ui: Support non-zero minimum values for absolute input axes

This patch refactors ui/input.c to support absolute axis
minimum values other than 0. All dependent calls to qemu_input_queue_abs
have been updated to explicitly supply 0 as the axis minimum value.

Signed-off-by: Philippe Voinov <philippevoinov@gmail.com>
Message-id: 20170505133952.29885-1-philippevoinov@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

hw/input/virtio-input-hid.c

@@ -484,12 +484,14 @@ static struct virtio_input_config virtio_tablet_config[] = {
         .select    = VIRTIO_INPUT_CFG_ABS_INFO,
         .subsel    = ABS_X,
         .size      = sizeof(virtio_input_absinfo),
-        .u.abs.max = const_le32(INPUT_EVENT_ABS_SIZE - 1),
+        .u.abs.min = const_le32(INPUT_EVENT_ABS_MIN),
+        .u.abs.max = const_le32(INPUT_EVENT_ABS_MAX),
     },{
         .select    = VIRTIO_INPUT_CFG_ABS_INFO,
         .subsel    = ABS_Y,
         .size      = sizeof(virtio_input_absinfo),
-        .u.abs.max = const_le32(INPUT_EVENT_ABS_SIZE - 1),
+        .u.abs.min = const_le32(INPUT_EVENT_ABS_MIN),
+        .u.abs.max = const_le32(INPUT_EVENT_ABS_MAX),
     },
     { /* end of list */ },
 };

include/ui/input.h

@@ -8,7 +8,8 @@
 #define INPUT_EVENT_MASK_REL   (1<<INPUT_EVENT_KIND_REL)
 #define INPUT_EVENT_MASK_ABS   (1<<INPUT_EVENT_KIND_ABS)
 
-#define INPUT_EVENT_ABS_SIZE   0x8000
+#define INPUT_EVENT_ABS_MIN    0x0000
+#define INPUT_EVENT_ABS_MAX    0x7FFF
 
 typedef struct QemuInputHandler QemuInputHandler;
 typedef struct QemuInputHandlerState QemuInputHandlerState;
@@ -54,12 +55,14 @@ void qemu_input_update_buttons(QemuConsole *src, uint32_t *button_map,
                                uint32_t button_old, uint32_t button_new);
 
 bool qemu_input_is_absolute(void);
-int qemu_input_scale_axis(int value, int size_in, int size_out);
+int qemu_input_scale_axis(int value,
+                          int min_in, int max_in,
+                          int min_out, int max_out);
 InputEvent *qemu_input_event_new_move(InputEventKind kind,
                                       InputAxis axis, int value);
 void qemu_input_queue_rel(QemuConsole *src, InputAxis axis, int value);
-void qemu_input_queue_abs(QemuConsole *src, InputAxis axis,
-                          int value, int size);
+void qemu_input_queue_abs(QemuConsole *src, InputAxis axis, int value,
+                          int min_in, int max_in);
 
 void qemu_input_check_mode_change(void);
 void qemu_add_mouse_mode_change_notifier(Notifier *notify);

ui/cocoa.m

@@ -749,8 +749,8 @@ - (void) handleEvent:(NSEvent *)event
                  * clicks in the titlebar.
                  */
                 if ([self screenContainsPoint:p]) {
-                    qemu_input_queue_abs(dcl->con, INPUT_AXIS_X, p.x, screen.width);
-                    qemu_input_queue_abs(dcl->con, INPUT_AXIS_Y, screen.height - p.y, screen.height);
+                    qemu_input_queue_abs(dcl->con, INPUT_AXIS_X, p.x, 0, screen.width);
+                    qemu_input_queue_abs(dcl->con, INPUT_AXIS_Y, screen.height - p.y, 0, screen.height);
                 }
             } else {
                 qemu_input_queue_rel(dcl->con, INPUT_AXIS_X, (int)[event deltaX]);

ui/gtk.c

@@ -912,9 +912,9 @@ static gboolean gd_motion_event(GtkWidget *widget, GdkEventMotion *motion,
             return TRUE;
         }
         qemu_input_queue_abs(vc->gfx.dcl.con, INPUT_AXIS_X, x,
-                             surface_width(vc->gfx.ds));
+                             0, surface_width(vc->gfx.ds));
         qemu_input_queue_abs(vc->gfx.dcl.con, INPUT_AXIS_Y, y,
-                             surface_height(vc->gfx.ds));
+                             0, surface_height(vc->gfx.ds));
         qemu_input_event_sync();
     } else if (s->last_set && s->ptr_owner == vc) {
         qemu_input_queue_rel(vc->gfx.dcl.con, INPUT_AXIS_X, x - s->last_x);

ui/input.c

@@ -166,6 +166,11 @@ void qmp_input_send_event(bool has_device, const char *device,
     qemu_input_event_sync();
 }
 
+static int qemu_input_transform_invert_abs_value(int value)
+{
+  return (int64_t)INPUT_EVENT_ABS_MAX - value + INPUT_EVENT_ABS_MIN;
+}
+
 static void qemu_input_transform_abs_rotate(InputEvent *evt)
 {
     InputMoveEvent *move = evt->u.abs.data;
@@ -175,16 +180,16 @@ static void qemu_input_transform_abs_rotate(InputEvent *evt)
             move->axis = INPUT_AXIS_Y;
         } else if (move->axis == INPUT_AXIS_Y) {
             move->axis = INPUT_AXIS_X;
-            move->value = INPUT_EVENT_ABS_SIZE - 1 - move->value;
+            move->value = qemu_input_transform_invert_abs_value(move->value);
         }
         break;
     case 180:
-        move->value = INPUT_EVENT_ABS_SIZE - 1 - move->value;
+        move->value = qemu_input_transform_invert_abs_value(move->value);
         break;
     case 270:
         if (move->axis == INPUT_AXIS_X) {
             move->axis = INPUT_AXIS_Y;
-            move->value = INPUT_EVENT_ABS_SIZE - 1 - move->value;
+            move->value = qemu_input_transform_invert_abs_value(move->value);
         } else if (move->axis == INPUT_AXIS_Y) {
             move->axis = INPUT_AXIS_X;
         }
@@ -467,12 +472,17 @@ bool qemu_input_is_absolute(void)
     return (s != NULL) && (s->handler->mask & INPUT_EVENT_MASK_ABS);
 }
 
-int qemu_input_scale_axis(int value, int size_in, int size_out)
+int qemu_input_scale_axis(int value,
+                          int min_in, int max_in,
+                          int min_out, int max_out)
 {
-    if (size_in < 2) {
-        return size_out / 2;
+    int64_t range_in = (int64_t)max_in - min_in;
+    int64_t range_out = (int64_t)max_out - min_out;
+
+    if (range_in < 1) {
+        return min_out + range_out / 2;
     }
-    return (int64_t)value * (size_out - 1) / (size_in - 1);
+    return ((int64_t)value - min_in) * range_out / range_in + min_out;
 }
 
 InputEvent *qemu_input_event_new_move(InputEventKind kind,
@@ -496,10 +506,13 @@ void qemu_input_queue_rel(QemuConsole *src, InputAxis axis, int value)
     qapi_free_InputEvent(evt);
 }
 
-void qemu_input_queue_abs(QemuConsole *src, InputAxis axis, int value, int size)
+void qemu_input_queue_abs(QemuConsole *src, InputAxis axis, int value,
+                          int min_in, int max_in)
 {
     InputEvent *evt;
-    int scaled = qemu_input_scale_axis(value, size, INPUT_EVENT_ABS_SIZE);
+    int scaled = qemu_input_scale_axis(value, min_in, max_in,
+                                       INPUT_EVENT_ABS_MIN,
+                                       INPUT_EVENT_ABS_MAX);
     evt = qemu_input_event_new_move(INPUT_EVENT_KIND_ABS, axis, scaled);
     qemu_input_event_send(src, evt);
     qapi_free_InputEvent(evt);

ui/sdl.c

@@ -490,9 +490,9 @@ static void sdl_send_mouse_event(int dx, int dy, int x, int y, int state)
 
     if (qemu_input_is_absolute()) {
         qemu_input_queue_abs(dcl->con, INPUT_AXIS_X, x,
-                             real_screen->w);
+                             0, real_screen->w);
         qemu_input_queue_abs(dcl->con, INPUT_AXIS_Y, y,
-                             real_screen->h);
+                             0, real_screen->h);
     } else {
         if (guest_cursor) {
             x -= guest_x;

ui/sdl2.c

@@ -298,8 +298,8 @@ static void sdl_send_mouse_event(struct sdl2_console *scon, int dx, int dy,
                 }
             }
         }
-        qemu_input_queue_abs(scon->dcl.con, INPUT_AXIS_X, off_x + x, max_w);
-        qemu_input_queue_abs(scon->dcl.con, INPUT_AXIS_Y, off_y + y, max_h);
+        qemu_input_queue_abs(scon->dcl.con, INPUT_AXIS_X, off_x + x, 0, max_w);
+        qemu_input_queue_abs(scon->dcl.con, INPUT_AXIS_Y, off_y + y, 0, max_h);
     } else {
         if (guest_cursor) {
             x -= guest_x;

ui/spice-input.c

@@ -172,8 +172,8 @@ static void tablet_position(SpiceTabletInstance* sin, int x, int y,
     QemuSpicePointer *pointer = container_of(sin, QemuSpicePointer, tablet);
 
     spice_update_buttons(pointer, 0, buttons_state);
-    qemu_input_queue_abs(NULL, INPUT_AXIS_X, x, pointer->width);
-    qemu_input_queue_abs(NULL, INPUT_AXIS_Y, y, pointer->height);
+    qemu_input_queue_abs(NULL, INPUT_AXIS_X, x, 0, pointer->width);
+    qemu_input_queue_abs(NULL, INPUT_AXIS_Y, y, 0, pointer->height);
     qemu_input_event_sync();
 }
 

ui/vnc.c

@@ -1556,8 +1556,8 @@ static void pointer_event(VncState *vs, int button_mask, int x, int y)
     }
 
     if (vs->absolute) {
-        qemu_input_queue_abs(con, INPUT_AXIS_X, x, width);
-        qemu_input_queue_abs(con, INPUT_AXIS_Y, y, height);
+        qemu_input_queue_abs(con, INPUT_AXIS_X, x, 0, width);
+        qemu_input_queue_abs(con, INPUT_AXIS_Y, y, 0, height);
     } else if (vnc_has_feature(vs, VNC_FEATURE_POINTER_TYPE_CHANGE)) {
         qemu_input_queue_rel(con, INPUT_AXIS_X, x - 0x7FFF);
         qemu_input_queue_rel(con, INPUT_AXIS_Y, y - 0x7FFF);