reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2006 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #ifndef SkPerspIter_DEFINED |
| 18 | #define SkPerspIter_DEFINED |
| 19 | |
| 20 | #include "SkMatrix.h" |
| 21 | |
| 22 | class SkPerspIter { |
| 23 | public: |
| 24 | /** Iterate a line through the matrix [x,y] ... [x+count-1, y]. |
| 25 | @param m The matrix we will be iterating a line through |
| 26 | @param x The initial X coordinate to be mapped through the matrix |
| 27 | @param y The initial Y coordinate to be mapped through the matrix |
| 28 | @param count The number of points (x,y) (x+1,y) (x+2,y) ... we will eventually map |
| 29 | */ |
| 30 | SkPerspIter(const SkMatrix& m, SkScalar x, SkScalar y, int count); |
| 31 | |
| 32 | /** Return the buffer of [x,y] fixed point values we will be filling. |
| 33 | This always returns the same value, so it can be saved across calls to |
| 34 | next(). |
| 35 | */ |
| 36 | const SkFixed* getXY() const { return fStorage; } |
| 37 | |
| 38 | /** Return the number of [x,y] pairs that have been filled in the getXY() buffer. |
| 39 | When this returns 0, the iterator is finished. |
| 40 | */ |
| 41 | int next(); |
| 42 | |
| 43 | private: |
| 44 | enum { |
| 45 | kShift = 4, |
| 46 | kCount = (1 << kShift) |
| 47 | }; |
| 48 | const SkMatrix& fMatrix; |
| 49 | SkFixed fStorage[kCount * 2]; |
| 50 | SkFixed fX, fY; |
| 51 | SkScalar fSX, fSY; |
| 52 | int fCount; |
| 53 | }; |
| 54 | |
| 55 | #endif |