/// <summary>
/// Sets the global alpha rejection approach for future renders.
/// </summary>
/// <param name="func">The comparison function which must pass for a pixel to be written.</param>
/// <param name="value">The value to compare each pixels alpha value to (0-255)</param>
/// <param name="alphaToCoverage">Whether to enable alpha to coverage, if supported</param>
public override void SetAlphaRejectSettings(CompareFunction func, byte value, bool alphaToCoverage)
{
var a2c = false;
if (func != CompareFunction.AlwaysPass)
{
a2c = alphaToCoverage;
}
StateManager.BlendState.AlphaBlendFunction = BlendFunction.Add /* XnaHelper.Convert( func )*/;
//StateManager.BlendState.ReferenceAlpha = val;
// Alpha to coverage
if (lasta2c != a2c && Capabilities.HasCapability(Graphics.Capabilities.AlphaToCoverage))
{
lasta2c = a2c;
}
}
/// <summary>
/// Sets the mode of operation for depth buffer tests from this point onwards.
/// </summary>
/// <remarks>
/// Sometimes you may wish to alter the behavior of the depth buffer to achieve
/// special effects. Because it's unlikely that you'll set these options for an entire frame,
/// but rather use them to tweak settings between rendering objects, this is intended for internal
/// uses, which will be used by a <see cref="SceneManager"/> implementation rather than directly from
/// the client application.
/// </remarks>
/// <param name="depthTest">
/// If true, the depth buffer is tested for each pixel and the frame buffer is only updated
/// if the depth function test succeeds. If false, no test is performed and pixels are always written.
/// </param>
/// <param name="depthWrite">
/// If true, the depth buffer is updated with the depth of the new pixel if the depth test succeeds.
/// If false, the depth buffer is left unchanged even if a new pixel is written.
/// </param>
/// <param name="depthFunction">Sets the function required for the depth test.</param>
public override void SetDepthBufferParams(bool depthTest, bool depthWrite, CompareFunction depthFunction)
{
StateManager.DepthStencilState.DepthBufferEnable = depthTest;
StateManager.DepthStencilState.DepthBufferWriteEnable = depthWrite;
StateManager.DepthStencilState.DepthBufferFunction = XnaHelper.Convert(depthFunction);
}
/// <summary>
/// Converts our CompareFunction enum to the XFG.Compare equivalent.
/// </summary>
/// <param name="func"></param>
/// <returns></returns>
public static XFG.CompareFunction Convert( CompareFunction func )
{
switch ( func )
{
case CompareFunction.AlwaysFail:
return XFG.CompareFunction.Never;
case CompareFunction.AlwaysPass:
return XFG.CompareFunction.Always;
case CompareFunction.Equal:
return XFG.CompareFunction.Equal;
case CompareFunction.Greater:
return XFG.CompareFunction.Greater;
case CompareFunction.GreaterEqual:
return XFG.CompareFunction.GreaterEqual;
case CompareFunction.Less:
return XFG.CompareFunction.Less;
case CompareFunction.LessEqual:
return XFG.CompareFunction.LessEqual;
case CompareFunction.NotEqual:
return XFG.CompareFunction.NotEqual;
}
return 0;
}