Fixed divide by zero with a 1x1 sized window

libsdl-org · Oct 12, 2017 · 5bed4ca · 5bed4ca
1 parent bef0fec
commit 5bed4ca
Showing 1 changed file with 26 additions and 18 deletions.
diff --git a/src/video/x11/SDL_x11xinput2.c b/src/video/x11/SDL_x11xinput2.c
@@ -74,23 +74,34 @@ xinput2_version_atleast(const int version, const int wantmajor, const int wantmi
     return ( version >= ((wantmajor * 1000) + wantminor) );
 }
 
+#if SDL_VIDEO_DRIVER_X11_XINPUT2_SUPPORTS_MULTITOUCH
 static void
 xinput2_normalize_touch_coordinates(SDL_VideoData *videodata, Window window,
     double in_x, double in_y, float *out_x, float *out_y)
 {
-   int i;
-   for (i = 0; i < videodata->numwindows; i++) {
-      SDL_WindowData *d = videodata->windowlist[i];
-      if (d->xwindow == window) {
-         *out_x = in_x / (d->window->w-1);
-         *out_y = in_y / (d->window->h-1);
-         return;
-      }
-   }
-   // couldn't find the window...
-   *out_x = in_x;
-   *out_y = in_y;
+    int i;
+    for (i = 0; i < videodata->numwindows; i++) {
+        SDL_WindowData *d = videodata->windowlist[i];
+        if (d->xwindow == window) {
+            if (d->window->w == 1) {
+                *out_x = 0.5f;
+            } else {
+                *out_x = in_x / (d->window->w - 1);
+            }
+            if (d->window->h == 1) {
+                *out_y = 0.5f;
+            } else {
+                *out_y = in_y / (d->window->h - 1);
+            }
+            return;
+        }
+    }
+    // couldn't find the window...
+    *out_x = in_x;
+    *out_y = in_y;
 }
+#endif /* SDL_VIDEO_DRIVER_X11_XINPUT2_SUPPORTS_MULTITOUCH */
+
 #endif /* SDL_VIDEO_DRIVER_X11_XINPUT2 */
 
 void
@@ -192,8 +203,7 @@ X11_HandleXinput2Event(SDL_VideoData *videodata,XGenericEventCookie *cookie)
             float x, y;
             xinput2_normalize_touch_coordinates(videodata, xev->event,
                                   xev->event_x, xev->event_y, &x, &y);
-            SDL_SendTouch(xev->sourceid,xev->detail,
-                      SDL_TRUE, x, y, 1.0);
+            SDL_SendTouch(xev->sourceid,xev->detail, SDL_TRUE, x, y, 1.0);
             return 1;
             }
             break;
@@ -202,8 +212,7 @@ X11_HandleXinput2Event(SDL_VideoData *videodata,XGenericEventCookie *cookie)
             float x, y;
             xinput2_normalize_touch_coordinates(videodata, xev->event,
                                   xev->event_x, xev->event_y, &x, &y);
-            SDL_SendTouch(xev->sourceid,xev->detail,
-                      SDL_FALSE, x, y, 1.0);
+            SDL_SendTouch(xev->sourceid,xev->detail, SDL_FALSE, x, y, 1.0);
             return 1;
             }
             break;
@@ -212,8 +221,7 @@ X11_HandleXinput2Event(SDL_VideoData *videodata,XGenericEventCookie *cookie)
             float x, y;
             xinput2_normalize_touch_coordinates(videodata, xev->event,
                                   xev->event_x, xev->event_y, &x, &y);
-            SDL_SendTouchMotion(xev->sourceid,xev->detail,
-                                x, y, 1.0);
+            SDL_SendTouchMotion(xev->sourceid,xev->detail, x, y, 1.0);
             return 1;
             }
             break;