/* * Copyright © 2012 Intel Corporation * * 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 (including the * next paragraph) 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 _WESTON_VERTEX_CLIPPING_H #define _WESTON_VERTEX_CLIPPING_H #include #include struct clip_vertex { float x, y; }; struct polygon8 { struct clip_vertex pos[8]; int n; }; struct gl_quad { struct polygon8 vertices; struct { float x1, y1, x2, y2; } bbox; /* Valid if !axis_aligned. */ bool axis_aligned; }; struct clip_context { struct clip_vertex prev; struct { float x1, y1; float x2, y2; } clip; struct clip_vertex *vertices; }; float float_difference(float a, float b); int clip_simple(struct clip_context *ctx, struct polygon8 *surf, struct clip_vertex *restrict vertices); int clip_transformed(struct clip_context *ctx, struct polygon8 *surf, struct clip_vertex *restrict vertices); /* * Compute the boundary vertices of the intersection of an arbitrary * quadrilateral 'quad' and the axis-aligned rectangle 'surf_rect'. The vertices * are written to 'vertices', and the return value is the number of vertices. * Vertices are produced in clockwise winding order. Guarantees to produce * either zero vertices, or 3-8 vertices with non-zero polygon area. */ int clip_quad(struct gl_quad *quad, pixman_box32_t *surf_rect, struct clip_vertex *vertices); #endif