blob: 19128ab98e80116e76be2fd70d1d1b6b41d7d6e5 [file] [log] [blame]
* Copyright 2015 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#ifndef GrTextBlob_DEFINED
#define GrTextBlob_DEFINED
#include "GrColor.h"
#include "GrDrawOpAtlas.h"
#include "GrGlyphCache.h"
#include "GrTextUtils.h"
#include "SkDescriptor.h"
#include "SkMaskFilterBase.h"
#include "SkOpts.h"
#include "SkPathEffect.h"
#include "SkPoint3.h"
#include "SkRectPriv.h"
#include "SkSurfaceProps.h"
#include "SkTInternalLList.h"
class GrAtlasManager;
struct GrDistanceFieldAdjustTable;
struct GrGlyph;
class SkDrawFilter;
class SkTextBlob;
class SkTextBlobRunIterator;
// With this flag enabled, the GrTextContext will, as a sanity check, regenerate every blob
// that comes in to verify the integrity of its cache
* A GrTextBlob contains a fully processed SkTextBlob, suitable for nearly immediate drawing
* on the GPU. These are initially created with valid positions and colors, but invalid
* texture coordinates. The GrTextBlob itself has a few Blob-wide properties, and also
* consists of a number of runs. Runs inside a blob are flushed individually so they can be
* reordered.
* The only thing(aside from a memcopy) required to flush a GrTextBlob is to ensure that
* the GrAtlas will not evict anything the Blob needs.
* Note: This struct should really be named GrCachedAtasTextBlob, but that is too verbose.
* *WARNING* If you add new fields to this struct, then you may need to to update AssertEqual
class GrTextBlob : public SkNVRefCnt<GrTextBlob> {
class VertexRegenerator;
static sk_sp<GrTextBlob> Make(int glyphCount, int runCount);
* We currently force regeneration of a blob if old or new matrix differ in having perspective.
* If we ever change that then the key must contain the perspectiveness when there are distance
* fields as perspective distance field use 3 component vertex positions and non-perspective
* uses 2.
struct Key {
Key() {
sk_bzero(this, sizeof(Key));
uint32_t fUniqueID;
// Color may affect the gamma of the mask we generate, but in a fairly limited way.
// Each color is assigned to on of a fixed number of buckets based on its
// luminance. For each luminance bucket there is a "canonical color" that
// represents the bucket. This functionality is currently only supported for A8
SkColor fCanonicalColor;
SkPaint::Style fStyle;
SkPixelGeometry fPixelGeometry;
bool fHasBlur;
uint32_t fScalerContextFlags;
bool operator==(const Key& other) const {
return 0 == memcmp(this, &other, sizeof(Key));
void setupKey(const GrTextBlob::Key& key,
const SkMaskFilterBase::BlurRec& blurRec,
const SkPaint& paint) {
fKey = key;
if (key.fHasBlur) {
fBlurRec = blurRec;
if (key.fStyle != SkPaint::kFill_Style) {
fStrokeInfo.fFrameWidth = paint.getStrokeWidth();
fStrokeInfo.fMiterLimit = paint.getStrokeMiter();
fStrokeInfo.fJoin = paint.getStrokeJoin();
static const Key& GetKey(const GrTextBlob& blob) {
return blob.fKey;
static uint32_t Hash(const Key& key) {
return SkOpts::hash(&key, sizeof(Key));
void operator delete(void* p) {
::operator delete(p);
void* operator new(size_t) {
SK_ABORT("All blobs are created by placement new.");
return sk_malloc_throw(0);
void* operator new(size_t, void* p) { return p; }
bool hasDistanceField() const { return SkToBool(fTextType & kHasDistanceField_TextType); }
bool hasBitmap() const { return SkToBool(fTextType & kHasBitmap_TextType); }
void setHasDistanceField() { fTextType |= kHasDistanceField_TextType; }
void setHasBitmap() { fTextType |= kHasBitmap_TextType; }
int runCount() const { return fRunCount; }
void push_back_run(int currRun) {
SkASSERT(currRun < fRunCount);
if (currRun > 0) {
Run::SubRunInfo& newRun = fRuns[currRun].fSubRunInfo.back();
Run::SubRunInfo& lastRun = fRuns[currRun - 1].fSubRunInfo.back();
// sets the last subrun of runIndex to use distance field text
void setSubRunHasDistanceFields(int runIndex, bool hasLCD, bool isAntiAlias, bool hasWCoord) {
Run& run = fRuns[runIndex];
Run::SubRunInfo& subRun = run.fSubRunInfo.back();
// sets the last subrun of runIndex to use w values
void setSubRunHasW(int runIndex, bool hasWCoord) {
Run& run = fRuns[runIndex];
Run::SubRunInfo& subRun = run.fSubRunInfo.back();
void setRunPaintFlags(int runIndex, uint16_t paintFlags) {
fRuns[runIndex].fPaintFlags = paintFlags & Run::kPaintFlagsMask;
void setMinAndMaxScale(SkScalar scaledMax, SkScalar scaledMin) {
// we init fMaxMinScale and fMinMaxScale in the constructor
fMaxMinScale = SkMaxScalar(scaledMax, fMaxMinScale);
fMinMaxScale = SkMinScalar(scaledMin, fMinMaxScale);
// inits the override descriptor on the current run. All following subruns must use this
// descriptor
void initOverride(int runIndex) {
Run& run = fRuns[runIndex];
// Push back a new subrun to fill and set the override descriptor
run.fOverrideDescriptor.reset(new SkAutoDescriptor);
SkExclusiveStrikePtr setupCache(int runIndex,
const SkSurfaceProps& props,
SkScalerContextFlags scalerContextFlags,
const SkPaint& skPaint,
const SkMatrix* viewMatrix);
// Appends a glyph to the blob. If the glyph is too large, the glyph will be appended
// as a path.
void appendGlyph(int runIndex,
const SkRect& positions,
GrColor color,
sk_sp<GrTextStrike> strike,
GrGlyph* glyph,
SkGlyphCache*, const SkGlyph& skGlyph,
SkScalar x, SkScalar y, SkScalar scale, bool preTransformed);
// Appends a glyph to the blob as a path only.
void appendPathGlyph(int runIndex, const SkPath& path,
SkScalar x, SkScalar y, SkScalar scale, bool preTransformed);
static size_t GetVertexStride(GrMaskFormat maskFormat, bool hasWCoord) {
switch (maskFormat) {
case kA8_GrMaskFormat:
return hasWCoord ? kGrayTextDFPerspectiveVASize : kGrayTextVASize;
case kARGB_GrMaskFormat:
return hasWCoord ? kColorTextPerspectiveVASize : kColorTextVASize;
return kLCDTextVASize;
bool mustRegenerate(const GrTextUtils::Paint&, const SkMaskFilterBase::BlurRec& blurRec,
const SkMatrix& viewMatrix, SkScalar x, SkScalar y);
void flush(GrTextUtils::Target*, const SkSurfaceProps& props,
const GrDistanceFieldAdjustTable* distanceAdjustTable,
const GrTextUtils::Paint& paint, const GrClip& clip,
const SkMatrix& viewMatrix, const SkIRect& clipBounds, SkScalar x,
SkScalar y);
void computeSubRunBounds(SkRect* outBounds, int runIndex, int subRunIndex,
const SkMatrix& viewMatrix, SkScalar x, SkScalar y,
bool needsGlyphTransform) {
// We don't yet position distance field text on the cpu, so we have to map the vertex bounds
// into device space.
// We handle vertex bounds differently for distance field text and bitmap text because
// the vertex bounds of bitmap text are in device space. If we are flushing multiple runs
// from one blob then we are going to pay the price here of mapping the rect for each run.
const Run& run = fRuns[runIndex];
const Run::SubRunInfo& subRun = run.fSubRunInfo[subRunIndex];
*outBounds = subRun.vertexBounds();
if (needsGlyphTransform) {
// Distance field text is positioned with the (X,Y) as part of the glyph position,
// and currently the view matrix is applied on the GPU
outBounds->offset(x - fInitialX, y - fInitialY);
} else {
// Bitmap text is fully positioned on the CPU, and offset by an (X,Y) translate in
// device space.
SkMatrix boundsMatrix = fInitialViewMatrixInverse;
boundsMatrix.postTranslate(-fInitialX, -fInitialY);
boundsMatrix.postTranslate(x, y);
// Due to floating point numerical inaccuracies, we have to round out here
// position + local coord
static const size_t kColorTextVASize = sizeof(SkPoint) + sizeof(SkIPoint16);
static const size_t kColorTextPerspectiveVASize = sizeof(SkPoint3) + sizeof(SkIPoint16);
static const size_t kGrayTextVASize = sizeof(SkPoint) + sizeof(GrColor) + sizeof(SkIPoint16);
static const size_t kGrayTextDFPerspectiveVASize =
sizeof(SkPoint3) + sizeof(GrColor) + sizeof(SkIPoint16);
static const size_t kLCDTextVASize = kGrayTextVASize;
static const size_t kMaxVASize = kGrayTextDFPerspectiveVASize;
static const int kVerticesPerGlyph = 4;
static void AssertEqual(const GrTextBlob&, const GrTextBlob&);
// The color here is the GrPaint color, and it is used to determine whether we
// have to regenerate LCD text blobs.
// We use this color vs the SkPaint color because it has the colorfilter applied.
void initReusableBlob(SkColor luminanceColor, const SkMatrix& viewMatrix,
SkScalar x, SkScalar y) {
fLuminanceColor = luminanceColor;
this->setupViewMatrix(viewMatrix, x, y);
void initThrowawayBlob(const SkMatrix& viewMatrix, SkScalar x, SkScalar y) {
this->setupViewMatrix(viewMatrix, x, y);
const Key& key() const { return fKey; }
size_t size() const { return fSize; }
~GrTextBlob() {
for (int i = 0; i < fRunCount; i++) {
// Internal test methods
std::unique_ptr<GrDrawOp> test_makeOp(int glyphCount, uint16_t run, uint16_t subRun,
const SkMatrix& viewMatrix, SkScalar x, SkScalar y,
const GrTextUtils::Paint&, const SkSurfaceProps&,
const GrDistanceFieldAdjustTable*,
: fMaxMinScale(-SK_ScalarMax)
, fMinMaxScale(SK_ScalarMax)
, fTextType(0) {}
// This function will only be called when we are generating a blob from scratch. We record the
// initial view matrix and initial offsets(x,y), because we record vertex bounds relative to
// these numbers. When blobs are reused with new matrices, we need to return to model space so
// we can update the vertex bounds appropriately.
void setupViewMatrix(const SkMatrix& viewMatrix, SkScalar x, SkScalar y) {
fInitialViewMatrix = viewMatrix;
if (!viewMatrix.invert(&fInitialViewMatrixInverse)) {
fInitialViewMatrixInverse = SkMatrix::I();
fInitialX = x;
fInitialY = y;
// make sure all initial subruns have the correct VM and X/Y applied
for (int i = 0; i < fRunCount; i++) {
fRuns[i].fSubRunInfo[0].init(fInitialViewMatrix, x, y);
* Each Run inside of the blob can have its texture coordinates regenerated if required.
* To determine if regeneration is necessary, fAtlasGeneration is used. If there have been
* any evictions inside of the atlas, then we will simply regenerate Runs. We could track
* this at a more fine grained level, but its not clear if this is worth it, as evictions
* should be fairly rare.
* One additional point, each run can contain glyphs with any of the three mask formats.
* We call these SubRuns. Because a subrun must be a contiguous range, we have to create
* a new subrun each time the mask format changes in a run. In theory, a run can have as
* many SubRuns as it has glyphs, ie if a run alternates between color emoji and A8. In
* practice, the vast majority of runs have only a single subrun.
* Finally, for runs where the entire thing is too large for the GrTextContext to
* handle, we have a bit to mark the run as flushable via rendering as paths or as scaled
* glyphs. It would be a bit expensive to figure out ahead of time whether or not a run
* can flush in this manner, so we always allocate vertices for the run, regardless of
* whether or not it is too large. The benefit of this strategy is that we can always reuse
* a blob allocation regardless of viewmatrix changes. We could store positions for these
* glyphs, however, it's not clear if this is a win because we'd still have to either go to the
* glyph cache to get the path at flush time, or hold onto the path in the cache, which
* would greatly increase the memory of these cached items.
struct Run {
Run() : fPaintFlags(0)
, fInitialized(false) {
// To ensure we always have one subrun, we push back a fresh run here
struct SubRunInfo {
: fAtlasGeneration(GrDrawOpAtlas::kInvalidAtlasGeneration)
, fVertexStartIndex(0)
, fVertexEndIndex(0)
, fGlyphStartIndex(0)
, fGlyphEndIndex(0)
, fColor(GrColor_ILLEGAL)
, fMaskFormat(kA8_GrMaskFormat)
, fFlags(0) {
fVertexBounds = SkRectPriv::MakeLargestInverted();
SubRunInfo(const SubRunInfo& that)
: fBulkUseToken(that.fBulkUseToken)
, fStrike(SkSafeRef(that.fStrike.get()))
, fCurrentViewMatrix(that.fCurrentViewMatrix)
, fVertexBounds(that.fVertexBounds)
, fAtlasGeneration(that.fAtlasGeneration)
, fVertexStartIndex(that.fVertexStartIndex)
, fVertexEndIndex(that.fVertexEndIndex)
, fGlyphStartIndex(that.fGlyphStartIndex)
, fGlyphEndIndex(that.fGlyphEndIndex)
, fX(that.fX)
, fY(that.fY)
, fColor(that.fColor)
, fMaskFormat(that.fMaskFormat)
, fFlags(that.fFlags) {
// TODO when this object is more internal, drop the privacy
void resetBulkUseToken() { fBulkUseToken.reset(); }
GrDrawOpAtlas::BulkUseTokenUpdater* bulkUseToken() { return &fBulkUseToken; }
void setStrike(sk_sp<GrTextStrike> strike) { fStrike = std::move(strike); }
GrTextStrike* strike() const { return fStrike.get(); }
sk_sp<GrTextStrike> refStrike() const { return fStrike; }
void setAtlasGeneration(uint64_t atlasGeneration) { fAtlasGeneration = atlasGeneration;}
uint64_t atlasGeneration() const { return fAtlasGeneration; }
size_t byteCount() const { return fVertexEndIndex - fVertexStartIndex; }
size_t vertexStartIndex() const { return fVertexStartIndex; }
size_t vertexEndIndex() const { return fVertexEndIndex; }
void appendVertices(size_t vertexStride) {
fVertexEndIndex += vertexStride * kVerticesPerGlyph;
uint32_t glyphCount() const { return fGlyphEndIndex - fGlyphStartIndex; }
uint32_t glyphStartIndex() const { return fGlyphStartIndex; }
uint32_t glyphEndIndex() const { return fGlyphEndIndex; }
void glyphAppended() { fGlyphEndIndex++; }
void setColor(GrColor color) { fColor = color; }
GrColor color() const { return fColor; }
void setMaskFormat(GrMaskFormat format) { fMaskFormat = format; }
GrMaskFormat maskFormat() const { return fMaskFormat; }
void setAsSuccessor(const SubRunInfo& prev) {
fGlyphStartIndex = prev.glyphEndIndex();
fGlyphEndIndex = prev.glyphEndIndex();
fVertexStartIndex = prev.vertexEndIndex();
fVertexEndIndex = prev.vertexEndIndex();
// copy over viewmatrix settings
this->init(prev.fCurrentViewMatrix, prev.fX, prev.fY);
const SkRect& vertexBounds() const { return fVertexBounds; }
void joinGlyphBounds(const SkRect& glyphBounds) {
void init(const SkMatrix& viewMatrix, SkScalar x, SkScalar y) {
fCurrentViewMatrix = viewMatrix;
fX = x;
fY = y;
// This function assumes the translation will be applied before it is called again
void computeTranslation(const SkMatrix& viewMatrix, SkScalar x, SkScalar y,
SkScalar* transX, SkScalar* transY);
// df properties
void setDrawAsDistanceFields() { fFlags |= kDrawAsSDF_Flag; }
bool drawAsDistanceFields() const { return SkToBool(fFlags & kDrawAsSDF_Flag); }
void setUseLCDText(bool useLCDText) {
fFlags = useLCDText ? fFlags | kUseLCDText_Flag : fFlags & ~kUseLCDText_Flag;
bool hasUseLCDText() const { return SkToBool(fFlags & kUseLCDText_Flag); }
void setAntiAliased(bool antiAliased) {
fFlags = antiAliased ? fFlags | kAntiAliased_Flag : fFlags & ~kAntiAliased_Flag;
bool isAntiAliased() const { return SkToBool(fFlags & kAntiAliased_Flag); }
void setHasWCoord(bool hasW) {
fFlags = hasW ? (fFlags | kHasWCoord_Flag) : fFlags & ~kHasWCoord_Flag;
bool hasWCoord() const { return SkToBool(fFlags & kHasWCoord_Flag); }
void setNeedsTransform(bool needsTransform) {
fFlags = needsTransform ? (fFlags | kNeedsTransform_Flag)
: fFlags & ~kNeedsTransform_Flag;
bool needsTransform() const { return SkToBool(fFlags & kNeedsTransform_Flag); }
enum Flag {
kDrawAsSDF_Flag = 0x01,
kUseLCDText_Flag = 0x02,
kAntiAliased_Flag = 0x04,
kHasWCoord_Flag = 0x08,
kNeedsTransform_Flag = 0x10
GrDrawOpAtlas::BulkUseTokenUpdater fBulkUseToken;
sk_sp<GrTextStrike> fStrike;
SkMatrix fCurrentViewMatrix;
SkRect fVertexBounds;
uint64_t fAtlasGeneration;
size_t fVertexStartIndex;
size_t fVertexEndIndex;
uint32_t fGlyphStartIndex;
uint32_t fGlyphEndIndex;
SkScalar fX;
SkScalar fY;
GrColor fColor;
GrMaskFormat fMaskFormat;
uint32_t fFlags;
}; // SubRunInfo
SubRunInfo& push_back() {
// Forward glyph / vertex information to seed the new sub run
SubRunInfo& newSubRun = fSubRunInfo.push_back();
const SubRunInfo& prevSubRun = fSubRunInfo.fromBack(1);
return newSubRun;
static const int kMinSubRuns = 1;
sk_sp<SkTypeface> fTypeface;
SkSTArray<kMinSubRuns, SubRunInfo> fSubRunInfo;
SkAutoDescriptor fDescriptor;
// Effects from the paint that are used to build a SkScalerContext.
sk_sp<SkPathEffect> fPathEffect;
sk_sp<SkMaskFilter> fMaskFilter;
// Distance field text cannot draw coloremoji, and so has to fall back. However,
// though the distance field text and the coloremoji may share the same run, they
// will have different descriptors. If fOverrideDescriptor is non-nullptr, then it
// will be used in place of the run's descriptor to regen texture coords
std::unique_ptr<SkAutoDescriptor> fOverrideDescriptor; // df properties
// Any glyphs that can't be rendered with the base or override descriptor
// are rendered as paths
struct PathGlyph {
PathGlyph(const SkPath& path, SkScalar x, SkScalar y, SkScalar scale, bool preXformed)
: fPath(path)
, fX(x)
, fY(y)
, fScale(scale)
, fPreTransformed(preXformed) {}
SkPath fPath;
SkScalar fX;
SkScalar fY;
SkScalar fScale;
bool fPreTransformed;
SkTArray<PathGlyph> fPathGlyphs;
struct {
unsigned fPaintFlags : 16; // needed mainly for rendering paths
bool fInitialized : 1;
// the only flags we need to set
static constexpr auto kPaintFlagsMask = SkPaint::kAntiAlias_Flag;
}; // Run
inline std::unique_ptr<GrAtlasTextOp> makeOp(
const Run::SubRunInfo& info, int glyphCount, uint16_t run, uint16_t subRun,
const SkMatrix& viewMatrix, SkScalar x, SkScalar y, const SkIRect& clipRect,
const GrTextUtils::Paint&, const SkSurfaceProps&,
const GrDistanceFieldAdjustTable*, GrTextUtils::Target*);
struct StrokeInfo {
SkScalar fFrameWidth;
SkScalar fMiterLimit;
SkPaint::Join fJoin;
enum TextType {
kHasDistanceField_TextType = 0x1,
kHasBitmap_TextType = 0x2,
// all glyph / vertex offsets are into these pools.
char* fVertices;
GrGlyph** fGlyphs;
Run* fRuns;
SkMaskFilterBase::BlurRec fBlurRec;
StrokeInfo fStrokeInfo;
Key fKey;
SkMatrix fInitialViewMatrix;
SkMatrix fInitialViewMatrixInverse;
size_t fSize;
SkColor fLuminanceColor;
SkScalar fInitialX;
SkScalar fInitialY;
// We can reuse distance field text, but only if the new viewmatrix would not result in
// a mip change. Because there can be multiple runs in a blob, we track the overall
// maximum minimum scale, and minimum maximum scale, we can support before we need to regen
SkScalar fMaxMinScale;
SkScalar fMinMaxScale;
int fRunCount;
uint8_t fTextType;
* Used to produce vertices for a subrun of a blob. The vertices are cached in the blob itself.
* This is invoked each time a sub run is drawn. It regenerates the vertex data as required either
* because of changes to the atlas or because of different draw parameters (e.g. color change). In
* rare cases the draw may have to interrupted and flushed in the middle of the sub run in order to
* free up atlas space. Thus, this generator is stateful and should be invoked in a loop until the
* entire sub run has been completed.
class GrTextBlob::VertexRegenerator {
* Consecutive VertexRegenerators often use the same SkGlyphCache. If the same instance of
* SkAutoGlyphCache is reused then it can save the cost of multiple detach/attach operations of
* SkGlyphCache.
VertexRegenerator(GrResourceProvider*, GrTextBlob*, int runIdx, int subRunIdx,
const SkMatrix& viewMatrix, SkScalar x, SkScalar y, GrColor color,
GrDeferredUploadTarget*, GrGlyphCache*, GrAtlasManager*,
struct Result {
* Was regenerate() able to draw all the glyphs from the sub run? If not flush all glyph
* draws and call regenerate() again.
bool fFinished = true;
* How many glyphs were regenerated. Will be equal to the sub run's glyph count if
* fType is kFinished.
int fGlyphsRegenerated = 0;
* Pointer where the caller finds the first regenerated vertex.
const char* fFirstVertex;
bool regenerate(Result*);
template <bool regenPos, bool regenCol, bool regenTexCoords, bool regenGlyphs>
bool doRegen(Result*);
GrResourceProvider* fResourceProvider;
const SkMatrix& fViewMatrix;
GrTextBlob* fBlob;
GrDeferredUploadTarget* fUploadTarget;
GrGlyphCache* fGlyphCache;
GrAtlasManager* fFullAtlasManager;
SkExclusiveStrikePtr* fLazyCache;
Run* fRun;
Run::SubRunInfo* fSubRun;
GrColor fColor;
SkScalar fTransX;
SkScalar fTransY;
uint32_t fRegenFlags = 0;
int fCurrGlyph = 0;
bool fBrokenRun = false;
#endif // GrTextBlob_DEFINED