/*! Render the model; the time parameter is ignored right now
* since this class doesn't currently support animation.
*/
void
ModelGeometry::render(RenderContext& rc, double /* t */)
{
// The first time the mesh is rendered, we will try and place the
// vertex data in a vertex buffer object and potentially get a huge
// rendering performance boost. This can consume a great deal of
// memory, since we're duplicating the vertex data. TODO: investigate
// the possibility of deleting the original data. We can always map
// read-only later on for things like picking, but this could be a low
// performance path.
if (!m_vbInitialized && isVBOSupported())
{
m_vbInitialized = true;
for (unsigned int i = 0; i < m_model->getMeshCount(); ++i)
{
Mesh* mesh = m_model->getMesh(i);
const Mesh::VertexDescription& vertexDesc = mesh->getVertexDescription();
GLuint vboId = 0;
if (mesh->getVertexCount() * vertexDesc.stride > MinVBOSize)
{
glGenBuffersARB(1, &vboId);
if (vboId != 0)
{
glBindBufferARB(GL_ARRAY_BUFFER_ARB, vboId);
glBufferDataARB(GL_ARRAY_BUFFER_ARB,
mesh->getVertexCount() * vertexDesc.stride,
mesh->getVertexData(),
GL_STATIC_DRAW_ARB);
glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
}
}
m_glData->vbos.push_back(vboId);
}
}
unsigned int lastMaterial = ~0u;
unsigned int materialCount = m_model->getMaterialCount();
// Iterate over all meshes in the model
for (unsigned int meshIndex = 0; meshIndex < m_model->getMeshCount(); ++meshIndex)
{
Mesh* mesh = m_model->getMesh(meshIndex);
GLuint vboId = 0;
if (m_glData && meshIndex < m_glData->vbos.size())
{
vboId = m_glData->vbos[meshIndex];
}
if (vboId != 0)
{
// Bind the vertex buffer object.
glBindBufferARB(GL_ARRAY_BUFFER_ARB, vboId);
rc.setVertexArrays(mesh->getVertexDescription(), NULL);
}
else
{
// No vertex buffer object; just use normal vertex arrays
rc.setVertexArrays(mesh->getVertexDescription(), mesh->getVertexData());
}
// Iterate over all primitive groups in the mesh
for (unsigned int groupIndex = 0; groupIndex < mesh->getGroupCount(); ++groupIndex)
{
const Mesh::PrimitiveGroup* group = mesh->getGroup(groupIndex);
// Set up the material
const Material* material = NULL;
unsigned int materialIndex = group->materialIndex;
if (materialIndex != lastMaterial && materialIndex < materialCount)
{
material = m_model->getMaterial(materialIndex);
}
rc.setMaterial(material);
rc.drawGroup(*group);
}
// If we set a VBO, unbind it.
if (vboId != 0)
{
glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
}
}
}
