On Wed, Jun 05 2013, Christopher Harvey <charvey at matrox.com> wrote: > G200 cards support, at best, 16 colour palleted images for the cursor > so we do a conversion in the cursor_set function, and reject cursors > with more than 16 colours, or cursors with partial transparency. Xorg > falls back gracefully to software cursors in this case. > > We can't disable/enable the cursor hardware without causing momentary > corruption around the cursor. Instead, once the cursor is on we leave > it on, and simulate turning the cursor off by moving it > offscreen. This works well. > > Since we can't disable -> update -> enable the cursors, we double > buffer cursor icons, then just move the base address that points to > the old cursor, to the new. This also works well, but uses an extra > page of memory. > > The cursor buffers are lazily-allocated on first cursor_set. This is > to make sure they don't take priority over any framebuffers in case of > limited memory. > > Here is a representation of how the bitmap for the cursor is mapped in G200 > memory : > > Each line of color cursor use 6 Slices of 8 bytes. Slices 0 to 3 > are used for the 4bpp bitmap, slice 4 for XOR mask and slice 5 for > AND mask. Each line has the following format: > > // Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 > // > // S0: P00-01 P02-03 P04-05 P06-07 P08-09 P10-11 P12-13 P14-15 > // S1: P16-17 P18-19 P20-21 P22-23 P24-25 P26-27 P28-29 P30-31 > // S2: P32-33 P34-35 P36-37 P38-39 P40-41 P42-43 P44-45 P46-47 > // S3: P48-49 P50-51 P52-53 P54-55 P56-57 P58-59 P60-61 P62-63 > // S4: X63-56 X55-48 X47-40 X39-32 X31-24 X23-16 X15-08 X07-00 > // S5: A63-56 A55-48 A47-40 A39-32 A31-24 A23-16 A15-08 A07-00 > // > // S0 to S5 = Slices 0 to 5 > // P00 to P63 = Bitmap - pixels 0 to 63 > // X00 to X63 = always 0 - pixels 0 to 63 > // A00 to A63 = transparent markers - pixels 0 to 63 > // 1 means colour, 0 means transparent > > Signed-off-by: Christopher Harvey <charvey at matrox.com> > Signed-off-by: Mathieu Larouche <mathieu.larouche at matrox.com> > Acked-by: Julia Lemire <jlemire at matrox.com> > Tested-by: Julia Lemire <jlemire at matrox.com>
ping.
