SkLayerDrawLooper.cpp revision 5da3f220034f89f3234b16b98bd86e7246941ffe 
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 "SkFlattenableBuffers.h"
11#include "SkLayerDrawLooper.h"
12#include "SkString.h"
13#include "SkStringUtils.h"
14#include "SkUnPreMultiply.h"
15
16SK_DEFINE_INST_COUNT(SkLayerDrawLooper)
17
18SkLayerDrawLooper::LayerInfo::LayerInfo() {
19    fFlagsMask = 0;                     // ignore our paint flags
20    fPaintBits = 0;                     // ignore our paint fields
21    fColorMode = SkXfermode::kDst_Mode; // ignore our color
22    fOffset.set(0, 0);
23    fPostTranslate = false;
24}
25
26SkLayerDrawLooper::SkLayerDrawLooper()
27        : fRecs(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
49    return &rec->fPaint;
50}
51
52void SkLayerDrawLooper::addLayer(SkScalar dx, SkScalar dy) {
53    LayerInfo info;
54
55    info.fOffset.set(dx, dy);
56    (void)this->addLayer(info);
57}
58
59void SkLayerDrawLooper::init(SkCanvas* canvas) {
60    fCurrRec = fRecs;
61    canvas->save(SkCanvas::kMatrix_SaveFlag);
62}
63
64static SkColor xferColor(SkColor src, SkColor dst, SkXfermode::Mode mode) {
65    switch (mode) {
66        case SkXfermode::kSrc_Mode:
67            return src;
68        case SkXfermode::kDst_Mode:
69            return dst;
70        default: {
71            SkPMColor pmS = SkPreMultiplyColor(src);
72            SkPMColor pmD = SkPreMultiplyColor(dst);
73            SkPMColor result = SkXfermode::GetProc(mode)(pmS, pmD);
74            return SkUnPreMultiply::PMColorToColor(result);
75        }
76    }
77}
78
79// Even with kEntirePaint_Bits, we always ensure that the master paint's
80// text-encoding is respected, since that controls how we interpret the
81// text/length parameters of a draw[Pos]Text call.
82void SkLayerDrawLooper::ApplyInfo(SkPaint* dst, const SkPaint& src,
83                                  const LayerInfo& info) {
84
85    uint32_t mask = info.fFlagsMask;
86    dst->setFlags((dst->getFlags() & ~mask) | (src.getFlags() & mask));
87    dst->setColor(xferColor(src.getColor(), dst->getColor(), info.fColorMode));
88
89    BitFlags bits = info.fPaintBits;
90    SkPaint::TextEncoding encoding = dst->getTextEncoding();
91
92    if (0 == bits) {
93        return;
94    }
95    if (kEntirePaint_Bits == bits) {
96        // we've already computed these, so save it from the assignment
97        uint32_t f = dst->getFlags();
98        SkColor c = dst->getColor();
99        *dst = src;
100        dst->setFlags(f);
101        dst->setColor(c);
102        dst->setTextEncoding(encoding);
103        return;
104    }
105
106    if (bits & kStyle_Bit) {
107        dst->setStyle(src.getStyle());
108        dst->setStrokeWidth(src.getStrokeWidth());
109        dst->setStrokeMiter(src.getStrokeMiter());
110        dst->setStrokeCap(src.getStrokeCap());
111        dst->setStrokeJoin(src.getStrokeJoin());
112    }
113
114    if (bits & kTextSkewX_Bit) {
115        dst->setTextSkewX(src.getTextSkewX());
116    }
117
118    if (bits & kPathEffect_Bit) {
119        dst->setPathEffect(src.getPathEffect());
120    }
121    if (bits & kMaskFilter_Bit) {
122        dst->setMaskFilter(src.getMaskFilter());
123    }
124    if (bits & kShader_Bit) {
125        dst->setShader(src.getShader());
126    }
127    if (bits & kColorFilter_Bit) {
128        dst->setColorFilter(src.getColorFilter());
129    }
130    if (bits & kXfermode_Bit) {
131        dst->setXfermode(src.getXfermode());
132    }
133
134    // we don't override these
135#if 0
136    dst->setTypeface(src.getTypeface());
137    dst->setTextSize(src.getTextSize());
138    dst->setTextScaleX(src.getTextScaleX());
139    dst->setRasterizer(src.getRasterizer());
140    dst->setLooper(src.getLooper());
141    dst->setTextEncoding(src.getTextEncoding());
142    dst->setHinting(src.getHinting());
143#endif
144}
145
146// Should we add this to canvas?
147static void postTranslate(SkCanvas* canvas, SkScalar dx, SkScalar dy) {
148    SkMatrix m = canvas->getTotalMatrix();
149    m.postTranslate(dx, dy);
150    canvas->setMatrix(m);
151}
152
153bool SkLayerDrawLooper::next(SkCanvas* canvas, SkPaint* paint) {
154    canvas->restore();
155    if (NULL == fCurrRec) {
156        return false;
157    }
158
159    ApplyInfo(paint, fCurrRec->fPaint, fCurrRec->fInfo);
160
161    canvas->save(SkCanvas::kMatrix_SaveFlag);
162    if (fCurrRec->fInfo.fPostTranslate) {
163        postTranslate(canvas, fCurrRec->fInfo.fOffset.fX,
164                      fCurrRec->fInfo.fOffset.fY);
165    } else {
166        canvas->translate(fCurrRec->fInfo.fOffset.fX, fCurrRec->fInfo.fOffset.fY);
167    }
168    fCurrRec = fCurrRec->fNext;
169
170    return true;
171}
172
173SkLayerDrawLooper::Rec* SkLayerDrawLooper::Rec::Reverse(Rec* head) {
174    Rec* rec = head;
175    Rec* prev = NULL;
176    while (rec) {
177        Rec* next = rec->fNext;
178        rec->fNext = prev;
179        prev = rec;
180        rec = next;
181    }
182    return prev;
183}
184
185///////////////////////////////////////////////////////////////////////////////
186
187void SkLayerDrawLooper::flatten(SkFlattenableWriteBuffer& buffer) const {
188    this->INHERITED::flatten(buffer);
189
190#ifdef SK_DEBUG
191    {
192        Rec* rec = fRecs;
193        int count = 0;
194        while (rec) {
195            rec = rec->fNext;
196            count += 1;
197        }
198        SkASSERT(count == fCount);
199    }
200#endif
201
202    buffer.writeInt(fCount);
203
204    Rec* rec = fRecs;
205    for (int i = 0; i < fCount; i++) {
206        buffer.writeInt(rec->fInfo.fFlagsMask);
207        buffer.writeInt(rec->fInfo.fPaintBits);
208        buffer.writeInt(rec->fInfo.fColorMode);
209        buffer.writePoint(rec->fInfo.fOffset);
210        buffer.writeBool(rec->fInfo.fPostTranslate);
211        buffer.writePaint(rec->fPaint);
212        rec = rec->fNext;
213    }
214}
215
216SkLayerDrawLooper::SkLayerDrawLooper(SkFlattenableReadBuffer& buffer)
217        : INHERITED(buffer),
218          fRecs(NULL),
219          fCount(0),
220          fCurrRec(NULL) {
221    int count = buffer.readInt();
222
223    for (int i = 0; i < count; i++) {
224        LayerInfo info;
225        info.fFlagsMask = buffer.readInt();
226        info.fPaintBits = buffer.readInt();
227        info.fColorMode = (SkXfermode::Mode)buffer.readInt();
228        buffer.readPoint(&info.fOffset);
229        info.fPostTranslate = buffer.readBool();
230        buffer.readPaint(this->addLayer(info));
231    }
232    SkASSERT(count == fCount);
233
234    // we're in reverse order, so fix it now
235    fRecs = Rec::Reverse(fRecs);
236
237#ifdef SK_DEBUG
238    {
239        Rec* rec = fRecs;
240        int n = 0;
241        while (rec) {
242            rec = rec->fNext;
243            n += 1;
244        }
245        SkASSERT(count == n);
246    }
247#endif
248}
249
250#ifdef SK_DEVELOPER
251void SkLayerDrawLooper::toString(SkString* str) const {
252    str->appendf("SkLayerDrawLooper (%d): ", fCount);
253
254    Rec* rec = fRecs;
255    for (int i = 0; i < fCount; i++) {
256        str->appendf("%d: ", i);
257
258        str->append("flagsMask: (");
259        if (0 == rec->fInfo.fFlagsMask) {
260            str->append("None");
261        } else {
262            bool needSeparator = false;
263            SkAddFlagToString(str, SkToBool(SkPaint::kAntiAlias_Flag & rec->fInfo.fFlagsMask),
264                              "AntiAlias", &needSeparator);
265            SkAddFlagToString(str, SkToBool(SkPaint::kFilterBitmap_Flag & rec->fInfo.fFlagsMask),
266                              "FilterBitmap", &needSeparator);
267            SkAddFlagToString(str, SkToBool(SkPaint::kDither_Flag & rec->fInfo.fFlagsMask),
268                              "Dither", &needSeparator);
269            SkAddFlagToString(str, SkToBool(SkPaint::kUnderlineText_Flag & rec->fInfo.fFlagsMask),
270                              "UnderlineText", &needSeparator);
271            SkAddFlagToString(str, SkToBool(SkPaint::kStrikeThruText_Flag & rec->fInfo.fFlagsMask),
272                              "StrikeThruText", &needSeparator);
273            SkAddFlagToString(str, SkToBool(SkPaint::kFakeBoldText_Flag & rec->fInfo.fFlagsMask),
274                              "FakeBoldText", &needSeparator);
275            SkAddFlagToString(str, SkToBool(SkPaint::kLinearText_Flag & rec->fInfo.fFlagsMask),
276                              "LinearText", &needSeparator);
277            SkAddFlagToString(str, SkToBool(SkPaint::kSubpixelText_Flag & rec->fInfo.fFlagsMask),
278                              "SubpixelText", &needSeparator);
279            SkAddFlagToString(str, SkToBool(SkPaint::kDevKernText_Flag & rec->fInfo.fFlagsMask),
280                              "DevKernText", &needSeparator);
281            SkAddFlagToString(str, SkToBool(SkPaint::kLCDRenderText_Flag & rec->fInfo.fFlagsMask),
282                              "LCDRenderText", &needSeparator);
283            SkAddFlagToString(str, SkToBool(SkPaint::kEmbeddedBitmapText_Flag & rec->fInfo.fFlagsMask),
284                              "EmbeddedBitmapText", &needSeparator);
285            SkAddFlagToString(str, SkToBool(SkPaint::kAutoHinting_Flag & rec->fInfo.fFlagsMask),
286                              "Autohinted", &needSeparator);
287            SkAddFlagToString(str, SkToBool(SkPaint::kVerticalText_Flag & rec->fInfo.fFlagsMask),
288                              "VerticalText", &needSeparator);
289            SkAddFlagToString(str, SkToBool(SkPaint::kGenA8FromLCD_Flag & rec->fInfo.fFlagsMask),
290                              "GenA8FromLCD", &needSeparator);
291        }
292        str->append(") ");
293
294        str->append("paintBits: (");
295        if (0 == rec->fInfo.fPaintBits) {
296            str->append("None");
297        } else if (kEntirePaint_Bits == rec->fInfo.fPaintBits) {
298            str->append("EntirePaint");
299        } else {
300            bool needSeparator = false;
301            SkAddFlagToString(str, SkToBool(kStyle_Bit & rec->fInfo.fPaintBits), "Style",
302                              &needSeparator);
303            SkAddFlagToString(str, SkToBool(kTextSkewX_Bit & rec->fInfo.fPaintBits), "TextSkewX",
304                              &needSeparator);
305            SkAddFlagToString(str, SkToBool(kPathEffect_Bit & rec->fInfo.fPaintBits), "PathEffect",
306                              &needSeparator);
307            SkAddFlagToString(str, SkToBool(kMaskFilter_Bit & rec->fInfo.fPaintBits), "MaskFilter",
308                              &needSeparator);
309            SkAddFlagToString(str, SkToBool(kShader_Bit & rec->fInfo.fPaintBits), "Shader",
310                              &needSeparator);
311            SkAddFlagToString(str, SkToBool(kColorFilter_Bit & rec->fInfo.fPaintBits), "ColorFilter",
312                              &needSeparator);
313            SkAddFlagToString(str, SkToBool(kXfermode_Bit & rec->fInfo.fPaintBits), "Xfermode",
314                              &needSeparator);
315        }
316        str->append(") ");
317
318        static const char* gModeStrings[SkXfermode::kLastMode+1] = {
319            "kClear", "kSrc", "kDst", "kSrcOver", "kDstOver", "kSrcIn", "kDstIn",
320            "kSrcOut", "kDstOut", "kSrcATop", "kDstATop", "kXor", "kPlus",
321            "kMultiply", "kScreen", "kOverlay", "kDarken", "kLighten", "kColorDodge",
322            "kColorBurn", "kHardLight", "kSoftLight", "kDifference", "kExclusion"
323        };
324
325        str->appendf("mode: %s ", gModeStrings[rec->fInfo.fColorMode]);
326
327        str->append("offset: (");
328        str->appendScalar(rec->fInfo.fOffset.fX);
329        str->append(", ");
330        str->appendScalar(rec->fInfo.fOffset.fY);
331        str->append(") ");
332
333        str->append("postTranslate: ");
334        if (rec->fInfo.fPostTranslate) {
335            str->append("true ");
336        } else {
337            str->append("false ");
338        }
339
340        rec->fPaint.toString(str);
341        rec = rec->fNext;
342    }
343}
344#endif
345