SH7764 Datasheet, PDF (1150/1752 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC Engine Family SH-4A Series

Section 23 G2D
When coordinate transformation is performed by the CLRWC command, the four vertices are
internally obtained from the input left and right X coordinate values and upper and lower Y
coordinate values, and the coordinates for these four vertices are transformed. The transformed
four vertices are then internally converted into a circumscribed rectangle drawn.
When coordinate transformation is performed by the FTRAPC or RFTRAPC command, the four
vertices are internally obtained from the coordinate values for the circumscribed quadrangle of the
input polygon, and the coordinates for these four vertices are transformed. The transformed four
vertices are then internally converted into a circumscribed rectangle, the left edge obtained, and
the polygon drawn. The BLKE bit should be set to 1 with the CLRWC, FTRAPC, and RFTRAPC
commands.
BLKE = 0
A POLYGON4 type command
Multi-valued
performs four-vertex drawing
while referencing the work
source
coordinates.
(DX1, DY1)
Destination
(DX2, DY2)
(DX3, DY3)
BLKE = 1
(DX1', DY1')
(DX2, DY2)
(DX2', DY2')
(DX1, DY1)
(DX3, DY3)
(DX1, DY1)
(DX2, DY2)
(DX4, DY4)
(DX3, DY3)
Input vertex coordinates are not transformed.
(DX4', DY4')
(DX4, DY4)
(DX3', DY3')
Input vertex coordinates (DXn, DYn) are transformed
to circumscribed rectangle coordinates (DX'n, DY'n).
(DX4, DY4)
Work coordinates
Figure 23.14 Example of Block Enable Specification
(19) Coordinate Transformation Enable (MTRE)
The coordinate transformation enable specification can be used with all drawing commands.
Setting the MTRE bit to 1 when the coordinate transformation enable bit (GTE) in the coordinate
transformation control register (GTRCR) is 1 performs coordinate transformation for the input
vertex.
Rev. 1.00 Nov. 22, 2007 Page 1094 of 1692
REJ09B0360-0100