Shader.h

Go to the documentation of this file.

/*           *
            ***
           *****
   *********************       Mercenaries Engineering SARL
     *****************              Copyright (C) 2020
       *************
         *********        http://www.mercenaries-engineering.com
        ***********
       ****     ****
      **           **/
# pragma once

# include "Maquina/Dict.h"
# include <gsl/span>

  namespace maquina {

    enum class ShaderParamType
    {
      Bool = 0,
      Int,
      Float,
      V2i,
      V3i,
      V4i,
      V2f,
      V3f,
      V4f,
      M44f,
      _LastPOD = M44f,
      Texture,  // A texture filename in ExprCall, a sampler2D in GLSL
      Token,    // A string in ExprCall, an integer in GLSL
      InternalExpression,  // Do not appear in ExprCall, a raw GLSL expression
      Ignore    // Anything in ExprCall, ignored in GLSL, the argument is not inserted
    };

    class MAQUINA_EXPORT ShaderParam
    {
    public:
      ShaderParam(
        std::string name,           
        const Value& default_value  
      );

      // TODO doc
      ShaderParam(
        std::string name,           
        ShaderParamType type,       
        const Value& default_value  
      );

      std::string name;             
      Value default_value;          
      int offset=-1;                
      ShaderParamType type;         
    };

    struct ShaderTexture
    {
      std::string name; 
      bool color_managed; 
    };

    struct ShaderProgram
    {
      enum Type
      {
        Geometry = 0,     
        Vertex,           
        Fragment,         
        SurfaceFragment,  
      };
      std::string code;   
      Type type;          
      std::string decl_code;   
    };


    MAQUINA_EXPORT void register_shader(
      std::string name,                 
      bool stream,                      
      std::vector<ShaderParam> parameters,    
      std::vector<ShaderProgram> programs     
    );

    MAQUINA_EXPORT void register_shading_node(
      std::string name,             
      std::vector<ShaderParam> parameters,    
      ShaderParamType output_type,  
      std::string post_fix=""       
    );

    MAQUINA_EXPORT void register_shading_token(const std::string& s, int token);

    MAQUINA_EXPORT void add_shader_glsl(const std::string_view& code);

    class MAQUINA_EXPORT Shader : public Value
    {
    public:
      // Create a new shader
      Shader();

      Shader(const Value& value);

      std::string program() const;

      void set_program(std::string name) const;

      Dict parameters() const;

      void set_parameters(const Dict& parameters) const;

      void set_expressions(const Dict& expressions) const;
    
      static const Shader default_value;

      Shader(std::shared_ptr<Impl> impl) { _impl=std::move(impl); }
    };

    // Preprocess a GLSL shader code to expand the include macros //!include_*!//
    MAQUINA_EXPORT std::string preprocess_shader_code(std::string code);
  }