//разбор примитива
void ParsePrimitive (Parser::Iterator primitive_iter, Mesh& mesh)
{
static const char* METHOD_NAME = "media::geometry::XmlMeshLibraryLoader::ParsePrimitive";
const char* type_string = get<const char*> (*primitive_iter, "type");
PrimitiveType type = get_primitive_type (type_string);
const char* material = get<const char*> (*primitive_iter, "material", "");
unsigned int vertex_buffer_index = get<unsigned int> (*primitive_iter, "vertex_buffer"),
first = get<unsigned int> (*primitive_iter, "first"),
count = get<unsigned int> (*primitive_iter, "count"),
base_vertex = get<unsigned int> (*primitive_iter, "base_vertex", 0u);
if (type >= PrimitiveType_Num)
throw xtl::make_argument_exception (METHOD_NAME, "type", type_string);
if (vertex_buffer_index >= mesh.VertexBuffersCount ())
throw xtl::make_range_exception (METHOD_NAME, "vertex_buffer", vertex_buffer_index, mesh.VertexBuffersCount ());
const VertexBuffer& vertex_buffer = mesh.VertexBuffer (vertex_buffer_index);
unsigned int vertices_count = vertex_buffer.VerticesCount (),
indices_count = mesh.IndexBuffer ().Size (),
max_primitives_count = 0,
max_count = indices_count ? indices_count : vertices_count;
if (first > max_count)
throw xtl::make_range_exception (METHOD_NAME, "first", first, max_count);
max_count -= first;
switch (type)
{
case PrimitiveType_LineList:
max_primitives_count = max_count / 2;
break;
case media::geometry::PrimitiveType_LineStrip:
max_primitives_count = max_count > 1 ? max_count - 1 : 0;
break;
case media::geometry::PrimitiveType_TriangleList:
max_primitives_count = max_count / 3;
break;
case media::geometry::PrimitiveType_TriangleStrip:
max_primitives_count = max_count > 2 ? max_count - 2 : 0;
break;
case media::geometry::PrimitiveType_TriangleFan:
max_primitives_count = max_count > 2 ? max_count - 2 : 0;
break;
default:
break;
}
if (count > max_primitives_count)
throw xtl::make_range_exception (METHOD_NAME, "count", count, max_primitives_count + 1);
if (base_vertex >= vertices_count)
throw xtl::make_range_exception (METHOD_NAME, "base_vertex", base_vertex, vertices_count);
if (!count)
{
primitive_iter->Log ().Warning (*primitive_iter, "Empty primitive");
return;
}
mesh.AddPrimitive (type, vertex_buffer_index, first, count, base_vertex, material);
}
