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.

See also Effects

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

class DirectX::AlphaTestEffect :
    public DirectX::IEffect,
    public DirectX::IEffectMatrices,
    public DirectX::IEffectFog

Header

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.

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

Exceptions

The ctor can throw std::bad_alloc.

Apply can throw std::runtime_error for an invalid alpha comparison function.

The property methods of this implementation do not throw C++ exceptions.

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.