// Copyright (C) 2002-2009 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

#ifndef __C_OPEN_GL_TEXTURE_H_INCLUDED__
#define __C_OPEN_GL_TEXTURE_H_INCLUDED__

#include "ITexture.h"
#include "IImage.h"

#include "IrrCompileConfig.h"
#ifdef _IRR_COMPILE_WITH_OPENGL_

#ifdef _IRR_WINDOWS_API_
	// include windows headers for HWND
	#define WIN32_LEAN_AND_MEAN
	#include <windows.h>
	#include <GL/gl.h>
	#include "glext.h"
#ifdef _MSC_VER
	#pragma comment(lib, "OpenGL32.lib")
	#pragma comment(lib, "GLu32.lib")
#endif
#else
	#if defined(_IRR_OPENGL_USE_EXTPOINTER_)
		#define GL_GLEXT_LEGACY 1
	#endif
	#if defined(_IRR_OSX_PLATFORM_)
		#include <OpenGL/gl.h>
	#else
		#include <GL/gl.h>
	#endif
	#if defined(_IRR_OPENGL_USE_EXTPOINTER_)
		#include "glext.h"
	#endif
#endif


namespace irr
{
namespace video
{

class COpenGLDriver;
//! OpenGL texture.
class COpenGLTexture : public ITexture
{
public:

	//! constructor
	COpenGLTexture(IImage* surface, const core::string<c16>& name, COpenGLDriver* driver=0);

	//! destructor
	virtual ~COpenGLTexture();

	//! lock function
	virtual void* lock(bool readOnly = false);

	//! unlock function
	virtual void unlock();

	//! Returns original size of the texture (image).
	virtual const core::dimension2d<u32>& getOriginalSize() const;

	//! Returns size of the texture.
	virtual const core::dimension2d<u32>& getSize() const;

	//! returns driver type of texture (=the driver, that created it)
	virtual E_DRIVER_TYPE getDriverType() const;

	//! returns color format of texture
	virtual ECOLOR_FORMAT getColorFormat() const;

	//! returns pitch of texture (in bytes)
	virtual u32 getPitch() const;

	//! return open gl texture name
	GLuint getOpenGLTextureName() const;

	//! return whether this texture has mipmaps
	virtual bool hasMipMaps() const;

	//! Regenerates the mip map levels of the texture. Useful after
	//! locking and modifying the texture
	virtual void regenerateMipMapLevels();

	//! Is it a render target?
	virtual bool isRenderTarget() const;

	//! Is it a FrameBufferObject?
	virtual bool isFrameBufferObject() const;

	//! Bind RenderTargetTexture
	virtual void bindRTT();

	//! Unbind RenderTargetTexture
	virtual void unbindRTT();

	//! sets whether this texture is intended to be used as a render target.
	void setIsRenderTarget(bool isTarget);

protected:

	//! protected constructor with basic setup, no GL texture name created, for derived classes
	COpenGLTexture(const core::string<c16>& name, COpenGLDriver* driver);

	//! get the desired color format based on texture creation flags and the input format.
	ECOLOR_FORMAT getBestColorFormat(ECOLOR_FORMAT format);

	//! convert the image into an internal image with better properties for this driver.
	void getImageData(IImage* image);

	//! copies the texture into an OpenGL texture.
	//! \param: newTexture is true if method is called from a newly created texture for the first time. Otherwise call with false to improve memory handling.
	void copyTexture(bool newTexture=true);

	core::dimension2d<u32> ImageSize;
	core::dimension2d<u32> TextureSize;
	ECOLOR_FORMAT ColorFormat;
	s32 Pitch;
	COpenGLDriver* Driver;
	IImage* Image;

	GLuint TextureName;
	GLint InternalFormat;
	GLenum PixelFormat;
	GLenum PixelType;

	bool HasMipMaps;
	bool IsRenderTarget;
	bool AutomaticMipmapUpdate;
	bool ReadOnlyLock;
	bool KeepImage;
};

//! OpenGL FBO texture.
class COpenGLFBOTexture : public COpenGLTexture
{
public:

	//! FrameBufferObject constructor
	COpenGLFBOTexture(const core::dimension2d<u32>& size, const core::string<c16>& name, COpenGLDriver* driver=0);

	//! destructor
	virtual ~COpenGLFBOTexture();

	//! Is it a FrameBufferObject?
	virtual bool isFrameBufferObject() const;

	//! Bind RenderTargetTexture
	virtual void bindRTT();

	//! Unbind RenderTargetTexture
	virtual void unbindRTT();

	ITexture* DepthTexture;
protected:
	GLuint ColorFrameBuffer;
};


//! OpenGL FBO depth texture.
class COpenGLFBODepthTexture : public COpenGLFBOTexture
{
public:
	//! FrameBufferObject depth constructor
	COpenGLFBODepthTexture(const core::dimension2d<u32>& size, const core::string<c16>& name, COpenGLDriver* driver=0, bool useStencil=false);

	//! destructor
	virtual ~COpenGLFBODepthTexture();

	//! Bind RenderTargetTexture
	virtual void bindRTT();

	//! Unbind RenderTargetTexture
	virtual void unbindRTT();

	bool attach(ITexture*);

protected:
	GLuint DepthRenderBuffer;
	GLuint StencilRenderBuffer;
	bool UseStencil;
};


} // end namespace video
} // end namespace irr

#endif
#endif // _IRR_COMPILE_WITH_OPENGL_