Fix #183 and address the change suggested by #184.

Minor bugfix, properly determine when switching screens is needed.

src/include/main.h

@@ -200,6 +200,7 @@ enum os_type_e {
 };
 
 enum screen_pos_e {
+    NONE   = 0,
     LEFT   = 1,
     RIGHT  = 2,
     MIDDLE = 3,

src/mouse.c

@@ -20,6 +20,17 @@
 #define MACOS_SWITCH_MOVE_X 10
 #define MACOS_SWITCH_MOVE_COUNT 5
 
+/* Check if our upcoming mouse movement would result in having to switch outputs */
+enum screen_pos_e is_screen_switch_needed(int position, int offset) {
+    if (position + offset < MIN_SCREEN_COORD - global_state.config.jump_treshold)
+        return LEFT;
+
+    if (position + offset > MAX_SCREEN_COORD + global_state.config.jump_treshold)
+        return RIGHT;
+
+    return NONE;
+}
+
 /* Move mouse coordinate 'position' by 'offset', but don't fall off the screen */
 int32_t move_and_keep_on_screen(int position, int offset) {
     /* Lowest we can go is 0 */
@@ -63,7 +74,8 @@ int32_t accelerate(int32_t offset) {
     return offset * acceleration[6].factor;
 }
 
-void update_mouse_position(device_t *state, mouse_values_t *values) {
+/* Returns LEFT if need to jump left, RIGHT if right, NONE otherwise */
+enum screen_pos_e update_mouse_position(device_t *state, mouse_values_t *values) {
     output_t *current    = &state->config.output[state->active_output];
     uint8_t reduce_speed = 0;
 
@@ -75,12 +87,17 @@ void update_mouse_position(device_t *state, mouse_values_t *values) {
     int offset_x = accelerate(values->move_x) * (current->speed_x >> reduce_speed);
     int offset_y = accelerate(values->move_y) * (current->speed_y >> reduce_speed);
 
+    /* Determine if our upcoming movement would stay within the screen */
+    enum screen_pos_e switch_direction = is_screen_switch_needed(state->pointer_x, offset_x);
+
     /* Update movement */
     state->pointer_x = move_and_keep_on_screen(state->pointer_x, offset_x);
     state->pointer_y = move_and_keep_on_screen(state->pointer_y, offset_y);
 
     /* Update buttons state */
     state->mouse_buttons = values->buttons;
+
+    return switch_direction;
 }
 
 /* If we are active output, queue packet to mouse queue, else send them through UART */
@@ -182,23 +199,13 @@ void switch_virtual_desktop(device_t *state, output_t *output, int new_index, in
        '---------'    '---------'  |  '---------'    '---------'    '---------'
           )___(          )___(     |     )___(          )___(          )___(
 */
-void check_screen_switch(const mouse_values_t *values, device_t *state) {
-    int new_x        = state->pointer_x + values->move_x;
+void do_screen_switch(device_t *state, int direction) {
     output_t *output = &state->config.output[state->active_output];
 
-    bool jump_left  = new_x < MIN_SCREEN_COORD - state->config.jump_treshold;
-    bool jump_right = new_x > MAX_SCREEN_COORD + state->config.jump_treshold;
-
-    int direction = jump_left ? LEFT : RIGHT;
-
     /* No switching allowed if explicitly disabled or in gaming mode */
     if (state->switch_lock || state->gaming_mode)
         return;
 
-    /* No jump condition met == nothing to do, return */
-    if (!jump_left && !jump_right)
-        return;
-
     /* We want to jump in the direction of the other computer */
     if (output->pos != direction) {
         if (output->screen_index == 1) { /* We are at the border -> switch outputs */
@@ -270,16 +277,17 @@ void process_mouse_report(uint8_t *raw_report, int len, uint8_t itf, hid_interfa
     extract_report_values(raw_report, state, &values, iface);
 
     /* Calculate and update mouse pointer movement. */
-    update_mouse_position(state, &values);
+    enum screen_pos_e switch_direction = update_mouse_position(state, &values);
 
     /* Create the report for the output PC based on the updated values */
     mouse_report_t report = create_mouse_report(state, &values);
 
     /* Move the mouse, depending where the output is supposed to go */
     output_mouse_report(&report, state);
 
-    /* We use the mouse to switch outputs, the logic is in check_screen_switch() */
-    check_screen_switch(&values, state);
+    /* We use the mouse to switch outputs, if switch_direction is LEFT or RIGHT */
+    if (switch_direction != NONE)
+        do_screen_switch(state, switch_direction);
 }
 
 /* ==================================================== *