The Tor Browser: gfx/skia/trunk/src/core/SkBlitter.cpp@deefc01c0e14 (annotated)

gfx/skia/trunk/src/core/SkBlitter.cpp@deefc01c0e14 (annotated)

gfx/skia/trunk/src/core/SkBlitter.cpp

Thu, 15 Jan 2015 21:03:48 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 21:03:48 +0100
branch: TOR_BUG_9701
changeset 11: deefc01c0e14
permissions: -rw-r--r--

Integrate friendly tips from Tor colleagues to make (or not) 4.5 alpha 3;
This includes removal of overloaded (but unused) methods, and addition of
a overlooked call to DataStruct::SetData(nsISupports, uint32_t, bool.)

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkBlitter.h"
 #include "SkAntiRun.h"
 #include "SkColor.h"
 #include "SkColorFilter.h"
 #include "SkCoreBlitters.h"
 #include "SkFilterShader.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkMask.h"
 #include "SkMaskFilter.h"
 #include "SkString.h"
 #include "SkTLazy.h"
 #include "SkUtils.h"
 #include "SkXfermode.h"
 SkBlitter::~SkBlitter() {}
 bool SkBlitter::isNullBlitter() const { return false; }
 const SkBitmap* SkBlitter::justAnOpaqueColor(uint32_t* value) {
     return NULL;
 }
 void SkBlitter::blitH(int x, int y, int width) {
     SkDEBUGFAIL("unimplemented");
 }
 void SkBlitter::blitAntiH(int x, int y, const SkAlpha antialias[],
                           const int16_t runs[]) {
     SkDEBUGFAIL("unimplemented");
 }
 void SkBlitter::blitV(int x, int y, int height, SkAlpha alpha) {
     if (alpha == 255) {
         this->blitRect(x, y, 1, height);
     } else {
         int16_t runs[2];
         runs[0] = 1;
         runs[1] = 0;
         while (--height >= 0) {
             this->blitAntiH(x, y++, &alpha, runs);
         }
     }
 }
 void SkBlitter::blitRect(int x, int y, int width, int height) {
     SkASSERT(width > 0);
     while (--height >= 0) {
         this->blitH(x, y++, width);
     }
 }
 /// Default implementation doesn't check for any easy optimizations
 /// such as alpha == 0 or 255; also uses blitV(), which some subclasses
 /// may not support.
 void SkBlitter::blitAntiRect(int x, int y, int width, int height,
                              SkAlpha leftAlpha, SkAlpha rightAlpha) {
     this->blitV(x++, y, height, leftAlpha);
     if (width > 0) {
         this->blitRect(x, y, width, height);
         x += width;
     }
     this->blitV(x, y, height, rightAlpha);
 }
 //////////////////////////////////////////////////////////////////////////////
 static inline void bits_to_runs(SkBlitter* blitter, int x, int y,
                                 const uint8_t bits[],
                                 U8CPU left_mask, int rowBytes,
                                 U8CPU right_mask) {
     int inFill = 0;
     int pos = 0;
     while (--rowBytes >= 0) {
         unsigned b = *bits++ & left_mask;
         if (rowBytes == 0) {
             b &= right_mask;
         }
         for (unsigned test = 0x80; test != 0; test >>= 1) {
             if (b & test) {
                 if (!inFill) {
                     pos = x;
                     inFill = true;
                 }
             } else {
                 if (inFill) {
                     blitter->blitH(pos, y, x - pos);
                     inFill = false;
                 }
             }
             x += 1;
         }
         left_mask = 0xFF;
     }
     // final cleanup
     if (inFill) {
         blitter->blitH(pos, y, x - pos);
     }
 }
 void SkBlitter::blitMask(const SkMask& mask, const SkIRect& clip) {
     SkASSERT(mask.fBounds.contains(clip));
     if (mask.fFormat == SkMask::kBW_Format) {
         int cx = clip.fLeft;
         int cy = clip.fTop;
         int maskLeft = mask.fBounds.fLeft;
         int mask_rowBytes = mask.fRowBytes;
         int height = clip.height();
         const uint8_t* bits = mask.getAddr1(cx, cy);
         if (cx == maskLeft && clip.fRight == mask.fBounds.fRight) {
             while (--height >= 0) {
                 bits_to_runs(this, cx, cy, bits, 0xFF, mask_rowBytes, 0xFF);
                 bits += mask_rowBytes;
                 cy += 1;
             }
         } else {
             int left_edge = cx - maskLeft;
             SkASSERT(left_edge >= 0);
             int rite_edge = clip.fRight - maskLeft;
             SkASSERT(rite_edge > left_edge);
             int left_mask = 0xFF >> (left_edge & 7);
             int rite_mask = 0xFF << (8 - (rite_edge & 7));
             int full_runs = (rite_edge >> 3) - ((left_edge + 7) >> 3);
             // check for empty right mask, so we don't read off the end (or go slower than we need to)
             if (rite_mask == 0) {
                 SkASSERT(full_runs >= 0);
                 full_runs -= 1;
                 rite_mask = 0xFF;
             }
             if (left_mask == 0xFF) {
                 full_runs -= 1;
             }
             // back up manually so we can keep in sync with our byte-aligned src
             // have cx reflect our actual starting x-coord
             cx -= left_edge & 7;
             if (full_runs < 0) {
                 SkASSERT((left_mask & rite_mask) != 0);
                 while (--height >= 0) {
                     bits_to_runs(this, cx, cy, bits, left_mask, 1, rite_mask);
                     bits += mask_rowBytes;
                     cy += 1;
                 }
             } else {
                 while (--height >= 0) {
                     bits_to_runs(this, cx, cy, bits, left_mask, full_runs + 2, rite_mask);
                     bits += mask_rowBytes;
                     cy += 1;
                 }
             }
         }
     } else {
         int                         width = clip.width();
         SkAutoSTMalloc<64, int16_t> runStorage(width + 1);
         int16_t*                    runs = runStorage.get();
         const uint8_t*              aa = mask.getAddr8(clip.fLeft, clip.fTop);
         sk_memset16((uint16_t*)runs, 1, width);
         runs[width] = 0;
         int height = clip.height();
         int y = clip.fTop;
         while (--height >= 0) {
             this->blitAntiH(clip.fLeft, y, aa, runs);
             aa += mask.fRowBytes;
             y += 1;
         }
     }
 }
 /////////////////////// these guys are not virtual, just a helpers
 void SkBlitter::blitMaskRegion(const SkMask& mask, const SkRegion& clip) {
     if (clip.quickReject(mask.fBounds)) {
         return;
     }
     SkRegion::Cliperator clipper(clip, mask.fBounds);
     while (!clipper.done()) {
         const SkIRect& cr = clipper.rect();
         this->blitMask(mask, cr);
         clipper.next();
     }
 }
 void SkBlitter::blitRectRegion(const SkIRect& rect, const SkRegion& clip) {
     SkRegion::Cliperator clipper(clip, rect);
     while (!clipper.done()) {
         const SkIRect& cr = clipper.rect();
         this->blitRect(cr.fLeft, cr.fTop, cr.width(), cr.height());
         clipper.next();
     }
 }
 void SkBlitter::blitRegion(const SkRegion& clip) {
     SkRegion::Iterator iter(clip);
     while (!iter.done()) {
         const SkIRect& cr = iter.rect();
         this->blitRect(cr.fLeft, cr.fTop, cr.width(), cr.height());
         iter.next();
     }
 }
 ///////////////////////////////////////////////////////////////////////////////
 void SkNullBlitter::blitH(int x, int y, int width) {}
 void SkNullBlitter::blitAntiH(int x, int y, const SkAlpha antialias[],
                               const int16_t runs[]) {}
 void SkNullBlitter::blitV(int x, int y, int height, SkAlpha alpha) {}
 void SkNullBlitter::blitRect(int x, int y, int width, int height) {}
 void SkNullBlitter::blitMask(const SkMask& mask, const SkIRect& clip) {}
 const SkBitmap* SkNullBlitter::justAnOpaqueColor(uint32_t* value) {
     return NULL;
 }
 bool SkNullBlitter::isNullBlitter() const { return true; }
 ///////////////////////////////////////////////////////////////////////////////
 static int compute_anti_width(const int16_t runs[]) {
     int width = 0;
     for (;;) {
         int count = runs[0];
         SkASSERT(count >= 0);
         if (count == 0) {
             break;
         }
         width += count;
         runs += count;
     }
     return width;
 }
 static inline bool y_in_rect(int y, const SkIRect& rect) {
     return (unsigned)(y - rect.fTop) < (unsigned)rect.height();
 }
 static inline bool x_in_rect(int x, const SkIRect& rect) {
     return (unsigned)(x - rect.fLeft) < (unsigned)rect.width();
 }
 void SkRectClipBlitter::blitH(int left, int y, int width) {
     SkASSERT(width > 0);
     if (!y_in_rect(y, fClipRect)) {
         return;
     }
     int right = left + width;
     if (left < fClipRect.fLeft) {
         left = fClipRect.fLeft;
     }
     if (right > fClipRect.fRight) {
         right = fClipRect.fRight;
     }
     width = right - left;
     if (width > 0) {
         fBlitter->blitH(left, y, width);
     }
 }
 void SkRectClipBlitter::blitAntiH(int left, int y, const SkAlpha aa[],
                                   const int16_t runs[]) {
     if (!y_in_rect(y, fClipRect) || left >= fClipRect.fRight) {
         return;
     }
     int x0 = left;
     int x1 = left + compute_anti_width(runs);
     if (x1 <= fClipRect.fLeft) {
         return;
     }
     SkASSERT(x0 < x1);
     if (x0 < fClipRect.fLeft) {
         int dx = fClipRect.fLeft - x0;
         SkAlphaRuns::BreakAt((int16_t*)runs, (uint8_t*)aa, dx);
         runs += dx;
         aa += dx;
         x0 = fClipRect.fLeft;
     }
     SkASSERT(x0 < x1 && runs[x1 - x0] == 0);
     if (x1 > fClipRect.fRight) {
         x1 = fClipRect.fRight;
         SkAlphaRuns::BreakAt((int16_t*)runs, (uint8_t*)aa, x1 - x0);
         ((int16_t*)runs)[x1 - x0] = 0;
     }
     SkASSERT(x0 < x1 && runs[x1 - x0] == 0);
     SkASSERT(compute_anti_width(runs) == x1 - x0);
     fBlitter->blitAntiH(x0, y, aa, runs);
 }
 void SkRectClipBlitter::blitV(int x, int y, int height, SkAlpha alpha) {
     SkASSERT(height > 0);
     if (!x_in_rect(x, fClipRect)) {
         return;
     }
     int y0 = y;
     int y1 = y + height;
     if (y0 < fClipRect.fTop) {
         y0 = fClipRect.fTop;
     }
     if (y1 > fClipRect.fBottom) {
         y1 = fClipRect.fBottom;
     }
     if (y0 < y1) {
         fBlitter->blitV(x, y0, y1 - y0, alpha);
     }
 }
 void SkRectClipBlitter::blitRect(int left, int y, int width, int height) {
     SkIRect    r;
     r.set(left, y, left + width, y + height);
     if (r.intersect(fClipRect)) {
         fBlitter->blitRect(r.fLeft, r.fTop, r.width(), r.height());
     }
 }
 void SkRectClipBlitter::blitAntiRect(int left, int y, int width, int height,
                                      SkAlpha leftAlpha, SkAlpha rightAlpha) {
     SkIRect    r;
     // The *true* width of the rectangle blitted is width+2:
     r.set(left, y, left + width + 2, y + height);
     if (r.intersect(fClipRect)) {
         if (r.fLeft != left) {
             SkASSERT(r.fLeft > left);
             leftAlpha = 255;
         }
         if (r.fRight != left + width + 2) {
             SkASSERT(r.fRight < left + width + 2);
             rightAlpha = 255;
         }
         if (255 == leftAlpha && 255 == rightAlpha) {
             fBlitter->blitRect(r.fLeft, r.fTop, r.width(), r.height());
         } else if (1 == r.width()) {
             if (r.fLeft == left) {
                 fBlitter->blitV(r.fLeft, r.fTop, r.height(), leftAlpha);
             } else {
                 SkASSERT(r.fLeft == left + width + 1);
                 fBlitter->blitV(r.fLeft, r.fTop, r.height(), rightAlpha);
             }
         } else {
             fBlitter->blitAntiRect(r.fLeft, r.fTop, r.width() - 2, r.height(),
                                    leftAlpha, rightAlpha);
         }
     }
 }
 void SkRectClipBlitter::blitMask(const SkMask& mask, const SkIRect& clip) {
     SkASSERT(mask.fBounds.contains(clip));
     SkIRect    r = clip;
     if (r.intersect(fClipRect)) {
         fBlitter->blitMask(mask, r);
     }
 }
 const SkBitmap* SkRectClipBlitter::justAnOpaqueColor(uint32_t* value) {
     return fBlitter->justAnOpaqueColor(value);
 }
 ///////////////////////////////////////////////////////////////////////////////
 void SkRgnClipBlitter::blitH(int x, int y, int width) {
     SkRegion::Spanerator span(*fRgn, y, x, x + width);
     int left, right;
     while (span.next(&left, &right)) {
         SkASSERT(left < right);
         fBlitter->blitH(left, y, right - left);
     }
 }
 void SkRgnClipBlitter::blitAntiH(int x, int y, const SkAlpha aa[],
                                  const int16_t runs[]) {
     int width = compute_anti_width(runs);
     SkRegion::Spanerator span(*fRgn, y, x, x + width);
     int left, right;
     SkDEBUGCODE(const SkIRect& bounds = fRgn->getBounds();)
     int prevRite = x;
     while (span.next(&left, &right)) {
         SkASSERT(x <= left);
         SkASSERT(left < right);
         SkASSERT(left >= bounds.fLeft && right <= bounds.fRight);
         SkAlphaRuns::Break((int16_t*)runs, (uint8_t*)aa, left - x, right - left);
         // now zero before left
         if (left > prevRite) {
             int index = prevRite - x;
             ((uint8_t*)aa)[index] = 0;   // skip runs after right
             ((int16_t*)runs)[index] = SkToS16(left - prevRite);
         }
         prevRite = right;
     }
     if (prevRite > x) {
         ((int16_t*)runs)[prevRite - x] = 0;
         if (x < 0) {
             int skip = runs[0];
             SkASSERT(skip >= -x);
             aa += skip;
             runs += skip;
             x += skip;
         }
         fBlitter->blitAntiH(x, y, aa, runs);
     }
 }
 void SkRgnClipBlitter::blitV(int x, int y, int height, SkAlpha alpha) {
     SkIRect    bounds;
     bounds.set(x, y, x + 1, y + height);
     SkRegion::Cliperator    iter(*fRgn, bounds);
     while (!iter.done()) {
         const SkIRect& r = iter.rect();
         SkASSERT(bounds.contains(r));
         fBlitter->blitV(x, r.fTop, r.height(), alpha);
         iter.next();
     }
 }
 void SkRgnClipBlitter::blitRect(int x, int y, int width, int height) {
     SkIRect    bounds;
     bounds.set(x, y, x + width, y + height);
     SkRegion::Cliperator    iter(*fRgn, bounds);
     while (!iter.done()) {
         const SkIRect& r = iter.rect();
         SkASSERT(bounds.contains(r));
         fBlitter->blitRect(r.fLeft, r.fTop, r.width(), r.height());
         iter.next();
     }
 }
 void SkRgnClipBlitter::blitAntiRect(int x, int y, int width, int height,
                                     SkAlpha leftAlpha, SkAlpha rightAlpha) {
     // The *true* width of the rectangle to blit is width + 2
     SkIRect    bounds;
     bounds.set(x, y, x + width + 2, y + height);
     SkRegion::Cliperator    iter(*fRgn, bounds);
     while (!iter.done()) {
         const SkIRect& r = iter.rect();
         SkASSERT(bounds.contains(r));
         SkASSERT(r.fLeft >= x);
         SkASSERT(r.fRight <= x + width + 2);
         SkAlpha effectiveLeftAlpha = (r.fLeft == x) ? leftAlpha : 255;
         SkAlpha effectiveRightAlpha = (r.fRight == x + width + 2) ?
                                       rightAlpha : 255;
         if (255 == effectiveLeftAlpha && 255 == effectiveRightAlpha) {
             fBlitter->blitRect(r.fLeft, r.fTop, r.width(), r.height());
         } else if (1 == r.width()) {
             if (r.fLeft == x) {
                 fBlitter->blitV(r.fLeft, r.fTop, r.height(),
                                 effectiveLeftAlpha);
             } else {
                 SkASSERT(r.fLeft == x + width + 1);
                 fBlitter->blitV(r.fLeft, r.fTop, r.height(),
                                 effectiveRightAlpha);
             }
         } else {
             fBlitter->blitAntiRect(r.fLeft, r.fTop, r.width() - 2, r.height(),
                                    effectiveLeftAlpha, effectiveRightAlpha);
         }
         iter.next();
     }
 }
 void SkRgnClipBlitter::blitMask(const SkMask& mask, const SkIRect& clip) {
     SkASSERT(mask.fBounds.contains(clip));
     SkRegion::Cliperator iter(*fRgn, clip);
     const SkIRect&       r = iter.rect();
     SkBlitter*           blitter = fBlitter;
     while (!iter.done()) {
         blitter->blitMask(mask, r);
         iter.next();
     }
 }
 const SkBitmap* SkRgnClipBlitter::justAnOpaqueColor(uint32_t* value) {
     return fBlitter->justAnOpaqueColor(value);
 }
 ///////////////////////////////////////////////////////////////////////////////
 SkBlitter* SkBlitterClipper::apply(SkBlitter* blitter, const SkRegion* clip,
                                    const SkIRect* ir) {
     if (clip) {
         const SkIRect& clipR = clip->getBounds();
         if (clip->isEmpty() || (ir && !SkIRect::Intersects(clipR, *ir))) {
             blitter = &fNullBlitter;
         } else if (clip->isRect()) {
             if (ir == NULL || !clipR.contains(*ir)) {
                 fRectBlitter.init(blitter, clipR);
                 blitter = &fRectBlitter;
             }
         } else {
             fRgnBlitter.init(blitter, clip);
             blitter = &fRgnBlitter;
         }
     }
     return blitter;
 }
 ///////////////////////////////////////////////////////////////////////////////
 #include "SkColorShader.h"
 #include "SkColorPriv.h"
 class Sk3DShader : public SkShader {
 public:
     Sk3DShader(SkShader* proxy) : fProxy(proxy) {
         SkSafeRef(proxy);
         fMask = NULL;
     }
     virtual ~Sk3DShader() {
         SkSafeUnref(fProxy);
     }
     void setMask(const SkMask* mask) { fMask = mask; }
     virtual bool setContext(const SkBitmap& device, const SkPaint& paint,
                             const SkMatrix& matrix) SK_OVERRIDE {
         if (!this->INHERITED::setContext(device, paint, matrix)) {
             return false;
         }
         if (fProxy) {
             if (!fProxy->setContext(device, paint, matrix)) {
                 // must keep our set/end context calls balanced
                 this->INHERITED::endContext();
                 return false;
             }
         } else {
             fPMColor = SkPreMultiplyColor(paint.getColor());
         }
         return true;
     }
     virtual void endContext() SK_OVERRIDE {
         if (fProxy) {
             fProxy->endContext();
         }
         this->INHERITED::endContext();
     }
     virtual void shadeSpan(int x, int y, SkPMColor span[], int count) SK_OVERRIDE {
         if (fProxy) {
             fProxy->shadeSpan(x, y, span, count);
         }
         if (fMask == NULL) {
             if (fProxy == NULL) {
                 sk_memset32(span, fPMColor, count);
             }
             return;
         }
         SkASSERT(fMask->fBounds.contains(x, y));
         SkASSERT(fMask->fBounds.contains(x + count - 1, y));
         size_t          size = fMask->computeImageSize();
         const uint8_t*  alpha = fMask->getAddr8(x, y);
         const uint8_t*  mulp = alpha + size;
         const uint8_t*  addp = mulp + size;
         if (fProxy) {
             for (int i = 0; i < count; i++) {
                 if (alpha[i]) {
                     SkPMColor c = span[i];
                     if (c) {
                         unsigned a = SkGetPackedA32(c);
                         unsigned r = SkGetPackedR32(c);
                         unsigned g = SkGetPackedG32(c);
                         unsigned b = SkGetPackedB32(c);
                         unsigned mul = SkAlpha255To256(mulp[i]);
                         unsigned add = addp[i];
                         r = SkFastMin32(SkAlphaMul(r, mul) + add, a);
                         g = SkFastMin32(SkAlphaMul(g, mul) + add, a);
                         b = SkFastMin32(SkAlphaMul(b, mul) + add, a);
                         span[i] = SkPackARGB32(a, r, g, b);
                     }
                 } else {
                     span[i] = 0;
                 }
             }
         } else {    // color
             unsigned a = SkGetPackedA32(fPMColor);
             unsigned r = SkGetPackedR32(fPMColor);
             unsigned g = SkGetPackedG32(fPMColor);
             unsigned b = SkGetPackedB32(fPMColor);
             for (int i = 0; i < count; i++) {
                 if (alpha[i]) {
                     unsigned mul = SkAlpha255To256(mulp[i]);
                     unsigned add = addp[i];
                     span[i] = SkPackARGB32( a,
                                     SkFastMin32(SkAlphaMul(r, mul) + add, a),
                                     SkFastMin32(SkAlphaMul(g, mul) + add, a),
                                     SkFastMin32(SkAlphaMul(b, mul) + add, a));
                 } else {
                     span[i] = 0;
                 }
             }
         }
     }
 #ifndef SK_IGNORE_TO_STRING
     virtual void toString(SkString* str) const SK_OVERRIDE {
         str->append("Sk3DShader: (");
         if (NULL != fProxy) {
             str->append("Proxy: ");
             fProxy->toString(str);
         }
         this->INHERITED::toString(str);
         str->append(")");
     }
 #endif
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(Sk3DShader)
 protected:
     Sk3DShader(SkReadBuffer& buffer) : INHERITED(buffer) {
         fProxy = buffer.readShader();
         fPMColor = buffer.readColor();
         fMask = NULL;
     }
     virtual void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE {
         this->INHERITED::flatten(buffer);
         buffer.writeFlattenable(fProxy);
         buffer.writeColor(fPMColor);
     }
 private:
     SkShader*       fProxy;
     SkPMColor       fPMColor;
     const SkMask*   fMask;
     typedef SkShader INHERITED;
 };
 class Sk3DBlitter : public SkBlitter {
 public:
     Sk3DBlitter(SkBlitter* proxy, Sk3DShader* shader)
         : fProxy(proxy)
         , f3DShader(SkRef(shader))
     {}
     virtual void blitH(int x, int y, int width) {
         fProxy->blitH(x, y, width);
     }
     virtual void blitAntiH(int x, int y, const SkAlpha antialias[],
                            const int16_t runs[]) {
         fProxy->blitAntiH(x, y, antialias, runs);
     }
     virtual void blitV(int x, int y, int height, SkAlpha alpha) {
         fProxy->blitV(x, y, height, alpha);
     }
     virtual void blitRect(int x, int y, int width, int height) {
         fProxy->blitRect(x, y, width, height);
     }
     virtual void blitMask(const SkMask& mask, const SkIRect& clip) {
         if (mask.fFormat == SkMask::k3D_Format) {
             f3DShader->setMask(&mask);
             ((SkMask*)&mask)->fFormat = SkMask::kA8_Format;
             fProxy->blitMask(mask, clip);
             ((SkMask*)&mask)->fFormat = SkMask::k3D_Format;
             f3DShader->setMask(NULL);
         } else {
             fProxy->blitMask(mask, clip);
         }
     }
 private:
     // fProxy is unowned. It will be deleted by SkSmallAllocator.
     SkBlitter*               fProxy;
     SkAutoTUnref<Sk3DShader> f3DShader;
 };
 ///////////////////////////////////////////////////////////////////////////////
 #include "SkCoreBlitters.h"
 static bool just_solid_color(const SkPaint& paint) {
     if (paint.getAlpha() == 0xFF && paint.getColorFilter() == NULL) {
         SkShader* shader = paint.getShader();
         if (NULL == shader ||
             (shader->getFlags() & SkShader::kOpaqueAlpha_Flag)) {
             return true;
         }
     }
     return false;
 }
 /** By analyzing the paint (with an xfermode), we may decide we can take
     special action. This enum lists our possible actions
  */
 enum XferInterp {
     kNormal_XferInterp,         // no special interpretation, draw normally
     kSrcOver_XferInterp,        // draw as if in srcover mode
     kSkipDrawing_XferInterp     // draw nothing
 };
 static XferInterp interpret_xfermode(const SkPaint& paint, SkXfermode* xfer,
                                      SkColorType deviceCT) {
     SkXfermode::Mode  mode;
     if (SkXfermode::AsMode(xfer, &mode)) {
         switch (mode) {
             case SkXfermode::kSrc_Mode:
                 if (just_solid_color(paint)) {
                     return kSrcOver_XferInterp;
                 }
                 break;
             case SkXfermode::kDst_Mode:
                 return kSkipDrawing_XferInterp;
             case SkXfermode::kSrcOver_Mode:
                 return kSrcOver_XferInterp;
             case SkXfermode::kDstOver_Mode:
                 if (kRGB_565_SkColorType == deviceCT) {
                     return kSkipDrawing_XferInterp;
                 }
                 break;
             case SkXfermode::kSrcIn_Mode:
                 if (kRGB_565_SkColorType == deviceCT &&
                     just_solid_color(paint)) {
                     return kSrcOver_XferInterp;
                 }
                 break;
             case SkXfermode::kDstIn_Mode:
                 if (just_solid_color(paint)) {
                     return kSkipDrawing_XferInterp;
                 }
                 break;
             default:
                 break;
         }
     }
     return kNormal_XferInterp;
 }
 SkBlitter* SkBlitter::Choose(const SkBitmap& device,
                              const SkMatrix& matrix,
                              const SkPaint& origPaint,
                              SkTBlitterAllocator* allocator,
                              bool drawCoverage) {
     SkASSERT(allocator != NULL);
     SkBlitter*  blitter = NULL;
     // which check, in case we're being called by a client with a dummy device
     // (e.g. they have a bounder that always aborts the draw)
     if (kUnknown_SkColorType == device.colorType() ||
             (drawCoverage && (kAlpha_8_SkColorType != device.colorType()))) {
         blitter = allocator->createT<SkNullBlitter>();
         return blitter;
     }
     SkShader* shader = origPaint.getShader();
     SkColorFilter* cf = origPaint.getColorFilter();
     SkXfermode* mode = origPaint.getXfermode();
     Sk3DShader* shader3D = NULL;
     SkTCopyOnFirstWrite<SkPaint> paint(origPaint);
     if (origPaint.getMaskFilter() != NULL &&
             origPaint.getMaskFilter()->getFormat() == SkMask::k3D_Format) {
         shader3D = SkNEW_ARGS(Sk3DShader, (shader));
         // we know we haven't initialized lazyPaint yet, so just do it
         paint.writable()->setShader(shader3D)->unref();
         shader = shader3D;
     }
     if (NULL != mode) {
         switch (interpret_xfermode(*paint, mode, device.colorType())) {
             case kSrcOver_XferInterp:
                 mode = NULL;
                 paint.writable()->setXfermode(NULL);
                 break;
             case kSkipDrawing_XferInterp:{
                 blitter = allocator->createT<SkNullBlitter>();
                 return blitter;
             }
             default:
                 break;
         }
     }
     /*
      *  If the xfermode is CLEAR, then we can completely ignore the installed
      *  color/shader/colorfilter, and just pretend we're SRC + color==0. This
      *  will fall into our optimizations for SRC mode.
      */
     if (SkXfermode::IsMode(mode, SkXfermode::kClear_Mode)) {
         SkPaint* p = paint.writable();
         shader = p->setShader(NULL);
         cf = p->setColorFilter(NULL);
         mode = p->setXfermodeMode(SkXfermode::kSrc_Mode);
         p->setColor(0);
     }
     if (NULL == shader) {
         if (mode) {
             // xfermodes (and filters) require shaders for our current blitters
             shader = SkNEW(SkColorShader);
             paint.writable()->setShader(shader)->unref();
         } else if (cf) {
             // if no shader && no xfermode, we just apply the colorfilter to
             // our color and move on.
             SkPaint* writablePaint = paint.writable();
             writablePaint->setColor(cf->filterColor(paint->getColor()));
             writablePaint->setColorFilter(NULL);
             cf = NULL;
         }
     }
     if (cf) {
         SkASSERT(shader);
         shader = SkNEW_ARGS(SkFilterShader, (shader, cf));
         paint.writable()->setShader(shader)->unref();
         // blitters should ignore the presence/absence of a filter, since
         // if there is one, the shader will take care of it.
     }
     /*
      *  We need to have balanced calls to the shader:
      *      setContext
      *      endContext
      *  We make the first call here, in case it fails we can abort the draw.
      *  The endContext() call is made by the blitter (assuming setContext did
      *  not fail) in its destructor.
      */
     if (shader && !shader->setContext(device, *paint, matrix)) {
         blitter = allocator->createT<SkNullBlitter>();
         return blitter;
     }
     switch (device.colorType()) {
         case kAlpha_8_SkColorType:
             if (drawCoverage) {
                 SkASSERT(NULL == shader);
                 SkASSERT(NULL == paint->getXfermode());
                 blitter = allocator->createT<SkA8_Coverage_Blitter>(device, *paint);
             } else if (shader) {
                 blitter = allocator->createT<SkA8_Shader_Blitter>(device, *paint);
             } else {
                 blitter = allocator->createT<SkA8_Blitter>(device, *paint);
             }
             break;
         case kRGB_565_SkColorType:
             blitter = SkBlitter_ChooseD565(device, *paint, allocator);
             break;
         case kPMColor_SkColorType:
             if (shader) {
                 blitter = allocator->createT<SkARGB32_Shader_Blitter>(device, *paint);
             } else if (paint->getColor() == SK_ColorBLACK) {
                 blitter = allocator->createT<SkARGB32_Black_Blitter>(device, *paint);
             } else if (paint->getAlpha() == 0xFF) {
                 blitter = allocator->createT<SkARGB32_Opaque_Blitter>(device, *paint);
             } else {
                 blitter = allocator->createT<SkARGB32_Blitter>(device, *paint);
             }
             break;
         default:
             SkDEBUGFAIL("unsupported device config");
             blitter = allocator->createT<SkNullBlitter>();
             break;
     }
     if (shader3D) {
         SkBlitter* innerBlitter = blitter;
         // innerBlitter was allocated by allocator, which will delete it.
         blitter = allocator->createT<Sk3DBlitter>(innerBlitter, shader3D);
     }
     return blitter;
 }
 ///////////////////////////////////////////////////////////////////////////////
 const uint16_t gMask_0F0F = 0xF0F;
 const uint32_t gMask_00FF00FF = 0xFF00FF;
 ///////////////////////////////////////////////////////////////////////////////
 SkShaderBlitter::SkShaderBlitter(const SkBitmap& device, const SkPaint& paint)
         : INHERITED(device) {
     fShader = paint.getShader();
     SkASSERT(fShader);
     SkASSERT(fShader->setContextHasBeenCalled());
     fShader->ref();
     fShaderFlags = fShader->getFlags();
 }
 SkShaderBlitter::~SkShaderBlitter() {
     SkASSERT(fShader->setContextHasBeenCalled());
     fShader->endContext();
     fShader->unref();
 }

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gfx/skia/trunk/src/core/SkBlitter.cpp@deefc01c0e14 (annotated)

gfx/skia/trunk/src/core/SkBlitter.cpp