/*
 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/>.
 
 */

#include "GLSpriteRenderer.h"
#include "GLRenderer.h"
#include "IGLDevice.h"
#include "../Core/Debug.h"
#include "GLProgram.h"
#include "GLImage.h"

namespace spades {
	namespace draw {
		
		GLSpriteRenderer::GLSpriteRenderer(GLRenderer *renderer):
		renderer(renderer), device(renderer->GetGLDevice()),
		projectionViewMatrix("projectionViewMatrix"),
		rightVector("rightVector"),
		upVector("upVector"),
		positionAttribute("positionAttribute"),
		spritePosAttribute("spritePosAttribute"),
		colorAttribute("colorAttribute"),
		texture("texture"),
		viewMatrix("viewMatrix"),
		fogDistance("fogDistance"),
		fogColor("fogColor")
		{
			SPADES_MARK_FUNCTION();
			
			program = renderer->RegisterProgram("Shaders/Sprite.program");
		}
		
		GLSpriteRenderer::~GLSpriteRenderer(){
			SPADES_MARK_FUNCTION();
			
		}
		
		void GLSpriteRenderer::Add(spades::draw::GLImage *img,
								   spades::Vector3 center, float rad, float ang,
								   Vector4 color){
			SPADES_MARK_FUNCTION_DEBUG();
			Sprite spr;
			spr.image = img;
			spr.center = center;
			spr.radius = rad;
			spr.angle = ang;
			spr.color = color;
			sprites.push_back(spr);
		}
		
		void GLSpriteRenderer::Clear(){
			SPADES_MARK_FUNCTION();
			sprites.clear();
		}
		
		void GLSpriteRenderer::Render() {
			SPADES_MARK_FUNCTION();
			lastImage = NULL;
			program->Use();
			
			projectionViewMatrix(program);
			rightVector(program);
			upVector(program);
			texture(program);
			viewMatrix(program);
			fogDistance(program);
			fogColor(program);
			
			positionAttribute(program);
			spritePosAttribute(program);
			colorAttribute(program);
			
			projectionViewMatrix.SetValue(renderer->GetProjectionViewMatrix());
			viewMatrix.SetValue(renderer->GetViewMatrix());
			
			fogDistance.SetValue(renderer->GetFogDistance());
			
			Vector3 fogCol = renderer->GetFogColor();
			fogColor.SetValue(fogCol.x,fogCol.y,fogCol.z);
			
			const client::SceneDefinition& def = renderer->GetSceneDef();
			rightVector.SetValue(def.viewAxis[0].x,
								 def.viewAxis[0].y,
								 def.viewAxis[0].z);
			upVector.SetValue(def.viewAxis[1].x,
							  def.viewAxis[1].y,
							  def.viewAxis[1].z);
			texture.SetValue(0);
			
			device->ActiveTexture(0);
			
			device->EnableVertexAttribArray(positionAttribute(), true);
			device->EnableVertexAttribArray(spritePosAttribute(), true);
			device->EnableVertexAttribArray(colorAttribute(), true);
			
			
			for(size_t i = 0; i < sprites.size(); i++){
				Sprite& spr = sprites[i];
				if(spr.image != lastImage){
					Flush();
					lastImage = spr.image;
					SPAssert(vertices.empty());
				}
				
				Vertex v;
				v.x = spr.center.x;
				v.y = spr.center.y;
				v.z = spr.center.z;
				v.radius = spr.radius;
				v.angle = spr.angle;
				v.r = spr.color.x;
				v.g = spr.color.y;
				v.b = spr.color.z;
				v.a = spr.color.w;
				
				uint32_t idx = (uint32_t)vertices.size();
				v.sx = -1; v.sy = -1;
				vertices.push_back(v);
				v.sx = 1; v.sy = -1;
				vertices.push_back(v);
				v.sx = -1; v.sy = 1;
				vertices.push_back(v);
				v.sx = 1; v.sy = 1;
				vertices.push_back(v);
				
				indices.push_back(idx);
				indices.push_back(idx + 1);
				indices.push_back(idx + 2);
				indices.push_back(idx + 1);
				indices.push_back(idx + 3);
				indices.push_back(idx + 2);
			}
		
			Flush();
			
			device->EnableVertexAttribArray(positionAttribute(), false);
			device->EnableVertexAttribArray(spritePosAttribute(), false);
			device->EnableVertexAttribArray(colorAttribute(), false);
		}
		
		void GLSpriteRenderer::Flush() {
			SPADES_MARK_FUNCTION_DEBUG();
			
			if(vertices.empty())
				return;
			
			device->VertexAttribPointer(positionAttribute(),
										4, IGLDevice::FloatType,
										false, sizeof(Vertex),
										&(vertices[0].x));
			device->VertexAttribPointer(spritePosAttribute(),
										4, IGLDevice::FloatType,
										false, sizeof(Vertex),
										&(vertices[0].sx));
			device->VertexAttribPointer(colorAttribute(),
										4, IGLDevice::FloatType,
										false, sizeof(Vertex),
										&(vertices[0].r));
			
			SPAssert(lastImage);
			lastImage->Bind(IGLDevice::Texture2D);
			
			device->DrawElements(IGLDevice::Triangles,
								 indices.size(),
								 IGLDevice::UnsignedInt,
								 indices.data());
			
			vertices.clear();
			indices.clear();
		}
	}
}