MB86296 Datasheet, PDF (107/352 Pages) Fujitsu Component Limited. – PCI Graphics Controller Specification

FUJITSU LIMITED PRELIMINARY AND CONFIDENTIAL
An example of the G_ViewVolumeZclip packet is shown below.
0xf1012010 //Setting of GMDR0
0x00000000 //Data format: Floating point data format
0x45000000 //G_ViewVolumeZclip packet
0xff7fffff //Zmin.float setting value (minimum value of IEEE single-precision floating point)
0x7f7fffff //Zmax.float setting value (maximum value of IEEE single-precision floating point)
Example of G_ViewVolumeZclip Packet when Z Clipping Off
“W” clipping at orthogonal projection transformation
“W” at orthogonal projection transformation (GMDR0[0] = 0) is treated as “Wcc=1.0”. For this
reason, to suppress “W” clipping, the set “Wmin” value must be larger than 0 and 1.0 or less.
Relationship with drawing clip frame
For the following reasons, the clip boundary values of the view volume should be set so that the
values after DC coordinate transformation will be larger than the drawing clip frame (2 pixels or
more).
(1) “XY” on the view volume clip frame of the “CC” coordinate system may be drawn one pixel
outside or inside the frame due to an operation error when it is finally mapped to the “DC”
coordinate system.
(2) When the end point of a line overlaps the view volume frame mapped to the “DC” coordinate
system, there are two cases, where the dots on the frame are drawn, and not drawn depending
on the specifying of the line drawing attribute (end point drawing/non-drawing).
(3) When the start point of a line overlaps the view volume frame mapped to the “DC” coordinate
system, the dots on the frame are always drawn. When the line drawing attribute is ‘end point
non-drawing,’ the dots on the frame are drawn at the starting point, but they may not be drawn
at the end point.
(4) When applying to triangle and polygon drawing the rasterizing rule ‘dots containing center of
pixel drawn. Dots on right side and base of triangle not drawn.’ depending on the value of the
fraction, a gap may be produced between the right side and base of the frame.
Drawing area
“DC” Coordinates image of view volume clip frame
Drawing clip frame
A space of two pixels or more is required.
MB86296S <Coral-PA>
97
Specification Manual Rev0.1