shader_source.hpp

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/*!
 * \file shader_source.hpp
 * \brief file shader_source.hpp
 *
 * Adapted from: WRATHGLProgram.hpp of WRATH:
 *
 * Copyright 2013 by Nomovok Ltd.
 * Contact: info@nomovok.com
 * This Source Code Form is subject to the
 * terms of the Mozilla Public License, v. 2.0.
 * If a copy of the MPL was not distributed with
 * this file, You can obtain one at
 * http://mozilla.org/MPL/2.0/.
 *
 * \author Kevin Rogovin <kevin.rogovin@nomovok.com>
 * \author Kevin Rogovin <kevin.rogovin@gmail.com>
 *
 */

#ifndef FASTUIDRAW_SHADER_SOURCE_HPP
#define FASTUIDRAW_SHADER_SOURCE_HPP

#include <fastuidraw/util/util.hpp>
#include <fastuidraw/util/vecN.hpp>
#include <fastuidraw/util/c_array.hpp>

namespace fastuidraw {
namespace glsl {
/*!\addtogroup GLSL
 * @{
 */

/*!
 * \brief
 * A ShaderSource represents the source code
 * to a GLSL shader, specifying blocks of source
 * code and macros to use.
 */
class ShaderSource
{
public:
  /*!
   * \brief
   * Enumeration to indiciate the source for a shader.
   */
  enum source_t
    {
      /*!
       * Shader source code is taken from the file whose
       * name is the passed string.
       */
      from_file,

      /*!
       * The passed string is the shader source code.
       */
      from_string,

      /*!
       * The passed string is label for a string of text
       * fetched with fastuidraw::fetch_static_resource().
       * The resource will be IGNORED if the last byte of
       * resource is not 0 (which indicates end-of-string).
       */
      from_resource,
    };

  /*!
   * \brief
   * Enumeration to determine if source
   * code or a macro
   */
  enum add_location_t
    {
      /*!
       * add the source code or macro
       * to the back.
       */
      push_back,

      /*!
       * add the source code or macro
       * to the front.
       */
      push_front
    };

  /*!
   * \brief
   * Enumeration to indicate extension
   * enable flags.
   */
  enum extension_enable_t
    {
      /*!
       * Requires the named GLSL extension,
       * i.e. will add <B>"#extension extension_name: require"</B>
       * to GLSL source code.
       */
      require_extension,

      /*!
       * Enables the named GLSL extension,
       * i.e. will add <B>"#extension extension_name: enable"</B>
       * to GLSL source code.
       */
      enable_extension,

      /*!
       * Enables the named GLSL extension,
       * but request that the GLSL compiler
       * issues warning when the extension
       * is used, i.e. will add
       * <B>"#extension extension_name: warn"</B>
       * to GLSL source code.
       */
      warn_extension,

      /*!
       * Disables the named GLSL extension,
       * i.e. will add <B>"#extension extension_name: disable"</B>
       * to GLSL source code.
       */
      disable_extension
    };

  /*!
   * A MacroSet represents a set of macros.
   */
  class MacroSet
  {
  public:
    /*!
     * Ctor.
     */
    MacroSet(void);

    /*!
     * Copy ctor.
     * \param obj value from which to copy
     */
    MacroSet(const MacroSet &obj);

    ~MacroSet();

    /*!
     * Assignment operator.
     * \param obj value from which to copy
     */
    MacroSet&
    operator=(const MacroSet &obj);

    /*!
     * Swap operation
     * \param obj object with which to swap
     */
    void
    swap(MacroSet &obj);

    /*!
     * Add a macro to this MacroSet.
     * \param macro_name name of macro
     * \param macro_value value to which macro is given
     */
    MacroSet&
    add_macro(c_string macro_name, c_string macro_value = "");

    /*!
     * Add a macro to this MacroSet.
     * \param macro_name name of macro
     * \param macro_value value to which macro is given
     */
    MacroSet&
    add_macro(c_string macro_name, uint32_t macro_value);

    /*!
     * Add a macro to this MacroSet.
     * \param macro_name name of macro
     * \param macro_value value to which macro is given
     */
    MacroSet&
    add_macro(c_string macro_name, int32_t macro_value);

    /*!
     * Add a macro to this MacroSet.
     * \param macro_name name of macro
     * \param macro_value value to which macro is given
     */
    MacroSet&
    add_macro(c_string macro_name, float macro_value);

    /*!
     * Add a macro to this MacroSet for casted to uint32_t
     * \param macro_name name of macro
     * \param macro_value value to which macro is given
     */
    template<typename T>
    MacroSet&
    add_macro_u32(c_string macro_name, T macro_value)
    {
      uint32_t v(macro_value);
      return add_macro(macro_name, v);
    }

    /*!
     * Add a macro to this MacroSet for casted to int32_t
     * \param macro_name name of macro
     * \param macro_value value to which macro is given
     */
    template<typename T>
    MacroSet&
    add_macro_i32(c_string macro_name, T macro_value)
    {
      int32_t v(macro_value);
      return add_macro(macro_name, v);
    }

    /*!
     * Add a macro to this MacroSet for casted to float
     * \param macro_name name of macro
     * \param macro_value value to which macro is given
     */
    template<typename T>
    MacroSet&
    add_macro_float(c_string macro_name, T macro_value)
    {
      float v(macro_value);
      return add_macro(macro_name, v);
    }

  private:
    friend class ShaderSource;
    void *m_d;
  };

  /*!
   * Ctor.
   */
  ShaderSource(void);

  /*!
   * Copy ctor.
   * \param obj value from which to copy
   */
  ShaderSource(const ShaderSource &obj);

  ~ShaderSource();

  /*!
   * Assignment operator.
   * \param obj value from which to copy
   */
  ShaderSource&
  operator=(const ShaderSource &obj);

  /*!
   * Swap operation
   * \param obj object with which to swap
   */
  void
  swap(ShaderSource &obj);

  /*!
   * Specifies the version of GLSL to which to
   * declare the shader. An empty string indicates
   * to not have a "#version" directive in the shader.
   * String is -copied-.
   */
  ShaderSource&
  specify_version(c_string v);

  /*!
   * Returns the value set by specify_version().
   * Returned pointer is only valid until the
   * next time that specify_version() is called.
   */
  c_string
  version(void) const;

  /*!
   * Add shader source code to this ShaderSource.
   * \param str string that is a filename, GLSL source or a resource name
   * \param tp interpretation of str, i.e. determines if
   *           str is a filename, raw GLSL source or a resource
   * \param loc location to add source
   */
  ShaderSource&
  add_source(c_string str, enum source_t tp = from_file,
             enum add_location_t loc = push_back);

  /*!
   * Add the sources from another ShaderSource object.
   * \param obj ShaderSource object from which to absorb
   */
  ShaderSource&
  add_source(const ShaderSource &obj);

  /*!
   * Add a macro to this ShaderSource.
   * Functionally, will insert \#define macro_name macro_value
   * in the GLSL source code.
   * \param macro_name name of macro
   * \param macro_value value to which macro is given
   * \param loc location to add macro within code
   */
  ShaderSource&
  add_macro(c_string macro_name, c_string macro_value = "",
            enum add_location_t loc = push_back);

  /*!
   * Add a macro to this ShaderSource.
   * Functionally, will insert \#define macro_name macro_value
   * in the GLSL source code.
   * \param macro_name name of macro
   * \param macro_value value to which macro is given
   * \param loc location to add macro within code
   */
  ShaderSource&
  add_macro(c_string macro_name, uint32_t macro_value,
            enum add_location_t loc = push_back);

  /*!
   * Add a macro to this ShaderSource.
   * Functionally, will insert \#define macro_name macro_value
   * in the GLSL source code.
   * \param macro_name name of macro
   * \param macro_value value to which macro is given
   * \param loc location to add macro within code
   */
  ShaderSource&
  add_macro(c_string macro_name, int32_t macro_value,
            enum add_location_t loc = push_back);

  /*!
   * Add a macro to this ShaderSource.
   * Functionally, will insert \#define macro_name macro_value
   * in the GLSL source code.
   * \param macro_name name of macro
   * \param macro_value value to which macro is given
   * \param loc location to add macro within code
   */
  ShaderSource&
  add_macro(c_string macro_name, float macro_value,
            enum add_location_t loc = push_back);

  /*!
   * Add a macro to this MacroSet for casted to uint32_t
   * \param macro_name name of macro
   * \param macro_value value to which macro is given
   */
  template<typename T>
  ShaderSource&
  add_macro_u32(c_string macro_name, T macro_value)
  {
    uint32_t v(macro_value);
    return add_macro(macro_name, v);
  }

  /*!
   * Add a macro to this MacroSet for casted to int32_t
   * \param macro_name name of macro
   * \param macro_value value to which macro is given
   */
  template<typename T>
  ShaderSource&
  add_macro_i32(c_string macro_name, T macro_value)
  {
    int32_t v(macro_value);
    return add_macro(macro_name, v);
  }

  /*!
   * Add a macro to this MacroSet for casted to float
   * \param macro_name name of macro
   * \param macro_value value to which macro is given
   */
  template<typename T>
  ShaderSource&
  add_macro_float(c_string macro_name, T macro_value)
  {
    float v(macro_value);
    return add_macro(macro_name, v);
  }

  /*!
   * Add macros of a MacroSet to this ShaderSource.
   * Functionally, will insert \#define macro_name macro_value
   * in the GLSL source code for each macro in the
   * \ref MacroSet.
   * \param macros set of macros to add
   * \param loc location to add macro within code
   */
  ShaderSource&
  add_macros(const MacroSet &macros,
             enum add_location_t loc = push_back);

  /*!
   * Functionally, will insert \#undef macro_name
   * in the GLSL source code.
   * \param macro_name name of macro
   * \param loc location to add macro within code
   */
  ShaderSource&
  remove_macro(c_string macro_name,
             enum add_location_t loc = push_back);

  /*!
   * Remove macros of a MacroSet to this ShaderSource.
   * Functionally, will insert \#undef macro_name
   * in the GLSL source code for each macro in the
   * \ref MacroSet.
   * \param macros set of macros to remove
   * \param loc location to add macro within code
   */
  ShaderSource&
  remove_macros(const MacroSet &macros,
                enum add_location_t loc = push_back);

  /*!
   * Specifiy an extension and usage.
   * \param ext_name name of GL extension
   * \param tp usage of extension
   */
  ShaderSource&
  specify_extension(c_string ext_name,
                    enum extension_enable_t tp = enable_extension);

  /*!
   * Add all the extension specifacation from another
   * ShaderSource object to this ShaderSource objects.
   * Extension already set in this ShaderSource that
   * are specified in obj are overwritten to the values
   * specified in obj.
   * \param obj ShaderSource object from which to take
   */
  ShaderSource&
  specify_extensions(const ShaderSource &obj);

  /*!
   * Returns the GLSL code assembled. The returned string is only
   * gauranteed to be valid up until the ShaderSource object
   * is modified.
   * \param code_only if true only, return the GLSL code without
   *                  the additions of version, extension and
   *                  FastUIDraw convenience functions and macros.
   */
  c_string
  assembled_code(bool code_only = false) const;

private:
  void *m_d;
};
/*! @} */

} //namespace glsl
} //namespace fastuidraw

#endif