blob: 953e87485428e33d806ba267365709b2d9904324 [file] [log] [blame]
* 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 "SkRecordDraw.h"
#include "SkImage.h"
#include "SkPatchUtils.h"
void SkRecordDraw(const SkRecord& record,
SkCanvas* canvas,
SkPicture const* const drawablePicts[],
SkDrawable* const drawables[],
int drawableCount,
const SkBBoxHierarchy* bbh,
SkPicture::AbortCallback* callback) {
SkAutoCanvasRestore saveRestore(canvas, true /*save now, restore at exit*/);
if (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. getLocalClipBounds() returns us
// this canvas' clip bounds transformed back into identity space, which
// lets us query the BBH.
SkRect query = canvas->getLocalClipBounds();
SkTDArray<int> ops;
bbh->search(query, &ops);
SkRecords::Draw draw(canvas, drawablePicts, drawables, drawableCount);
for (int i = 0; i < ops.count(); i++) {
if (callback && callback->abort()) {
// This visit call uses the SkRecords::Draw::operator() to call
// methods on the |canvas|, wrapped by methods defined with the
// DRAW() macro.
record.visit(ops[i], draw);
} else {
// Draw all ops.
SkRecords::Draw draw(canvas, drawablePicts, drawables, drawableCount);
for (int i = 0; i < record.count(); i++) {
if (callback && callback->abort()) {
// This visit call uses the SkRecords::Draw::operator() to call
// methods on the |canvas|, wrapped by methods defined with the
// DRAW() macro.
record.visit(i, draw);
void SkRecordPartialDraw(const SkRecord& record, SkCanvas* canvas,
SkPicture const* const drawablePicts[], int drawableCount,
int start, int stop,
const SkMatrix& initialCTM) {
SkAutoCanvasRestore saveRestore(canvas, true /*save now, restore at exit*/);
stop = SkTMin(stop, record.count());
SkRecords::Draw draw(canvas, drawablePicts, nullptr, drawableCount, &initialCTM);
for (int i = start; i < stop; i++) {
record.visit(i, draw);
namespace SkRecords {
// NoOps draw nothing.
template <> void Draw::draw(const NoOp&) {}
#define DRAW(T, call) template <> void Draw::draw(const T& r) { fCanvas->call; }
DRAW(Restore, restore());
DRAW(Save, save());
DRAW(SaveLayer, saveLayer(SkCanvas::SaveLayerRec(r.bounds,
DRAW(SetMatrix, setMatrix(SkMatrix::Concat(fInitialCTM, r.matrix)));
DRAW(Concat, concat(r.matrix));
DRAW(Translate, translate(r.dx, r.dy));
DRAW(ClipPath, clipPath(r.path, r.opAA.op(), r.opAA.aa()));
DRAW(ClipRRect, clipRRect(r.rrect, r.opAA.op(), r.opAA.aa()));
DRAW(ClipRect, clipRect(r.rect, r.opAA.op(), r.opAA.aa()));
DRAW(ClipRegion, clipRegion(r.region, r.op));
DRAW(DrawArc, drawArc(r.oval, r.startAngle, r.sweepAngle, r.useCenter, r.paint));
DRAW(DrawDRRect, drawDRRect(r.outer, r.inner, r.paint));
DRAW(DrawImage, drawImage(r.image.get(), r.left,, r.paint));
template <> void Draw::draw(const DrawImageLattice& r) {
SkCanvas::Lattice lattice;
lattice.fXCount = r.xCount;
lattice.fXDivs = r.xDivs;
lattice.fYCount = r.yCount;
lattice.fYDivs = r.yDivs;
lattice.fFlags = (0 == r.flagCount) ? nullptr : r.flags;
lattice.fBounds = &r.src;
fCanvas->drawImageLattice(r.image.get(), lattice, r.dst, r.paint);
DRAW(DrawImageRect, legacy_drawImageRect(r.image.get(), r.src, r.dst, r.paint, r.constraint));
DRAW(DrawImageNine, drawImageNine(r.image.get(),, r.dst, r.paint));
DRAW(DrawOval, drawOval(r.oval, r.paint));
DRAW(DrawPaint, drawPaint(r.paint));
DRAW(DrawPath, drawPath(r.path, r.paint));
DRAW(DrawPatch, drawPatch(r.cubics, r.colors, r.texCoords, r.bmode, r.paint));
DRAW(DrawPicture, drawPicture(r.picture.get(), &r.matrix, r.paint));
DRAW(DrawPoints, drawPoints(r.mode, r.count, r.pts, r.paint));
DRAW(DrawPosText, drawPosText(r.text, r.byteLength, r.pos, r.paint));
DRAW(DrawPosTextH, drawPosTextH(r.text, r.byteLength, r.xpos, r.y, r.paint));
DRAW(DrawRRect, drawRRect(r.rrect, r.paint));
DRAW(DrawRect, drawRect(r.rect, r.paint));
DRAW(DrawRegion, drawRegion(r.region, r.paint));
DRAW(DrawText, drawText(r.text, r.byteLength, r.x, r.y, r.paint));
DRAW(DrawTextBlob, drawTextBlob(r.blob.get(), r.x, r.y, r.paint));
DRAW(DrawTextOnPath, drawTextOnPath(r.text, r.byteLength, r.path, &r.matrix, r.paint));
DRAW(DrawTextRSXform, drawTextRSXform(r.text, r.byteLength, r.xforms, r.cull, r.paint));
DRAW(DrawAtlas, drawAtlas(r.atlas.get(),
r.xforms, r.texs, r.colors, r.count, r.mode, r.cull, r.paint));
DRAW(DrawVertices, drawVertices(r.vertices, r.bmode, r.paint));
DRAW(DrawShadowRec, private_draw_shadow_rec(r.path, r.rec));
DRAW(DrawAnnotation, drawAnnotation(r.rect, r.key.c_str(), r.value.get()));
#undef DRAW
template <> void Draw::draw(const DrawDrawable& r) {
SkASSERT(r.index >= 0);
SkASSERT(r.index < fDrawableCount);
if (fDrawables) {
SkASSERT(nullptr == fDrawablePicts);
fCanvas->drawDrawable(fDrawables[r.index], r.matrix);
} else {
fCanvas->drawPicture(fDrawablePicts[r.index], r.matrix, nullptr);
// This is an SkRecord visitor that fills an SkBBoxHierarchy.
// The interesting part here is how to calculate bounds for ops which don't
// have intrinsic bounds. What is the bounds of a Save or a Translate?
// We answer this by thinking about a particular definition of bounds: if I
// don't execute this op, pixels in this rectangle might draw incorrectly. So
// the bounds of a Save, a Translate, a Restore, etc. are the union of the
// bounds of Draw* ops that they might have an effect on. For any given
// Save/Restore block, the bounds of the Save, the Restore, and any other
// non-drawing ("control") ops inside are exactly the union of the bounds of
// the drawing ops inside that block.
// To implement this, we keep a stack of active Save blocks. As we consume ops
// inside the Save/Restore block, drawing ops are unioned with the bounds of
// the block, and control ops are stashed away for later. When we finish the
// block with a Restore, our bounds are complete, and we go back and fill them
// in for all the control ops we stashed away.
class FillBounds : SkNoncopyable {
FillBounds(const SkRect& cullRect, const SkRecord& record, SkRect bounds[])
: fNumRecords(record.count())
, fCullRect(cullRect)
, fBounds(bounds) {
fCTM = SkMatrix::I();
fCurrentClipBounds = fCullRect;
void cleanUp() {
// If we have any lingering unpaired Saves, simulate restores to make
// sure all ops in those Save blocks have their bounds calculated.
while (!fSaveStack.isEmpty()) {
// Any control ops not part of any Save/Restore block draw everywhere.
while (!fControlIndices.isEmpty()) {
void setCurrentOp(int currentOp) { fCurrentOp = currentOp; }
template <typename T> void operator()(const T& op) {
// In this file, SkRect are in local coordinates, Bounds are translated back to identity space.
typedef SkRect Bounds;
int currentOp() const { return fCurrentOp; }
const SkMatrix& ctm() const { return fCTM; }
const Bounds& getBounds(int index) const { return fBounds[index]; }
// Adjust rect for all paints that may affect its geometry, then map it to identity space.
Bounds adjustAndMap(SkRect rect, const SkPaint* paint) const {
// Inverted rectangles really confuse our BBHs.
// Adjust the rect for its own paint.
if (!AdjustForPaint(paint, &rect)) {
// The paint could do anything to our bounds. The only safe answer is the current clip.
return fCurrentClipBounds;
// Adjust rect for all the paints from the SaveLayers we're inside.
if (!this->adjustForSaveLayerPaints(&rect)) {
// Same deal as above.
return fCurrentClipBounds;
// Map the rect back to identity space.
// Nothing can draw outside the current clip.
if (!rect.intersect(fCurrentClipBounds)) {
return Bounds::MakeEmpty();
return rect;
struct SaveBounds {
int controlOps; // Number of control ops in this Save block, including the Save.
Bounds bounds; // Bounds of everything in the block.
const SkPaint* paint; // Unowned. If set, adjusts the bounds of all ops in this block.
SkMatrix ctm;
// Only Restore, SetMatrix, Concat, and Translate change the CTM.
template <typename T> void updateCTM(const T&) {}
void updateCTM(const Restore& op) { fCTM = op.matrix; }
void updateCTM(const SetMatrix& op) { fCTM = op.matrix; }
void updateCTM(const Concat& op) { fCTM.preConcat(op.matrix); }
void updateCTM(const Translate& op) { fCTM.preTranslate(op.dx, op.dy); }
// Most ops don't change the clip.
template <typename T> void updateClipBounds(const T&) {}
// Clip{Path,RRect,Rect,Region} obviously change the clip. They all know their bounds already.
void updateClipBounds(const ClipPath& op) { this->updateClipBoundsForClipOp(op.devBounds); }
void updateClipBounds(const ClipRRect& op) { this->updateClipBoundsForClipOp(op.devBounds); }
void updateClipBounds(const ClipRect& op) { this->updateClipBoundsForClipOp(op.devBounds); }
void updateClipBounds(const ClipRegion& op) { this->updateClipBoundsForClipOp(op.devBounds); }
// The bounds of clip ops need to be adjusted for the paints of saveLayers they're inside.
void updateClipBoundsForClipOp(const SkIRect& devBounds) {
Bounds clip = SkRect::Make(devBounds);
// We don't call adjustAndMap() because as its last step it would intersect the adjusted
// clip bounds with the previous clip, exactly what we can't do when the clip grows.
if (this->adjustForSaveLayerPaints(&clip)) {
fCurrentClipBounds = clip.intersect(fCullRect) ? clip : Bounds::MakeEmpty();
} else {
fCurrentClipBounds = fCullRect;
// Restore holds the devBounds for the clip after the {save,saveLayer}/restore block completes.
void updateClipBounds(const Restore& op) {
// This is just like the clip ops above, but we need to skip the effects (if any) of our
// paired saveLayer (if it is one); it has not yet been popped off the save stack. Our
// devBounds reflect the state of the world after the saveLayer/restore block is done,
// so they are not affected by the saveLayer's paint.
const int kSavesToIgnore = 1;
Bounds clip = SkRect::Make(op.devBounds);
if (this->adjustForSaveLayerPaints(&clip, kSavesToIgnore)) {
fCurrentClipBounds = clip.intersect(fCullRect) ? clip : Bounds::MakeEmpty();
} else {
fCurrentClipBounds = fCullRect;
// We also take advantage of SaveLayer bounds when present to further cut the clip down.
void updateClipBounds(const SaveLayer& op) {
if (op.bounds) {
// adjustAndMap() intersects these layer bounds with the previous clip for us.
fCurrentClipBounds = this->adjustAndMap(*op.bounds, op.paint);
// The bounds of these ops must be calculated when we hit the Restore
// from the bounds of the ops in the same Save block.
void trackBounds(const Save&) { this->pushSaveBlock(nullptr); }
void trackBounds(const SaveLayer& op) { this->pushSaveBlock(op.paint); }
void trackBounds(const Restore&) { fBounds[fCurrentOp] = this->popSaveBlock(); }
void trackBounds(const SetMatrix&) { this->pushControl(); }
void trackBounds(const Concat&) { this->pushControl(); }
void trackBounds(const Translate&) { this->pushControl(); }
void trackBounds(const ClipRect&) { this->pushControl(); }
void trackBounds(const ClipRRect&) { this->pushControl(); }
void trackBounds(const ClipPath&) { this->pushControl(); }
void trackBounds(const ClipRegion&) { this->pushControl(); }
// For all other ops, we can calculate and store the bounds directly now.
template <typename T> void trackBounds(const T& op) {
fBounds[fCurrentOp] = this->bounds(op);
void pushSaveBlock(const SkPaint* paint) {
// Starting a new Save block. Push a new entry to represent that.
SaveBounds sb;
sb.controlOps = 0;
// If the paint affects transparent black, the bound shouldn't be smaller
// than the current clip bounds.
sb.bounds =
PaintMayAffectTransparentBlack(paint) ? fCurrentClipBounds : Bounds::MakeEmpty();
sb.paint = paint;
sb.ctm = this->fCTM;
static bool PaintMayAffectTransparentBlack(const SkPaint* paint) {
if (paint) {
// FIXME: this is very conservative
if (paint->getImageFilter() || paint->getColorFilter()) {
return true;
// Unusual blendmodes require us to process a saved layer
// even with operations outisde the clip.
// For example, DstIn is used by masking layers.
switch (paint->getBlendMode()) {
// For each of the following transfer modes, if the source
// alpha is zero (our transparent black), the resulting
// blended alpha is not necessarily equal to the original
// destination alpha.
case SkBlendMode::kClear:
case SkBlendMode::kSrc:
case SkBlendMode::kSrcIn:
case SkBlendMode::kDstIn:
case SkBlendMode::kSrcOut:
case SkBlendMode::kDstATop:
case SkBlendMode::kModulate:
return true;
return false;
Bounds popSaveBlock() {
// We're done the Save block. Apply the block's bounds to all control ops inside it.
SaveBounds sb;
while (sb.controlOps --> 0) {
// This whole Save block may be part another Save block.
// If called from a real Restore (not a phony one for balance), it'll need the bounds.
return sb.bounds;
void pushControl() {
if (!fSaveStack.isEmpty()) {;
void popControl(const Bounds& bounds) {
fBounds[] = bounds;
void updateSaveBounds(const Bounds& bounds) {
// If we're in a Save block, expand its bounds to cover these bounds too.
if (!fSaveStack.isEmpty()) {;
// FIXME: this method could use better bounds
Bounds bounds(const DrawText&) const { return fCurrentClipBounds; }
Bounds bounds(const DrawPaint&) const { return fCurrentClipBounds; }
Bounds bounds(const NoOp&) const { return Bounds::MakeEmpty(); } // NoOps don't draw.
Bounds bounds(const DrawRect& op) const { return this->adjustAndMap(op.rect, &op.paint); }
Bounds bounds(const DrawRegion& op) const {
SkRect rect = SkRect::Make(op.region.getBounds());
return this->adjustAndMap(rect, &op.paint);
Bounds bounds(const DrawOval& op) const { return this->adjustAndMap(op.oval, &op.paint); }
// Tighter arc bounds?
Bounds bounds(const DrawArc& op) const { return this->adjustAndMap(op.oval, &op.paint); }
Bounds bounds(const DrawRRect& op) const {
return this->adjustAndMap(op.rrect.rect(), &op.paint);
Bounds bounds(const DrawDRRect& op) const {
return this->adjustAndMap(op.outer.rect(), &op.paint);
Bounds bounds(const DrawImage& op) const {
const SkImage* image = op.image.get();
SkRect rect = SkRect::MakeXYWH(op.left,, image->width(), image->height());
return this->adjustAndMap(rect, op.paint);
Bounds bounds(const DrawImageLattice& op) const {
return this->adjustAndMap(op.dst, op.paint);
Bounds bounds(const DrawImageRect& op) const {
return this->adjustAndMap(op.dst, op.paint);
Bounds bounds(const DrawImageNine& op) const {
return this->adjustAndMap(op.dst, op.paint);
Bounds bounds(const DrawPath& op) const {
return op.path.isInverseFillType() ? fCurrentClipBounds
: this->adjustAndMap(op.path.getBounds(), &op.paint);
Bounds bounds(const DrawPoints& op) const {
SkRect dst;
dst.set(op.pts, op.count);
// Pad the bounding box a little to make sure hairline points' bounds aren't empty.
SkScalar stroke = SkMaxScalar(op.paint.getStrokeWidth(), 0.01f);
dst.outset(stroke/2, stroke/2);
return this->adjustAndMap(dst, &op.paint);
Bounds bounds(const DrawPatch& op) const {
SkRect dst;
dst.set(op.cubics, SkPatchUtils::kNumCtrlPts);
return this->adjustAndMap(dst, &op.paint);
Bounds bounds(const DrawVertices& op) const {
return this->adjustAndMap(op.vertices->bounds(), &op.paint);
Bounds bounds(const DrawAtlas& op) const {
if (op.cull) {
// TODO: <reed> can we pass nullptr for the paint? Isn't cull already "correct"
// for the paint (by the caller)?
return this->adjustAndMap(*op.cull, op.paint);
} else {
return fCurrentClipBounds;
Bounds bounds(const DrawShadowRec& op) const {
return this->adjustAndMap(op.path.getBounds(), nullptr);
Bounds bounds(const DrawPicture& op) const {
SkRect dst = op.picture->cullRect();
return this->adjustAndMap(dst, op.paint);
Bounds bounds(const DrawPosText& op) const {
const int N = op.paint.countText(op.text, op.byteLength);
if (N == 0) {
return Bounds::MakeEmpty();
SkRect dst;
dst.set(op.pos, N);
AdjustTextForFontMetrics(&dst, op.paint);
return this->adjustAndMap(dst, &op.paint);
Bounds bounds(const DrawPosTextH& op) const {
const int N = op.paint.countText(op.text, op.byteLength);
if (N == 0) {
return Bounds::MakeEmpty();
SkScalar left = op.xpos[0], right = op.xpos[0];
for (int i = 1; i < N; i++) {
left = SkMinScalar(left, op.xpos[i]);
right = SkMaxScalar(right, op.xpos[i]);
SkRect dst = { left, op.y, right, op.y };
AdjustTextForFontMetrics(&dst, op.paint);
return this->adjustAndMap(dst, &op.paint);
Bounds bounds(const DrawTextOnPath& op) const {
SkRect dst = op.path.getBounds();
// Pad all sides by the maximum padding in any direction we'd normally apply.
SkRect pad = { 0, 0, 0, 0};
AdjustTextForFontMetrics(&pad, op.paint);
// That maximum padding happens to always be the right pad today.
SkASSERT(pad.fLeft == -pad.fRight);
SkASSERT(pad.fTop == -pad.fBottom);
SkASSERT(pad.fRight > pad.fBottom);
dst.outset(pad.fRight, pad.fRight);
return this->adjustAndMap(dst, &op.paint);
Bounds bounds(const DrawTextRSXform& op) const {
if (op.cull) {
return this->adjustAndMap(*op.cull, nullptr);
} else {
return fCurrentClipBounds;
Bounds bounds(const DrawTextBlob& op) const {
SkRect dst = op.blob->bounds();
dst.offset(op.x, op.y);
return this->adjustAndMap(dst, &op.paint);
Bounds bounds(const DrawDrawable& op) const {
return this->adjustAndMap(op.worstCaseBounds, nullptr);
Bounds bounds(const DrawAnnotation& op) const {
return this->adjustAndMap(op.rect, nullptr);
static void AdjustTextForFontMetrics(SkRect* rect, const SkPaint& paint) {
#ifdef SK_DEBUG
SkRect correct = *rect;
// ~~> xPad = 4x yPad
// ~~> bump yPad from 2x text size to 2.5x
const SkScalar yPad = 2.5f * paint.getTextSize(),
xPad = 4.0f * yPad;
rect->outset(xPad, yPad);
#ifdef SK_DEBUG
SkPaint::FontMetrics metrics;
correct.fLeft += metrics.fXMin;
correct.fTop += metrics.fTop;
correct.fRight += metrics.fXMax;
correct.fBottom += metrics.fBottom;
// See skia:2862 for why we ignore small text sizes.
SkASSERTF(paint.getTextSize() < 0.001f || rect->contains(correct),
"%f %f %f %f vs. %f %f %f %f\n",
-xPad, -yPad, +xPad, +yPad,
metrics.fXMin, metrics.fTop, metrics.fXMax, metrics.fBottom);
// Returns true if rect was meaningfully adjusted for the effects of paint,
// false if the paint could affect the rect in unknown ways.
static bool AdjustForPaint(const SkPaint* paint, SkRect* rect) {
if (paint) {
if (paint->canComputeFastBounds()) {
*rect = paint->computeFastBounds(*rect, rect);
return true;
return false;
return true;
bool adjustForSaveLayerPaints(SkRect* rect, int savesToIgnore = 0) const {
for (int i = fSaveStack.count() - 1 - savesToIgnore; i >= 0; i--) {
SkMatrix inverse;
if (!fSaveStack[i].ctm.invert(&inverse)) {
return false;
if (!AdjustForPaint(fSaveStack[i].paint, rect)) {
return false;
return true;
const int fNumRecords;
// We do not guarantee anything for operations outside of the cull rect
const SkRect fCullRect;
// Conservative identity-space bounds for each op in the SkRecord.
Bounds* fBounds;
// We walk fCurrentOp through the SkRecord, as we go using updateCTM()
// and updateClipBounds() to maintain the exact CTM (fCTM) and conservative
// identity-space bounds of the current clip (fCurrentClipBounds).
int fCurrentOp;
SkMatrix fCTM;
Bounds fCurrentClipBounds;
// Used to track the bounds of Save/Restore blocks and the control ops inside them.
SkTDArray<SaveBounds> fSaveStack;
SkTDArray<int> fControlIndices;
} // namespace SkRecords
void SkRecordFillBounds(const SkRect& cullRect, const SkRecord& record, SkRect bounds[]) {
SkRecords::FillBounds visitor(cullRect, record, bounds);
for (int curOp = 0; curOp < record.count(); curOp++) {
record.visit(curOp, visitor);