mi: switch miPointerSetPosition to take doubles

Don't switch between doubles and ints in the caller, instead take doubles in
miPointerSetPosition and do the conversion there. For full feature we should
change everything down from here for doubles too.

Functional change: previously we'd restore the remainder regardless of
screen switching/confinement (despite what the comment said). Now,
screen changing or cursor constraints will cause the remainder be clipped
off. This should happen for cursor constraints but arguably not for screen
crossing.

This also corrects a currently wrong comment about miPointerSetPosition's
input coordinates.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>

dix/getevents.c

@@ -805,8 +805,8 @@ static ScreenPtr
 positionSprite(DeviceIntPtr dev, int mode, ValuatorMask *mask,
                double *screenx, double *screeny)
 {
-    int isx, isy; /* screen {x, y}, in int */
     double x, y;
+    double tmpx, tmpy;
     ScreenPtr scr = miPointerGetScreen(dev);
 
     if (!dev->valuator || dev->valuator->numAxes < 2)
@@ -827,25 +827,22 @@ positionSprite(DeviceIntPtr dev, int mode, ValuatorMask *mask,
     *screeny = rescaleValuatorAxis(y, dev->valuator->axes + 1, NULL,
                                    scr->height);
 
+    tmpx = *screenx;
+    tmpy = *screeny;
     /* miPointerSetPosition takes care of crossing screens for us, as well as
-     * clipping to the current screen.  In the event we actually change screen,
-     * we just drop the float component on the floor, then convert from
-     * screenx back into device co-ordinates. */
-    isx = trunc(*screenx);
-    isy = trunc(*screeny);
-    scr = miPointerSetPosition(dev, mode, &isx, &isy);
-    if (isx != trunc(*screenx))
-    {
-        *screenx -= trunc(*screenx) - isx;
+     * clipping to the current screen. */
+    scr = miPointerSetPosition(dev, mode, screenx, screeny);
+
+    /* If we were constrained, rescale x/y from the screen coordinates so
+     * the device valuators reflect the correct position. For screen
+     * crossing this doesn't matter much, the coords would be 0 or max.
+     */
+    if (tmpx != *screenx)
         x = rescaleValuatorAxis(*screenx, NULL, dev->valuator->axes + 0,
                                 scr->width);
-    }
-    if (isy != trunc(*screeny))
-    {
-        *screeny -= trunc(*screeny) - isy;
+    if (tmpy != *screeny)
         y = rescaleValuatorAxis(*screeny, NULL, dev->valuator->axes + 1,
                                 scr->height);
-    }
 
     /* Update the MD's co-ordinates, which are always in screen space. */
     if (!IsMaster(dev) || !IsFloating(dev)) {

mi/mipointer.c

@@ -569,17 +569,16 @@ miPointerMoveNoEvent (DeviceIntPtr pDev, ScreenPtr pScreen,
  *
  * @param pDev The device to move
  * @param mode Movement mode (Absolute or Relative)
- * @param[in,out] x The x coordinate in screen coordinates (in regards to total
- * desktop size)
- * @param[in,out] y The y coordinate in screen coordinates (in regards to total
- * desktop size)
+ * @param[in,out] screenx The x coordinate in screen coordinates
+ * @param[in,out] screeny The y coordinate in screen coordinates
  */
 ScreenPtr
-miPointerSetPosition(DeviceIntPtr pDev, int mode, int *x, int *y)
+miPointerSetPosition(DeviceIntPtr pDev, int mode, double *screenx, double *screeny)
 {
     miPointerScreenPtr	pScreenPriv;
     ScreenPtr		pScreen;
     ScreenPtr		newScreen;
+    int			x, y;
 
     miPointerPtr        pPointer; 
 
@@ -591,13 +590,16 @@ miPointerSetPosition(DeviceIntPtr pDev, int mode, int *x, int *y)
     if (!pScreen)
 	return NULL;    /* called before ready */
 
-    if (*x < 0 || *x >= pScreen->width || *y < 0 || *y >= pScreen->height)
+    x = trunc(*screenx);
+    y = trunc(*screeny);
+
+    if (x < 0 || x >= pScreen->width || y < 0 || y >= pScreen->height)
     {
 	pScreenPriv = GetScreenPrivate (pScreen);
 	if (!pPointer->confined)
 	{
 	    newScreen = pScreen;
-	    (*pScreenPriv->screenFuncs->CursorOffScreen) (&newScreen, x, y);
+	    (*pScreenPriv->screenFuncs->CursorOffScreen) (&newScreen, &x, &y);
 	    if (newScreen != pScreen)
 	    {
 		pScreen = newScreen;
@@ -610,21 +612,30 @@ miPointerSetPosition(DeviceIntPtr pDev, int mode, int *x, int *y)
 	}
     }
     /* Constrain the sprite to the current limits. */
-    if (*x < pPointer->limits.x1)
-	*x = pPointer->limits.x1;
-    if (*x >= pPointer->limits.x2)
-	*x = pPointer->limits.x2 - 1;
-    if (*y < pPointer->limits.y1)
-	*y = pPointer->limits.y1;
-    if (*y >= pPointer->limits.y2)
-	*y = pPointer->limits.y2 - 1;
+    if (x < pPointer->limits.x1)
+	x = pPointer->limits.x1;
+    if (x >= pPointer->limits.x2)
+	x = pPointer->limits.x2 - 1;
+    if (y < pPointer->limits.y1)
+	y = pPointer->limits.y1;
+    if (y >= pPointer->limits.y2)
+	y = pPointer->limits.y2 - 1;
 
     if (pScreen->ConstrainCursorHarder)
-       pScreen->ConstrainCursorHarder(pDev, pScreen, mode, x, y);
+       pScreen->ConstrainCursorHarder(pDev, pScreen, mode, &x, &y);
 
-    if (pPointer->x != *x || pPointer->y != *y ||
+    if (pPointer->x != x || pPointer->y != y ||
             pPointer->pScreen != pScreen)
-        miPointerMoveNoEvent(pDev, pScreen, *x, *y);
+        miPointerMoveNoEvent(pDev, pScreen, x, y);
+
+    /* In the event we actually change screen or we get confined, we just
+     * drop the float component on the floor
+     * FIXME: only drop remainder for ConstrainCursorHarder, not for screen
+     * crossings */
+    if (x != trunc(*screenx))
+        *screenx = x;
+    if (y != trunc(*screeny))
+        *screeny = y;
 
     return pScreen;
 }

mi/mipointer.h

@@ -134,8 +134,8 @@ extern _X_EXPORT void miPointerGetPosition(
 extern _X_EXPORT ScreenPtr miPointerSetPosition(
     DeviceIntPtr pDev,
     int mode,
-    int *x,
-    int *y);
+    double *x,
+    double *y);
 
 extern _X_EXPORT void miPointerUpdateSprite(
     DeviceIntPtr pDev);