Renderable::SetBlendState

Defined in: C4Renderable.h

Sets the ambient pass blend state.

Prototype

void SetBlendState(unsigned long state);

Parameters

state The new ambient pass blend state.

Description

The SetBlendState function sets the blending function used when an object is rendered in the ambient pass. The state parameter encodes the blending factors and can be constructed using the BlendState function. The first two parameters of the BlendState function specify one of the following constants for the source blend factor and the destination blend factor, respectively.

`kBlendZero`	Zero.
`kBlendOne`	One.
`kBlendSourceColor`	Source color.
`kBlendDestColor`	Destination color.
`kBlendSourceAlpha`	Source alpha.
`kBlendDestAlpha`	Destination alpha.
`kBlendInvSourceColor`	One minus source color.
`kBlendInvDestColor`	One minus destination color.
`kBlendInvSourceAlpha`	One minus source alpha.
`kBlendInvDestAlpha`	One minus destination alpha.

For example, BlendState(kBlendOne, kBlendZero) returns the blend state corresponding to replacement of the destination color by the source color. BlendState(kBlendOne, kBlendOne) adds the source color to the destination color.

There are several predefined constants that can also be passed to the state parameter, listed below.

`kBlendReplace`	Replace the destination color with the source color.
`kBlendAccumulate`	Add the source color to the destination color.
`kBlendModulate`	Multiply the destination color by the source color.
`kBlendInterpolate`	Interpolate between the source and destination colors using the source alpha.