COM_morphological_distance_feather_weights.hh

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/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#pragma once
 
#include <cstdint>
#include <memory>
 
#include "BLI_map.hh"
 
#include "GPU_shader.hh"
#include "GPU_texture.hh"
 
#include "COM_cached_resource.hh"
 
namespace blender::realtime_compositor {
 
class Context;
 
/* ------------------------------------------------------------------------------------------------
 * Morphological Distance Feather Key.
 */
class MorphologicalDistanceFeatherWeightsKey {
 public:
  int type;
  float radius;
 
  MorphologicalDistanceFeatherWeightsKey(int type, float radius);
 
  uint64_t hash() const;
};
 
bool operator==(const MorphologicalDistanceFeatherWeightsKey &a,
                const MorphologicalDistanceFeatherWeightsKey &b);
 
/* -------------------------------------------------------------------------------------------------
 * Morphological Distance Feather Weights.
 *
 * A cached resource that computes and caches 1D GPU textures containing the weights of the
 * separable Gaussian filter of the given radius as well as an inverse distance falloff of the
 * given type and radius. The weights and falloffs are symmetric, because the Gaussian and falloff
 * functions are all even functions. Consequently, only the positive half of the filter is computed
 * and the shader takes that into consideration. */
class MorphologicalDistanceFeatherWeights : public CachedResource {
 private:
  GPUTexture *weights_texture_ = nullptr;
  GPUTexture *distance_falloffs_texture_ = nullptr;
 
 public:
  MorphologicalDistanceFeatherWeights(Context &context, int type, int radius);
 
  ~MorphologicalDistanceFeatherWeights();
 
  void compute_weights(Context &context, int radius);
 
  void compute_distance_falloffs(Context &context, int type, int radius);
 
  void bind_weights_as_texture(GPUShader *shader, const char *texture_name) const;
 
  void unbind_weights_as_texture() const;
 
  void bind_distance_falloffs_as_texture(GPUShader *shader, const char *texture_name) const;
 
  void unbind_distance_falloffs_as_texture() const;
};
 
/* ------------------------------------------------------------------------------------------------
 * Morphological Distance Feather Key.
 */
class MorphologicalDistanceFeatherWeightsContainer : CachedResourceContainer {
 private:
  Map<MorphologicalDistanceFeatherWeightsKey, std::unique_ptr<MorphologicalDistanceFeatherWeights>>
      map_;
 
 public:
  void reset() override;
 
  /* Check if there is an available MorphologicalDistanceFeatherWeights cached resource with the
   * given parameters in the container, if one exists, return it, otherwise, return a newly created
   * one and add it to the container. In both cases, tag the cached resource as needed to keep it
   * cached for the next evaluation. */
  MorphologicalDistanceFeatherWeights &get(Context &context, int type, int radius);
};
 
}  // namespace blender::realtime_compositor