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AlphaTestEffect

Chuck Walbourn edited this page Aug 15, 2022 · 15 revisions
DirectXTK Effects

This is a native Direct3D 11 implementation of the built-in AlphaTestEffect from XNA Game Studio 4 (Microsoft.Xna.Framework.Graphics.AlphaTestEffect) which supports per-pixel alpha testing, vertex color, and fogging.

classDiagram
class IEffect{
    <<Interface>>
    +Apply()
    +GetVertexShaderBytecode()
}
class IEffectMatrices{
    <<Interface>>
    +SetWorld()
    +SetView()
    +SetProjection()
    +SetMatrices()
}
class IEffectFog{
    <<Interface>>
    +SetFogEnabled()
    +SetFogStart()
    +SetFogEnd()
    +SetFogColor()
}
class AlphaTestEffect{
    +SetDiffuseColor()
    +SetAlpha()
    +SetColorAndAlpha()
    +SetVertexColorEnabled()
    +SetTexture()
    +SetAlphaFunction()
    +SetReferenceAlpha()
}
AlphaTestEffect --|> IEffect
AlphaTestEffect --|> IEffectMatrices
AlphaTestEffect --|> IEffectFog
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Header

#include <Effects.h>

Initialization

Construction requires a Direct3D 11 device.

std::unique_ptr<AlphaTestEffect> effect;
effect = std::make_unique<AlphaTestEffect>(device);

For exception safety, it is recommended you make use of the C++ RAII pattern and use a std::unique_ptr or std::shared_ptr

Interfaces

AlphaTestEffect supports IEffect, IEffectMatrices, and IEffectFog

Input layout

This effect requires SV_Position and TEXCOORD0. It also requires COLOR if per-vertex colors are enabled,

Properties

  • SetVertexColorEnabled: Enables per-vertex color. Defaults to false. Modifying this setting requires recreating associated input layouts, and enabling it requires COLOR.

  • SetTexture: Associates a texture shader resource view with the effect. Can be set to nullptr to remove a reference.

  • SetAlphaFunction: Sets the alpha comparison function. See D3D11_COMPARISON_FUNC.

  • SetReferenceAlpha: Sets the alpha reference value for the test.

Remarks

This effect is primarily used to implement techniques that relied on legacy Direct3D 9 alpha testing render state. This effect is independent of the depth/stencil tests set in D3D11_DEPTH_STENCIL_DESC.DepthFunc and StencilFunc.

For Use

  • Universal Windows Platform apps
  • Windows desktop apps
  • Windows 11
  • Windows 10
  • Windows 8.1
  • Windows 7 Service Pack 1
  • Xbox One

For Development

  • Visual Studio 2022
  • Visual Studio 2019 (16.11)
  • clang/LLVM v12 - v18
  • MinGW 12.2, 13.2
  • CMake 3.20

Related Projects

DirectX Tool Kit for DirectX 12

DirectXMesh

DirectXTex

DirectXMath

Win2D

Tools

Test Suite

Model Viewer

Content Exporter

DxCapsViewer

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