private static async Task <IReadOnlyList <Primitive> > ReadPrimitives(BufferedReader reader, int materialsCount, int vertexCount)
{
var primitives = new List <Primitive>();
while (true)
{
var token = await reader.ReadInt16().ConfigureAwait(false);
if (token == (short)Token.EndMesh)
{
return(primitives);
}
var primitiveType = (PrimitiveType)token;
if (!Enum.IsDefined(primitiveType))
{
throw new CmodException("Unknown primitive type");
}
var materialIndex = await reader.ReadInt32().ConfigureAwait(false);
if (materialIndex < 0 || materialIndex >= materialsCount)
{
throw new CmodException("Material index out of range");
}
var indexCount = await reader.ReadInt32().ConfigureAwait(false);
if (indexCount <= 0)
{
throw new CmodException("Index count out of range");
}
var primitive = new Primitive(primitiveType, materialIndex, indexCount);
for (var i = 0; i < indexCount; ++i)
{
var index = await reader.ReadInt32().ConfigureAwait(false);
if (index < 0 || index >= vertexCount)
{
throw new CmodException("Index out of range");
}
primitive.Indices.Add(index);
}
primitives.Add(primitive);
}
}
private static async Task <IReadOnlyList <VertexAttribute> > ReadVertexDescription(BufferedReader reader)
{
if (await reader.ReadToken().ConfigureAwait(false) != Token.VertexDesc)
{
throw new CmodException("Expected vertex description");
}
var attributes = new List <VertexAttribute>();
while (true)
{
var token = await reader.ReadInt16().ConfigureAwait(false);
if (token == (short)Token.EndVertexDesc)
{
return(attributes);
}
var attribute = (AttributeType)token;
if (!Enum.IsDefined(attribute))
{
throw new CmodException("Unknown vertex attribute");
}
if (attributes.Any(a => a.AttributeType == attribute))
{
throw new CmodException("Duplicate vertex attribute");
}
var format = await reader.ReadAttributeFormat().ConfigureAwait(false);
if (!Enum.IsDefined(format))
{
throw new CmodException("Invalid attribute format");
}
attributes.Add(VertexAttribute.Create(attribute, format));
}
}