OLD | NEW |
(Empty) | |
| 1 /* |
| 2 * Copyright 2013 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 SkCanvasStateUtils_DEFINED |
| 9 #define SkCanvasStateUtils_DEFINED |
| 10 |
| 11 #include "SkCanvas.h" |
| 12 |
| 13 struct SkCanvasState; |
| 14 |
| 15 /** |
| 16 * A set of functions that are useful for copying an SkCanvas across a library |
| 17 * boundary where the Skia libraries on either side of the boundary may not be |
| 18 * version identical. The expected usage is outline below... |
| 19 * |
| 20 * Lib Boundary |
| 21 * CaptureCanvasState(...) ||| |
| 22 * SkCanvas --> SkCanvasState ||| |
| 23 * ||| CreateFromCanvasState(...) |
| 24 * ||| SkCanvasState --> SkCanvas` |
| 25 * ||| Draw into SkCanvas` |
| 26 * ||| Unref SkCanvas` |
| 27 * ReleaseCanvasState(...) ||| |
| 28 * |
| 29 */ |
| 30 namespace SkCanvasStateUtils { |
| 31 /** |
| 32 * Captures the current state of the canvas into an opaque ptr that is safe |
| 33 * to pass between different instances of Skia (which may or may not be the |
| 34 * same version). The function will return NULL in the event that one of the |
| 35 * following conditions are true. |
| 36 * 1) the canvas device type is not supported (currently only raster is sup
ported) |
| 37 * 2) the canvas clip type is not supported (currently only non-AA clips ar
e supported) |
| 38 * |
| 39 * It is recommended that the original canvas also not be used until all |
| 40 * canvases that have been created using its captured state have been derefe
renced. |
| 41 * |
| 42 * Finally, it is important to note that any draw filters attached to the |
| 43 * canvas are NOT currently captured. |
| 44 * |
| 45 * @param canvas The canvas you wish to capture the current state of. |
| 46 * @return NULL or an opaque ptr that can be passed to CreateFromCanvasState |
| 47 * to reconstruct the canvas. The caller is responsible for calling |
| 48 * ReleaseCanvasState to free the memory associated with this state. |
| 49 */ |
| 50 SK_API SkCanvasState* CaptureCanvasState(SkCanvas* canvas); |
| 51 |
| 52 /** |
| 53 * Create a new SkCanvas from the captured state of another SkCanvas. The |
| 54 * function will return NULL in the event that one of the |
| 55 * following conditions are true. |
| 56 * 1) the captured state is in an unrecognized format |
| 57 * 2) the captured canvas device type is not supported |
| 58 * |
| 59 * @param canvas The canvas you wish to capture the current state of. |
| 60 * @return NULL or an SkCanvas* whose devices and matrix/clip state are |
| 61 * identical to the captured canvas. The caller is responsible for |
| 62 * calling unref on the SkCanvas. |
| 63 */ |
| 64 SK_API SkCanvas* CreateFromCanvasState(const SkCanvasState* state); |
| 65 |
| 66 /** |
| 67 * Free the memory associated with the captured canvas state. The state |
| 68 * should not be released until all SkCanvas objects created using that |
| 69 * state have been dereferenced. |
| 70 * |
| 71 * @param state The captured state you wish to dispose of. |
| 72 */ |
| 73 SK_API void ReleaseCanvasState(SkCanvasState* state); |
| 74 }; |
| 75 |
| 76 #endif |
OLD | NEW |