cgfx 里会有这个
float4X4 View : View;
:后面这个 view 是一种 叫做user defined semantic
provide the correct data to the shader without having to decipher the var names
cgusersManual.pdf
cg Toolkit
vs_4_0这种 叫做profile
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http://msdn.microsoft.com/en-us/library/windows/desktop/bb509647(v=vs.85).aspx
dx的semantic
shader 之间传递的var必须定义semantic