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djsollen@google.com5587ac02013-08-29 20:20:40 +00001/*
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#include "SkCanvasStateUtils.h"
9
10#include "SkBitmapDevice.h"
11#include "SkCanvas.h"
djsollen@google.com339e79f2013-09-04 17:16:00 +000012#include "SkCanvasStack.h"
commit-bot@chromium.org07f6cf32013-09-18 20:15:12 +000013#include "SkErrorInternals.h"
djsollen@google.com5587ac02013-08-29 20:20:40 +000014#include "SkWriter32.h"
15
16#define CANVAS_STATE_VERSION 1
17/*
18 * WARNING: The structs below are part of a stable ABI and as such we explicitly
19 * use unambigious primitives (e.g. int32_t instead of an enum).
20 *
21 * ANY CHANGES TO THE STRUCTS BELOW THAT IMPACT THE ABI SHOULD RESULT IN AN
22 * UPDATE OF THE CANVAS_STATE_VERSION. SUCH CHANGES SHOULD ONLY BE MADE IF
23 * ABSOLUTELY NECESSARY!
24 */
25enum RasterConfigs {
26 kUnknown_RasterConfig = 0,
27 kRGB_565_RasterConfig = 1,
28 kARGB_8888_RasterConfig = 2
29};
30typedef int32_t RasterConfig;
31
32enum CanvasBackends {
33 kUnknown_CanvasBackend = 0,
34 kRaster_CanvasBackend = 1,
35 kGPU_CanvasBackend = 2,
36 kPDF_CanvasBackend = 3
37};
38typedef int32_t CanvasBackend;
39
40struct ClipRect {
41 int32_t left, top, right, bottom;
42};
43
44struct SkMCState {
45 float matrix[9];
46 // NOTE: this only works for non-antialiased clips
47 int32_t clipRectCount;
48 ClipRect* clipRects;
49};
50
51// NOTE: If you add more members, bump CanvasState::version.
52struct SkCanvasLayerState {
53 CanvasBackend type;
54 int32_t x, y;
55 int32_t width;
56 int32_t height;
57
58 SkMCState mcState;
59
60 union {
61 struct {
62 RasterConfig config; // pixel format: a value from RasterConfigs.
robertphillips@google.com8b169312013-10-15 17:47:36 +000063 size_t rowBytes; // Number of bytes from start of one line to next.
djsollen@google.com5587ac02013-08-29 20:20:40 +000064 void* pixels; // The pixels, all (height * rowBytes) of them.
65 } raster;
66 struct {
67 int32_t textureID;
68 } gpu;
69 };
70};
71
72class SkCanvasState {
73public:
74 SkCanvasState(SkCanvas* canvas) {
75 SkASSERT(canvas);
76 version = CANVAS_STATE_VERSION;
77 width = canvas->getDeviceSize().width();
78 height = canvas->getDeviceSize().height();
79 layerCount = 0;
80 layers = NULL;
81 originalCanvas = SkRef(canvas);
82
83 mcState.clipRectCount = 0;
84 mcState.clipRects = NULL;
85 }
86
87 ~SkCanvasState() {
88 // loop through the layers and free the data allocated to the clipRects
89 for (int i = 0; i < layerCount; ++i) {
90 sk_free(layers[i].mcState.clipRects);
91 }
92
93 sk_free(mcState.clipRects);
94 sk_free(layers);
95
96 // it is now safe to free the canvas since there should be no remaining
97 // references to the content that is referenced by this canvas (e.g. pixels)
98 originalCanvas->unref();
99 }
100
101 /**
102 * The version this struct was built with. This field must always appear
103 * first in the struct so that when the versions don't match (and the
104 * remaining contents and size are potentially different) we can still
105 * compare the version numbers.
106 */
107 int32_t version;
108
109 int32_t width;
110 int32_t height;
111
112 SkMCState mcState;
113
114 int32_t layerCount;
115 SkCanvasLayerState* layers;
116
117private:
118 SkCanvas* originalCanvas;
119};
120
121////////////////////////////////////////////////////////////////////////////////
122
123class ClipValidator : public SkCanvas::ClipVisitor {
124public:
125 ClipValidator() : fFailed(false) {}
126 bool failed() { return fFailed; }
127
128 // ClipVisitor
129 virtual void clipRect(const SkRect& rect, SkRegion::Op op, bool antialias) SK_OVERRIDE {
130 fFailed |= antialias;
131 }
132
commit-bot@chromium.orge5b2af92014-02-16 13:25:24 +0000133 virtual void clipRRect(const SkRRect& rrect, SkRegion::Op op, bool antialias) SK_OVERRIDE {
134 fFailed |= antialias;
135 }
136
djsollen@google.com5587ac02013-08-29 20:20:40 +0000137 virtual void clipPath(const SkPath&, SkRegion::Op, bool antialias) SK_OVERRIDE {
138 fFailed |= antialias;
139 }
140
141private:
142 bool fFailed;
143};
144
145static void setup_MC_state(SkMCState* state, const SkMatrix& matrix, const SkRegion& clip) {
146 // initialize the struct
147 state->clipRectCount = 0;
148
149 // capture the matrix
150 for (int i = 0; i < 9; i++) {
151 state->matrix[i] = matrix.get(i);
152 }
153
154 /*
155 * capture the clip
156 *
157 * storage is allocated on the stack for the first 4 rects. This value was
158 * chosen somewhat arbitrarily, but does allow us to represent simple clips
159 * and some more common complex clips (e.g. a clipRect with a sub-rect
160 * clipped out of its interior) without needing to malloc any additional memory.
161 */
commit-bot@chromium.org19382422014-01-14 20:51:26 +0000162 SkSWriter32<4*sizeof(ClipRect)> clipWriter;
djsollen@google.com5587ac02013-08-29 20:20:40 +0000163
164 if (!clip.isEmpty()) {
165 // only returns the b/w clip so aa clips fail
166 SkRegion::Iterator clip_iterator(clip);
167 for (; !clip_iterator.done(); clip_iterator.next()) {
168 // this assumes the SkIRect is stored in l,t,r,b ordering which
169 // matches the ordering of our ClipRect struct
170 clipWriter.writeIRect(clip_iterator.rect());
171 state->clipRectCount++;
172 }
173 }
174
175 // allocate memory for the clip then and copy them to the struct
reed@google.com44699382013-10-31 17:28:30 +0000176 state->clipRects = (ClipRect*) sk_malloc_throw(clipWriter.bytesWritten());
djsollen@google.com5587ac02013-08-29 20:20:40 +0000177 clipWriter.flatten(state->clipRects);
178}
179
180
181
182SkCanvasState* SkCanvasStateUtils::CaptureCanvasState(SkCanvas* canvas) {
183 SkASSERT(canvas);
184
185 // Check the clip can be decomposed into rectangles (i.e. no soft clips).
186 ClipValidator validator;
187 canvas->replayClips(&validator);
188 if (validator.failed()) {
commit-bot@chromium.org07f6cf32013-09-18 20:15:12 +0000189 SkErrorInternals::SetError(kInvalidOperation_SkError,
190 "CaptureCanvasState does not support canvases with antialiased clips.\n");
djsollen@google.com5587ac02013-08-29 20:20:40 +0000191 return NULL;
192 }
193
194 SkAutoTDelete<SkCanvasState> canvasState(SkNEW_ARGS(SkCanvasState, (canvas)));
195
196 // decompose the total matrix and clip
commit-bot@chromium.org5c70cdc2014-03-08 03:57:19 +0000197 setup_MC_state(&canvasState->mcState, canvas->getTotalMatrix(),
198 canvas->internal_private_getTotalClip());
djsollen@google.com5587ac02013-08-29 20:20:40 +0000199
200 /*
201 * decompose the layers
202 *
203 * storage is allocated on the stack for the first 3 layers. It is common in
204 * some view systems (e.g. Android) that a few non-clipped layers are present
205 * and we will not need to malloc any additional memory in those cases.
206 */
commit-bot@chromium.org19382422014-01-14 20:51:26 +0000207 SkSWriter32<3*sizeof(SkCanvasLayerState)> layerWriter;
djsollen@google.com5587ac02013-08-29 20:20:40 +0000208 int layerCount = 0;
209 for (SkCanvas::LayerIter layer(canvas, true/*skipEmptyClips*/); !layer.done(); layer.next()) {
210
211 // we currently only work for bitmap backed devices
212 const SkBitmap& bitmap = layer.device()->accessBitmap(true/*changePixels*/);
213 if (bitmap.empty() || bitmap.isNull() || !bitmap.lockPixelsAreWritable()) {
214 return NULL;
215 }
216
217 SkCanvasLayerState* layerState =
218 (SkCanvasLayerState*) layerWriter.reserve(sizeof(SkCanvasLayerState));
219 layerState->type = kRaster_CanvasBackend;
220 layerState->x = layer.x();
221 layerState->y = layer.y();
222 layerState->width = bitmap.width();
223 layerState->height = bitmap.height();
224
commit-bot@chromium.orge24ad232014-02-16 22:03:38 +0000225 switch (bitmap.colorType()) {
commit-bot@chromium.org28fcae22014-04-11 17:15:40 +0000226 case kN32_SkColorType:
djsollen@google.com5587ac02013-08-29 20:20:40 +0000227 layerState->raster.config = kARGB_8888_RasterConfig;
228 break;
commit-bot@chromium.orge24ad232014-02-16 22:03:38 +0000229 case kRGB_565_SkColorType:
djsollen@google.com5587ac02013-08-29 20:20:40 +0000230 layerState->raster.config = kRGB_565_RasterConfig;
231 break;
232 default:
233 return NULL;
234 }
235 layerState->raster.rowBytes = bitmap.rowBytes();
236 layerState->raster.pixels = bitmap.getPixels();
237
238 setup_MC_state(&layerState->mcState, layer.matrix(), layer.clip());
239 layerCount++;
240 }
241
242 // allocate memory for the layers and then and copy them to the struct
reed@google.com44699382013-10-31 17:28:30 +0000243 SkASSERT(layerWriter.bytesWritten() == layerCount * sizeof(SkCanvasLayerState));
djsollen@google.com5587ac02013-08-29 20:20:40 +0000244 canvasState->layerCount = layerCount;
reed@google.com44699382013-10-31 17:28:30 +0000245 canvasState->layers = (SkCanvasLayerState*) sk_malloc_throw(layerWriter.bytesWritten());
djsollen@google.com5587ac02013-08-29 20:20:40 +0000246 layerWriter.flatten(canvasState->layers);
247
248 // for now, just ignore any client supplied DrawFilter.
249 if (canvas->getDrawFilter()) {
commit-bot@chromium.org07f6cf32013-09-18 20:15:12 +0000250// SkDEBUGF(("CaptureCanvasState will ignore the canvases draw filter.\n"));
djsollen@google.com5587ac02013-08-29 20:20:40 +0000251 }
252
253 return canvasState.detach();
254}
255
256////////////////////////////////////////////////////////////////////////////////
257
258static void setup_canvas_from_MC_state(const SkMCState& state, SkCanvas* canvas) {
259 // reconstruct the matrix
260 SkMatrix matrix;
261 for (int i = 0; i < 9; i++) {
262 matrix.set(i, state.matrix[i]);
263 }
264
265 // reconstruct the clip
266 SkRegion clip;
267 for (int i = 0; i < state.clipRectCount; ++i) {
268 clip.op(SkIRect::MakeLTRB(state.clipRects[i].left,
269 state.clipRects[i].top,
270 state.clipRects[i].right,
271 state.clipRects[i].bottom),
272 SkRegion::kUnion_Op);
273 }
274
275 canvas->setMatrix(matrix);
276 canvas->setClipRegion(clip);
277}
278
279static SkCanvas* create_canvas_from_canvas_layer(const SkCanvasLayerState& layerState) {
280 SkASSERT(kRaster_CanvasBackend == layerState.type);
281
282 SkBitmap bitmap;
commit-bot@chromium.orge24ad232014-02-16 22:03:38 +0000283 SkColorType colorType =
commit-bot@chromium.org28fcae22014-04-11 17:15:40 +0000284 layerState.raster.config == kARGB_8888_RasterConfig ? kN32_SkColorType :
commit-bot@chromium.orge24ad232014-02-16 22:03:38 +0000285 layerState.raster.config == kRGB_565_RasterConfig ? kRGB_565_SkColorType :
286 kUnknown_SkColorType;
djsollen@google.com5587ac02013-08-29 20:20:40 +0000287
commit-bot@chromium.orge24ad232014-02-16 22:03:38 +0000288 if (colorType == kUnknown_SkColorType) {
djsollen@google.com5587ac02013-08-29 20:20:40 +0000289 return NULL;
290 }
291
commit-bot@chromium.orge24ad232014-02-16 22:03:38 +0000292 bitmap.installPixels(SkImageInfo::Make(layerState.width, layerState.height,
293 colorType, kPremul_SkAlphaType),
294 layerState.raster.pixels, layerState.raster.rowBytes,
295 NULL, NULL);
djsollen@google.com5587ac02013-08-29 20:20:40 +0000296
297 SkASSERT(!bitmap.empty());
298 SkASSERT(!bitmap.isNull());
299
commit-bot@chromium.orge24ad232014-02-16 22:03:38 +0000300 SkAutoTUnref<SkCanvas> canvas(SkNEW_ARGS(SkCanvas, (bitmap)));
djsollen@google.com5587ac02013-08-29 20:20:40 +0000301
302 // setup the matrix and clip
303 setup_canvas_from_MC_state(layerState.mcState, canvas.get());
304
305 return canvas.detach();
306}
307
308SkCanvas* SkCanvasStateUtils::CreateFromCanvasState(const SkCanvasState* state) {
309 SkASSERT(state);
310
311 // check that the versions match
312 if (CANVAS_STATE_VERSION != state->version) {
313 SkDebugf("CreateFromCanvasState version does not match the one use to create the input");
314 return NULL;
315 }
316
317 if (state->layerCount < 1) {
318 return NULL;
319 }
320
djsollen@google.com339e79f2013-09-04 17:16:00 +0000321 SkAutoTUnref<SkCanvasStack> canvas(SkNEW_ARGS(SkCanvasStack, (state->width, state->height)));
djsollen@google.com5587ac02013-08-29 20:20:40 +0000322
323 // setup the matrix and clip on the n-way canvas
324 setup_canvas_from_MC_state(state->mcState, canvas);
325
326 // Iterate over the layers and add them to the n-way canvas
djsollen@google.com339e79f2013-09-04 17:16:00 +0000327 for (int i = state->layerCount - 1; i >= 0; --i) {
djsollen@google.com5587ac02013-08-29 20:20:40 +0000328 SkAutoTUnref<SkCanvas> canvasLayer(create_canvas_from_canvas_layer(state->layers[i]));
329 if (!canvasLayer.get()) {
330 return NULL;
331 }
djsollen@google.com339e79f2013-09-04 17:16:00 +0000332 canvas->pushCanvas(canvasLayer.get(), SkIPoint::Make(state->layers[i].x,
333 state->layers[i].y));
djsollen@google.com5587ac02013-08-29 20:20:40 +0000334 }
335
336 return canvas.detach();
337}
338
339////////////////////////////////////////////////////////////////////////////////
340
341void SkCanvasStateUtils::ReleaseCanvasState(SkCanvasState* state) {
342 SkDELETE(state);
343}