chromium/third_party/skia/src/gpu/AtlasTypes.h

/*
 * Copyright 2022 Google LLC
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef skgpu_AtlasTypes_DEFINED
#define skgpu_AtlasTypes_DEFINED

#include "include/core/SkColorType.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkTypes.h"
#include "include/private/base/SkDebug.h"
#include "include/private/base/SkTArray.h"
#include "include/private/base/SkTo.h"
#include "src/base/SkTInternalLList.h"
#include "src/core/SkIPoint16.h"
#include "src/gpu/RectanizerSkyline.h"

#include <array>
#include <cstdint>
#include <cstring>
#include <utility>

class GrOpFlushState;
class SkAutoPixmapStorage;
class TestingUploadTarget;
namespace skgpu::graphite { class RecorderPriv; }

/**
 * This file includes internal types that are used by all of our gpu backends for atlases.
 */

namespace skgpu {

struct IRect16 { … };

/**
 *  Formats for masks, used by the font cache. Important that these are 0-based.
 */
enum class MaskFormat : int { … };
static const int kMaskFormatCount = …;

/**
 *  Return the number of bytes-per-pixel for the specified mask format.
 */
inline constexpr int MaskFormatBytesPerPixel(MaskFormat format) { … }

static constexpr SkColorType MaskFormatToColorType(MaskFormat format) { … }

/**
 * Keep track of generation number for atlases and Plots.
 */
class AtlasGenerationCounter { … };

/**
 * AtlasToken is used to sequence uploads relative to each other and to batches of draws.
 */
class AtlasToken { … };

/**
 * The TokenTracker encapsulates the incrementing and distribution of AtlasTokens.
 */
class TokenTracker { … };

/**
 * A PlotLocator specifies the plot and is analogous to a directory path:
 *    page/plot/plotGeneration
 *
 * In fact PlotLocator is a portion of a glyph image location in the atlas fully specified by:
 *    format/atlasGeneration/page/plot/plotGeneration/rect
 */
class PlotLocator { … };

// AtlasLocator handles atlas position information. It keeps a left-top, right-bottom pair of
// encoded UV coordinates. The bits 13 & 14 of the U coordinates hold the atlas page index.
// This information is handed directly as is from fUVs. This encoding has the nice property
// that width = fUVs[2] - fUVs[0]; the page encoding in the top bits subtracts to zero.
class AtlasLocator { … };

/**
 * An interface for eviction callbacks. Whenever an atlas evicts a specific PlotLocator,
 * it will call all of the registered listeners so they can process the eviction.
 */
class PlotEvictionCallback { … };

/**
 * A class which can be handed back to an atlas for updating plots in bulk.  The
 * current max number of plots per page an atlas can handle is 32. If in the future
 * this is insufficient then we can move to a 64 bit int.
 */
class BulkUsePlotUpdater { … };

/**
 * The backing texture for an atlas is broken into a spatial grid of Plots. The Plots
 * keep track of subimage placement via their Rectanizer. A Plot may be subclassed if
 * the atlas class needs to track additional information.
 */
class Plot : public SkRefCnt { … };

PlotList;

} // namespace skgpu

#endif // skgpu_AtlasTypes_DEFINED