27 files changed, 179 insertions, 549 deletions

diff --git a/src/controller/actions/pan.c b/src/controller/actions/pan.c
index cdc5cad..2f856b0 100644
--- a/src/controller/actions/pan.c
+++ b/src/controller/actions/pan.c
@@ -1,8 +1,61 @@
 #include "pan.h"
+#include "../../util/check_error.h"
+#include "../../view/state0.h"
+#include <GL/glut.h>
+
+#define S state0
 
 void
-pan ()
+pan (int x1, int y1, int x2, int y2)
 {
-
+  int dx = x1 - x2;
+  int dy = y1 - x2;
+  
+  if (dx == 0 && dy == 0)
+    return;
+  
+  /*
+   * Convert the selection boundary from window coordinates to
+   * world coordinates.
+   */
+  glMatrixMode (GL_MODELVIEW);
+  glLoadIdentity ();
+  GLdouble model[16];
+  glGetDoublev (GL_MODELVIEW_MATRIX, model);
+  GLdouble projection[16];
+  glGetDoublev (GL_PROJECTION_MATRIX, projection);
+  GLint viewport[4];
+  glGetIntegerv (GL_VIEWPORT, viewport);
+  
+  check_error (__FILE__, __LINE__);
+  
+  GLdouble start_position[3];
+  gluUnProject (x1,
+                y1,
+                0,
+                model,
+                projection,
+                viewport,
+                &start_position[0],
+                &start_position[1], &start_position[2]);
+  
+  check_error (__FILE__, __LINE__);
+  
+  GLdouble end_position[3];
+  gluUnProject (x2,
+                y2,
+                0,
+                model,
+                projection,
+                viewport,
+                &end_position[0], &end_position[1], &end_position[2]);
+  
+  check_error (__FILE__, __LINE__);
+  
+  S.pan.trans[0] += end_position[0] - start_position[0];
+  S.pan.trans[1] -= end_position[1] - start_position[1];
+  
+  glutPostRedisplay ();
+  
   return;
 }