sdl2: fix mouse x,y on retina screens

Previously, retina resolution was added to lem for rendering its fonts.
This accidentally skipped over doing the same scaling calculation for
the mouse coordinates so we fix that here.

frontends/sdl2/main.lisp

@@ -648,12 +648,12 @@
                 ((eql button sdl2-ffi:+sdl-button-middle+) :button-2)
                 ((eql button 4) :button-4))))
     (when button
-      (let ((pixel-x x)
-            (pixel-y y)
-            (char-x (floor x (char-width)))
-            (char-y (floor y (char-height))))
-        (lem:send-event (lambda ()
-                          (lem:receive-mouse-button-down char-x char-y pixel-x pixel-y button clicks)))))))
+      (let ((char-x (scaled-char-width *display* x))
+            (char-y (scaled-char-height *display* y)))
+        (lem:send-event
+          (lambda ()
+            (lem:receive-mouse-button-down char-x char-y x y button
+                                           clicks)))))))
 
 (defun on-mouse-button-up (button x y)
   (show-cursor)
@@ -662,37 +662,34 @@
                 ((eql button sdl2-ffi:+sdl-button-right+) :button-3)
                 ((eql button sdl2-ffi:+sdl-button-middle+) :button-2)
                 ((eql button 4) :button-4)))
-        (pixel-x x)
-        (pixel-y y)
-        (char-x (floor x (char-width)))
-        (char-y (floor y (char-height))))
-    (lem:send-event (lambda ()
-                      (lem:receive-mouse-button-up char-x char-y pixel-x pixel-y button)))))
+        (char-x (scaled-char-width *display* x))
+        (char-y (scaled-char-height *display* y)))
+    (lem:send-event
+     (lambda ()
+       (lem:receive-mouse-button-up char-x char-y x y button)))))
 
 (defun on-mouse-motion (x y state)
   (show-cursor)
   (let ((button (if (= sdl2-ffi:+sdl-button-lmask+ (logand state sdl2-ffi:+sdl-button-lmask+))
                     :button-1
                     nil)))
-    (let ((pixel-x x)
-          (pixel-y y)
-          (char-x (floor x (char-width)))
-          (char-y (floor y (char-height))))
-      (lem:send-event (lambda ()
-                        (lem:receive-mouse-motion char-x char-y pixel-x pixel-y button))))))
+    (let ((char-x (scaled-char-width *display* x))
+          (char-y (scaled-char-height *display* y)))
+      (lem:send-event
+       (lambda ()
+         (lem:receive-mouse-motion char-x char-y x y button))))))
 
 (defun on-mouse-wheel (wheel-x wheel-y which direction)
   (declare (ignore which direction))
   (show-cursor)
   (multiple-value-bind (x y) (sdl2:mouse-state)
-    (let ((pixel-x x)
-          (pixel-y y)
-          (char-x (floor x (char-width)))
-          (char-y (floor y (char-height))))
-      (lem:send-event (lambda ()
-                        (lem:receive-mouse-wheel char-x char-y pixel-x pixel-y wheel-x wheel-y)
-                        (when (= 0 (lem:event-queue-length))
-                          (lem:redraw-display)))))))
+    (let ((char-x (scaled-char-width *display* x))
+          (char-y (scaled-char-height *display* y)))
+      (lem:send-event
+       (lambda ()
+         (lem:receive-mouse-wheel char-x char-y x y wheel-x wheel-y)
+         (when (= 0 (lem:event-queue-length))
+           (lem:redraw-display)))))))
 
 (defun on-textediting (text)
   (handle-textediting (get-platform) text)
@@ -1021,8 +1018,8 @@
       (multiple-value-bind (x y bitmask)
           (sdl2:mouse-state)
         (declare (ignore bitmask))
-        (values (floor x (display-char-width *display*))
-                (floor y (display-char-height *display*))))))
+        (values (scaled-char-width *display* x)
+                (scaled-char-height *display* y)))))
 
 (defmethod lem-if:get-char-width ((implementation sdl2))
   (char-width))