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* Copyright 2018 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.
#ifndef SkGlyphRunPainter_DEFINED
#define SkGlyphRunPainter_DEFINED
#include "include/core/SkSurfaceProps.h"
#include "src/core/SkDistanceFieldGen.h"
#include "src/core/SkGlyphBuffer.h"
#include "src/core/SkGlyphRun.h"
#include "src/core/SkScalerContext.h"
#include "src/core/SkTextBlobPriv.h"
#include "src/gpu/text/GrSDFTControl.h"
class GrColorInfo;
namespace skgpu { namespace v1 { class SurfaceDrawContext; }}
class SkGlyphRunPainterInterface;
class SkStrikeSpec;
// round and ignorePositionMask are used to calculate the subpixel position of a glyph.
// The per component (x or y) calculation is:
// subpixelOffset = (floor((viewportPosition + rounding) & mask) >> 14) & 3
// where mask is either 0 or ~0, and rounding is either
// 1/2 for non-subpixel or 1/8 for subpixel.
struct SkGlyphPositionRoundingSpec {
SkGlyphPositionRoundingSpec(bool isSubpixel, SkAxisAlignment axisAlignment);
const SkVector halfAxisSampleFreq;
const SkIPoint ignorePositionMask;
const SkIPoint ignorePositionFieldMask;
static SkVector HalfAxisSampleFreq(bool isSubpixel, SkAxisAlignment axisAlignment);
static SkIPoint IgnorePositionMask(bool isSubpixel, SkAxisAlignment axisAlignment);
static SkIPoint IgnorePositionFieldMask(bool isSubpixel, SkAxisAlignment axisAlignment);
class SkStrikeCommon {
// An atlas consists of plots, and plots hold glyphs. The minimum a plot can be is 256x256.
// This means that the maximum size a glyph can be is 256x256.
inline static constexpr uint16_t kSkSideTooBigForAtlas = 256;
class SkGlyphRunListPainter {
// Constructor for SkBitmpapDevice.
SkGlyphRunListPainter(const SkSurfaceProps& props,
SkColorType colorType,
SkColorSpace* cs,
SkStrikeForGPUCacheInterface* strikeCache);
// The following two ctors are used exclusively by the GPU, and will always use the global
// strike cache.
SkGlyphRunListPainter(const SkSurfaceProps&, const GrColorInfo&);
explicit SkGlyphRunListPainter(const skgpu::v1::SurfaceDrawContext&);
#endif // SK_SUPPORT_GPU
class BitmapDevicePainter {
BitmapDevicePainter() = default;
BitmapDevicePainter(const BitmapDevicePainter&) = default;
virtual ~BitmapDevicePainter() = default;
virtual void paintPaths(
SkDrawableGlyphBuffer* drawables, SkScalar scale, SkPoint origin,
const SkPaint& paint) const = 0;
virtual void paintMasks(SkDrawableGlyphBuffer* drawables, const SkPaint& paint) const = 0;
virtual void drawBitmap(const SkBitmap&, const SkMatrix&, const SkRect* dstOrNull,
const SkSamplingOptions&, const SkPaint&) const = 0;
void drawForBitmapDevice(
const SkGlyphRunList& glyphRunList, const SkPaint& paint, const SkMatrix& deviceMatrix,
const BitmapDevicePainter* bitmapDevice);
// A nullptr for process means that the calls to the cache will be performed, but none of the
// callbacks will be called.
void processGlyphRun(const SkGlyphRun& glyphRun,
const SkMatrix& drawMatrix,
const SkPaint& drawPaint,
const GrSDFTControl& control,
SkGlyphRunPainterInterface* process,
const char* tag = nullptr);
#endif // SK_SUPPORT_GPU
SkGlyphRunListPainter(const SkSurfaceProps& props, SkColorType colorType,
SkScalerContextFlags flags, SkStrikeForGPUCacheInterface* strikeCache);
struct ScopedBuffers {
ScopedBuffers(SkGlyphRunListPainter* painter, size_t size);
// Required until C++17 copy elision
ScopedBuffers(const ScopedBuffers&) = default;
SkGlyphRunListPainter* fPainter;
ScopedBuffers SK_WARN_UNUSED_RESULT ensureBuffers(const SkGlyphRunList& glyphRunList);
ScopedBuffers SK_WARN_UNUSED_RESULT ensureBuffers(const SkGlyphRun& glyphRun);
// The props as on the actual device.
const SkSurfaceProps fDeviceProps;
// The props for when the bitmap device can't draw LCD text.
const SkSurfaceProps fBitmapFallbackProps;
const SkColorType fColorType;
const SkScalerContextFlags fScalerContextFlags;
SkStrikeForGPUCacheInterface* const fStrikeCache;
SkDrawableGlyphBuffer fDrawable;
SkSourceGlyphBuffer fRejects;
// SkGlyphRunPainterInterface are all the ways that Ganesh generates glyphs. The first
// distinction is between Device and Source.
// * Device - the data in the cache is scaled to the device. There is no transformation from the
// cache to the screen.
// * Source - the data in the cache needs to be scaled from the cache to source space using the
// factor cacheToSourceScale. When drawn the system must combine cacheToSourceScale and the
// deviceView matrix to transform the cache data onto the screen. This allows zooming and
// simple animation to reuse the same glyph data by just changing the transform.
// In addition to transformation type above, Masks, Paths, SDFT, and Fallback (or really the
// rendering method of last resort) are the different
// formats of data used from the cache.
class SkGlyphRunPainterInterface {
virtual ~SkGlyphRunPainterInterface() = default;
#if SK_GPU_V1
virtual void processDeviceMasks(const SkZip<SkGlyphVariant, SkPoint>& drawables,
const SkStrikeSpec& strikeSpec) = 0;
virtual void processSourceMasks(const SkZip<SkGlyphVariant, SkPoint>& drawables,
const SkStrikeSpec& strikeSpec) = 0;
virtual void processSourcePaths(const SkZip<SkGlyphVariant, SkPoint>& drawables,
const SkFont& runFont,
const SkStrikeSpec& strikeSpec) = 0;
virtual void processSourceSDFT(const SkZip<SkGlyphVariant, SkPoint>& drawables,
const SkStrikeSpec& strikeSpec,
const SkFont& runFont,
SkScalar minScale,
SkScalar maxScale) = 0;
#endif // SK_GPU_V1
#endif // SkGlyphRunPainter_DEFINED