SH7764 Datasheet, PDF (1140/1752 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC Engine Family SH-4A Series

Section 23 G2D
23.1.5 Rendering Attributes
(1) Source Transparency Specification (STRANS)
When referencing source data, the STRANS bit can be used to select transparency or non-
transparency on an individual drawing command basis. If transparency is selected, the source
color becomes transparent at register value = source color when the source transparent color
polarity bit (STP) in the rendering control register (RCLR) is 0, and the source color becomes
transparent at register value ≠ source color when the STP bit is 1, and the pixels are not drawn in
either case. The source transparency specification can be used with the POLYGON4A,
POLYGON4B, LINEA, LINEB, RLINEA, RLINEB, BITBLTA, and BITBLTB commands. The
STRANS bit should be cleared to 0 in other commands. When the source pixel format is ARGB,
the A value is not compared. Note that when the STRANS bit is set to 1, the source data is always
read in the BITBLTA or BITBLTB command, regardless of the ROP code.
(2) Destination Transparency Specification (DTRANS)
When referencing destination data, the DTRANS bit can be used to select transparency or non-
transparency on an individual drawing command basis. If transparency is selected, the destination
color becomes transparent at register value = destination color when the destination transparent
color polarity bit (DTP) in the rendering control register (RCLR) is 0, and the destination color
becomes transparent at register value ≠ destination color when the DTP bit is 1, and the pixels are
not drawn in either case. The destination transparency specification can be used with the
BITBLTA, BITBLTB, and BITBLTC commands. The DTRANS bit should be cleared to 0 in
other commands. When the destination pixel format is ARGB, the A value is not compared. Note
that when the DTRANS bit is set to 1, the destination data is always read, regardless of the ROP
code.
(3) Source Style Specification (STYLE)
The STYLE bit can be used to select, on an individual drawing command basis, whether to
enlarge or reduce the source data or repeatedly reference it. If no style specification is made, the
source data is enlarged or reduced in proportion to the size of the rendering area. When a style
specification is made, the source data is referenced repeatedly in proportion to the size of the
rendering area. This attribute is therefore used when drawing repeated patterns such as hatch
patterns. The source style specification can be used with the POLYGON4A, POLYGON4B,
LINEA, LINEB, RLINEA, and RLINEB commands. The STYLE bit should be cleared to 0 in
other commands. The STYLE bit must be set to 1 when BLKE = 1 in the POLYGON4A,
POLYGON4B, LINEA, LINEB, RLINEA, or RLINEB command.
Rev. 1.00 Nov. 22, 2007 Page 1084 of 1692
REJ09B0360-0100