Added selection by bounding box with mouse.

1 files changed, 98 insertions, 67 deletions

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;