Action

Specify pixel arithmetic.

Syntax

BlendFunc src, dst

src	Specifies how the source blending factor is computed. One of ZERO, ONE, SRC_ALPHA,DST_ALPHA,ONE_MINUS_SRC_ALPHA or ONE_MINUS_DST_ALPHA.
dst	Specifies how the destination blending factor is computed, One of ZERO, ONE, SRC_ALPHA,DST_ALPHA,ONE_MINUS_SRC_ALPHA or ONE_MINUS_DST_ALPHA.

The blend function controls how new color values are combined with the values already in the color buffer.

Given a pixel value source and a previous value in the color buffer destination, the computed color is:

source × src + destination × dst

for each color channel: red, green, blue and alpha.

For more details please refer to the FT800 Series Programmer Guide.PDF from FTDI.