From http://www.jwz.org/xscreensaver/xscreensaver-5.22.tar.gz

[xscreensaver] / hacks / glx / gltrackball.c

diff --git a/hacks/glx/gltrackball.c b/hacks/glx/gltrackball.c
index c7ddc8b3364d89a0c462f62a52470cd41d21f08d..ee54cf91d2432f4a541774a742621d77286a54c4 100644 (file)
--- a/hacks/glx/gltrackball.c
+++ b/hacks/glx/gltrackball.c
@@ -1,4 +1,4 @@
-/* gltrackball, Copyright (c) 2002 Jamie Zawinski <jwz@jwz.org>
+/* gltrackball, Copyright (c) 2002-2012 Jamie Zawinski <jwz@jwz.org>
  * GL-flavored wrapper for trackball.c
  *
  * Permission to use, copy, modify, distribute, and sell this software and its
@@ -10,13 +10,27 @@
  * implied warranty.
  */
 
-#include "config.h"
-#include <stdlib.h>
 #include <math.h>
-#include <GL/gl.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#ifndef HAVE_COCOA
+# include <GL/gl.h>
+#endif
+
+#ifdef HAVE_JWZGLES
+# include "jwzgles.h"
+#endif /* HAVE_JWZGLES */
+
 #include "trackball.h"
 #include "gltrackball.h"
 
+extern double current_device_rotation (void);  /* Bah, it's in fps.h */
+
 struct trackball_state {
   int x, y;
   GLfloat q[4];
@@ -34,6 +48,16 @@ gltrackball_init (void)
   return ts;
 }
 
+/* Reset the trackball to the default unrotated state.
+ */
+void
+gltrackball_reset (trackball_state *ts)
+{
+  memset (ts, 0, sizeof(*ts));
+  trackball (ts->q, 0, 0, 0, 0);
+}
+
+
 /* Begin tracking the mouse: Call this when the mouse button goes down.
    x and y are the mouse position relative to the window.
    w and h are the size of the window.
@@ -73,3 +97,60 @@ gltrackball_rotate (trackball_state *ts)
   build_rotmatrix (m, ts->q);
   glMultMatrixf (&m[0][0]);
 }
+
+
+# define Button4 4  /* X11/Xlib.h */
+# define Button5 5
+# define Button6 6
+# define Button7 7
+
+/* Call this when a mouse-wheel click is detected.
+   Clicks act like horizontal or vertical drags.
+   Percent is the length of the drag as a percentage of the screen size.
+   Button is 'Button4' or 'Button5' (for the vertical wheel)
+   or 'Button5' or 'Button6' (for the horizontal wheel).
+   If `flip_p' is true, swap the horizontal and vertical axes.
+ */
+void
+gltrackball_mousewheel (trackball_state *ts,
+                        int button, int percent, int flip_p)
+{
+  int up_p;
+  int horizontal_p;
+  int mx, my, move, scale;
+
+#ifdef HAVE_COCOA
+  flip_p = 0;      /* MacOS has already handled this. */
+#endif
+
+  switch (button) {
+  case Button4: up_p = 1; horizontal_p = 0; break;
+  case Button5: up_p = 0; horizontal_p = 0; break;
+  case Button6: up_p = 1; horizontal_p = 1; break;
+  case Button7: up_p = 0; horizontal_p = 1; break;
+  default: abort(); break;
+  }
+
+  if (flip_p)
+    {
+      horizontal_p = !horizontal_p;
+      up_p = !up_p;
+    }
+
+  scale = mx = my = 1000;
+  move = (up_p
+          ? floor (scale * (1.0 - (percent / 100.0)))
+          : ceil  (scale * (1.0 + (percent / 100.0))));
+  if (horizontal_p) mx = move;
+  else              my = move;
+  gltrackball_start (ts, scale, scale, scale*2, scale*2);
+  gltrackball_track (ts, mx, my, scale*2, scale*2);
+}
+
+void
+gltrackball_get_quaternion (trackball_state *ts, float q[4])
+{
+  int i;
+  for (i=0; i<4; i++)
+    q[i] = ts->q[i];
+}