/* Copyright (C) 2009 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. 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.
 *
 * 0 A.D. 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 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "precompiled.h"

#include <map>

#include "lib/ogl.h"
#include "lib/res/graphics/ogl_tex.h"

#include "ps/CLogger.h"

#include "TextureEntry.h"
#include "TextureManager.h"
#include "TerrainProperties.h"
#include "Texture.h"
#include "renderer/Renderer.h"

#define LOG_CATEGORY L"graphics"

std::map<Handle, CTextureEntry *> CTextureEntry::m_LoadedTextures;

/////////////////////////////////////////////////////////////////////////////////////
// CTextureEntry constructor
CTextureEntry::CTextureEntry(CTerrainPropertiesPtr props, const VfsPath& path):
	m_pProperties(props),
	m_Bitmap(NULL),
	m_Handle(-1),
	m_BaseColor(0),
	m_BaseColorValid(false),
	m_TexturePath(path)
{
	if (m_pProperties)
		m_Groups = m_pProperties->GetGroups();
	
	GroupVector::iterator it=m_Groups.begin();
	for (;it!=m_Groups.end();++it)
		(*it)->AddTerrain(this);
	
	m_Tag = fs::basename(m_TexturePath);
}

/////////////////////////////////////////////////////////////////////////////////////
// CTextureEntry destructor
CTextureEntry::~CTextureEntry()
{
	std::map<Handle,CTextureEntry *>::iterator it=m_LoadedTextures.find(m_Handle);
	if (it != m_LoadedTextures.end())
		m_LoadedTextures.erase(it);
	
	if (m_Handle > 0)
		(void)ogl_tex_free(m_Handle);

	for (GroupVector::iterator it=m_Groups.begin();it!=m_Groups.end();++it)
		(*it)->RemoveTerrain(this);
}

/////////////////////////////////////////////////////////////////////////////////////
// LoadTexture: actually load the texture resource from file
void CTextureEntry::LoadTexture()	
{
	CTexture texture(m_TexturePath);
	if (g_Renderer.LoadTexture(&texture,GL_REPEAT)) {
		m_Handle=texture.GetHandle();
		m_LoadedTextures[m_Handle] = this;
	} else {
		m_Handle=0;
	}
}


////////////////////////////////////////////////////////////////////////////////////////////////////////////
// BuildBaseColor: calculate the root colour of the texture, used for coloring minimap, and store
// in m_BaseColor member
void CTextureEntry::BuildBaseColor()
{
	if (m_pProperties && m_pProperties->HasBaseColor())
	{
		m_BaseColor=m_pProperties->GetBaseColor();
		m_BaseColorValid=true;
		return;
	}

	LibError ret = ogl_tex_bind(GetHandle());
	debug_assert(ret == INFO::OK);

	// get root colour for coloring minimap by querying root level of the texture 
	// (this should decompress any compressed textures for us),
	// then scaling it down to a 1x1 size 
	//	- an alternative approach of just grabbing the top level of the mipmap tree fails 
	//	(or gives an incorrect colour) in some cases: 
	//		- suspect bug on Radeon cards when SGIS_generate_mipmap is used 
	//		- any textures without mipmaps
	// we'll just take the basic approach here.
	//
	// jw: this is horribly inefficient (taking 750ms for 10 texture types),
	// but it is no longer called, since terrain XML files are supposed to
	// include a minimap color attribute. therefore, leave it as-is.
	GLint width,height;
	glGetTexLevelParameteriv(GL_TEXTURE_2D,0,GL_TEXTURE_WIDTH,&width);
	glGetTexLevelParameteriv(GL_TEXTURE_2D,0,GL_TEXTURE_HEIGHT,&height);

	unsigned char* buf=new unsigned char[width*height*4];
	glGetTexImage(GL_TEXTURE_2D,0,GL_BGRA_EXT,GL_UNSIGNED_BYTE,buf);
	gluScaleImage(GL_BGRA_EXT,width,height,GL_UNSIGNED_BYTE,buf,
			1,1,GL_UNSIGNED_BYTE,&m_BaseColor);
	delete[] buf;

	m_BaseColorValid=true;
}


CTextureEntry *CTextureEntry::GetByHandle(Handle handle)
{
	std::map<Handle, CTextureEntry *>::iterator it=m_LoadedTextures.find(handle);
	if (it != m_LoadedTextures.end())
		return it->second;
	else
		return NULL;
}