Replace SkPictureReplacementPlayback with GrRecordReplaceDraw

src/gpu/GrRecordReplaceDraw.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrRecordReplaceDraw.h"
+#include "SkRecordDraw.h"
+
+GrReplacements::ReplacementInfo* GrReplacements::push() {
+    SkDEBUGCODE(this->validate());
+    return fReplacements.push();
+}
+
+void GrReplacements::freeAll() {
+    for (int i = 0; i < fReplacements.count(); ++i) {
+        SkDELETE(fReplacements[i].fBM);
+    }
+    fReplacements.reset();
+}
+
+#ifdef SK_DEBUG
+void GrReplacements::validate() const {
+    // Check that the ranges are monotonically increasing and non-overlapping
+    if (fReplacements.count() > 0) {
+        SkASSERT(fReplacements[0].fStart < fReplacements[0].fStop);
+
+        for (int i = 1; i < fReplacements.count(); ++i) {
+            SkASSERT(fReplacements[i].fStart < fReplacements[i].fStop);
+            SkASSERT(fReplacements[i - 1].fStop < fReplacements[i].fStart);
+        }
+    }
+}
+#endif
+
+const GrReplacements::ReplacementInfo*
+GrReplacements::lookupByStart(size_t start, int* searchStart) const {
+    SkDEBUGCODE(this->validate());
+    for (int i = *searchStart; i < fReplacements.count(); ++i) {
+        if (start == fReplacements[i].fStart) {
+            *searchStart = i + 1;
+            return &fReplacements[i];
+        } else if (start < fReplacements[i].fStart) {
+            return NULL;  // the ranges are monotonically increasing and non-overlapping
+        }
+    }
+
+    return NULL;
+}
+
+static inline void draw_replacement_bitmap(const GrReplacements::ReplacementInfo* ri,
+                                           SkRecords::Draw* draw) {
+    SkRect src = SkRect::Make(ri->fSrcRect);
+    SkRect dst = SkRect::MakeXYWH(SkIntToScalar(ri->fPos.fX),
+                                  SkIntToScalar(ri->fPos.fY),
+                                  SkIntToScalar(ri->fSrcRect.width()), 
+                                  SkIntToScalar(ri->fSrcRect.height()));
+    SkRecords::DrawBitmapRectToRect dbmr2r(const_cast<SkPaint*>(ri->fPaint), 

[mtklein, 2014/09/03 15:46:11]

Hrm.  This isn't going to work.  dbmr2r will destroy (but not free the memory)
of rf->fPaint when it goes out of scope.  Shame on your const_cast!

I think if we're going to do things this way, it'd have to look like this:

SkAutoTMalloc<SkPaint> buffer(1);
SkNEW_PLACEMENT_ARGS(buffer.get(), SkPaint, (*rf->fPaint));
SkRecords::DBRTR dmbr2r(buffer.get(), *ri->fBM, ...);
(*draw)(dbmr2r);


This all raises the question of whether it'd be better to modify the SkRecord
before playing it back rather than playing it back differently.  Can't we just
no-op away the old commands and insert a new draw bitmap?

+                                           *ri->fBM, 
+                                           &src, 
+                                           dst, 
+                                           SkCanvas::kNone_DrawBitmapRectFlag);
+    (*draw)(dbmr2r);

[mtklein, 2014/09/03 15:49:14]

Wait a sec, maybe that's still even too complicated.  Why don't we pass the
canvas in here instead of the SkRecords::Draw?  Then we can just replace all
this with:

  canvas->drawBitmapRectToRect(*ri->fBM, &src, dst, ri->fPaint);

[robertphillips, 2014/09/03 17:36:24]

Done.

+}
+
+void GrRecordReplaceDraw(const SkRecord& record,
+                         SkCanvas* canvas,
+                         const SkBBoxHierarchy* bbh,
+                         const GrReplacements* replacements,
+                         SkDrawPictureCallback* callback) {
+    SkAutoCanvasRestore saveRestore(canvas, true /*save now, restore at exit*/);
+
+    SkRecords::Draw draw(canvas);
+    const GrReplacements::ReplacementInfo* ri = NULL;
+    int searchStart = 0;
+
+    if (NULL != bbh) {
+        // Draw only ops that affect pixels in the canvas's current clip.
+        // The SkRecord and BBH were recorded in identity space.  This canvas
+        // is not necessarily in that same space.  getClipBounds() returns us
+        // this canvas' clip bounds transformed back into identity space, which
+        // lets us query the BBH.
+        SkRect query = { 0, 0, 0, 0 };
+        (void)canvas->getClipBounds(&query);
+
+        SkTDArray<void*> ops;
+        bbh->search(query, &ops);
+
+        for (int i = 0; i < ops.count(); i++) {
+            if (NULL != callback && callback->abortDrawing()) {
+                return;
+            }
+            ri = replacements->lookupByStart(i, &searchStart);
+            if (NULL != ri) {
+                draw_replacement_bitmap(ri, &draw);
+
+                for (; (uintptr_t)ops[i] < ri->fStop; ++i)

[bsalomon, 2014/09/03 15:43:50]

while ((uintptr_t)ops[i] < ri->fStop) {
 ++i;
}

while ((uintptr_t)ops[i++] < ri->fStop) {
}

?

[robertphillips, 2014/09/03 17:36:24]

Done.

+                    ;
+                SkASSERT((uintptr_t)ops[i] == ri->fStop);
+                continue;
+            }
+
+            record.visit<void>((uintptr_t)ops[i], draw);
+        }
+    } else {
+        for (unsigned int i = 0; i < record.count(); ++i) {
+            if (NULL != callback && callback->abortDrawing()) {
+                return;
+            }
+            ri = replacements->lookupByStart(i, &searchStart);
+            if (NULL != ri) {
+                draw_replacement_bitmap(ri, &draw);
+
+                i = ri->fStop;
+                continue;
+            }
+
+            record.visit<void>(i, draw);
+        }
+    }
+}