New C++ dmnsn_camera* wrapper.

1 files changed, 81 insertions, 0 deletions

diff --git a/libdimensionxx/camera.cpp b/libdimensionxx/camera.cpp
new file mode 100644
index 0000000..a5f894a
--- /dev/null
+++ b/libdimensionxx/camera.cpp
@@ -0,0 +1,81 @@
+/*************************************************************************
+ * Copyright (C) 2008 Tavian Barnes <tavianator@gmail.com>               *
+ *                                                                       *
+ * This file is part of The Dimension Library.                           *
+ *                                                                       *
+ * The Dimension Library is free software; you can redistribute it and/  *
+ * or modify it under the terms of the GNU Lesser General Public License *
+ * as published by the Free Software Foundation; either version 3 of the *
+ * License, or (at your option) any later version.                       *
+ *                                                                       *
+ * The Dimension Library is distributed in the hope that it will be      *
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty   *
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  *
+ * Lesser General Public License for more details.                       *
+ *                                                                       *
+ * You should have received a copy of the GNU Lesser General Public      *
+ * License along with this program.  If not, see                         *
+ * <http://www.gnu.org/licenses/>.                                       *
+ *************************************************************************/
+
+#include "dimensionxx.hpp"
+
+namespace Dimension
+{
+  // Pure virtual no-op destructor
+  Camera::~Camera()
+  { }
+
+  // Return the wrapped camera
+  dmnsn_camera*
+  Camera::dmnsn()
+  {
+    return m_camera;
+  }
+
+  // Return a const version of the wrapped canvas
+  const dmnsn_camera*
+  Camera::dmnsn() const
+  {
+    return m_camera;
+  }
+
+  // Protected default no-op constructor
+  Camera::Camera()
+  { }
+
+  // Protected manual constructor
+  Camera::Camera(dmnsn_camera *camera)
+    : m_camera(camera)
+  { }
+
+  // Custom camera callbacks
+  namespace {
+    dmnsn_line
+    ray_fn(const dmnsn_camera *camera, const dmnsn_canvas *canvas,
+           unsigned int x, unsigned int y)
+    {
+      Custom_Camera* ccamera = reinterpret_cast<Custom_Camera*>(camera->ptr);
+      // Yes the const_cast is ugly, but there's no other way because C++
+      // doesn't have `const' constructors.  Luckily const Camera's treat their
+      // dmnsn_camera* as a const dmnsn_camera*.
+      return ccamera->ray(
+        Canvas(const_cast<dmnsn_canvas*>(canvas)), x, y
+      ).dmnsn();
+    }
+  }
+
+  // Initialize a new camera, using member functions as callbacks
+  Custom_Camera::Custom_Camera()
+    : Camera(dmnsn_new_camera())
+  {
+    m_camera->ptr = this;
+    m_camera->ray_fn = &ray_fn;
+  }
+
+  // Delete the camera
+  Custom_Camera::~Custom_Camera()
+  {
+    dmnsn_delete_camera(m_camera);
+  }
+}