Add some comments.

1 files changed, 51 insertions, 0 deletions

diff --git a/libdimensionxx/canvas.cpp b/libdimensionxx/canvas.cpp
index 2340066..411d4e8 100644
--- a/libdimensionxx/canvas.cpp
+++ b/libdimensionxx/canvas.cpp
@@ -22,8 +22,59 @@
 
 namespace Dimension
 {
+  // Allocate the canvas with dmnsn_new_canvas()
+  Canvas::Canvas(unsigned int width, unsigned int height)
+    : m_canvas(dmnsn_new_canvas(width, height)) { }
+
+  // Virtual destructor: delete the canvas with dmnsn_delete_canvas().
   Canvas::~Canvas()
   {
     dmnsn_delete_canvas(m_canvas);
   }
+
+  // Get the width
+  unsigned int
+  Canvas::width() const
+  {
+    return m_canvas->x;
+  }
+
+  // Get the height
+  unsigned int
+  Canvas::height() const
+  {
+    return m_canvas->y;
+  }
+
+  // Get a particular pixel, thread-safely, with dmnsn_get_pixel().
+  Color
+  Canvas::pixel(unsigned int x, unsigned int y) const
+  {
+    return Color(dmnsn_get_pixel(m_canvas, x, y));
+  }
+
+  // Set a particular pixel, thread-safely, with dmnsn_set_pixel().
+  void
+  Canvas::pixel(unsigned int x, unsigned int y, const Color& c)
+  {
+    dmnsn_set_pixel(m_canvas, x, y, c.dmnsn());
+  }
+
+  // Return the wrapped canvas
+  dmnsn_canvas* 
+  Canvas::dmnsn()
+  {
+    return m_canvas;
+  }
+
+  // Return a const version of the wrapped canvas
+  const dmnsn_canvas*
+  Canvas::dmnsn() const
+  {
+    return m_canvas;
+  }
+
+  // Protected default constructor: set m_canvas to NULL.
+  Canvas::Canvas()
+    : m_canvas(0) { }
 }