text: /*
   * Copyright 2011-2013 Blender Foundation
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #ifndef __SHADER_H__
  #define __SHADER_H__
  
  #ifdef WITH_OSL
  /* So no context pollution happens from indirectly included windows.h */
  #  include "util/util_windows.h"
  #  include <OSL/oslexec.h>
  #endif
  
  #include "kernel/kernel_types.h"
  #include "render/attribute.h"
  
  #include "graph/node.h"
  
  #include "util/util_map.h"
  #include "util/util_param.h"
  #include "util/util_string.h"
  #include "util/util_thread.h"
  #include "util/util_types.h"
  
  CCL_NAMESPACE_BEGIN
  
  class Device;
  class DeviceScene;
  class DeviceRequestedFeatures;
  class Mesh;
  class Progress;
  class Scene;
  class ShaderGraph;
  struct float3;
  
  enum ShadingSystem { SHADINGSYSTEM_OSL, SHADINGSYSTEM_SVM };
  
  /* Keep those in sync with the python-defined enum. */
  enum VolumeSampling {
    VOLUME_SAMPLING_DISTANCE = 0,
    VOLUME_SAMPLING_EQUIANGULAR = 1,
    VOLUME_SAMPLING_MULTIPLE_IMPORTANCE = 2,
  
    VOLUME_NUM_SAMPLING,
  };
  
  enum VolumeInterpolation {
    VOLUME_INTERPOLATION_LINEAR = 0,
    VOLUME_INTERPOLATION_CUBIC = 1,
  
    VOLUME_NUM_INTERPOLATION,
  };
  
  enum DisplacementMethod {
    DISPLACE_BUMP = 0,
    DISPLACE_TRUE = 1,
    DISPLACE_BOTH = 2,
  
    DISPLACE_NUM_METHODS,
  };
  
  /* Shader describing the appearance of a Mesh, Light or Background.
   *
   * While there is only a single shader graph, it has three outputs: surface,
   * volume and displacement, that the shader manager will compile and execute
   * separately. */
  
  class Shader : public Node {
   public:
    NODE_DECLARE
  
    int pass_id;
  
    /* shader graph */
    ShaderGraph *graph;
  
    /* sampling */
    bool use_mis;
    bool use_transparent_shadow;
    bool heterogeneous_volume;
    VolumeSampling volume_sampling_method;
    int volume_interpolation_method;
    float volume_step_rate;
    float prev_volume_step_rate;
  
    /* synchronization */
    bool need_update;
    bool need_update_geometry;
    bool need_sync_object;
  
    /* If the shader has only volume components, the surface is assumed to
     * be transparent.
     * However, graph optimization might remove the volume subgraph, but
     * since the user connected something to the volume output the surface
     * should still be transparent.
     * Therefore, has_volume_connected stores whether some volume subtree
     * was connected before optimization. */
    bool has_volume_connected;
  
    /* information about shader after compiling */
    bool has_surface;
    bool has_surface_emission;
    bool has_surface_transparent;
    bool has_volume;
    bool has_displacement;
    bool has_surface_bssrdf;
    bool has_bump;
    bool has_bssrdf_bump;
    bool has_surface_spatial_varying;
    bool has_volume_spatial_varying;
    bool has_volume_attribute_dependency;
    bool has_object_dependency;
    bool has_integrator_dependency;
  
    /* displacement */
    DisplacementMethod displacement_method;
  
    /* requested mesh attributes */
    AttributeRequestSet attributes;
  
    /* determined before compiling */
    uint id;
    bool used;
  
  #ifdef WITH_OSL
    /* osl shading state references */
    OSL::ShaderGroupRef osl_surface_ref;
    OSL::ShaderGroupRef osl_surface_bump_ref;
    OSL::ShaderGroupRef osl_volume_ref;
    OSL::ShaderGroupRef osl_displacement_ref;
  #endif
  
    Shader();
    ~Shader();
  
    /* Checks whether the shader consists of just a emission node with fixed inputs that's connected
     * directly to the output.
     * If yes, it sets the content of emission to the constant value (color * strength), which is
     * then used for speeding up light evaluation. */
    bool is_constant_emission(float3 *emission);
  
    void set_graph(ShaderGraph *graph);
    void tag_update(Scene *scene);
    void tag_used(Scene *scene);
  };
  
  /* Shader Manager virtual base class
   *
   * From this the SVM and OSL shader managers are derived, that do the actual
   * shader compiling and device updating. */
  
  class ShaderManager {
   public:
    bool need_update;
  
    static ShaderManager *create(int shadingsystem);
    virtual ~ShaderManager();
  
    virtual void reset(Scene *scene) = 0;
  
    virtual bool use_osl()
    {
      return false;
    }
  
    /* device update */
    virtual void device_update(Device *device,
                               DeviceScene *dscene,
                               Scene *scene,
                               Progress &progress) = 0;
    virtual void device_free(Device *device, DeviceScene *dscene, Scene *scene) = 0;
  
    void device_update_common(Device *device, DeviceScene *dscene, Scene *scene, Progress &progress);
    void device_free_common(Device *device, DeviceScene *dscene, Scene *scene);
  
    /* get globally unique id for a type of attribute */
    uint get_attribute_id(ustring name);
    uint get_attribute_id(AttributeStandard std);
  
    /* get shader id for mesh faces */
    int get_shader_id(Shader *shader, bool smooth = false);
  
    /* add default shaders to scene, to use as default for things that don't
     * have any shader assigned explicitly */
    static void add_default(Scene *scene);
  
    /* Selective nodes compilation. */
    void update_shaders_used(Scene *scene);
    void get_requested_features(Scene *scene, DeviceRequestedFeatures *requested_features);
  
    static void free_memory();
  
    float linear_rgb_to_gray(float3 c);
  
    string get_cryptomatte_materials(Scene *scene);
  
   protected:
    ShaderManager();
  
    typedef unordered_map<ustring, uint, ustringHash> AttributeIDMap;
    AttributeIDMap unique_attribute_id;
  
    static thread_mutex lookup_table_mutex;
    static vector<float> beckmann_table;
    static bool beckmann_table_ready;
  
    size_t beckmann_table_offset;
  
    void get_requested_graph_features(ShaderGraph *graph,
                                      DeviceRequestedFeatures *requested_features);
  
    thread_spin_lock attribute_lock_;
  
    float3 xyz_to_r;
    float3 xyz_to_g;
    float3 xyz_to_b;
    float3 rgb_to_y;
  };
  
  CCL_NAMESPACE_END
  
  #endif /* __SHADER_H__ */
  