1 /* 2 ** 3 ** Copyright 2007, The Android Open Source Project 4 ** 5 ** Licensed under the Apache License, Version 2.0 (the "License"); 6 ** you may not use this file except in compliance with the License. 7 ** You may obtain a copy of the License at 8 ** 9 ** http://www.apache.org/licenses/LICENSE-2.0 10 ** 11 ** Unless required by applicable law or agreed to in writing, software 12 ** distributed under the License is distributed on an "AS IS" BASIS, 13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 ** See the License for the specific language governing permissions and 15 ** limitations under the License. 16 */ 17 18 /* Based on the public domain code: 19 * Generic Convex Polygon Scan Conversion and Clipping 20 * by Paul Heckbert 21 * from "Graphics Gems", Academic Press, 1990 22 */ 23 24 25 #ifndef POLY_HDR 26 #define POLY_HDR 27 28 namespace android { 29 30 #define POLY_NMAX 10 /* max #sides to a polygon; change if needed */ 31 /* note that poly_clip, given an n-gon as input, might output an (n+6)gon */ 32 /* POLY_NMAX=10 is thus appropriate if input polygons are triangles or quads */ 33 34 typedef struct { /* A POLYGON VERTEX */ 35 float sx, sy, sz, sw; /* screen space position (sometimes homo.) */ 36 } Poly_vert; 37 38 typedef struct { /* A POLYGON */ 39 int n; /* number of sides */ 40 Poly_vert vert[POLY_NMAX]; /* vertices */ 41 } Poly; 42 43 #define POLY_CLIP_OUT 0 /* polygon entirely outside box */ 44 #define POLY_CLIP_PARTIAL 1 /* polygon partially inside */ 45 #define POLY_CLIP_IN 2 /* polygon entirely inside box */ 46 47 int poly_clip_to_frustum(Poly *p1); 48 49 } // namespace android 50 51 #endif 52
