1f0826543e
This adds a utility function that can determine if a given point intersects an arbitrary polygon, by counting how many edges a "semi-infinite" horizontal ray crosses from that point. The plan is to use this for a software based read-pixel fast path that avoids using the GPU to rasterize journaled primitives and can instead intersect a point being read with quads in the journal to determine the correct color.
41 lines
1.2 KiB
C
41 lines
1.2 KiB
C
/*
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* Cogl
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*
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* An object oriented GL/GLES Abstraction/Utility Layer
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*
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* Copyright (C) 2011 Intel Corporation.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library. If not, see
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* <http://www.gnu.org/licenses/>.
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*/
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#ifndef __COGL_POINT_INT_POLYGON_PRIVATE_H
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#define __COGL_POINT_INT_POLYGON_PRIVATE_H
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#include <glib.h>
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G_BEGIN_DECLS
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int
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_cogl_util_point_in_poly (float point_x,
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float point_y,
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void *vertices,
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size_t stride,
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int n_vertices);
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G_END_DECLS
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#endif /* __COGL_POINT_INT_POLYGON_PRIVATE_H */
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