sampler_descriptor.h

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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#ifndef FLUTTER_IMPELLER_CORE_SAMPLER_DESCRIPTOR_H_
#define FLUTTER_IMPELLER_CORE_SAMPLER_DESCRIPTOR_H_
 
#include "impeller/core/formats.h"
 
namespace impeller {
 
class Context;
 
struct SamplerDescriptor final {
  MinMagFilter min_filter = MinMagFilter::kNearest;
  MinMagFilter mag_filter = MinMagFilter::kNearest;
  MipFilter mip_filter = MipFilter::kNearest;
 
  SamplerAddressMode width_address_mode = SamplerAddressMode::kClampToEdge;
  SamplerAddressMode height_address_mode = SamplerAddressMode::kClampToEdge;
  SamplerAddressMode depth_address_mode = SamplerAddressMode::kClampToEdge;
 
  /// The maximum anisotropy clamp used when sampling. A value of 1 disables
  /// anisotropic filtering. Values greater than 1 are clamped to the device
  /// limit reported by `Capabilities::GetMaxSamplerAnisotropy`. Anisotropic
  /// filtering only applies when all filters are linear.
  uint8_t max_anisotropy = 1;
 
  std::string_view label = "NN Clamp Sampler";
 
  SamplerDescriptor();
 
  SamplerDescriptor(std::string_view label,
                    MinMagFilter min_filter,
                    MinMagFilter mag_filter,
                    MipFilter mip_filter);
 
  static uint64_t ToKey(const SamplerDescriptor& d) {
    static_assert(sizeof(MinMagFilter) == 1);
    static_assert(sizeof(MipFilter) == 1);
    static_assert(sizeof(SamplerAddressMode) == 1);
 
    return static_cast<uint64_t>(d.min_filter) << 0 |
           static_cast<uint64_t>(d.mag_filter) << 8 |
           static_cast<uint64_t>(d.mip_filter) << 16 |
           static_cast<uint64_t>(d.width_address_mode) << 24 |
           static_cast<uint64_t>(d.height_address_mode) << 32 |
           static_cast<uint64_t>(d.depth_address_mode) << 40 |
           static_cast<uint64_t>(d.max_anisotropy) << 48;
  }
};
 
}  // namespace impeller
 
#endif  // FLUTTER_IMPELLER_CORE_SAMPLER_DESCRIPTOR_H_