SkLayerDrawLooper.cpp revision 8b0e8ac5f582de80356019406e2975079bf0829d 
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    fFlagsMask = 0;                     // ignore our paint flags
19    fPaintBits = 0;                     // ignore our paint fields
20    fColorMode = SkXfermode::kDst_Mode; // ignore our color
21    fOffset.set(0, 0);
22    fPostTranslate = false;
23}
24
25SkLayerDrawLooper::SkLayerDrawLooper()
26        : fRecs(NULL),
27          fTopRec(NULL),
28          fCount(0),
29          fCurrRec(NULL) {
30}
31
32SkLayerDrawLooper::~SkLayerDrawLooper() {
33    Rec* rec = fRecs;
34    while (rec) {
35        Rec* next = rec->fNext;
36        SkDELETE(rec);
37        rec = next;
38    }
39}
40
41SkPaint* SkLayerDrawLooper::addLayer(const LayerInfo& info) {
42    fCount += 1;
43
44    Rec* rec = SkNEW(Rec);
45    rec->fNext = fRecs;
46    rec->fInfo = info;
47    fRecs = rec;
48    if (NULL == fTopRec) {
49        fTopRec = rec;
50    }
51
52    return &rec->fPaint;
53}
54
55void SkLayerDrawLooper::addLayer(SkScalar dx, SkScalar dy) {
56    LayerInfo info;
57
58    info.fOffset.set(dx, dy);
59    (void)this->addLayer(info);
60}
61
62SkPaint* SkLayerDrawLooper::addLayerOnTop(const LayerInfo& info) {
63    fCount += 1;
64
65    Rec* rec = SkNEW(Rec);
66    rec->fNext = NULL;
67    rec->fInfo = info;
68    if (NULL == fRecs) {
69        fRecs = rec;
70    } else {
71        SkASSERT(NULL != fTopRec);
72        fTopRec->fNext = rec;
73    }
74    fTopRec = rec;
75
76    return &rec->fPaint;
77}
78
79void SkLayerDrawLooper::init(SkCanvas* canvas) {
80    fCurrRec = fRecs;
81    canvas->save(SkCanvas::kMatrix_SaveFlag);
82}
83
84static SkColor xferColor(SkColor src, SkColor dst, SkXfermode::Mode mode) {
85    switch (mode) {
86        case SkXfermode::kSrc_Mode:
87            return src;
88        case SkXfermode::kDst_Mode:
89            return dst;
90        default: {
91            SkPMColor pmS = SkPreMultiplyColor(src);
92            SkPMColor pmD = SkPreMultiplyColor(dst);
93            SkPMColor result = SkXfermode::GetProc(mode)(pmS, pmD);
94            return SkUnPreMultiply::PMColorToColor(result);
95        }
96    }
97}
98
99// Even with kEntirePaint_Bits, we always ensure that the master paint's
100// text-encoding is respected, since that controls how we interpret the
101// text/length parameters of a draw[Pos]Text call.
102void SkLayerDrawLooper::ApplyInfo(SkPaint* dst, const SkPaint& src,
103                                  const LayerInfo& info) {
104
105    uint32_t mask = info.fFlagsMask;
106    dst->setFlags((dst->getFlags() & ~mask) | (src.getFlags() & mask));
107    dst->setColor(xferColor(src.getColor(), dst->getColor(), info.fColorMode));
108
109    BitFlags bits = info.fPaintBits;
110    SkPaint::TextEncoding encoding = dst->getTextEncoding();
111
112    if (0 == bits) {
113        return;
114    }
115    if (kEntirePaint_Bits == bits) {
116        // we've already computed these, so save it from the assignment
117        uint32_t f = dst->getFlags();
118        SkColor c = dst->getColor();
119        *dst = src;
120        dst->setFlags(f);
121        dst->setColor(c);
122        dst->setTextEncoding(encoding);
123        return;
124    }
125
126    if (bits & kStyle_Bit) {
127        dst->setStyle(src.getStyle());
128        dst->setStrokeWidth(src.getStrokeWidth());
129        dst->setStrokeMiter(src.getStrokeMiter());
130        dst->setStrokeCap(src.getStrokeCap());
131        dst->setStrokeJoin(src.getStrokeJoin());
132    }
133
134    if (bits & kTextSkewX_Bit) {
135        dst->setTextSkewX(src.getTextSkewX());
136    }
137
138    if (bits & kPathEffect_Bit) {
139        dst->setPathEffect(src.getPathEffect());
140    }
141    if (bits & kMaskFilter_Bit) {
142        dst->setMaskFilter(src.getMaskFilter());
143    }
144    if (bits & kShader_Bit) {
145        dst->setShader(src.getShader());
146    }
147    if (bits & kColorFilter_Bit) {
148        dst->setColorFilter(src.getColorFilter());
149    }
150    if (bits & kXfermode_Bit) {
151        dst->setXfermode(src.getXfermode());
152    }
153
154    // we don't override these
155#if 0
156    dst->setTypeface(src.getTypeface());
157    dst->setTextSize(src.getTextSize());
158    dst->setTextScaleX(src.getTextScaleX());
159    dst->setRasterizer(src.getRasterizer());
160    dst->setLooper(src.getLooper());
161    dst->setTextEncoding(src.getTextEncoding());
162    dst->setHinting(src.getHinting());
163#endif
164}
165
166// Should we add this to canvas?
167static void postTranslate(SkCanvas* canvas, SkScalar dx, SkScalar dy) {
168    SkMatrix m = canvas->getTotalMatrix();
169    m.postTranslate(dx, dy);
170    canvas->setMatrix(m);
171}
172
173bool SkLayerDrawLooper::next(SkCanvas* canvas, SkPaint* paint) {
174    canvas->restore();
175    if (NULL == fCurrRec) {
176        return false;
177    }
178
179    ApplyInfo(paint, fCurrRec->fPaint, fCurrRec->fInfo);
180
181    canvas->save(SkCanvas::kMatrix_SaveFlag);
182    if (fCurrRec->fInfo.fPostTranslate) {
183        postTranslate(canvas, fCurrRec->fInfo.fOffset.fX,
184                      fCurrRec->fInfo.fOffset.fY);
185    } else {
186        canvas->translate(fCurrRec->fInfo.fOffset.fX, fCurrRec->fInfo.fOffset.fY);
187    }
188    fCurrRec = fCurrRec->fNext;
189
190    return true;
191}
192
193///////////////////////////////////////////////////////////////////////////////
194
195void SkLayerDrawLooper::flatten(SkWriteBuffer& buffer) const {
196    this->INHERITED::flatten(buffer);
197
198#ifdef SK_DEBUG
199    {
200        Rec* rec = fRecs;
201        int count = 0;
202        while (rec) {
203            rec = rec->fNext;
204            count += 1;
205        }
206        SkASSERT(count == fCount);
207    }
208#endif
209
210    buffer.writeInt(fCount);
211
212    Rec* rec = fRecs;
213    for (int i = 0; i < fCount; i++) {
214        buffer.writeInt(rec->fInfo.fFlagsMask);
215        buffer.writeInt(rec->fInfo.fPaintBits);
216        buffer.writeInt(rec->fInfo.fColorMode);
217        buffer.writePoint(rec->fInfo.fOffset);
218        buffer.writeBool(rec->fInfo.fPostTranslate);
219        buffer.writePaint(rec->fPaint);
220        rec = rec->fNext;
221    }
222}
223
224SkLayerDrawLooper::SkLayerDrawLooper(SkReadBuffer& buffer)
225        : INHERITED(buffer),
226          fRecs(NULL),
227          fTopRec(NULL),
228          fCount(0),
229          fCurrRec(NULL) {
230    int count = buffer.readInt();
231
232    for (int i = 0; i < count; i++) {
233        LayerInfo info;
234        info.fFlagsMask = buffer.readInt();
235        info.fPaintBits = buffer.readInt();
236        info.fColorMode = (SkXfermode::Mode)buffer.readInt();
237        buffer.readPoint(&info.fOffset);
238        info.fPostTranslate = buffer.readBool();
239        buffer.readPaint(this->addLayerOnTop(info));
240    }
241    SkASSERT(count == fCount);
242
243#ifdef SK_DEBUG
244    {
245        Rec* rec = fRecs;
246        int n = 0;
247        while (rec) {
248            rec = rec->fNext;
249            n += 1;
250        }
251        SkASSERT(count == n);
252    }
253#endif
254}
255
256#ifdef SK_DEVELOPER
257void SkLayerDrawLooper::toString(SkString* str) const {
258    str->appendf("SkLayerDrawLooper (%d): ", fCount);
259
260    Rec* rec = fRecs;
261    for (int i = 0; i < fCount; i++) {
262        str->appendf("%d: ", i);
263
264        str->append("flagsMask: (");
265        if (0 == rec->fInfo.fFlagsMask) {
266            str->append("None");
267        } else {
268            bool needSeparator = false;
269            SkAddFlagToString(str, SkToBool(SkPaint::kAntiAlias_Flag & rec->fInfo.fFlagsMask),
270                              "AntiAlias", &needSeparator);
271//            SkAddFlagToString(str, SkToBool(SkPaint::kFilterBitmap_Flag & rec->fInfo.fFlagsMask), "FilterBitmap", &needSeparator);
272            SkAddFlagToString(str, SkToBool(SkPaint::kDither_Flag & rec->fInfo.fFlagsMask),
273                              "Dither", &needSeparator);
274            SkAddFlagToString(str, SkToBool(SkPaint::kUnderlineText_Flag & rec->fInfo.fFlagsMask),
275                              "UnderlineText", &needSeparator);
276            SkAddFlagToString(str, SkToBool(SkPaint::kStrikeThruText_Flag & rec->fInfo.fFlagsMask),
277                              "StrikeThruText", &needSeparator);
278            SkAddFlagToString(str, SkToBool(SkPaint::kFakeBoldText_Flag & rec->fInfo.fFlagsMask),
279                              "FakeBoldText", &needSeparator);
280            SkAddFlagToString(str, SkToBool(SkPaint::kLinearText_Flag & rec->fInfo.fFlagsMask),
281                              "LinearText", &needSeparator);
282            SkAddFlagToString(str, SkToBool(SkPaint::kSubpixelText_Flag & rec->fInfo.fFlagsMask),
283                              "SubpixelText", &needSeparator);
284            SkAddFlagToString(str, SkToBool(SkPaint::kDevKernText_Flag & rec->fInfo.fFlagsMask),
285                              "DevKernText", &needSeparator);
286            SkAddFlagToString(str, SkToBool(SkPaint::kLCDRenderText_Flag & rec->fInfo.fFlagsMask),
287                              "LCDRenderText", &needSeparator);
288            SkAddFlagToString(str, SkToBool(SkPaint::kEmbeddedBitmapText_Flag & rec->fInfo.fFlagsMask),
289                              "EmbeddedBitmapText", &needSeparator);
290            SkAddFlagToString(str, SkToBool(SkPaint::kAutoHinting_Flag & rec->fInfo.fFlagsMask),
291                              "Autohinted", &needSeparator);
292            SkAddFlagToString(str, SkToBool(SkPaint::kVerticalText_Flag & rec->fInfo.fFlagsMask),
293                              "VerticalText", &needSeparator);
294            SkAddFlagToString(str, SkToBool(SkPaint::kGenA8FromLCD_Flag & rec->fInfo.fFlagsMask),
295                              "GenA8FromLCD", &needSeparator);
296        }
297        str->append(") ");
298
299        str->append("paintBits: (");
300        if (0 == rec->fInfo.fPaintBits) {
301            str->append("None");
302        } else if (kEntirePaint_Bits == rec->fInfo.fPaintBits) {
303            str->append("EntirePaint");
304        } else {
305            bool needSeparator = false;
306            SkAddFlagToString(str, SkToBool(kStyle_Bit & rec->fInfo.fPaintBits), "Style",
307                              &needSeparator);
308            SkAddFlagToString(str, SkToBool(kTextSkewX_Bit & rec->fInfo.fPaintBits), "TextSkewX",
309                              &needSeparator);
310            SkAddFlagToString(str, SkToBool(kPathEffect_Bit & rec->fInfo.fPaintBits), "PathEffect",
311                              &needSeparator);
312            SkAddFlagToString(str, SkToBool(kMaskFilter_Bit & rec->fInfo.fPaintBits), "MaskFilter",
313                              &needSeparator);
314            SkAddFlagToString(str, SkToBool(kShader_Bit & rec->fInfo.fPaintBits), "Shader",
315                              &needSeparator);
316            SkAddFlagToString(str, SkToBool(kColorFilter_Bit & rec->fInfo.fPaintBits), "ColorFilter",
317                              &needSeparator);
318            SkAddFlagToString(str, SkToBool(kXfermode_Bit & rec->fInfo.fPaintBits), "Xfermode",
319                              &needSeparator);
320        }
321        str->append(") ");
322
323        static const char* gModeStrings[SkXfermode::kLastMode+1] = {
324            "kClear", "kSrc", "kDst", "kSrcOver", "kDstOver", "kSrcIn", "kDstIn",
325            "kSrcOut", "kDstOut", "kSrcATop", "kDstATop", "kXor", "kPlus",
326            "kMultiply", "kScreen", "kOverlay", "kDarken", "kLighten", "kColorDodge",
327            "kColorBurn", "kHardLight", "kSoftLight", "kDifference", "kExclusion"
328        };
329
330        str->appendf("mode: %s ", gModeStrings[rec->fInfo.fColorMode]);
331
332        str->append("offset: (");
333        str->appendScalar(rec->fInfo.fOffset.fX);
334        str->append(", ");
335        str->appendScalar(rec->fInfo.fOffset.fY);
336        str->append(") ");
337
338        str->append("postTranslate: ");
339        if (rec->fInfo.fPostTranslate) {
340            str->append("true ");
341        } else {
342            str->append("false ");
343        }
344
345        rec->fPaint.toString(str);
346        rec = rec->fNext;
347    }
348}
349#endif
350