On 02 Feb 2005 21:57:39 +0100, Peter Osterlund <[EMAIL PROTECTED]> wrote:
> Please try this patch instead. It works well with my alps touchpad. (I
> don't have a synaptics touchpad.) It does the following:
>
> * Compensates for the lack of floating point arithmetic by keeping
> track of remainders from the integer divisions.
> * Removes the xres/yres scaling so that you get the same speed in the
> X and Y directions even if your screen is not square.
> * Sets scale factors so that the speed for synaptics and alps should
> be equal to each other and equal to the synaptics speed from 2.6.10.
Thanks a lot, Peter. I think I like the result even better than the one
after the simple-minded removal that I posted. It's possible that when
I accepted the case of (pktcount == 1) it hurt smoothness.
Do you think it makes sense to zero fractions when pktcount is dropped?
Also, I think the extra unary minus is uncoth.
-- Pete
--- linux-2.6.11-rc2/drivers/input/mousedev.c 2005-01-22 14:54:14.000000000
-0800
+++ linux-2.6.11-rc2-lem/drivers/input/mousedev.c 2005-02-02
14:03:07.000000000 -0800
@@ -71,6 +71,7 @@
struct mousedev_hw_data packet;
unsigned int pkt_count;
int old_x[4], old_y[4];
+ int frac_dx, frac_dy;
unsigned long touch;
};
@@ -117,24 +118,31 @@
static void mousedev_touchpad_event(struct input_dev *dev, struct mousedev
*mousedev, unsigned int code, int value)
{
- int size;
+ int size, tmp;
+ enum { FRACTION_DENOM = 100 };
if (mousedev->touch) {
+ size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
+ if (size == 0) size = xres;
switch (code) {
case ABS_X:
- size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
- if (size == 0) size = xres;
fx(0) = value;
- if (mousedev->pkt_count >= 2)
- mousedev->packet.dx = ((fx(0) - fx(1))
/ 2 + (fx(1) - fx(2)) / 2) * xres / (size * 2);
+ if (mousedev->pkt_count >= 2) {
+ tmp = ((value - fx(2)) * (250 *
FRACTION_DENOM)) / size;
+ tmp += mousedev->frac_dx;
+ mousedev->packet.dx = tmp /
FRACTION_DENOM;
+ mousedev->frac_dx = tmp -
mousedev->packet.dx * FRACTION_DENOM;
+ }
break;
case ABS_Y:
- size = dev->absmax[ABS_Y] - dev->absmin[ABS_Y];
- if (size == 0) size = yres;
fy(0) = value;
- if (mousedev->pkt_count >= 2)
- mousedev->packet.dy = -((fy(0) - fy(1))
/ 2 + (fy(1) - fy(2)) / 2) * yres / (size * 2);
+ if (mousedev->pkt_count >= 2) {
+ tmp = ((fy(2) - value) * (250 *
FRACTION_DENOM)) / size;
+ tmp += mousedev->frac_dy;
+ mousedev->packet.dy = tmp /
FRACTION_DENOM;
+ mousedev->frac_dy = tmp -
mousedev->packet.dy * FRACTION_DENOM;
+ }
break;
}
}
@@ -268,6 +276,8 @@
clear_bit(0, &mousedev_mix.packet.buttons);
}
mousedev->touch = mousedev->pkt_count = 0;
+ mousedev->frac_dx = 0;
+ mousedev->frac_dy = 0;
}
else
if (!mousedev->touch)
-
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