NEC µPD72257 Preliminary User's Manual page 259

Drawing Engine
Bit Bit name
TEXTURE
17
FILTERY
TEXTURE
16
FILTERX
TEXTURE
15
CLAMPY
TEXTURE
14
CLAMPX
13 BC2
12 BDI
11 BSI
10 BDF
9 BSF
READFORMAT
4
3
PATTERN
2
SOURCEL5
TEXTURE
1
ENABLE
PATTERN
0
ENABLE
Function
001
16 bpp RGB(565)
B
010
32 bpp RGB(8888)
B
011
16 bpp aRGB(4444)
B
100
16 bpp aRGB(1555)
B
Linear filtering on texture V axis
0 no filtering on texture V axis
1 linear filtering on texture V axis
Linear filtering on texture U axis
0 no filtering on texture U axis
1 linear filtering on texture U axis
Clamp instead of mask V coordinate
0 mask texture V coordinate
1 clamp texture V coordinate
Clamp instead of mask U coordinate
0 mask texture U coordinate
1 clamp texture U coordinate
Blend color 2 instead of framebuffer pixel
0 use pixel from framebuffer as destination
1 use colour 2 as destination
dst factor will be inverted (meaning 1-a or 1-1 depending on BDF)
0 use blend factor as specified through BDF
1 invert destination blend factor (1-x)
src factor will be inverted (meaning 1-a or 1-1 depending on BSF)
0 use blend factor as specified through BSF
1 invert source blend factor (1-x)
dst factor is alpha (factor is 1 per default)
0 use 1.0 as destination blend factor
1 use alpha as destination blend factor
rc factor is alpha (factor is 1 per default)
0 use 1.0 as source blend factor
1 use alpha as source blend factor
Bit 3 of the texture buffer format. See READFORMAT above for description.
Limiter 5 is used as pattern index instead of the default U limiter
Pixel source is read from texture and used as an alpha to blend between DRWCOLOR1
and DRWCOLOR2.
0 disable texture
1 enable texture
Pixel source is a pattern colour (blend of DRWCOLOR1 and DRWCOLOR2 depending
on DRWPATTERN and pattern index)
0 disable pattern
1 enable pattern
Preliminary User's Manual S19203EE1V3UM00
Chapter 8
259