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;
+}