Bridgetek FT800, Programming Manual

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FT800 Series Programmer Guide
Version 2.1
Document Reference No.: BRT_000030 Clearance No.: BRT#037
112
Product Page
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4.19 CLEAR
Clear buffers to preset values
Encoding
31 24 23 3 2 1 0
0x26 Reserved C S T
Parameters
c
Clear color buffer. Setting this bit to 1 will clear the color buffer of the FT800
to the preset value. Setting this bit to 0 will maintain the color buffer of the
FT800 with an unchanged value. The preset value is defined in command
CLEAR_COLOR_RGB for RGB channel and CLEAR_COLOR_A for alpha channel.
s
Clear stencil buffer. Setting this bit to 1 will clear the stencil buffer of the
FT800 to the preset value. Setting this bit to 0 will maintain the stencil
buffer of the FT800 with an unchanged value. The preset value is defined in
command CLEAR_STENCIL.
t
Clear tag buffer. Setting this bit to 1 will clear the tag buffer of the FT800 to
the preset value. Setting this bit to 0 will maintain the tag buffer of the
FT800 with an unchanged value. The preset value is defined in command
CLEAR_TAG.
Description
The scissor test and the buffer write masks affect the operation of the clear. Scissor
limits the cleared rectangle, and the buffer write masks limit the affected buffers.
The state of the alpha function, blend function, and stenciling do not affect the clear.
Examples
To clear the screen to bright blue:
dl( CLEAR_COLOR_RGB(0, 0, 255) );
dl( CLEAR(1, 0, 0) );