//========================================================================
// Lights.h - implements a simple light class for the GameCode4 scene graph
//
// Part of the GameCode4 Application
//
// GameCode4 is the sample application that encapsulates much of the source code
// discussed in "Game Coding Complete - 4th Edition" by Mike McShaffry and David
// "Rez" Graham, published by Charles River Media. 
// ISBN-10: 1133776574 | ISBN-13: 978-1133776574
//
// If this source code has found it's way to you, and you think it has helped you
// in any way, do the authors a favor and buy a new copy of the book - there are 
// detailed explanations in it that compliment this code well. Buy a copy at Amazon.com
// by clicking here: 
//    http://www.amazon.com/gp/product/1133776574/ref=olp_product_details?ie=UTF8&me=&seller=
//
// There's a companion web site at http://www.mcshaffry.com/GameCode/
// 
// The source code is managed and maintained through Google Code: 
//    http://code.google.com/p/gamecode4/
//
// (c) Copyright 2012 Michael L. McShaffry and David Graham
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser GPL v3
// as published by the Free Software Foundation.
//
// 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 
// http://www.gnu.org/licenses/lgpl-3.0.txt for more details.
//
// You should have received a copy of the GNU Lesser GPL v3
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
//========================================================================

#include "../Unix/GameCodeStd.h"

#include "../GameCode4/GameCode.h"
#include "../Actors/RenderComponent.h"
#include "Lights.h"

LightNode::LightNode(const ActorId actorId, WeakBaseRenderComponentPtr renderComponent, const LightProperties &props, const glm::mat4 t)
	: SceneNode(actorId, renderComponent, RenderPass_NotRendered, t)
{
	m_LightProps = props;
}

int OpenGLLightNode46::VOnUpdate(Scene*, uint64_t const elapsedMs)
{
	// light color can change anytime! Check the BaseRenderComponent!
	LightRenderComponent* lrc = static_cast<LightRenderComponent*>(m_RenderComponent);
	m_Props.GetMaterial().SetDiffuse(lrc->GetColor());
	return 0;
}

void LightManager::CalcLighting(Scene *pScene)
{
	// FUTURE WORK: There might be all kinds of things you'd want to do here for optimization, especially turning off lights on actors that can't be seen, etc.
	pScene->GetRenderer()->VCalcLighting(&m_Lights, MAXIMUM_LIGHTS_SUPPORTED);

	int count = 0;

	GCC_ASSERT(m_Lights.size() < MAXIMUM_LIGHTS_SUPPORTED);
	for (Lights::iterator i=m_Lights.begin(); i!=m_Lights.end(); ++i, ++count)
	{
		std::shared_ptr<LightNode> light = *i;

		if (count==0)
		{
			// Light 0 is the only one we use for ambient lighting. The rest are ignored in the simple shaders used for GameCode4.
			Color ambient = light->VGet()->GetMaterial().GetAmbient();
			m_vLightAmbient = glm::vec4(ambient.r, ambient.g, ambient.b, 1.0f);
		}

		glm::vec3 lightDir = light->GetDirection();
		m_vLightDir[count] = glm::vec4(lightDir.x, lightDir.y, lightDir.z, 1.0f);		
		m_vLightDiffuse[count] = light->VGet()->GetMaterial().GetDiffuse();
	}	
}

void LightManager::CalcLighting(ConstantBuffer_Lighting* pLighting, SceneNode* pNode)
{
	int count = GetLightCount(pNode);
	if (count)
	{
		pLighting->m_vLightAmbient = *GetLightAmbient(pNode);
		memcpy(pLighting->m_vLightDir, GetLightDirection(pNode), sizeof(glm::vec4) * count);
		memcpy(pLighting->m_vLightDiffuse, GetLightDiffuse(pNode), sizeof(glm::vec4) * count);
		pLighting->m_nNumLights = count;
	}
}