/*
Minetest-c55
Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>

This program 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.

This program 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 this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#ifndef MAPBLOCK_MESH_HEADER
#define MAPBLOCK_MESH_HEADER

#include "common_irrlicht.h"
#include "mapblock_nodemod.h"
#include "voxel.h"

/*
	Mesh making stuff
*/

/*
	This is used because CMeshBuffer::append() is very slow
*/
struct PreMeshBuffer
{
	video::SMaterial material;
	core::array<u16> indices;
	core::array<video::S3DVertex> vertices;
};

class MeshCollector
{
public:
	void append(
			video::SMaterial material,
			const video::S3DVertex* const vertices,
			u32 numVertices,
			const u16* const indices,
			u32 numIndices
		)
	{
		PreMeshBuffer *p = NULL;
		for(u32 i=0; i<m_prebuffers.size(); i++)
		{
			PreMeshBuffer &pp = m_prebuffers[i];
			if(pp.material != material)
				continue;

			p = &pp;
			break;
		}

		if(p == NULL)
		{
			PreMeshBuffer pp;
			pp.material = material;
			m_prebuffers.push_back(pp);
			p = &m_prebuffers[m_prebuffers.size()-1];
		}

		u32 vertex_count = p->vertices.size();
		for(u32 i=0; i<numIndices; i++)
		{
			u32 j = indices[i] + vertex_count;
			if(j > 65535)
			{
				dstream<<"FIXME: Meshbuffer ran out of indices"<<std::endl;
				// NOTE: Fix is to just add an another MeshBuffer
			}
			p->indices.push_back(j);
		}
		for(u32 i=0; i<numVertices; i++)
		{
			p->vertices.push_back(vertices[i]);
		}
	}

	void fillMesh(scene::SMesh *mesh)
	{
		/*dstream<<"Filling mesh with "<<m_prebuffers.size()
				<<" meshbuffers"<<std::endl;*/
		for(u32 i=0; i<m_prebuffers.size(); i++)
		{
			PreMeshBuffer &p = m_prebuffers[i];

			/*dstream<<"p.vertices.size()="<<p.vertices.size()
					<<", p.indices.size()="<<p.indices.size()
					<<std::endl;*/
			
			// Create meshbuffer
			
			// This is a "Standard MeshBuffer",
			// it's a typedeffed CMeshBuffer<video::S3DVertex>
			scene::SMeshBuffer *buf = new scene::SMeshBuffer();
			// Set material
			buf->Material = p.material;
			//((scene::SMeshBuffer*)buf)->Material = p.material;
			// Use VBO
			//buf->setHardwareMappingHint(scene::EHM_STATIC);
			// Add to mesh
			mesh->addMeshBuffer(buf);
			// Mesh grabbed it
			buf->drop();

			buf->append(p.vertices.pointer(), p.vertices.size(),
					p.indices.pointer(), p.indices.size());
		}
	}

private:
	core::array<PreMeshBuffer> m_prebuffers;
};

// Helper functions
video::SColor MapBlock_LightColor(u8 alpha, u8 light);

class MapBlock;

struct MeshMakeData
{
	u32 m_daynight_ratio;
	NodeModMap m_temp_mods;
	VoxelManipulator m_vmanip;
	v3s16 m_blockpos;
	
	/*
		Copy central data directly from block, and other data from
		parent of block.
	*/
	void fill(u32 daynight_ratio, MapBlock *block);
};

// This is the highest-level function in here
scene::SMesh* makeMapBlockMesh(MeshMakeData *data);

#endif