From f4abe0abb00210e9ef6b3277060634ba3db4f6d5 Mon Sep 17 00:00:00 2001
From: Don Pellegrino <don@drexel.edu>
Date: Sat, 13 Jun 2009 21:51:03 +0000
Subject: Added selection by bounding box with mouse.

---
diff --git a/src/controller/exp004mouse.c b/src/controller/exp004mouse.c
index 11117bf..8e8f986 100644
--- a/src/controller/exp004mouse.c
+++ b/src/controller/exp004mouse.c
@@ -3,87 +3,118 @@
 #include "../view/exp004geometry.h"
 #include "../view/exp004state0.h"
 #include "../util/check_error.h"
+#include "../util/pick_convert.h"
 #include <GL/glut.h>
 #include <stdio.h>
 
-#define SIZE 500
-#define N 3
+/*
+ * A simple alias to make the code more readable.
+ */
+#define S exp004state0
 
 void
 exp004mouse (int button, int state, int x, int y)
 {
-
-  if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
+  if (button == GLUT_LEFT_BUTTON && state == GLUT_UP)
     {
-
-      /*
-       * "Specify the array to be used for the returned hit records
-       * with glSelectBuffer () [Redbook]."
-       */
-      GLuint select_buf[SIZE];
-      glSelectBuffer (SIZE, select_buf);
-
       /*
-       * "Enter selection mode by specifying GL_SELECT with
-       * glRenderMode () [Redbook]."
+       * Complete a selection if one was started and not cancelled.
        */
-      glRenderMode (GL_SELECT);
+      if (S.selecting == true)
+	{
+	  
+	  /*
+	   * "Specify the array to be used for the returned hit records
+	   * with glSelectBuffer () [Redbook]."
+	   */
+	  GLuint select_buf[ROWS];
+	  glSelectBuffer (ROWS, select_buf);
+	  
+	  /*
+	   * "Enter selection mode by specifying GL_SELECT with
+	   * glRenderMode () [Redbook]."
+	   */
+	  glRenderMode (GL_SELECT);
+	  
+	  /*
+	   * "Initialize the name stack using glInitNames () and glPush
+	   * Names () [Redbook]."
+	   */
+	  glInitNames ();
+	  glPushName (0);
+	  
+	  /*
+	   * "Define the viewing volume you want to use for selection.
+	   * Usually this is different from the viewing volume you
+	   * originally used to draw the scene, so you probably want to
+	   * save and then restore the current transformation state with
+	   * glPushMatrix () and glPopMatrix () [Redbook]."
+	   */
+	  glMatrixMode (GL_PROJECTION);
+	  glPushMatrix ();
+	  glLoadIdentity ();
+	  
+	  GLint viewport[4];
+	  glGetIntegerv (GL_VIEWPORT, viewport);
+	  
+	  /*
+	  gluPickMatrix ((GLdouble) x,
+			 (GLdouble) (viewport[3] - y),
+			 N,
+			 N,
+			 viewport);
+	  */
 
-      /*
-       * "Initialize the name stack using glInitNames () and glPush
-       * Names () [Redbook]."
-       */
-      glInitNames ();
-      glPushName (0);
-
-      /*
-       * "Define the viewing volume you want to use for selection.
-       * Usually this is different from the viewing volume you
-       * originally used to draw the scene, so you probably want to
-       * save and then restore the current transformation state with
-       * glPushMatrix () and glPopMatrix () [Redbook]."
-       */
-      glMatrixMode (GL_PROJECTION);
-      glPushMatrix ();
-      glLoadIdentity ();
+	  double c_x = 0.0;
+	  double c_y = 0.0;
+	  double w = 0.0;
+	  double h = 0.0;
+	  pick_convert (S.select_x, S.select_y, x, y,
+			&c_x, &c_y, &w, &h);
 
-      GLint viewport[4];
-      glGetIntegerv (GL_VIEWPORT, viewport);
+	  gluPickMatrix (c_x,
+			 (GLdouble)viewport[3] - c_y,
+			 w,
+			 h,
+			 viewport);	  
+	  
+	  gluOrtho2D(S.ortho.min_x,
+		     S.ortho.max_x,
+		     S.ortho.min_y,
+		     S.ortho.max_y);      
+	  
+	  /*
+	   * "Alternately issue primitive drawing commands and commands to
+	   * manipulate the name stack so that each primitive of interest
+	   * has appropriate names assigned [Redbook]."
+	   */
+	  exp004geometry (GL_SELECT);
+	  
+	  glMatrixMode (GL_PROJECTION);      
+	  glPopMatrix ();
+	  glutSwapBuffers ();
+	  
+	  /*
+	   * "Exit selection mode and process the returned selection data
+	   * (the hit records) [Redbook]."
+	   */
+	  GLint hits = glRenderMode (GL_RENDER);
+	  check_error (__FILE__, __LINE__);
+	  
+	  /* "process hits from selection mode rendering [Angel,2008]." */
+	  exp004processhits (hits, select_buf);
+	  
+	  /* "normal render [Angel,2008]." */      
+	  glutPostRedisplay ();	 
+	}
 
-      gluPickMatrix ((GLdouble) x,
-		     (GLdouble) (viewport[3] - y),
-		     N,
-		     N,
-		     viewport);
-
-      gluOrtho2D(exp004state0.ortho.min_x,
-		 exp004state0.ortho.max_x,
-		 exp004state0.ortho.min_y,
-		 exp004state0.ortho.max_y);      
-
-      /*
-       * "Alternately issue primitive drawing commands and commands to
-       * manipulate the name stack so that each primitive of interest
-       * has appropriate names assigned [Redbook]."
-       */
-      exp004geometry (GL_SELECT);
-
-      glMatrixMode (GL_PROJECTION);      
-      glPopMatrix ();
-      glutSwapBuffers ();
+    }
 
-      /*
-       * "Exit selection mode and process the returned selection data
-       * (the hit records) [Redbook]."
-       */
-      GLint hits = glRenderMode (GL_RENDER);
-      check_error (__FILE__, __LINE__);
-      
-      /* "process hits from selection mode rendering [Angel,2008]." */
-      exp004processhits (hits, select_buf);
-      
-      /* "normal render [Angel,2008]." */      
-      glutPostRedisplay ();
+  if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
+    {
+      S.selecting = true;
+      S.select_x = x;
+      S.select_y = y;
     }
 
   return;
--
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