From 0f0b704144bddc045657f7ed852b49d5e349b0bd Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@gmail.com>
Date: Sat, 21 May 2011 20:27:09 -0600
Subject: Add refcounts to cameras.

---
 libdimension/camera.c             | 8 +++++---
 libdimension/dimension/camera.h   | 5 +++--
 libdimension/dimension/refcount.h | 3 +++
 libdimension/dimension/scene.h    | 7 +++++++
 libdimension/scene.c              | 8 ++++++++
 libdimension/tests/render.c       | 5 +++--
 6 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/libdimension/camera.c b/libdimension/camera.c
index 67117f9..e76200a 100644
--- a/libdimension/camera.c
+++ b/libdimension/camera.c
@@ -31,8 +31,9 @@ dmnsn_camera *
 dmnsn_new_camera(void)
 {
   dmnsn_camera *camera = dmnsn_malloc(sizeof(dmnsn_camera));
-  camera->free_fn = NULL;
-  camera->trans   = dmnsn_identity_matrix();
+  camera->free_fn  = NULL;
+  camera->trans    = dmnsn_identity_matrix();
+  camera->refcount = dmnsn_new_refcount();
   return camera;
 }
 
@@ -40,7 +41,8 @@ dmnsn_new_camera(void)
 void
 dmnsn_delete_camera(dmnsn_camera *camera)
 {
-  if (camera) {
+  if (camera && DMNSN_DECREF(camera)) {
+    dmnsn_delete_refcount(camera->refcount);
     if (camera->free_fn) {
       camera->free_fn(camera->ptr);
     }
diff --git a/libdimension/dimension/camera.h b/libdimension/dimension/camera.h
index c3ad65b..67fffc0 100644
--- a/libdimension/dimension/camera.h
+++ b/libdimension/dimension/camera.h
@@ -44,8 +44,9 @@ struct dmnsn_camera {
 
   dmnsn_matrix trans; /**< Transformation matrix. */
 
-  /** Generic pointer for camera info. */
-  void *ptr;
+  void *ptr; /**< @internal Generic pointer for camera info. */
+
+  dmnsn_refcount *refcount; /**< @internal reference count. */
 };
 
 /**
diff --git a/libdimension/dimension/refcount.h b/libdimension/dimension/refcount.h
index 14f31ab..9d2c304 100644
--- a/libdimension/dimension/refcount.h
+++ b/libdimension/dimension/refcount.h
@@ -30,6 +30,7 @@
 #define DMNSN_INCREF(obj) ((void)++(*(obj)->refcount))
 
 /**
+ * @internal
  * Decrement a reference count.
  * @param[in,out] object  The reference-counted object to release.
  * @return Whether the object is now garbage.
@@ -42,6 +43,7 @@
 typedef unsigned int dmnsn_refcount;
 
 /**
+ * @internal
  * Create a reference count.
  * @return A new reference counter, initialized to zero (a "borrowed" reference,
  *         which will be garbage-collected the first time it is deleted).
@@ -49,6 +51,7 @@ typedef unsigned int dmnsn_refcount;
 dmnsn_refcount *dmnsn_new_refcount(void);
 
 /**
+ * @internal
  * Delete a reference count.  Raises an error if the reference count wasn't
  * zero.
  */
diff --git a/libdimension/dimension/scene.h b/libdimension/dimension/scene.h
index ffe5fb3..b726a77 100644
--- a/libdimension/dimension/scene.h
+++ b/libdimension/dimension/scene.h
@@ -99,6 +99,13 @@ void dmnsn_initialize_scene(dmnsn_scene *scene);
  */
 void dmnsn_scene_set_canvas(dmnsn_scene *scene, dmnsn_canvas *canvas);
 
+/**
+ * Set the camera for a scene.
+ * @param[in,out] scene   The scene for which to set the canvas.
+ * @param[in]     camera  The camera to set.
+ */
+void dmnsn_scene_set_camera(dmnsn_scene *scene, dmnsn_camera *camera);
+
 /**
  * Add an object to a scene.
  * @param[in,out] scene   The scene to which to add the object.
diff --git a/libdimension/scene.c b/libdimension/scene.c
index 51b8215..ec9fdbd 100644
--- a/libdimension/scene.c
+++ b/libdimension/scene.c
@@ -91,6 +91,14 @@ dmnsn_scene_set_canvas(dmnsn_scene *scene, dmnsn_canvas *canvas)
   scene->canvas = canvas;
 }
 
+void
+dmnsn_scene_set_camera(dmnsn_scene *scene, dmnsn_camera *camera)
+{
+  DMNSN_INCREF(camera);
+  dmnsn_delete_camera(scene->camera);
+  scene->camera = camera;
+}
+
 void
 dmnsn_scene_add_object(dmnsn_scene *scene, dmnsn_object *object)
 {
diff --git a/libdimension/tests/render.c b/libdimension/tests/render.c
index a84ba63..a79c85c 100644
--- a/libdimension/tests/render.c
+++ b/libdimension/tests/render.c
@@ -62,8 +62,9 @@ dmnsn_new_test_scene(void)
   );
 
   /* Create a perspective camera */
-  scene->camera = dmnsn_new_perspective_camera();
-  scene->camera->trans = trans;
+  dmnsn_camera *camera = dmnsn_new_perspective_camera();
+  camera->trans = trans;
+  dmnsn_scene_set_camera(scene, camera);
 
   /* Background color */
   scene->background = dmnsn_clear;
-- 
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