To: sdl@libsdl.org From: Christian Walther <cwalther@gmx.ch> Date: Fri, 18 Nov 2005 23:39:02 +0100 Subject: [SDL] Mouse position bugs on Mac OS X The attached patch fixes a few bugs in SDL related to the mouse position in windowed mode on Mac OS X, reproduced using the attached minimal test program - at least here on 10.3.9, with SDL CVS from today. Could anyone test whether the bugs exist and are fixed by the patch on 10.2 and 10.4? 1. When using OpenGL, the vertical mouse positions obtained through events or SDL_GetMouseState() are off by one. 2. When using OpenGL, SDL_WarpMouse() inverts the y coordinate. 3. Clicks on the topmost pixel row of the window are not recognized. 1 and 2 do not occur in non-OpenGL mode, while 3 does. All three only occur in windowed mode, not in fullscreen. The cause for 1 and 3 is that in Cocoa, "the location of the mouse" seems to be defined as "the location of the top left corner of the mouse pointer's hot pixel" (this is not documented, it's just what I found out here), which together with the fact that Cocoa's usual y coordinates start at the bottom and increase upwards means that the y coordinate of the mouse runs from 1 to h, not from 0 to h-1, in a window of height h. If it does work on 10.2 and 10.4 (I'll try to test it as soon as I can, but at the moment all I have at hand is 10.3.9), can this be applied to the CVS? -Christian To: sdl@libsdl.org From: Christian Walther <cwalther@gmx.ch> Date: Mon, 28 Nov 2005 10:41:51 +0100 Subject: [SDL] Re: Mouse position bugs on Mac OS X I wrote: > I'll try to test it as soon as I can, but at the moment all I have at hand is 10.3.9 So, here are the results of my tests (with patched and unpatched frameworks compiled with Xcode 1.5 (gcc 3.3) on 10.3.9): On 10.1.5, my test program doesn't run because of "Undefined symbols: SDL undefined reference to _CGMainDisplayID expected to be defined in Carbon". I guess not supporting 10.1 was a deliberate decision then and that's OK with me. On 10.2.8, 10.3.9, and 10.4.0, the bugs exist as described in my original post and are fixed by my patch. That is, there is no difference between pre/post 10.3 and the patched version works correctly in all combinations of GL/non-GL and windowed/fullscreen. I therefore recommend the patch for inclusion. -Christian

--- a/src/video/quartz/SDL_QuartzWM.m	Wed Nov 23 11:46:36 2005 +0000
+++ b/src/video/quartz/SDL_QuartzWM.m	Mon Nov 28 13:58:26 2005 +0000
@@ -85,7 +85,12 @@
 }
 
 BOOL QZ_IsMouseInWindow (_THIS) {
-    return (mode_flags & SDL_FULLSCREEN) ? true : NSPointInRect([ qz_window mouseLocationOutsideOfEventStream ], [ window_view frame ]);
+    if (mode_flags & SDL_FULLSCREEN) return YES;
+    else {
+        NSPoint p = [ qz_window mouseLocationOutsideOfEventStream ];
+        p.y -= 1.0f; /* Apparently y goes from 1 to h, not from 0 to h-1 (i.e. the "location of the mouse" seems to be defined as "the location of the top left corner of the mouse pointer's hot pixel" */
+        return NSPointInRect(p, [ window_view frame ]);
+    }
 }
 
 int QZ_ShowWMCursor (_THIS, WMcursor *cursor) { 
@@ -140,6 +145,11 @@
     else {
        
         *p = [ window_view convertPoint:*p toView: nil ];
+        
+        /* We need a workaround in OpenGL mode */
+        if ( SDL_VideoSurface->flags & SDL_OPENGL ) {
+            p->y = [window_view frame].size.height - p->y;
+        }
     }
 }
 
@@ -156,7 +166,7 @@
         
         /* We need a workaround in OpenGL mode */
         if ( SDL_VideoSurface->flags & SDL_OPENGL ) {
-            p->y = [window_view frame].size.height - p->y - 1;
+            p->y = [window_view frame].size.height - p->y;
         }
     }
 }