7 files changed, 149 insertions, 44 deletions

diff --git a/src/controller/performzoom.c b/src/controller/performzoom.c
new file mode 100644
index 0000000..2fed1d2
--- a/dev/null
+++ b/src/controller/performzoom.c
@@ -0,0 +1,65 @@
+#include "performzoom.h"
+#include "exp004reshape.h"
+#include "../util/check_error.h"
+#include "../view/exp004state0.h"
+#include <GL/glut.h>
+#include <math.h>
+
+/*
+ * A simple alias to make the code more readable.
+ */
+#define S exp004state0
+
+void
+performzoom (int x1, int y1, int x2, int y2)
+{
+  /*
+   * 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.zoom.active = true;
+  S.zoom.coords[0] = fmin (start_position[0], end_position[0]);
+  S.zoom.coords[1] = fmax (start_position[0], end_position[0]);
+  S.zoom.coords[2] = fmin (start_position[1], end_position[1]);
+  S.zoom.coords[3] = fmax (start_position[1], end_position[1]);
+  
+  exp004reshape (S.viewport.w, S.viewport.h);
+  
+  glutPostRedisplay ();
+  
+  return;
+}