83 lines
2.4 KiB
C
83 lines
2.4 KiB
C
/*
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* Copyright © 2012 Intel Corporation
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice (including the
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* next paragraph) shall be included in all copies or substantial
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* portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#ifndef _WESTON_VERTEX_CLIPPING_H
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#define _WESTON_VERTEX_CLIPPING_H
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#include <stdbool.h>
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#include <pixman.h>
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struct clip_vertex {
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float x, y;
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};
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struct polygon8 {
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struct clip_vertex pos[8];
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int n;
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};
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struct gl_quad {
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struct polygon8 vertices;
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struct { float x1, y1, x2, y2; } bbox; /* Valid if !axis_aligned. */
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bool axis_aligned;
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};
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struct clip_context {
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struct clip_vertex prev;
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struct {
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float x1, y1;
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float x2, y2;
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} clip;
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struct clip_vertex *vertices;
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};
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float
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float_difference(float a, float b);
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int
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clip_simple(struct clip_context *ctx,
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struct polygon8 *surf,
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struct clip_vertex *restrict vertices);
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int
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clip_transformed(struct clip_context *ctx,
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const struct polygon8 *surf,
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struct clip_vertex *restrict vertices);
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/*
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* Compute the boundary vertices of the intersection of an arbitrary
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* quadrilateral 'quad' and the axis-aligned rectangle 'surf_rect'. The vertices
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* are written to 'vertices', and the return value is the number of vertices.
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* Vertices are produced in clockwise winding order. Guarantees to produce
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* either zero vertices, or 3-8 vertices with non-zero polygon area.
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*/
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int
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clip_quad(struct gl_quad *quad,
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pixman_box32_t *surf_rect,
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struct clip_vertex *vertices);
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#endif
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