genesis-3d_engine/Engine/addons/vegetation/GrassInstanceMap.cc

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Copyright (c) 2011-2013,WebJet Business Division,CYOU

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#include "stdneb.h"
#include "vegetation/GrassInstanceMap.h"
#include "vegetation/VegetationObejct.h"

namespace Vegetation
{	

	using namespace RenderBase;
	using namespace Math;

	__ImplementClass( Vegetation::GrassInstanceMap, 'VGIM', Vegetation::VegeInstanceMap);

	GrassInstanceMap::GrassInstanceMap():VegeInstanceMap()
	{		
		mRenderMode = eBillboard;
		//m_Name = Util::String("GrassInstanceMap");
	}

	//------------------------------------------------------------------------
	GrassInstanceMap::~GrassInstanceMap()
	{

	}
	//------------------------------------------------------------------------
	bool GrassInstanceMap::BuildPrimitive()
	{

		//if use shaderInstancing


		if (m_bHWInstancing)
		{
			m_nInstUsingCount = 1;
			m_nVertLimitCount = 1;
		}
		else
		{
			m_nInstUsingCount = mInstances.Size();

			if ( m_nInstUsingCount > g_nNumBatchInstance)
			{
				m_nVertLimitCount = g_nNumBatchInstance;
			}
			else
				m_nVertLimitCount = m_nInstUsingCount;
		}

		Graphic::VertexBufferData2 vbd2;
		Graphic::IndexBufferData2 ibd2;
		RenderBase::VertexComponents& vertexComponents = vbd2.GetVertexComponents();
		BuildVertexComponents(GPtr<Resources::MeshRes>());
		vertexComponents = m_vVerDeclare;

		// copy vbo & ibo

		SizeT numVertex = g_VertexCount * m_nVertLimitCount;
		SizeT numIndex = m_nInstUsingCount * g_IndexCount;
		SizeT indexSizeInByte = numIndex * RenderBase::IndexBufferData::SizeOf(RenderBase::IndexBufferData::Int16);
		vbd2.Setup(numVertex, sizeof(VEGE_VERTEX_INSTANCE), RenderBase::BufferData::Static, RenderBase::PrimitiveTopology::TriangleList, true);
		ibd2.Setup(numIndex, RenderBase::BufferData::Static, RenderBase::IndexBufferData::Int16, true);
		mVegeObject->GetVertices().Resize(numVertex);
		mVegeObject->GetIndices().Resize(indexSizeInByte);

		ushort* indices =  (ushort*)&(mVegeObject->GetIndices()[0]);

		VEGE_VERTEX_INSTANCE* instanceVertex = &(mVegeObject->GetVertices()[0]);

		for (SizeT si = 0; si < m_nInstUsingCount; ++si)
		{
			//TODO : Transform vertex wave
			if ( si < g_nNumBatchInstance )
			{
				_GenerateVertex(instanceVertex, si);
				_GenerateIndices(indices, si);
				instanceVertex += g_VertexCount;
				indices += g_IndexCount;
			}
			else
			{
				SizeT curIndex =  si % g_nNumBatchInstance;
				_GenerateIndices(indices, curIndex);
				indices += g_IndexCount;
			}
			//_GenerateIndices(indices, curIndex);

		}

		vbd2.SetVertices(&mVegeObject->GetVertices()[0], numVertex);
		ibd2.SetIndices(&mVegeObject->GetIndices()[0], numIndex);
		RenderBase::PrimitiveHandle handle = Graphic::GraphicSystem::Instance()->CreatePrimitiveHandle(&vbd2, &ibd2);

		RenderBase::PrimitiveHandle& old = mVegeObject->GetPrimHandle();
		if (old.IsValid())
		{
			Graphic::GraphicSystem::Instance()->RemovePrimitive(old);
		}
		mVegeObject->SetPrimHandle(handle);

		SetDirty(false);
		return true;
	}
	//------------------------------------------------------------------------
	void GrassInstanceMap::_GenerateVertex(VEGE_VERTEX_INSTANCE* vertext, IndexT instIndex)
	{
		float u0 = 0.0f;
		float u1 = 1.0f;
		float v0 = 0.0f;
		float v1 = 1.0f;
		Math::Color32 defClr(255,255,255,255);

		Math::scalar fIndex =  (Math::scalar)instIndex;
		Math::scalar fWave = Math::n_rand(0.5f, 1.0f);
		vertext[0].pos = Math::float3(-1.0f , 2.0f, 0)/* * mInstances[instIndex].scale*/;
		vertext[0].color.Set(defClr);
		vertext[0].uv.set( u0, v0 );
		vertext[0].index = Math::float2(fIndex, fWave);

		vertext[1].pos = Math::float3(-1.0f , 0.0f, 0);
		vertext[1].color.Set(defClr);
		vertext[1].uv.set( u0, v1 );
		vertext[1].index = Math::float2(fIndex, 0.f);

		vertext[2].pos = Math::float3(1.0f , 0.0f, 0);
		vertext[2].color.Set(defClr);
		vertext[2].uv.set( u1, v1  );
		vertext[2].index = Math::float2(fIndex, 0.f);

		vertext[3].pos = Math::float3(1.0f , 2.0f, 0); 
		vertext[3].color.Set(defClr);
		vertext[3].uv.set( u1, v0  );
		vertext[3].index = Math::float2(fIndex, fWave);


		Math::float3 normal = Math::float3::normalize(vertext[1].pos - vertext[0].pos);
		normal = normal.crossProduct( Math::float3::normalize(vertext[1].pos - vertext[2].pos) );
		normal = Math::float3::normalize( normal );

		vertext[0].normal = normal;
		vertext[1].normal = normal;
		vertext[2].normal = normal;
		vertext[3].normal = normal;


	}

	void GrassInstanceMap::_GenerateIndices(ushort* indices, IndexT instIndex)
	{

		IndexT curVertIndex = instIndex * g_VertexCount;
		indices[0] = curVertIndex;
		indices[1] = curVertIndex + 1;
		indices[2] = curVertIndex + 2;
		indices[3] = curVertIndex + 2;
		indices[4] = curVertIndex + 3;
		indices[5] = curVertIndex;
	}
	//------------------------------------------------------------------------
	void GrassInstanceMap::Update()
	{


		if ( !mVegeObject || mInstances.IsEmpty())
			return;		

		if ( m_bInstDirty )
		{
			BuildPrimitive();
		}	

	}
}