xinput: Fix axis scaling arithmetic.

Cast difference to ULONGLONG to ensure unsigned division, and correct off-by-one error present when inverting axes (previously hidden by signed division bug). Fixes a regression introduced by bd9e130e. Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=46623Signed-off-by: Zebediah Figura <z.figura12@gmail.com> Signed-off-by: Aric Stewart <aric@codeweavers.com> Signed-off-by: Alexandre Julliard <julliard@winehq.org>

xinput: Fix axis scaling arithmetic.
7fd8ae1e · Zebediah Figura · Alexandre Julliard · c1c6ca2e · 7fd8ae1e
Commit 7fd8ae1e authored Feb 12, 2019 by Zebediah Figura Committed by Alexandre Julliard Feb 15, 2019
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Showing with 15 additions and 8 deletions

hid.c dlls/xinput1_3/hid.c +15 -8

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--- a/dlls/xinput1_3/hid.c
+++ b/dlls/xinput1_3/hid.c
@@ -318,8 +318,15 @@ void HID_destroy_gamepads(xinput_controller *devices)
    LeaveCriticalSection(&hid_xinput_crit);
 }

-#define SCALE_SHORT(v,r) (SHORT)((((0xffff)*(v - (r).min))/(r).range)-32767)
-#define SCALE_BYTE(v,r) (BYTE)((((0xff)*(v - (r).min))/(r).range))
+static SHORT scale_short(LONG value, const struct axis_info *axis)
+{
+    return ((((ULONGLONG)(value - axis->min)) * 0xffff) / axis->range) - 32768;
+}
+
+static BYTE scale_byte(LONG value, const struct axis_info *axis)
+{
+    return (((ULONGLONG)(value - axis->min)) * 0xff) / axis->range;
+}

 void HID_update_state(xinput_controller* device)
 {
@@ -382,22 +389,22 @@ void HID_update_state(xinput_controller* device)
    }

    HidP_GetScaledUsageValue(HidP_Input, HID_USAGE_PAGE_GENERIC, 0, HID_USAGE_GENERIC_X, &value, private->ppd, target_report, private->report_length);
-    device->state.Gamepad.sThumbLX = SCALE_SHORT(value, private->lx);
+    device->state.Gamepad.sThumbLX = scale_short(value, &private->lx);

    HidP_GetScaledUsageValue(HidP_Input, HID_USAGE_PAGE_GENERIC, 0, HID_USAGE_GENERIC_Y, &value, private->ppd, target_report, private->report_length);
-    device->state.Gamepad.sThumbLY = -SCALE_SHORT(value, private->ly);
+    device->state.Gamepad.sThumbLY = -scale_short(value, &private->ly) - 1;

    HidP_GetScaledUsageValue(HidP_Input, HID_USAGE_PAGE_GENERIC, 0, HID_USAGE_GENERIC_RX, &value, private->ppd, target_report, private->report_length);
-    device->state.Gamepad.sThumbRX = SCALE_SHORT(value, private->rx);
+    device->state.Gamepad.sThumbRX = scale_short(value, &private->rx);

    HidP_GetScaledUsageValue(HidP_Input, HID_USAGE_PAGE_GENERIC, 0, HID_USAGE_GENERIC_RY, &value, private->ppd, target_report, private->report_length);
-    device->state.Gamepad.sThumbRY = -SCALE_SHORT(value, private->ry);
+    device->state.Gamepad.sThumbRY = -scale_short(value, &private->ry) - 1;

    HidP_GetScaledUsageValue(HidP_Input, HID_USAGE_PAGE_GENERIC, 0, HID_USAGE_GENERIC_RZ, &value, private->ppd, target_report, private->report_length);
-    device->state.Gamepad.bRightTrigger = SCALE_BYTE(value, private->rtrigger);
+    device->state.Gamepad.bRightTrigger = scale_byte(value, &private->rtrigger);

    HidP_GetScaledUsageValue(HidP_Input, HID_USAGE_PAGE_GENERIC, 0, HID_USAGE_GENERIC_Z, &value, private->ppd, target_report, private->report_length);
-    device->state.Gamepad.bLeftTrigger = SCALE_BYTE(value, private->ltrigger);
+    device->state.Gamepad.bLeftTrigger = scale_byte(value, &private->ltrigger);
    LeaveCriticalSection(&private->crit);
 }