Feature levels in Direct3D: Difference between revisions

There are seven feature levels provided by {{code|D3D_FEATURE_LEVEL}} structure; levels 9_1, 9_2 and 9_3 (collectively known as '''Direct3D 10 Level 9''') re-encapsulate various features of popular Direct3D 9 cards conforming to Shader Model 2.0, while levels 10_0, 10_1, 11_0 and 11_1 refer to respective versions of the Direct3D API.<ref name="D3D11_downlevel"/> "10 Level 9" feature levels contain a subset of the Direct3D 10/11 API<ref>{{cite web|url=http://msdn.microsoft.com/en-us/library/windows/desktop/ff476148 |title=10Level9 reference|accessdate=2012-11-18|publisher=MSDN}}</ref> and require shaders to be written in [[HLSL]] conforming to [[Shader Model 4.0]] {{code|4_0_LEVEL_9_x}} compiler profiles, and not in the actual [[Shading language#DirectX Shader Assembly Language|"shader assembly"]] language<ref name="shader_asm">[https://msdn.microsoft.com/en-us/library/windows/desktop/bb219840 MSDN - DirectX and Gaming - Asm Shader Reference]</ref> of Shader Model 1.1/2.0; SM 3.0 ({{code|vs_3_0}}/{{code|ps_3_0}}) has been omitted deliberately in Direct3D 1011 Level 95.<ref name=D3DFeatureLevels_chuckw/>

Since Direct3D 11.10 for Windows 810, some mandatory features introduced for level 11_1 are available as optional on levels 10_0, 10_1 and 11_0 - these features can be checked individually via <code>CheckFeatureSupport</code> function<ref name="CheckFeatureSupport">{{cite web | url=https://msdn.microsoft.com/en-us/library/windows/desktop/hh404562#check_support_of_new_direct3d_11.1_features_and_formats | title=Direct3D 11.10 Features -10 Win3264xbit apps }}</ref> however feature level 11_1 and optional features are not available in Direct3D 11.10 for Windows 7 [[Windows 7#Platform Update|platform update]]<ref>{{cite web|url=http://blogs.msdn.com/b/chuckw/archive/2012/06/20/direct3d-feature-levels.aspx|title=MSDN Blogs|publisher=|accessdate=30 September 2014}}</ref> because it does not support WDDM 1.2.<ref>{{cite web | url=https://msdn.microsoft.com/en-us/library/windows/desktop/jj863687.aspx | title=Platform Update for Windows 10 - 64xbit