1
2/*
3 * Copyright 2006 The Android Open Source Project
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
9
10#include "SkScanPriv.h"
11#include "SkPath.h"
12#include "SkMatrix.h"
13#include "SkBlitter.h"
14#include "SkRegion.h"
15#include "SkAntiRun.h"
16
17#define SHIFT   2
18#define SCALE   (1 << SHIFT)
19#define MASK    (SCALE - 1)
20
21/** @file
22    We have two techniques for capturing the output of the supersampler:
23    - SUPERMASK, which records a large mask-bitmap
24        this is often faster for small, complex objects
25    - RLE, which records a rle-encoded scanline
26        this is often faster for large objects with big spans
27
28    These blitters use two coordinate systems:
29    - destination coordinates, scale equal to the output - often
30        abbreviated with 'i' or 'I' in variable names
31    - supersampled coordinates, scale equal to the output * SCALE
32
33    Enabling SK_USE_LEGACY_AA_COVERAGE keeps the aa coverage calculations as
34    they were before the fix that unified the output of the RLE and MASK
35    supersamplers.
36 */
37
38//#define FORCE_SUPERMASK
39//#define FORCE_RLE
40//#define SK_USE_LEGACY_AA_COVERAGE
41
42///////////////////////////////////////////////////////////////////////////////
43
44/// Base class for a single-pass supersampled blitter.
45class BaseSuperBlitter : public SkBlitter {
46public:
47    BaseSuperBlitter(SkBlitter* realBlitter, const SkIRect& ir,
48                     const SkRegion& clip);
49
50    /// Must be explicitly defined on subclasses.
51    virtual void blitAntiH(int x, int y, const SkAlpha antialias[],
52                           const int16_t runs[]) SK_OVERRIDE {
53        SkDEBUGFAIL("How did I get here?");
54    }
55    /// May not be called on BaseSuperBlitter because it blits out of order.
56    virtual void blitV(int x, int y, int height, SkAlpha alpha) SK_OVERRIDE {
57        SkDEBUGFAIL("How did I get here?");
58    }
59
60protected:
61    SkBlitter*  fRealBlitter;
62    /// Current y coordinate, in destination coordinates.
63    int         fCurrIY;
64    /// Widest row of region to be blitted, in destination coordinates.
65    int         fWidth;
66    /// Leftmost x coordinate in any row, in destination coordinates.
67    int         fLeft;
68    /// Leftmost x coordinate in any row, in supersampled coordinates.
69    int         fSuperLeft;
70
71    SkDEBUGCODE(int fCurrX;)
72    /// Current y coordinate in supersampled coordinates.
73    int fCurrY;
74    /// Initial y coordinate (top of bounds).
75    int fTop;
76};
77
78BaseSuperBlitter::BaseSuperBlitter(SkBlitter* realBlitter, const SkIRect& ir,
79                                   const SkRegion& clip) {
80    fRealBlitter = realBlitter;
81
82    /*
83     *  We use the clip bounds instead of the ir, since we may be asked to
84     *  draw outside of the rect if we're a inverse filltype
85     */
86    const int left = clip.getBounds().fLeft;
87    const int right = clip.getBounds().fRight;
88
89    fLeft = left;
90    fSuperLeft = left << SHIFT;
91    fWidth = right - left;
92#if 0
93    fCurrIY = -1;
94    fCurrY = -1;
95#else
96    fTop = ir.fTop;
97    fCurrIY = ir.fTop - 1;
98    fCurrY = (ir.fTop << SHIFT) - 1;
99#endif
100    SkDEBUGCODE(fCurrX = -1;)
101}
102
103/// Run-length-encoded supersampling antialiased blitter.
104class SuperBlitter : public BaseSuperBlitter {
105public:
106    SuperBlitter(SkBlitter* realBlitter, const SkIRect& ir,
107                 const SkRegion& clip);
108
109    virtual ~SuperBlitter() {
110        this->flush();
111        sk_free(fRuns.fRuns);
112    }
113
114    /// Once fRuns contains a complete supersampled row, flush() blits
115    /// it out through the wrapped blitter.
116    void flush();
117
118    /// Blits a row of pixels, with location and width specified
119    /// in supersampled coordinates.
120    virtual void blitH(int x, int y, int width) SK_OVERRIDE;
121    /// Blits a rectangle of pixels, with location and size specified
122    /// in supersampled coordinates.
123    virtual void blitRect(int x, int y, int width, int height) SK_OVERRIDE;
124
125private:
126    SkAlphaRuns fRuns;
127    int         fOffsetX;
128};
129
130SuperBlitter::SuperBlitter(SkBlitter* realBlitter, const SkIRect& ir,
131                           const SkRegion& clip)
132        : BaseSuperBlitter(realBlitter, ir, clip) {
133    const int width = fWidth;
134
135    // extra one to store the zero at the end
136    fRuns.fRuns = (int16_t*)sk_malloc_throw((width + 1 + (width + 2)/2) * sizeof(int16_t));
137    fRuns.fAlpha = (uint8_t*)(fRuns.fRuns + width + 1);
138    fRuns.reset(width);
139
140    fOffsetX = 0;
141}
142
143void SuperBlitter::flush() {
144    if (fCurrIY >= fTop) {
145        if (!fRuns.empty()) {
146        //  SkDEBUGCODE(fRuns.dump();)
147            fRealBlitter->blitAntiH(fLeft, fCurrIY, fRuns.fAlpha, fRuns.fRuns);
148            fRuns.reset(fWidth);
149            fOffsetX = 0;
150        }
151        fCurrIY = fTop - 1;
152        SkDEBUGCODE(fCurrX = -1;)
153    }
154}
155
156/** coverage_to_partial_alpha() is being used by SkAlphaRuns, which
157    *accumulates* SCALE pixels worth of "alpha" in [0,(256/SCALE)]
158    to produce a final value in [0, 255] and handles clamping 256->255
159    itself, with the same (alpha - (alpha >> 8)) correction as
160    coverage_to_exact_alpha().
161*/
162static inline int coverage_to_partial_alpha(int aa) {
163    aa <<= 8 - 2*SHIFT;
164#ifdef SK_USE_LEGACY_AA_COVERAGE
165    aa -= aa >> (8 - SHIFT - 1);
166#endif
167    return aa;
168}
169
170/** coverage_to_exact_alpha() is being used by our blitter, which wants
171    a final value in [0, 255].
172*/
173static inline int coverage_to_exact_alpha(int aa) {
174    int alpha = (256 >> SHIFT) * aa;
175    // clamp 256->255
176    return alpha - (alpha >> 8);
177}
178
179void SuperBlitter::blitH(int x, int y, int width) {
180    SkASSERT(width > 0);
181
182    int iy = y >> SHIFT;
183    SkASSERT(iy >= fCurrIY);
184
185    x -= fSuperLeft;
186    // hack, until I figure out why my cubics (I think) go beyond the bounds
187    if (x < 0) {
188        width += x;
189        x = 0;
190    }
191
192#ifdef SK_DEBUG
193    SkASSERT(y != fCurrY || x >= fCurrX);
194#endif
195    SkASSERT(y >= fCurrY);
196    if (fCurrY != y) {
197        fOffsetX = 0;
198        fCurrY = y;
199    }
200
201    if (iy != fCurrIY) {  // new scanline
202        this->flush();
203        fCurrIY = iy;
204    }
205
206    int start = x;
207    int stop = x + width;
208
209    SkASSERT(start >= 0 && stop > start);
210    // integer-pixel-aligned ends of blit, rounded out
211    int fb = start & MASK;
212    int fe = stop & MASK;
213    int n = (stop >> SHIFT) - (start >> SHIFT) - 1;
214
215    if (n < 0) {
216        fb = fe - fb;
217        n = 0;
218        fe = 0;
219    } else {
220        if (fb == 0) {
221            n += 1;
222        } else {
223            fb = SCALE - fb;
224        }
225    }
226
227    fOffsetX = fRuns.add(x >> SHIFT, coverage_to_partial_alpha(fb),
228                         n, coverage_to_partial_alpha(fe),
229                         (1 << (8 - SHIFT)) - (((y & MASK) + 1) >> SHIFT),
230                         fOffsetX);
231
232#ifdef SK_DEBUG
233    fRuns.assertValid(y & MASK, (1 << (8 - SHIFT)));
234    fCurrX = x + width;
235#endif
236}
237
238#if 0 // UNUSED
239static void set_left_rite_runs(SkAlphaRuns& runs, int ileft, U8CPU leftA,
240                               int n, U8CPU riteA) {
241    SkASSERT(leftA <= 0xFF);
242    SkASSERT(riteA <= 0xFF);
243
244    int16_t* run = runs.fRuns;
245    uint8_t* aa = runs.fAlpha;
246
247    if (ileft > 0) {
248        run[0] = ileft;
249        aa[0] = 0;
250        run += ileft;
251        aa += ileft;
252    }
253
254    SkASSERT(leftA < 0xFF);
255    if (leftA > 0) {
256        *run++ = 1;
257        *aa++ = leftA;
258    }
259
260    if (n > 0) {
261        run[0] = n;
262        aa[0] = 0xFF;
263        run += n;
264        aa += n;
265    }
266
267    SkASSERT(riteA < 0xFF);
268    if (riteA > 0) {
269        *run++ = 1;
270        *aa++ = riteA;
271    }
272    run[0] = 0;
273}
274#endif
275
276void SuperBlitter::blitRect(int x, int y, int width, int height) {
277    SkASSERT(width > 0);
278    SkASSERT(height > 0);
279
280    // blit leading rows
281    while ((y & MASK)) {
282        this->blitH(x, y++, width);
283        if (--height <= 0) {
284            return;
285        }
286    }
287    SkASSERT(height > 0);
288
289    // Since this is a rect, instead of blitting supersampled rows one at a
290    // time and then resolving to the destination canvas, we can blit
291    // directly to the destintion canvas one row per SCALE supersampled rows.
292    int start_y = y >> SHIFT;
293    int stop_y = (y + height) >> SHIFT;
294    int count = stop_y - start_y;
295    if (count > 0) {
296        y += count << SHIFT;
297        height -= count << SHIFT;
298
299        // save original X for our tail blitH() loop at the bottom
300        int origX = x;
301
302        x -= fSuperLeft;
303        // hack, until I figure out why my cubics (I think) go beyond the bounds
304        if (x < 0) {
305            width += x;
306            x = 0;
307        }
308
309        // There is always a left column, a middle, and a right column.
310        // ileft is the destination x of the first pixel of the entire rect.
311        // xleft is (SCALE - # of covered supersampled pixels) in that
312        // destination pixel.
313        int ileft = x >> SHIFT;
314        int xleft = x & MASK;
315        // irite is the destination x of the last pixel of the OPAQUE section.
316        // xrite is the number of supersampled pixels extending beyond irite;
317        // xrite/SCALE should give us alpha.
318        int irite = (x + width) >> SHIFT;
319        int xrite = (x + width) & MASK;
320        if (!xrite) {
321            xrite = SCALE;
322            irite--;
323        }
324
325        // Need to call flush() to clean up pending draws before we
326        // even consider blitV(), since otherwise it can look nonmonotonic.
327        SkASSERT(start_y > fCurrIY);
328        this->flush();
329
330        int n = irite - ileft - 1;
331        if (n < 0) {
332            // If n < 0, we'll only have a single partially-transparent column
333            // of pixels to render.
334            xleft = xrite - xleft;
335            SkASSERT(xleft <= SCALE);
336            SkASSERT(xleft > 0);
337            xrite = 0;
338            fRealBlitter->blitV(ileft + fLeft, start_y, count,
339                coverage_to_exact_alpha(xleft));
340        } else {
341            // With n = 0, we have two possibly-transparent columns of pixels
342            // to render; with n > 0, we have opaque columns between them.
343
344            xleft = SCALE - xleft;
345
346            // Using coverage_to_exact_alpha is not consistent with blitH()
347            const int coverageL = coverage_to_exact_alpha(xleft);
348            const int coverageR = coverage_to_exact_alpha(xrite);
349
350            SkASSERT(coverageL > 0 || n > 0 || coverageR > 0);
351            SkASSERT((coverageL != 0) + n + (coverageR != 0) <= fWidth);
352
353            fRealBlitter->blitAntiRect(ileft + fLeft, start_y, n, count,
354                                       coverageL, coverageR);
355        }
356
357        // preamble for our next call to blitH()
358        fCurrIY = stop_y - 1;
359        fOffsetX = 0;
360        fCurrY = y - 1;
361        fRuns.reset(fWidth);
362        x = origX;
363    }
364
365    // catch any remaining few rows
366    SkASSERT(height <= MASK);
367    while (--height >= 0) {
368        this->blitH(x, y++, width);
369    }
370}
371
372///////////////////////////////////////////////////////////////////////////////
373
374/// Masked supersampling antialiased blitter.
375class MaskSuperBlitter : public BaseSuperBlitter {
376public:
377    MaskSuperBlitter(SkBlitter* realBlitter, const SkIRect& ir,
378                     const SkRegion& clip);
379    virtual ~MaskSuperBlitter() {
380        fRealBlitter->blitMask(fMask, fClipRect);
381    }
382
383    virtual void blitH(int x, int y, int width) SK_OVERRIDE;
384
385    static bool CanHandleRect(const SkIRect& bounds) {
386#ifdef FORCE_RLE
387        return false;
388#endif
389        int width = bounds.width();
390        int64_t rb = SkAlign4(width);
391        // use 64bits to detect overflow
392        int64_t storage = rb * bounds.height();
393
394        return (width <= MaskSuperBlitter::kMAX_WIDTH) &&
395               (storage <= MaskSuperBlitter::kMAX_STORAGE);
396    }
397
398private:
399    enum {
400#ifdef FORCE_SUPERMASK
401        kMAX_WIDTH = 2048,
402        kMAX_STORAGE = 1024 * 1024 * 2
403#else
404        kMAX_WIDTH = 32,    // so we don't try to do very wide things, where the RLE blitter would be faster
405        kMAX_STORAGE = 1024
406#endif
407    };
408
409    SkMask      fMask;
410    SkIRect     fClipRect;
411    // we add 1 because add_aa_span can write (unchanged) 1 extra byte at the end, rather than
412    // perform a test to see if stopAlpha != 0
413    uint32_t    fStorage[(kMAX_STORAGE >> 2) + 1];
414};
415
416MaskSuperBlitter::MaskSuperBlitter(SkBlitter* realBlitter, const SkIRect& ir,
417                                   const SkRegion& clip)
418        : BaseSuperBlitter(realBlitter, ir, clip) {
419    SkASSERT(CanHandleRect(ir));
420
421    fMask.fImage    = (uint8_t*)fStorage;
422    fMask.fBounds   = ir;
423    fMask.fRowBytes = ir.width();
424    fMask.fFormat   = SkMask::kA8_Format;
425
426    fClipRect = ir;
427    fClipRect.intersect(clip.getBounds());
428
429    // For valgrind, write 1 extra byte at the end so we don't read
430    // uninitialized memory. See comment in add_aa_span and fStorage[].
431    memset(fStorage, 0, fMask.fBounds.height() * fMask.fRowBytes + 1);
432}
433
434static void add_aa_span(uint8_t* alpha, U8CPU startAlpha) {
435    /*  I should be able to just add alpha[x] + startAlpha.
436        However, if the trailing edge of the previous span and the leading
437        edge of the current span round to the same super-sampled x value,
438        I might overflow to 256 with this add, hence the funny subtract.
439    */
440    unsigned tmp = *alpha + startAlpha;
441    SkASSERT(tmp <= 256);
442    *alpha = SkToU8(tmp - (tmp >> 8));
443}
444
445static inline uint32_t quadplicate_byte(U8CPU value) {
446    uint32_t pair = (value << 8) | value;
447    return (pair << 16) | pair;
448}
449
450// Perform this tricky subtract, to avoid overflowing to 256. Our caller should
451// only ever call us with at most enough to hit 256 (never larger), so it is
452// enough to just subtract the high-bit. Actually clamping with a branch would
453// be slower (e.g. if (tmp > 255) tmp = 255;)
454//
455static inline void saturated_add(uint8_t* ptr, U8CPU add) {
456    unsigned tmp = *ptr + add;
457    SkASSERT(tmp <= 256);
458    *ptr = SkToU8(tmp - (tmp >> 8));
459}
460
461// minimum count before we want to setup an inner loop, adding 4-at-a-time
462#define MIN_COUNT_FOR_QUAD_LOOP  16
463
464static void add_aa_span(uint8_t* alpha, U8CPU startAlpha, int middleCount,
465                        U8CPU stopAlpha, U8CPU maxValue) {
466    SkASSERT(middleCount >= 0);
467
468    saturated_add(alpha, startAlpha);
469    alpha += 1;
470
471    if (middleCount >= MIN_COUNT_FOR_QUAD_LOOP) {
472        // loop until we're quad-byte aligned
473        while (SkTCast<intptr_t>(alpha) & 0x3) {
474            alpha[0] = SkToU8(alpha[0] + maxValue);
475            alpha += 1;
476            middleCount -= 1;
477        }
478
479        int bigCount = middleCount >> 2;
480        uint32_t* qptr = reinterpret_cast<uint32_t*>(alpha);
481        uint32_t qval = quadplicate_byte(maxValue);
482        do {
483            *qptr++ += qval;
484        } while (--bigCount > 0);
485
486        middleCount &= 3;
487        alpha = reinterpret_cast<uint8_t*> (qptr);
488        // fall through to the following while-loop
489    }
490
491    while (--middleCount >= 0) {
492        alpha[0] = SkToU8(alpha[0] + maxValue);
493        alpha += 1;
494    }
495
496    // potentially this can be off the end of our "legal" alpha values, but that
497    // only happens if stopAlpha is also 0. Rather than test for stopAlpha != 0
498    // every time (slow), we just do it, and ensure that we've allocated extra space
499    // (see the + 1 comment in fStorage[]
500    saturated_add(alpha, stopAlpha);
501}
502
503void MaskSuperBlitter::blitH(int x, int y, int width) {
504    int iy = (y >> SHIFT);
505
506    SkASSERT(iy >= fMask.fBounds.fTop && iy < fMask.fBounds.fBottom);
507    iy -= fMask.fBounds.fTop;   // make it relative to 0
508
509    // This should never happen, but it does.  Until the true cause is
510    // discovered, let's skip this span instead of crashing.
511    // See http://crbug.com/17569.
512    if (iy < 0) {
513        return;
514    }
515
516#ifdef SK_DEBUG
517    {
518        int ix = x >> SHIFT;
519        SkASSERT(ix >= fMask.fBounds.fLeft && ix < fMask.fBounds.fRight);
520    }
521#endif
522
523    x -= (fMask.fBounds.fLeft << SHIFT);
524
525    // hack, until I figure out why my cubics (I think) go beyond the bounds
526    if (x < 0) {
527        width += x;
528        x = 0;
529    }
530
531    uint8_t* row = fMask.fImage + iy * fMask.fRowBytes + (x >> SHIFT);
532
533    int start = x;
534    int stop = x + width;
535
536    SkASSERT(start >= 0 && stop > start);
537    int fb = start & MASK;
538    int fe = stop & MASK;
539    int n = (stop >> SHIFT) - (start >> SHIFT) - 1;
540
541
542    if (n < 0) {
543        SkASSERT(row >= fMask.fImage);
544        SkASSERT(row < fMask.fImage + kMAX_STORAGE + 1);
545        add_aa_span(row, coverage_to_partial_alpha(fe - fb));
546    } else {
547        fb = SCALE - fb;
548        SkASSERT(row >= fMask.fImage);
549        SkASSERT(row + n + 1 < fMask.fImage + kMAX_STORAGE + 1);
550        add_aa_span(row,  coverage_to_partial_alpha(fb),
551                    n, coverage_to_partial_alpha(fe),
552                    (1 << (8 - SHIFT)) - (((y & MASK) + 1) >> SHIFT));
553    }
554
555#ifdef SK_DEBUG
556    fCurrX = x + width;
557#endif
558}
559
560///////////////////////////////////////////////////////////////////////////////
561
562static bool fitsInsideLimit(const SkRect& r, SkScalar max) {
563    const SkScalar min = -max;
564    return  r.fLeft > min && r.fTop > min &&
565            r.fRight < max && r.fBottom < max;
566}
567
568static int overflows_short_shift(int value, int shift) {
569    const int s = 16 + shift;
570    return (value << s >> s) - value;
571}
572
573/**
574  Would any of the coordinates of this rectangle not fit in a short,
575  when left-shifted by shift?
576*/
577static int rect_overflows_short_shift(SkIRect rect, int shift) {
578    SkASSERT(!overflows_short_shift(8191, SHIFT));
579    SkASSERT(overflows_short_shift(8192, SHIFT));
580    SkASSERT(!overflows_short_shift(32767, 0));
581    SkASSERT(overflows_short_shift(32768, 0));
582
583    // Since we expect these to succeed, we bit-or together
584    // for a tiny extra bit of speed.
585    return overflows_short_shift(rect.fLeft, SHIFT) |
586           overflows_short_shift(rect.fRight, SHIFT) |
587           overflows_short_shift(rect.fTop, SHIFT) |
588           overflows_short_shift(rect.fBottom, SHIFT);
589}
590
591static bool safeRoundOut(const SkRect& src, SkIRect* dst, int32_t maxInt) {
592    const SkScalar maxScalar = SkIntToScalar(maxInt);
593
594    if (fitsInsideLimit(src, maxScalar)) {
595        src.roundOut(dst);
596        return true;
597    }
598    return false;
599}
600
601void SkScan::AntiFillPath(const SkPath& path, const SkRegion& origClip,
602                          SkBlitter* blitter, bool forceRLE) {
603    if (origClip.isEmpty()) {
604        return;
605    }
606
607    SkIRect ir;
608
609    if (!safeRoundOut(path.getBounds(), &ir, SK_MaxS32 >> SHIFT)) {
610#if 0
611        const SkRect& r = path.getBounds();
612        SkDebugf("--- bounds can't fit in SkIRect\n", r.fLeft, r.fTop, r.fRight, r.fBottom);
613#endif
614        return;
615    }
616    if (ir.isEmpty()) {
617        if (path.isInverseFillType()) {
618            blitter->blitRegion(origClip);
619        }
620        return;
621    }
622
623    // If the intersection of the path bounds and the clip bounds
624    // will overflow 32767 when << by SHIFT, we can't supersample,
625    // so draw without antialiasing.
626    SkIRect clippedIR;
627    if (path.isInverseFillType()) {
628       // If the path is an inverse fill, it's going to fill the entire
629       // clip, and we care whether the entire clip exceeds our limits.
630       clippedIR = origClip.getBounds();
631    } else {
632       if (!clippedIR.intersect(ir, origClip.getBounds())) {
633           return;
634       }
635    }
636    if (rect_overflows_short_shift(clippedIR, SHIFT)) {
637        SkScan::FillPath(path, origClip, blitter);
638        return;
639    }
640
641    // Our antialiasing can't handle a clip larger than 32767, so we restrict
642    // the clip to that limit here. (the runs[] uses int16_t for its index).
643    //
644    // A more general solution (one that could also eliminate the need to
645    // disable aa based on ir bounds (see overflows_short_shift) would be
646    // to tile the clip/target...
647    SkRegion tmpClipStorage;
648    const SkRegion* clipRgn = &origClip;
649    {
650        static const int32_t kMaxClipCoord = 32767;
651        const SkIRect& bounds = origClip.getBounds();
652        if (bounds.fRight > kMaxClipCoord || bounds.fBottom > kMaxClipCoord) {
653            SkIRect limit = { 0, 0, kMaxClipCoord, kMaxClipCoord };
654            tmpClipStorage.op(origClip, limit, SkRegion::kIntersect_Op);
655            clipRgn = &tmpClipStorage;
656        }
657    }
658    // for here down, use clipRgn, not origClip
659
660    SkScanClipper   clipper(blitter, clipRgn, ir);
661    const SkIRect*  clipRect = clipper.getClipRect();
662
663    if (clipper.getBlitter() == NULL) { // clipped out
664        if (path.isInverseFillType()) {
665            blitter->blitRegion(*clipRgn);
666        }
667        return;
668    }
669
670    // now use the (possibly wrapped) blitter
671    blitter = clipper.getBlitter();
672
673    if (path.isInverseFillType()) {
674        sk_blit_above(blitter, ir, *clipRgn);
675    }
676
677    SkIRect superRect, *superClipRect = NULL;
678
679    if (clipRect) {
680        superRect.set(  clipRect->fLeft << SHIFT, clipRect->fTop << SHIFT,
681                        clipRect->fRight << SHIFT, clipRect->fBottom << SHIFT);
682        superClipRect = &superRect;
683    }
684
685    SkASSERT(SkIntToScalar(ir.fTop) <= path.getBounds().fTop);
686
687    // MaskSuperBlitter can't handle drawing outside of ir, so we can't use it
688    // if we're an inverse filltype
689    if (!path.isInverseFillType() && MaskSuperBlitter::CanHandleRect(ir) && !forceRLE) {
690        MaskSuperBlitter    superBlit(blitter, ir, *clipRgn);
691        SkASSERT(SkIntToScalar(ir.fTop) <= path.getBounds().fTop);
692        sk_fill_path(path, superClipRect, &superBlit, ir.fTop, ir.fBottom, SHIFT, *clipRgn);
693    } else {
694        SuperBlitter    superBlit(blitter, ir, *clipRgn);
695        sk_fill_path(path, superClipRect, &superBlit, ir.fTop, ir.fBottom, SHIFT, *clipRgn);
696    }
697
698    if (path.isInverseFillType()) {
699        sk_blit_below(blitter, ir, *clipRgn);
700    }
701}
702
703///////////////////////////////////////////////////////////////////////////////
704
705#include "SkRasterClip.h"
706
707void SkScan::FillPath(const SkPath& path, const SkRasterClip& clip,
708                          SkBlitter* blitter) {
709    if (clip.isEmpty()) {
710        return;
711    }
712
713    if (clip.isBW()) {
714        FillPath(path, clip.bwRgn(), blitter);
715    } else {
716        SkRegion        tmp;
717        SkAAClipBlitter aaBlitter;
718
719        tmp.setRect(clip.getBounds());
720        aaBlitter.init(blitter, &clip.aaRgn());
721        SkScan::FillPath(path, tmp, &aaBlitter);
722    }
723}
724
725void SkScan::AntiFillPath(const SkPath& path, const SkRasterClip& clip,
726                          SkBlitter* blitter) {
727    if (clip.isEmpty()) {
728        return;
729    }
730
731    if (clip.isBW()) {
732        AntiFillPath(path, clip.bwRgn(), blitter);
733    } else {
734        SkRegion        tmp;
735        SkAAClipBlitter aaBlitter;
736
737        tmp.setRect(clip.getBounds());
738        aaBlitter.init(blitter, &clip.aaRgn());
739        SkScan::AntiFillPath(path, tmp, &aaBlitter, true);
740    }
741}
742