FT800 Series Programmer Guide
Version 2.1
Document Reference No.: BRT_000030 Clearance No.: BRT#037
107
Copyright © Bridgetek Limited
4.16
BLEND_FUNC
Specify pixel arithmetic
Encoding
31 24 23 6 5 3 2 0
0x0B
reserved
src
dst
Parameters
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. The initial value is SRC_ALPHA (2).
dst
Specifies how the destination blending factor is computed, one of the same
constants as src. The initial value is ONE_MINUS_SRC_ALPHA(4)
Table 8 BLEND_FUNC constant value definition
NAME
VALUE
Description
ZERO
0
Check openGL definition
ONE
1
Check openGL definition
SRC_ALPHA
2
Check openGL definition
DST_ALPHA
3
Check openGL definition
ONE_MINUS_SRC_ALPHA
4
Check openGL definition
ONE_MINUS_DST_ALPHA
5
Check openGL definition
Description
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.
Examples