SkLayerDrawLooper.cpp revision 091a594dbc4116ec2e54724432472bf37dae794a 
1
2/*
3 * Copyright 2011 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8#include "SkCanvas.h"
9#include "SkColor.h"
10#include "SkReadBuffer.h"
11#include "SkWriteBuffer.h"
12#include "SkLayerDrawLooper.h"
13#include "SkString.h"
14#include "SkStringUtils.h"
15#include "SkUnPreMultiply.h"
16
17SkLayerDrawLooper::LayerInfo::LayerInfo() {
18    fPaintBits = 0;                     // ignore our paint fields
19    fColorMode = SkXfermode::kDst_Mode; // ignore our color
20    fOffset.set(0, 0);
21    fPostTranslate = false;
22}
23
24SkLayerDrawLooper::SkLayerDrawLooper()
25        : fRecs(NULL),
26          fTopRec(NULL),
27          fCount(0) {
28}
29
30SkLayerDrawLooper::~SkLayerDrawLooper() {
31    Rec* rec = fRecs;
32    while (rec) {
33        Rec* next = rec->fNext;
34        SkDELETE(rec);
35        rec = next;
36    }
37}
38
39SkLayerDrawLooper::Context* SkLayerDrawLooper::createContext(SkCanvas* canvas, void* storage) const {
40    canvas->save();
41    return SkNEW_PLACEMENT_ARGS(storage, LayerDrawLooperContext, (this));
42}
43
44static SkColor xferColor(SkColor src, SkColor dst, SkXfermode::Mode mode) {
45    switch (mode) {
46        case SkXfermode::kSrc_Mode:
47            return src;
48        case SkXfermode::kDst_Mode:
49            return dst;
50        default: {
51            SkPMColor pmS = SkPreMultiplyColor(src);
52            SkPMColor pmD = SkPreMultiplyColor(dst);
53            SkPMColor result = SkXfermode::GetProc(mode)(pmS, pmD);
54            return SkUnPreMultiply::PMColorToColor(result);
55        }
56    }
57}
58
59// Even with kEntirePaint_Bits, we always ensure that the master paint's
60// text-encoding is respected, since that controls how we interpret the
61// text/length parameters of a draw[Pos]Text call.
62void SkLayerDrawLooper::LayerDrawLooperContext::ApplyInfo(
63        SkPaint* dst, const SkPaint& src, const LayerInfo& info) {
64
65    dst->setColor(xferColor(src.getColor(), dst->getColor(), info.fColorMode));
66
67    BitFlags bits = info.fPaintBits;
68    SkPaint::TextEncoding encoding = dst->getTextEncoding();
69
70    if (0 == bits) {
71        return;
72    }
73    if (kEntirePaint_Bits == bits) {
74        // we've already computed these, so save it from the assignment
75        uint32_t f = dst->getFlags();
76        SkColor c = dst->getColor();
77        *dst = src;
78        dst->setFlags(f);
79        dst->setColor(c);
80        dst->setTextEncoding(encoding);
81        return;
82    }
83
84    if (bits & kStyle_Bit) {
85        dst->setStyle(src.getStyle());
86        dst->setStrokeWidth(src.getStrokeWidth());
87        dst->setStrokeMiter(src.getStrokeMiter());
88        dst->setStrokeCap(src.getStrokeCap());
89        dst->setStrokeJoin(src.getStrokeJoin());
90    }
91
92    if (bits & kTextSkewX_Bit) {
93        dst->setTextSkewX(src.getTextSkewX());
94    }
95
96    if (bits & kPathEffect_Bit) {
97        dst->setPathEffect(src.getPathEffect());
98    }
99    if (bits & kMaskFilter_Bit) {
100        dst->setMaskFilter(src.getMaskFilter());
101    }
102    if (bits & kShader_Bit) {
103        dst->setShader(src.getShader());
104    }
105    if (bits & kColorFilter_Bit) {
106        dst->setColorFilter(src.getColorFilter());
107    }
108    if (bits & kXfermode_Bit) {
109        dst->setXfermode(src.getXfermode());
110    }
111
112    // we don't override these
113#if 0
114    dst->setTypeface(src.getTypeface());
115    dst->setTextSize(src.getTextSize());
116    dst->setTextScaleX(src.getTextScaleX());
117    dst->setRasterizer(src.getRasterizer());
118    dst->setLooper(src.getLooper());
119    dst->setTextEncoding(src.getTextEncoding());
120    dst->setHinting(src.getHinting());
121#endif
122}
123
124// Should we add this to canvas?
125static void postTranslate(SkCanvas* canvas, SkScalar dx, SkScalar dy) {
126    SkMatrix m = canvas->getTotalMatrix();
127    m.postTranslate(dx, dy);
128    canvas->setMatrix(m);
129}
130
131SkLayerDrawLooper::LayerDrawLooperContext::LayerDrawLooperContext(
132        const SkLayerDrawLooper* looper) : fCurrRec(looper->fRecs) {}
133
134bool SkLayerDrawLooper::LayerDrawLooperContext::next(SkCanvas* canvas,
135                                                     SkPaint* paint) {
136    canvas->restore();
137    if (NULL == fCurrRec) {
138        return false;
139    }
140
141    ApplyInfo(paint, fCurrRec->fPaint, fCurrRec->fInfo);
142
143    canvas->save();
144    if (fCurrRec->fInfo.fPostTranslate) {
145        postTranslate(canvas, fCurrRec->fInfo.fOffset.fX,
146                      fCurrRec->fInfo.fOffset.fY);
147    } else {
148        canvas->translate(fCurrRec->fInfo.fOffset.fX,
149                          fCurrRec->fInfo.fOffset.fY);
150    }
151    fCurrRec = fCurrRec->fNext;
152
153    return true;
154}
155
156///////////////////////////////////////////////////////////////////////////////
157
158void SkLayerDrawLooper::flatten(SkWriteBuffer& buffer) const {
159    this->INHERITED::flatten(buffer);
160
161#ifdef SK_DEBUG
162    {
163        Rec* rec = fRecs;
164        int count = 0;
165        while (rec) {
166            rec = rec->fNext;
167            count += 1;
168        }
169        SkASSERT(count == fCount);
170    }
171#endif
172
173    buffer.writeInt(fCount);
174
175    Rec* rec = fRecs;
176    for (int i = 0; i < fCount; i++) {
177        // Legacy "flagsmask" field -- now ignored, remove when we bump version
178        buffer.writeInt(0);
179
180        buffer.writeInt(rec->fInfo.fPaintBits);
181        buffer.writeInt(rec->fInfo.fColorMode);
182        buffer.writePoint(rec->fInfo.fOffset);
183        buffer.writeBool(rec->fInfo.fPostTranslate);
184        buffer.writePaint(rec->fPaint);
185        rec = rec->fNext;
186    }
187}
188
189SkFlattenable* SkLayerDrawLooper::CreateProc(SkReadBuffer& buffer) {
190    int count = buffer.readInt();
191
192    Builder builder;
193    for (int i = 0; i < count; i++) {
194        LayerInfo info;
195        // Legacy "flagsmask" field -- now ignored, remove when we bump version
196        (void)buffer.readInt();
197
198        info.fPaintBits = buffer.readInt();
199        info.fColorMode = (SkXfermode::Mode)buffer.readInt();
200        buffer.readPoint(&info.fOffset);
201        info.fPostTranslate = buffer.readBool();
202        buffer.readPaint(builder.addLayerOnTop(info));
203    }
204    SkLayerDrawLooper* looper = builder.detachLooper();
205    SkASSERT(count == looper->fCount);
206
207#ifdef SK_DEBUG
208    {
209        Rec* rec = looper->fRecs;
210        int n = 0;
211        while (rec) {
212            rec = rec->fNext;
213            n += 1;
214        }
215        SkASSERT(count == n);
216    }
217#endif
218
219    return looper;
220}
221
222#ifndef SK_IGNORE_TO_STRING
223void SkLayerDrawLooper::toString(SkString* str) const {
224    str->appendf("SkLayerDrawLooper (%d): ", fCount);
225
226    Rec* rec = fRecs;
227    for (int i = 0; i < fCount; i++) {
228        str->appendf("%d: paintBits: (", i);
229        if (0 == rec->fInfo.fPaintBits) {
230            str->append("None");
231        } else if (kEntirePaint_Bits == rec->fInfo.fPaintBits) {
232            str->append("EntirePaint");
233        } else {
234            bool needSeparator = false;
235            SkAddFlagToString(str, SkToBool(kStyle_Bit & rec->fInfo.fPaintBits), "Style",
236                              &needSeparator);
237            SkAddFlagToString(str, SkToBool(kTextSkewX_Bit & rec->fInfo.fPaintBits), "TextSkewX",
238                              &needSeparator);
239            SkAddFlagToString(str, SkToBool(kPathEffect_Bit & rec->fInfo.fPaintBits), "PathEffect",
240                              &needSeparator);
241            SkAddFlagToString(str, SkToBool(kMaskFilter_Bit & rec->fInfo.fPaintBits), "MaskFilter",
242                              &needSeparator);
243            SkAddFlagToString(str, SkToBool(kShader_Bit & rec->fInfo.fPaintBits), "Shader",
244                              &needSeparator);
245            SkAddFlagToString(str, SkToBool(kColorFilter_Bit & rec->fInfo.fPaintBits), "ColorFilter",
246                              &needSeparator);
247            SkAddFlagToString(str, SkToBool(kXfermode_Bit & rec->fInfo.fPaintBits), "Xfermode",
248                              &needSeparator);
249        }
250        str->append(") ");
251
252        static const char* gModeStrings[SkXfermode::kLastMode+1] = {
253            "kClear", "kSrc", "kDst", "kSrcOver", "kDstOver", "kSrcIn", "kDstIn",
254            "kSrcOut", "kDstOut", "kSrcATop", "kDstATop", "kXor", "kPlus",
255            "kMultiply", "kScreen", "kOverlay", "kDarken", "kLighten", "kColorDodge",
256            "kColorBurn", "kHardLight", "kSoftLight", "kDifference", "kExclusion"
257        };
258
259        str->appendf("mode: %s ", gModeStrings[rec->fInfo.fColorMode]);
260
261        str->append("offset: (");
262        str->appendScalar(rec->fInfo.fOffset.fX);
263        str->append(", ");
264        str->appendScalar(rec->fInfo.fOffset.fY);
265        str->append(") ");
266
267        str->append("postTranslate: ");
268        if (rec->fInfo.fPostTranslate) {
269            str->append("true ");
270        } else {
271            str->append("false ");
272        }
273
274        rec->fPaint.toString(str);
275        rec = rec->fNext;
276    }
277}
278#endif
279
280SkLayerDrawLooper::Builder::Builder()
281        : fRecs(NULL),
282          fTopRec(NULL),
283          fCount(0) {
284}
285
286SkLayerDrawLooper::Builder::~Builder() {
287    Rec* rec = fRecs;
288    while (rec) {
289        Rec* next = rec->fNext;
290        SkDELETE(rec);
291        rec = next;
292    }
293}
294
295SkPaint* SkLayerDrawLooper::Builder::addLayer(const LayerInfo& info) {
296    fCount += 1;
297
298    Rec* rec = SkNEW(Rec);
299    rec->fNext = fRecs;
300    rec->fInfo = info;
301    fRecs = rec;
302    if (NULL == fTopRec) {
303        fTopRec = rec;
304    }
305
306    return &rec->fPaint;
307}
308
309void SkLayerDrawLooper::Builder::addLayer(SkScalar dx, SkScalar dy) {
310    LayerInfo info;
311
312    info.fOffset.set(dx, dy);
313    (void)this->addLayer(info);
314}
315
316SkPaint* SkLayerDrawLooper::Builder::addLayerOnTop(const LayerInfo& info) {
317    fCount += 1;
318
319    Rec* rec = SkNEW(Rec);
320    rec->fNext = NULL;
321    rec->fInfo = info;
322    if (NULL == fRecs) {
323        fRecs = rec;
324    } else {
325        SkASSERT(NULL != fTopRec);
326        fTopRec->fNext = rec;
327    }
328    fTopRec = rec;
329
330    return &rec->fPaint;
331}
332
333SkLayerDrawLooper* SkLayerDrawLooper::Builder::detachLooper() {
334    SkLayerDrawLooper* looper = SkNEW(SkLayerDrawLooper);
335    looper->fCount = fCount;
336    looper->fRecs = fRecs;
337
338    fCount = 0;
339    fRecs = NULL;
340    fTopRec = NULL;
341
342    return looper;
343}
344