/*
Copyright (C) 1999-2007 id Software, Inc. and contributors.
For a list of contributors, see the accompanying CONTRIBUTORS file.

This file is part of GtkRadiant.

GtkRadiant is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

GtkRadiant is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GtkRadiant; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#ifndef _ISHADERSMANAGER_H_
#define _ISHADERSMANAGER_H_

class IShadersManager
{
 public:
  IShadersManager ();
  virtual ~IShadersManager ();

  // Increment the number of references to this object
  virtual void IncRef () = 0;
  // Decrement the reference count
  virtual void DecRef () = 0;

  // free all shaders
  // free the shaders, will not free the qtexture_t*
  virtual void FreeShaders () = 0;

  // reload all the shaders
  // this will free everything (shaders and their textures), then reload all in use stuff
  virtual void ReloadShaders () = 0;

  // load all shaders in a given directory
  // this will scan the list of in-memory shaders, and load the related qtexture_t if needed
  virtual void LoadShadersFromDir (const char* path) = 0;

  // load a shader file (ie a set of shaders)
  // after LoadShaderFile shaders will be in memory, next step is to load the qtexture_t Radiant uses
  // to represent them if a shader with the same name exists, new one will not be loaded
  // don't use this to refresh the shaders!
  virtual void LoadShaderFile (const char* filename) = 0;

  // tell if a given shader exists in our shader table
  // NOTE: this doesn't tell wether it's corresponding qtexture is loaded 
  virtual int HasShader (const char* name) = 0;

  // return the shader for a given name
  // if the qtexture is not already in memory, will try loading it
  // if the qtexture could not be found, will use default
  // will return NULL on shader not found
  virtual IShader* Try_Shader_ForName (const char* name) = 0;

  // return the shader for a given name
  // if the qtexture is not already in memory, will try loading it
  // will create a default shader if not found (will use a default texture)
  virtual IShader* Shader_ForName (const char* name) = 0;

  // query / load a texture
  // will not try loading a shader, will look for the actual image file ..
  // returns NULL on file not found
  // NOTE: strategy for file lookup:
  //   paths must be relative, ie. textures/me/myfile
  //   if a 3-letters filename extension (such as .jpg or .tga) is provided, it will get loaded first
  //   if not found or no extension, will try loading after adding .tga and .jpg (in this order)
  virtual qtexture_t* Try_Texture_ForName (const char* filename) = 0;

  // query / load a texture
  // will not try loading a shader, will look for the actual image file ..
  // on file not found will use the "texture not found"
  virtual qtexture_t* Texture_ForName (const char* filename) = 0;

  // get the number of active shaders
  // these are the shaders currently loaded, that have an associated qtexture_t*
  virtual int GetActiveShaderCount () = 0;

  // for stuff that needs to be represented by a plain texture
  // the shader will get a "color" name, use GetColor to get the actual color
  virtual IShader* ColorShader_ForName (const char* name) = 0;

  // reload a shaderfile - update shaders and their display properties/qtexture_t if needed
  // will not reload the texture files
  // will switch to "show in use" atfer use
  // filename must be reletive path of the shader, ex. scripts/gothic_wall.shader
  virtual void ReloadShaderFile (const char* filename) = 0;

  // retrieve a shader if exists, without loading the textures for it etc.
  // use this function if you want special info on a shader
  virtual IShader* Shader_ForName_NoLoad (const char* name) = 0;
};

#endif // _ISHADERSMANAGER_H_