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dix: pre-scale x by the screen:device:resolution ratio

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commit 61a99aff9d
    dix: pre-scale relative events from abs devices to desktop ratio (#31636)

added pre-scaling of relative coordinates coming from absolute devices to
undo uneven scaling based on the screen dimensions.

Devices have their own device width/height ratio as well (in a specific
resolution) and this must be applied for relative devices as well to avoid
scaling of the relative events into the device's ratio.

e.g. a Wacom Intuos4 6x9 is in 16:10 format with equal horiz/vert
resolution (dpi). A movement by 1000/1000 coordinates is a perfect diagonal
on the tablet and must be reflected as such on the screen.

However, we map the relative device-coordinate events to absolute screen
coordinates based on the axis ranges. This results in an effective scaling
of 1000/(1000 * 1.6) and thus an uneven x/y axis movement - the y
axis is always faster.

So we need to pre-scale not only by the desktop dimenstions but also by the
device width/height ratio _and_ the resolution ratio.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
This commit is contained in:
Peter Hutterer 2013-03-09 20:43:51 +10:00
parent 7e97166c4f
commit 5cc2c96f82
1 changed files with 28 additions and 18 deletions
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46
dix/getevents.c
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@ -770,6 +770,29 @@ add_to_scroll_valuator(DeviceIntPtr dev, ValuatorMask *mask, int valuator, doubl
}
static void
scale_for_device_resolution(DeviceIntPtr dev, ValuatorMask *mask)
{
double x;
ValuatorClassPtr v = dev->valuator;
int xrange = v->axes[0].max_value - v->axes[0].min_value + 1;
int yrange = v->axes[1].max_value - v->axes[1].min_value + 1;
double screen_ratio = 1.0 * screenInfo.width/screenInfo.height;
double device_ratio = 1.0 * xrange/yrange;
double resolution_ratio = 1.0;
double ratio;
if (!valuator_mask_fetch_double(mask, 0, &x))
return;
if (v->axes[0].resolution != 0 && v->axes[1].resolution != 0)
resolution_ratio = 1.0 * v->axes[0].resolution/v->axes[1].resolution;
ratio = device_ratio/resolution_ratio/screen_ratio;
valuator_mask_set_double(mask, 0, x * ratio);
}
/**
* Move the device's pointer by the values given in @valuators.
*
@ -781,27 +804,14 @@ moveRelative(DeviceIntPtr dev, int flags, ValuatorMask *mask)
{
int i;
Bool clip_xy = IsMaster(dev) || !IsFloating(dev);
ValuatorClassPtr v = dev->valuator;
/* for abs devices in relative mode, we've just scaled wrong, since we
mapped the device's shape into the screen shape. Undo this. */
if ((flags & POINTER_ABSOLUTE) == 0 && dev->valuator &&
dev->valuator->axes[0].min_value < dev->valuator->axes[0].max_value) {
double ratio = 1.0 * screenInfo.width/screenInfo.height;
if (ratio > 1.0) {
double y;
if (valuator_mask_fetch_double(mask, 1, &y)) {
y *= ratio;
valuator_mask_set_double(mask, 1, y);
}
} else {
double x;
if (valuator_mask_fetch_double(mask, 0, &x)) {
x *= ratio;
valuator_mask_set_double(mask, 0, x);
}
}
if ((flags & POINTER_ABSOLUTE) == 0 && v && v->numAxes > 1 &&
v->axes[0].min_value < v->axes[0].max_value &&
v->axes[1].min_value < v->axes[1].max_value) {
scale_for_device_resolution(dev, mask);
}
/* calc other axes, clip, drop back into valuators */