On Fri, 25 Oct 2024, Lei Huang wrote:
Use a convergence factor to make the VM's input
global coordinates more closely approach the global
coordinates of DOM0.
Dom0 is some Xen terminology. Do you mean "host" which is more often used
in QEMU?
Change-Id: I2c3f12f1fe7dfb9306d1fc40c4fd4d299937f4c6
Signed-off-by: Lei Huang <lei.hu...@amd.com>
---
ui/sdl2.c | 32 ++++++++++++++++++++++++++++++--
1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/ui/sdl2.c b/ui/sdl2.c
index bd4f5a9da14..8f504dd8727 100644
--- a/ui/sdl2.c
+++ b/ui/sdl2.c
@@ -303,6 +303,34 @@ static void sdl_mouse_mode_change(Notifier *notify, void
*data)
}
}
+/*
+ *guest_x and guest_y represent the global coordinates on the VM side,
+ *while x and y represent the global coordinates on the dom0 side.
+ *The goal of this entire process is to align the global coordinates of
+ *the VM with those of dom0 using dx and dy. The current approach aims
+ *for precise calibration in once attempt; however, because guest_x
"in one attempt" also add a space after the * at the beginning of lines.
+ *and guest_y are non-zero values, they are not accurate values when
+ *they are counted out to become negative.Therefore, achieving perfect
+ *alignment in one attempt is impossible.Since the same calibration method
+ *is used each time, repeated attempts cannot achieve alignment either.
+ *By introducing a convergence factor, guest_x and guest_y can be made to
+ *approach dom0's x and y indefinitely.
+ *
+ * QEMU (dx,dy) VM
+ *calculates dx and dy using guest_x and guest_y ----> input driver
+ * ^ |
+ * | |
+ * | V
+ * | update
+ * | guest_x,guest_y input dispatcher ---> WindowManager
+ * | | |
+ * | | |
+ * | libdrm V |
+ * virtio-gpu <------ drmModeMoveCursor <------ compositor <------- |
+ * (guest_x,guest_y) calculates guest_x and
+ * guest_y dy using dx and dy
+ */
What about other display devices than virtio-gpu? Does this work with
those or do they need some update? If this is independent of graphics
device maybe add a note that virtio-gpu is an example and could be any
graphics device.
Regards,
BALATON Zoltan
+#define CONVERGENCE_FACTOR 3
static void sdl_send_mouse_event(struct sdl2_console *scon, int dx, int dy,
int x, int y, int state)
{
@@ -331,8 +359,8 @@ static void sdl_send_mouse_event(struct sdl2_console *scon,
int dx, int dy,
y -= guest_y;
guest_x += x;
guest_y += y;
- dx = x;
- dy = y;
+ dx = x / CONVERGENCE_FACTOR;
+ dy = y / CONVERGENCE_FACTOR;
}
qemu_input_queue_rel(scon->dcl.con, INPUT_AXIS_X, dx);
qemu_input_queue_rel(scon->dcl.con, INPUT_AXIS_Y, dy);
--
2.45.2
