C++ LLVertexBuffer::allocateBuffer方法代码示例

//create a vertex buffer for efficiently rendering cubes
LLVertexBuffer* ll_create_cube_vb(U32 type_mask, U32 usage)
{
	LLVertexBuffer* ret = new LLVertexBuffer(type_mask, usage);

	ret->allocateBuffer(8, 64, true);

	LLStrider<LLVector3> pos;
	LLStrider<U16> idx;

	ret->getVertexStrider(pos);
	ret->getIndexStrider(idx);

	pos[0] = LLVector3(-1,-1,-1);
	pos[1] = LLVector3(-1,-1, 1);
	pos[2] = LLVector3(-1, 1,-1);
	pos[3] = LLVector3(-1, 1, 1);
	pos[4] = LLVector3( 1,-1,-1);
	pos[5] = LLVector3( 1,-1, 1);
	pos[6] = LLVector3( 1, 1,-1);
	pos[7] = LLVector3( 1, 1, 1);

	for (U32 i = 0; i < 64; i++)
	{
		idx[i] = sOcclusionIndices[i];
	}

	ret->flush();

	return ret;
}

void create_vertex_buffers_from_model(LLModel* model, std::vector<LLPointer <LLVertexBuffer> >& vertex_buffers)
{
#if 0 //VECTORIZE THIS ?
	vertex_buffers.clear();
	
	for (S32 i = 0; i < model->getNumVolumeFaces(); ++i)
	{
		const LLVolumeFace &vf = model->getVolumeFace(i);
		U32 num_vertices = vf.mNumVertices;
		U32 num_indices = vf.mNumIndices;

		if (!num_vertices || ! num_indices)
		{
			continue;
		}

		LLVertexBuffer* vb =
			new LLVertexBuffer(LLVertexBuffer::MAP_VERTEX | LLVertexBuffer::MAP_NORMAL | LLVertexBuffer::MAP_TEXCOORD0, 0);
		
		vb->allocateBuffer(num_vertices, num_indices, TRUE);

		LLStrider<LLVector3> vertex_strider;
		LLStrider<LLVector3> normal_strider;
		LLStrider<LLVector2> tc_strider;
		LLStrider<U16> index_strider;

		vb->getVertexStrider(vertex_strider);
		vb->getNormalStrider(normal_strider);
		vb->getTexCoord0Strider(tc_strider);

		vb->getIndexStrider(index_strider);

		// build vertices and normals
		for (U32 i = 0; (S32)i < num_vertices; i++)
		{
			*(vertex_strider++) = vf.mVertices[i].mPosition;
			*(tc_strider++) = vf.mVertices[i].mTexCoord;
			LLVector3 normal = vf.mVertices[i].mNormal;
			normal.normalize();
			*(normal_strider++) = normal;
		}

		// build indices
		for (U32 i = 0; i < num_indices; i++)
		{
			*(index_strider++) = vf.mIndices[i];
		}


		vertex_buffers.push_back(vb);
	}
#endif
}

BOOL LLVOWater::updateGeometry(LLDrawable *drawable)
{
	LLFastTimer ftm(LLFastTimer::FTM_UPDATE_WATER);
	LLFace *face;

	if (drawable->getNumFaces() < 1)
	{
		LLDrawPoolWater *poolp = (LLDrawPoolWater*) gPipeline.getPool(LLDrawPool::POOL_WATER);
		drawable->addFace(poolp, NULL);
	}
	face = drawable->getFace(0);

//	LLVector2 uvs[4];
//	LLVector3 vtx[4];

	LLStrider<LLVector3> verticesp, normalsp;
	LLStrider<LLVector2> texCoordsp;
	LLStrider<U16> indicesp;
	U16 index_offset;


	// A quad is 4 vertices and 6 indices (making 2 triangles)
	static const unsigned int vertices_per_quad = 4;
	static const unsigned int indices_per_quad = 6;

	static const LLCachedControl<bool> render_transparent_water("RenderTransparentWater",false);
	const S32 size = (render_transparent_water && !LLGLSLShader::sNoFixedFunction) ? 16 : 1;
	const S32 num_quads = size * size;
	face->setSize(vertices_per_quad * num_quads,
				  indices_per_quad * num_quads);
	
	LLVertexBuffer* buff = face->getVertexBuffer();
	if (!buff)
	{
		buff = new LLVertexBuffer(LLDrawPoolWater::VERTEX_DATA_MASK, GL_DYNAMIC_DRAW_ARB);
		buff->allocateBuffer(face->getGeomCount(), face->getIndicesCount(), TRUE);
		face->setIndicesIndex(0);
		face->setGeomIndex(0);
		face->setVertexBuffer(buff);
	}
	else
	{
		buff->resizeBuffer(face->getGeomCount(), face->getIndicesCount());
	}
		
	index_offset = face->getGeometry(verticesp,normalsp,texCoordsp, indicesp);
		
	LLVector3 position_agent;
	position_agent = getPositionAgent();
	face->mCenterAgent = position_agent;
	face->mCenterLocal = position_agent;

	S32 x, y;
	F32 step_x = getScale().mV[0] / size;
	F32 step_y = getScale().mV[1] / size;

	const LLVector3 up(0.f, step_y * 0.5f, 0.f);
	const LLVector3 right(step_x * 0.5f, 0.f, 0.f);
	const LLVector3 normal(0.f, 0.f, 1.f);

	F32 size_inv = 1.f / size;

	for (y = 0; y < size; y++)
	{
		for (x = 0; x < size; x++)
		{
			S32 toffset = index_offset + 4*(y*size + x);
			position_agent = getPositionAgent() - getScale() * 0.5f;
			position_agent.mV[VX] += (x + 0.5f) * step_x;
			position_agent.mV[VY] += (y + 0.5f) * step_y;

			*verticesp++  = position_agent - right + up;
			*verticesp++  = position_agent - right - up;
			*verticesp++  = position_agent + right + up;
			*verticesp++  = position_agent + right - up;

			*texCoordsp++ = LLVector2(x*size_inv, (y+1)*size_inv);
			*texCoordsp++ = LLVector2(x*size_inv, y*size_inv);
			*texCoordsp++ = LLVector2((x+1)*size_inv, (y+1)*size_inv);
			*texCoordsp++ = LLVector2((x+1)*size_inv, y*size_inv);
			
			*normalsp++   = normal;
			*normalsp++   = normal;
			*normalsp++   = normal;
			*normalsp++   = normal;

			*indicesp++ = toffset + 0;
			*indicesp++ = toffset + 1;
			*indicesp++ = toffset + 2;

			*indicesp++ = toffset + 1;
			*indicesp++ = toffset + 3;
			*indicesp++ = toffset + 2;
		}
	}
	
	buff->flush();

	mDrawable->movePartition();
	LLPipeline::sCompiles++;
//.........这里部分代码省略.........

void LLVOTree::updateMesh()
{
	LLMatrix4 matrix;
	
	// Translate to tree base  HACK - adjustment in Z plants tree underground
	const LLVector3 &pos_agent = getPositionAgent();
	//gGL.translatef(pos_agent.mV[VX], pos_agent.mV[VY], pos_agent.mV[VZ] - 0.1f);
	LLMatrix4 trans_mat;
	trans_mat.setTranslation(pos_agent.mV[VX], pos_agent.mV[VY], pos_agent.mV[VZ] - 0.1f);
	trans_mat *= matrix;
	
	// Rotate to tree position and bend for current trunk/wind
	// Note that trunk stiffness controls the amount of bend at the trunk as 
	// opposed to the crown of the tree
	// 
	const F32 TRUNK_STIFF = 22.f;
	
	LLQuaternion rot = 
		LLQuaternion(mTrunkBend.magVec()*TRUNK_STIFF*DEG_TO_RAD, LLVector4(mTrunkBend.mV[VX], mTrunkBend.mV[VY], 0)) *
		LLQuaternion(90.f*DEG_TO_RAD, LLVector4(0,0,1)) *
		getRotation();

	LLMatrix4 rot_mat(rot);
	rot_mat *= trans_mat;

	F32 radius = getScale().magVec()*0.05f;
	LLMatrix4 scale_mat;
	scale_mat.mMatrix[0][0] = 
		scale_mat.mMatrix[1][1] =
		scale_mat.mMatrix[2][2] = radius;

	scale_mat *= rot_mat;

//	const F32 THRESH_ANGLE_FOR_BILLBOARD = 15.f;
//	const F32 BLEND_RANGE_FOR_BILLBOARD = 3.f;

	F32 droop = mDroop + 25.f*(1.f - mTrunkBend.magVec());
	
	S32 stop_depth = 0;
	F32 alpha = 1.0;
	

	U32 vert_count = 0;
	U32 index_count = 0;
	
	calcNumVerts(vert_count, index_count, mTrunkLOD, stop_depth, mDepth, mTrunkDepth, mBranches);

	LLFace* facep = mDrawable->getFace(0);
	LLVertexBuffer* buff = new LLVertexBuffer(LLDrawPoolTree::VERTEX_DATA_MASK, GL_STATIC_DRAW_ARB);
	buff->allocateBuffer(vert_count, index_count, TRUE);
	facep->setVertexBuffer(buff);
	
	LLStrider<LLVector3> vertices;
	LLStrider<LLVector3> normals;
	LLStrider<LLVector2> tex_coords;
	LLStrider<U16> indices;
	U16 idx_offset = 0;

	buff->getVertexStrider(vertices);
	buff->getNormalStrider(normals);
	buff->getTexCoord0Strider(tex_coords);
	buff->getIndexStrider(indices);

	genBranchPipeline(vertices, normals, tex_coords, indices, idx_offset, scale_mat, mTrunkLOD, stop_depth, mDepth, mTrunkDepth, 1.0, mTwist, droop, mBranches, alpha);
	
	mReferenceBuffer->flush();
	buff->flush();
}

BOOL LLVOGround::updateGeometry(LLDrawable *drawable)
{
	LLStrider<LLVector3> verticesp;
	LLStrider<LLVector3> normalsp;
	LLStrider<LLVector2> texCoordsp;
	LLStrider<U16> indicesp;
	S32 index_offset;
	LLFace *face;	

	LLDrawPoolGround *poolp = (LLDrawPoolGround*) gPipeline.getPool(LLDrawPool::POOL_GROUND);

	if (drawable->getNumFaces() < 1)
		drawable->addFace(poolp, NULL);
	face = drawable->getFace(0); 
		
	if (!face->getVertexBuffer())
	{
		face->setSize(5, 12);
		LLVertexBuffer* buff = new LLVertexBuffer(LLDrawPoolGround::VERTEX_DATA_MASK, GL_STREAM_DRAW_ARB);
		buff->allocateBuffer(face->getGeomCount(), face->getIndicesCount(), TRUE);
		face->setGeomIndex(0);
		face->setIndicesIndex(0);
		face->setVertexBuffer(buff);
	}
	
	index_offset = face->getGeometry(verticesp,normalsp,texCoordsp, indicesp);
	if (-1 == index_offset)
	{
		return TRUE;
	}

	///////////////////////////////////////
	//
	//
	//
	LLVector3 at_dir = LLViewerCamera::getInstance()->getAtAxis();
	at_dir.mV[VZ] = 0.f;
	if (at_dir.normVec() < 0.01)
	{
		// We really don't care, as we're not looking anywhere near the horizon.
	}
	LLVector3 left_dir = LLViewerCamera::getInstance()->getLeftAxis();
	left_dir.mV[VZ] = 0.f;
	left_dir.normVec();

	// Our center top point
	LLColor4 ground_color = gSky.getFogColor();
	ground_color.mV[3] = 1.f;
	face->setFaceColor(ground_color);
	
	*(verticesp++)  = LLVector3(64, 64, 0);
	*(verticesp++)  = LLVector3(-64, 64, 0);
	*(verticesp++)  = LLVector3(-64, -64, 0);
	*(verticesp++)  = LLVector3(64, -64, 0);
	*(verticesp++)  = LLVector3(0, 0, -1024);
	
	
	// Triangles for each side
	*indicesp++ = index_offset + 0;
	*indicesp++ = index_offset + 1;
	*indicesp++ = index_offset + 4;

	*indicesp++ = index_offset + 1;
	*indicesp++ = index_offset + 2;
	*indicesp++ = index_offset + 4;

	*indicesp++ = index_offset + 2;
	*indicesp++ = index_offset + 3;
	*indicesp++ = index_offset + 4;

	*indicesp++ = index_offset + 3;
	*indicesp++ = index_offset + 0;
	*indicesp++ = index_offset + 4;

	*(texCoordsp++) = LLVector2(0.f, 0.f);
	*(texCoordsp++) = LLVector2(1.f, 0.f);
	*(texCoordsp++) = LLVector2(1.f, 1.f);
	*(texCoordsp++) = LLVector2(0.f, 1.f);
	*(texCoordsp++) = LLVector2(0.5f, 0.5f);
	
	face->getVertexBuffer()->flush();
	LLPipeline::sCompiles++;
	return TRUE;
}