/*
 Copyright (c) 2013 yvt
 
 This file is part of OpenSpades.
 
 OpenSpades 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 3 of the License, or
 (at your option) any later version.
 
 OpenSpades 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 OpenSpades.  If not, see <http://www.gnu.org/licenses/>.
 
 */

#pragma once

#include "../Core/Math.h"
#include <vector>
#include "../Core/Debug.h"
#include "IGLDevice.h"

namespace spades {
	namespace client {
		class GameMap;
	}
	namespace draw {
		class GLRenderer;
		class IGLDevice;
		class GLAmbientShadowRenderer {
			
			class UpdateDispatch;
			enum {
				NumRays = 16,
				ChunkSize = 16,
				ChunkSizeBits = 4
			};
			GLRenderer *renderer;
			IGLDevice *device;
			client::GameMap *map;
			Vector3 rays[NumRays];
			
			struct Chunk {
				int cx, cy, cz;
				float data[ChunkSize][ChunkSize][ChunkSize];
				bool dirty;
				int dirtyMinX, dirtyMaxX;
				int dirtyMinY, dirtyMaxY;
				int dirtyMinZ, dirtyMaxZ;
				
				volatile bool transfered;
			};
			
			IGLDevice::UInteger texture;
			
			int w, h, d;
			int chunkW, chunkH, chunkD;
			
			std::vector<Chunk> chunks;
			
			inline Chunk& GetChunk(int cx, int cy, int cz) {
				SPAssert(cx >= 0); SPAssert(cx < chunkW);
				SPAssert(cy >= 0); SPAssert(cy < chunkH);
				SPAssert(cz >= 0); SPAssert(cz < chunkD);
				return chunks[(cx + cy * chunkW) * chunkD + cz];
			}
			
			inline Chunk& GetChunkWrapped(int cx, int cy, int cz) {
				// FIXME: support for non-POT dimensions?
				return GetChunk(cx&(chunkW-1),cy&(chunkH-1),cz);
			}
			
			void Invalidate(int minX, int minY, int minZ,
							int maxX, int maxY, int maxZ);
			
			void UpdateChunk(int cx, int cy, int cz);
			void UpdateDirtyChunks();
			int GetNumDirtyChunks();
			
			UpdateDispatch *dispatch;
		public:
			GLAmbientShadowRenderer(GLRenderer *renderer,
									client::GameMap *map);
			~GLAmbientShadowRenderer();
			
			float Evaluate(IntVector3);
			
			void GameMapChanged(int x, int y, int z, client::GameMap *);
			
			void Update();
			
			IGLDevice::UInteger GetTexture() { return texture; }
		};
	}
}