chromium/third_party/skia/src/gpu/ganesh/GrUserStencilSettings.h

/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


#ifndef GrUserStencilSettings_DEFINED
#define GrUserStencilSettings_DEFINED

#include "include/gpu/ganesh/GrTypes.h"  // IWYU pragma: keep

#include <cstdint>

/**
 * Gr uses the stencil buffer to implement complex clipping inside the
 * OpsTask class. The OpsTask makes a subset of the stencil buffer
 * bits available for other uses by external code (user bits). Client code can
 * modify these bits. OpsTask will ignore ref, mask, and writemask bits
 * provided by clients that fall outside the user range.
 *
 * When code outside the OpsTask class uses the stencil buffer the contract
 * is as follows:
 *
 * > Normal stencil funcs allow the client to pass / fail regardless of the
 *   reserved clip bits.
 * > Additional functions allow a test against the clip along with a limited
 *   set of tests against the user bits.
 * > Client can assume all user bits are zero initially.
 * > Client must ensure that after all its passes are finished it has only
 *   written to the color buffer in the region inside the clip. Furthermore, it
 *   must zero all user bits that were modifed (both inside and outside the
 *   clip).
 */

enum GrStencilFlags : int { … };

template<typename TTest, typename TOp> struct GrTStencilFaceSettings { … };

enum class GrUserStencilTest : uint16_t { … };
constexpr static GrUserStencilTest kLastClippedStencilTest = …;
constexpr static int kGrUserStencilTestCount = …;

enum class GrUserStencilOp : uint8_t { … };
constexpr static GrUserStencilOp kLastUserOnlyStencilOp = …;
constexpr static GrUserStencilOp kLastClipOnlyStencilOp = …;
constexpr static int kGrUserStencilOpCount = …;

/**
 * This struct is a compile-time constant representation of user stencil settings. It describes in
 * abstract terms how a draw will use the stencil buffer. It gets ODR-used at runtime to define a
 * draw's stencil settings, and is later translated into concrete settings when the pipeline is
 * finalized.
 */
struct GrUserStencilSettings { … };

template<GrUserStencilTest Test, GrUserStencilOp PassOp, GrUserStencilOp FailOp>
struct GrUserStencilSettings::Attrs { … };

#endif