line_segment_t s,
48 const graphene_point_t *a,
49 const graphene_point_t *b)
50{
51 const float delta_x = (s.end.x - s.start.x);
52 const float delta_y = (s.end.y - s.start.y);
53
54 const float one = delta_x * (a->y - s.start.y) - delta_y * (a->x - s.start.x);
55 const float two = delta_x * (b->y - s.start.y) - delta_y * (b->x - s.start.x);
56
57 if ((one >= 0.f && two >= 0.f) || (one <= 0.f && two <= 0.f))
58 return true;
59
60 return false;
61}
62

source code of gtk/subprojects/graphene/src/graphene-line-segment-private.h