diff --git a/ddio/lnxmouse.cpp b/ddio/lnxmouse.cpp
index 558d25196..644dffb6b 100644
--- a/ddio/lnxmouse.cpp
+++ b/ddio/lnxmouse.cpp
@@ -192,195 +192,127 @@ void ddio_MouseSetVCoords(int width, int height) { ddio_MouseSetLimits(0, 0, wid
 int sdlMouseButtonDownFilter(SDL_Event const *event) {
   ASSERT(event->type == SDL_MOUSEBUTTONDOWN);
 
-  const SDL_MouseButtonEvent *ev = &event->button;
-  t_mse_event mevt;
-
-  if (ev->button == 1) {
-    DDIO_mouse_state.btn_mask |= MOUSE_LB;
-    DIM_buttons.down_count[0]++;
-    DIM_buttons.time_down[0] = timer_GetTime();
-    DIM_buttons.is_down[0] = true;
-    mevt.btn = 0;
-    mevt.state = true;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 0: Down\n");
-  } else if (ev->button == 2) {
-    DDIO_mouse_state.btn_mask |= MOUSE_RB;
-    DIM_buttons.down_count[1]++;
-    DIM_buttons.time_down[1] = timer_GetTime();
-    DIM_buttons.is_down[1] = true;
-    mevt.btn = 1;
-    mevt.state = true;
-    MB_queue.send(mevt);
-    //     	mprintf(0, "MOUSE Button 1: Down\n");
-  }
-  else if (ev->button == 3) {
-    DDIO_mouse_state.btn_mask |= MOUSE_CB;
-    DIM_buttons.down_count[2]++;
-    DIM_buttons.time_down[2] = timer_GetTime();
-    DIM_buttons.is_down[2] = true;
-    mevt.btn = 2;
-    mevt.state = true;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 2: Down\n");
-  }
-
+  auto register_press = [](int button_bits, std::size_t button_index) {
+    DDIO_mouse_state.btn_mask |= button_bits;
+    DIM_buttons.down_count[button_index]++;
+    DIM_buttons.time_down[button_index] = timer_GetTime();
+    DIM_buttons.is_down[button_index] = true;
+    {
+      t_mse_event mevt;
+      mevt.btn = button_index;
+      mevt.state = true;
+      MB_queue.send(mevt);
+    }
+  };
+
+  switch (event->button.button) {
+  case 1:
+    register_press(MOUSE_LB, 0);
+    break;
+  case 2:
+    register_press(MOUSE_RB, 1);
+    break;
+  case 3:
+    register_press(MOUSE_CB, 2);
+    break;
   // buttons 4 and 5 are reserved for the mouse wheel...that's how the engine works...adjust in here.
-
-  else if (ev->button == 4) {
-    DDIO_mouse_state.btn_mask |= MOUSE_B6;
-    DIM_buttons.down_count[5]++;
-    DIM_buttons.time_down[5] = timer_GetTime();
-    DIM_buttons.is_down[5] = true;
-    mevt.btn = 5;
-    mevt.state = true;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 5: Down\n");
-  }
-  else if (ev->button == 5) {
-    DDIO_mouse_state.btn_mask |= MOUSE_B7;
-    DIM_buttons.down_count[6]++;
-    DIM_buttons.time_down[6] = timer_GetTime();
-    DIM_buttons.is_down[6] = true;
-    mevt.btn = 6;
-    mevt.state = true;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 6: Down\n");
-  }
-  else if (ev->button == 6) {
-    DDIO_mouse_state.btn_mask |= MOUSE_B8;
-    DIM_buttons.down_count[7]++;
-    DIM_buttons.time_down[7] = timer_GetTime();
-    DIM_buttons.is_down[7] = true;
-    mevt.btn = 7;
-    mevt.state = true;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 7: Down\n");
+  case 4:
+    register_press(MOUSE_B6, 5);
+    break;
+  case 5:
+    register_press(MOUSE_B7, 6);
+    break;
+  case 6:
+    register_press(MOUSE_B8, 7);
+    break;
+  default:
+    break;
   }
 
-  return (0);
+  return 0;
 }
 
 int sdlMouseButtonUpFilter(SDL_Event const *event) {
   ASSERT(event->type == SDL_MOUSEBUTTONUP);
 
-  const SDL_MouseButtonEvent *ev = &event->button;
-  t_mse_event mevt;
-
-  if (ev->button == 1) {
-    DDIO_mouse_state.btn_mask &= (~MOUSE_LB);
-    DIM_buttons.up_count[0]++;
-    DIM_buttons.is_down[0] = false;
-    DIM_buttons.time_up[0] = timer_GetTime();
-    mevt.btn = 0;
-    mevt.state = false;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 0: Up\n");
-  }
-  else if (ev->button == 2) {
-    DDIO_mouse_state.btn_mask &= (~MOUSE_RB);
-    DIM_buttons.up_count[1]++;
-    DIM_buttons.is_down[1] = false;
-    DIM_buttons.time_up[1] = timer_GetTime();
-    mevt.btn = 1;
-    mevt.state = false;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 1: Up\n");
-  }
-  else if (ev->button == 3) {
-    DDIO_mouse_state.btn_mask &= (~MOUSE_CB);
-    DIM_buttons.up_count[2]++;
-    DIM_buttons.is_down[2] = false;
-    DIM_buttons.time_up[2] = timer_GetTime();
-    mevt.btn = 2;
-    mevt.state = false;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 2: Up\n");
-
-  }
-
+  auto register_release = [](int button_bits, std::size_t button_index) {
+    DDIO_mouse_state.btn_mask &= (~button_bits);
+    DIM_buttons.up_count[button_index]++;
+    DIM_buttons.is_down[button_index] = false;
+    DIM_buttons.time_up[button_index] = timer_GetTime();
+    {
+      t_mse_event mevt;
+      mevt.btn = button_index;
+      mevt.state = false;
+      MB_queue.send(mevt);
+    }
+  };
+
+  switch (event->button.button) {
+  case 1:
+    register_release(MOUSE_LB, 0);
+    break;
+  case 2:
+    register_release(MOUSE_RB, 1);
+    break;
+  case 3:
+    register_release(MOUSE_CB, 2);
+    break;
   // buttons 4 and 5 are reserved for the mouse wheel...that's how the engine works...adjust in here.
-
-  else if (ev->button == 4) {
-    DDIO_mouse_state.btn_mask &= (~MOUSE_B6);
-    DIM_buttons.up_count[5]++;
-    DIM_buttons.is_down[5] = false;
-    DIM_buttons.time_up[5] = timer_GetTime();
-    mevt.btn = 5;
-    mevt.state = false;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 5: Up\n");
-  }
-  else if (ev->button == 5) {
-    DDIO_mouse_state.btn_mask &= (~MOUSE_B7);
-    DIM_buttons.up_count[6]++;
-    DIM_buttons.is_down[6] = false;
-    DIM_buttons.time_up[6] = timer_GetTime();
-    mevt.btn = 6;
-    mevt.state = false;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 6: Up\n");
-  }
-  else if (ev->button == 6) {
-    DDIO_mouse_state.btn_mask &= (~MOUSE_B8);
-    DIM_buttons.up_count[7]++;
-    DIM_buttons.is_down[7] = false;
-    DIM_buttons.time_up[7] = timer_GetTime();
-    mevt.btn = 7;
-    mevt.state = false;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Button 7: Up\n");
+  case 4:
+    register_release(MOUSE_B6, 5);
+    break;
+  case 5:
+    register_release(MOUSE_B7, 6);
+    break;
+  case 6:
+    register_release(MOUSE_B8, 7);
+    break;
+  default:
+    break;
   }
 
-  return (0);
+  return 0;
 }
 
 int sdlMouseWheelFilter(SDL_Event const *event) {
   ASSERT(event->type == SDL_MOUSEWHEEL);
 
-  const SDL_MouseWheelEvent *ev = &event->wheel;
-  t_mse_event mevt;
-
   // !!! FIXME: this ignores horizontal wheels for now, since Descent3 doesn't currently have a concept of them
   // !!! FIXME: (vertical mouse wheels are represented as mouse buttons 4 and 5, incorrectly, on all platforms).
   // !!! FIXME: this will require improvements to the engine before this changes here, though.
 
-  if (ev->y > 0) { /* Mouse scroll up */
-    DDIO_mouse_state.btn_mask |= MOUSE_B5;
-    DIM_buttons.down_count[4]++;
-    DIM_buttons.time_down[4] = timer_GetTime();
-    DIM_buttons.is_down[4] = true;
-    mevt.btn = 4;
-    mevt.state = true;
-    MB_queue.send(mevt);
-
-    // send an immediate release event, as if the "button" was clicked. !!! FIXME: this also needs improvements in the engine.
-    // don't remove from btn_mask
-    DIM_buttons.up_count[4]++;
-    DIM_buttons.is_down[4] = false;
-    DIM_buttons.time_up[4] = timer_GetTime();
-    mevt.btn = 4;
-    mevt.state = false;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Scrollwheel: Rolled Up\n");
-  } else if (ev->y < 0) { /* Mouse scroll down */
-    DDIO_mouse_state.btn_mask |= MOUSE_B6;
-    DIM_buttons.down_count[5]++;
-    DIM_buttons.time_down[5] = timer_GetTime();
-    DIM_buttons.is_down[5] = true;
-    mevt.btn = 5;
-    mevt.state = true;
-    MB_queue.send(mevt);
+  auto register_clicked = [](int button_bits, std::size_t button_index) {
+    DDIO_mouse_state.btn_mask |= button_bits;
+    DIM_buttons.down_count[button_index]++;
+    DIM_buttons.time_down[button_index] = timer_GetTime();
+    DIM_buttons.is_down[button_index] = true;
+    {
+      t_mse_event mevt;
+      mevt.btn = button_index;
+      mevt.state = true;
+      MB_queue.send(mevt);
+    }
 
     // send an immediate release event, as if the "button" was clicked. !!! FIXME: this also needs improvements in the engine.
     // don't remove from btn_mask
-    DIM_buttons.up_count[5]++;
-    DIM_buttons.is_down[5] = false;
-    DIM_buttons.time_up[5] = timer_GetTime();
-    mevt.btn = 5;
-    mevt.state = false;
-    MB_queue.send(mevt);
-    //		mprintf(0, "MOUSE Scrollwheel: Rolled Down\n");
+    DIM_buttons.up_count[button_index]++;
+    DIM_buttons.is_down[button_index] = false;
+    DIM_buttons.time_up[button_index] = timer_GetTime();
+    {
+      t_mse_event mevt;
+      mevt.btn = button_index;
+      mevt.state = false;
+      MB_queue.send(mevt);
+    }
+  };
+
+  if (event->wheel.y > 0) {
+    // Mouse scroll up
+    register_clicked(MOUSE_B5, 4);
+  } else if (event->wheel.y < 0) {
+    // Mouse scroll down
+    register_clicked(MOUSE_B6, 5);
   }
 
   return 0;