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/* graphene-line-segment-private.h: Segments
*
* Copyright 2014 Emmanuele Bassi
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef __GRAPHENE_LINE_SEGMENT_PRIVATE_H__
#define __GRAPHENE_LINE_SEGMENT_PRIVATE_H__
#include "graphene-point.h"
typedef struct {
graphene_point_t start;
graphene_point_t end;
} graphene_line_segment_t;
static inline graphene_line_segment_t
graphene_line_segment_init (const graphene_point_t *start,
const graphene_point_t *end)
{
graphene_line_segment_t l;
l.start = *start;
l.end = *end;
return l;
}
static inline bool
graphene_line_segment_points_on_same_side (graphene_line_segment_t s,
const graphene_point_t *a,
const graphene_point_t *b)
{
const float delta_x = (s.end.x - s.start.x);
const float delta_y = (s.end.y - s.start.y);
const float one = delta_x * (a->y - s.start.y) - delta_y * (a->x - s.start.x);
const float two = delta_x * (b->y - s.start.y) - delta_y * (b->x - s.start.x);
if ((one >= 0.f && two >= 0.f) || (one <= 0.f && two <= 0.f))
return true;
return false;
}
#endif /* __GRAPHENE_LINE_SEGMENT_PRIVATE_H__ */
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