Advanced D3D10 Rendering课件.ppt

Clean API Vista only Everything is mandatory (almost) No legacy hardware support Clean starting point for future evolution of the API Limited market short-term Some old features deprecated Fixed function Assembly shaders Alpha test Triangle fans Point sprites Clip planes 精品文档 Dealing with deprecated features Fixed function Write a few über-shaders Assembly shaders Convert to HLSL Alpha test Use discard or clip() in pixel shader Use alpha-to-coverage Triangle fans Seldom used anyway, usually just for a quad Convert to triangle list or strip Point sprites Expand point to 2 triangles in GS Clip planes Use clip distance and/or cull distance 精品文档 SM 4.0 Geometry shader Processes a full primitive (point, line, triangle) Has access to adjacency information (optional) Useful for silhouette detection, shadow volume extrusion etc. May output multiple primitives Output limitation is 1024 floats May output nothing (to kill primitive) 精品文档 SM 4.0 Infinite instruction count Very long shaders may have lower throughput though Integer and bitwise instruction Indexable temporaries Allows for local arrays May be used to emulate a stack Useful system generated values SV_VertexID SV_PrimitiveID SV_InstanceID SV_Position (Like VPOS, but now .zw are defined too) SV_IsFrontFace (Like VFACE) SV_RenderTargetArrayIndex SV_ViewportArrayIndex SV_ClipDistance SV_CullDistance 精品文档 SM 4.0 Integer bitwise instructions Signed and unsigned No idiv though, just udiv Same registers as floats Can alias without conversion with asint(), asuint(), asfloat() etc. Integer texture sample values Syntax: Texture2D uint4 myTex; Access to individual samples in MSAA surface Allows for custom AA resolve Syntax: Texture2DMS float4, 4 myTex; 精品文档 Pixel center Half pixel offset is gone! ? Affects SV_Position as well Now matches OpenGL DX10 DX9 精品文档 Pixel center Pixels and texels align TexCoord = SV_Position.xy / float2(width, height) Texel center