reed | 026beb5 | 2015-06-10 14:23:15 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2015 Google Inc. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license that can be |
| 5 | * found in the LICENSE file. |
| 6 | */ |
| 7 | |
| 8 | #ifndef SkPathPriv_DEFINED |
| 9 | #define SkPathPriv_DEFINED |
| 10 | |
| 11 | #include "SkPath.h" |
| 12 | |
| 13 | class SkPathPriv { |
| 14 | public: |
| 15 | enum FirstDirection { |
| 16 | kCW_FirstDirection, // == SkPath::kCW_Direction |
| 17 | kCCW_FirstDirection, // == SkPath::kCCW_Direction |
| 18 | kUnknown_FirstDirection, |
| 19 | }; |
| 20 | |
| 21 | static FirstDirection AsFirstDirection(SkPath::Direction dir) { |
| 22 | // since we agree numerically for the values in Direction, we can just cast. |
| 23 | return (FirstDirection)dir; |
| 24 | } |
| 25 | |
| 26 | /** |
| 27 | * Return the opposite of the specified direction. kUnknown is its own |
| 28 | * opposite. |
| 29 | */ |
| 30 | static FirstDirection OppositeFirstDirection(FirstDirection dir) { |
| 31 | static const FirstDirection gOppositeDir[] = { |
| 32 | kCCW_FirstDirection, kCW_FirstDirection, kUnknown_FirstDirection, |
| 33 | }; |
| 34 | return gOppositeDir[dir]; |
| 35 | } |
| 36 | |
| 37 | /** |
| 38 | * Tries to quickly compute the direction of the first non-degenerate |
| 39 | * contour. If it can be computed, return true and set dir to that |
| 40 | * direction. If it cannot be (quickly) determined, return false and ignore |
| 41 | * the dir parameter. If the direction was determined, it is cached to make |
| 42 | * subsequent calls return quickly. |
| 43 | */ |
| 44 | static bool CheapComputeFirstDirection(const SkPath&, FirstDirection* dir); |
| 45 | |
| 46 | /** |
| 47 | * Returns true if the path's direction can be computed via |
| 48 | * cheapComputDirection() and if that computed direction matches the |
| 49 | * specified direction. If dir is kUnknown, returns true if the direction |
| 50 | * cannot be computed. |
| 51 | */ |
| 52 | static bool CheapIsFirstDirection(const SkPath& path, FirstDirection dir) { |
| 53 | FirstDirection computedDir = kUnknown_FirstDirection; |
| 54 | (void)CheapComputeFirstDirection(path, &computedDir); |
| 55 | return computedDir == dir; |
| 56 | } |
| 57 | |
| 58 | }; |
| 59 | |
| 60 | #endif |