36 files changed, 332 insertions, 176 deletions
diff --git a/src/controller/callbacks/mouse.c b/src/controller/callbacks/mouse.c
new file mode 100644
index 0000000..fc48eff
--- a/dev/null
+++ b/src/controller/callbacks/mouse.c
@@ -0,0 +1,127 @@
+#include "../../util/check_error.h"
+#include "../../util/pick_convert.h"
+#include "../../view/exp004geometry.h"
+#include "../../view/exp004state0.h"
+#include "../actions/process_hits.h"
+#include "../actions/set_ortho.h"
+#include "../actions/zoom.h"
+#include "mouse.h"
+#include "reshape.h"
+#include <GL/glut.h>
+#include <math.h>
+#include <stdlib.h>
+
+/*
+ * A simple alias to make the code more readable.
+ */
+#define S exp004state0
+
+void
+mouse (int button, int state, int x, int y)
+{
+  if (button == GLUT_LEFT_BUTTON && state == GLUT_UP)
+    {
+      if (S.selection.active && S.selection.purpose == ZOOM)
+	{
+	  /*
+	   * NOOP if the mouse was not moved.
+	   */
+	  if (x == S.selection.x || y == S.selection.y)
+	    return;
+
+	  GLint viewport[4];
+	  glGetIntegerv (GL_VIEWPORT, viewport);
+
+	  zoom (S.selection.x, 
+		viewport[3] - S.selection.y, 
+		x, 
+		viewport[3] - y);
+	}
+
+      /*
+       * Complete a selection if one was started and not cancelled.
+       */
+      if (S.selection.active && S.selection.purpose == SET)
+	{
+
+	  /*
+	   * "Specify the array to be used for the returned hit records
+	   * with glSelectBuffer () [Redbook]."
+	   */
+	  GLuint *select_buf = calloc (S.rows, sizeof (GLuint));
+	  glSelectBuffer (S.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);
+
+	  double c_x = 0.0;
+	  double c_y = 0.0;
+	  double w = 0.0;
+	  double h = 0.0;
+	  pick_convert (S.selection.x, S.selection.y, x, y,
+			&c_x, &c_y, &w, &h);
+
+	  gluPickMatrix (c_x, (GLdouble) viewport[3] - c_y, w, h, viewport);
+
+	  set_ortho ();
+
+	  /*
+	   * "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]." */
+	  process_hits (hits, select_buf);
+
+	  /* "normal render [Angel,2008]." */
+	  glutPostRedisplay ();
+	}
+
+    }
+
+  if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
+    {
+      S.selection.active = true;
+      S.selection.x = x;
+      S.selection.y = y;
+    }
+
+  return;
+}