Add node getters and iterators.

2 files changed, 115 insertions, 25 deletions

diff --git a/gfx/include/gfx/scene/node.h b/gfx/include/gfx/scene/node.h
index ab6ca12..5d168c9 100644
--- a/gfx/include/gfx/scene/node.h
+++ b/gfx/include/gfx/scene/node.h
@@ -1,7 +1,11 @@
 #pragma once
 
 #include "animation.h"
+
 #include <math/fwd.h>
+#include <math/mat4.h>
+
+#include <stdint.h>
 
 typedef struct Anima       Anima;
 typedef struct Joint       Joint;
@@ -9,6 +13,9 @@ typedef struct Light       Light;
 typedef struct SceneCamera SceneCamera;
 typedef struct SceneObject SceneObject;
 
+/// Scene node iterator.
+typedef uint32_t NodeIter;
+
 /// Scene node type.
 typedef enum NodeType {
   LogicalNode,
@@ -25,6 +32,10 @@ typedef enum NodeType {
 /// Light, SceneObject, etc), as well as of child nodes.
 typedef struct SceneNode SceneNode;
 
+// -----------------------------------------------------------------------------
+// Constructors and destructor.
+// -----------------------------------------------------------------------------
+
 /// Create a new scene node.
 ///
 /// This node does not contain any camera, light, object, etc. and exists simply
@@ -68,6 +79,10 @@ void gfx_construct_object_node(SceneNode*, SceneObject*);
 /// Node resources -- cameras, lights, objects, etc. -- are also destroyed.
 void gfx_destroy_node(SceneNode**);
 
+// -----------------------------------------------------------------------------
+// Getters.
+// -----------------------------------------------------------------------------
+
 /// Return the node's type.
 NodeType gfx_get_node_type(const SceneNode*);
 
@@ -76,6 +91,45 @@ NodeType gfx_get_node_type(const SceneNode*);
 /// The node must be of type AnimaNode.
 Anima* gfx_get_node_anima(const SceneNode*);
 
+/// Get the node's camera.
+///
+/// The node must be of type CameraNode.
+SceneCamera* gfx_get_node_camera(const SceneNode* node);
+
+/// Get the node's joint.
+///
+/// The node must be of type JointNode.
+Joint* gfx_get_node_joint(const SceneNode*);
+
+/// Get the node's light.
+///
+/// The node must be of type LightNode.
+Light* gfx_get_node_light(const SceneNode*);
+
+/// Get the node's scene object.
+///
+/// The node must be of type ObjectNode.
+SceneObject* gfx_get_node_object(const SceneNode*);
+
+/// Get an iterator to the node's first child.
+NodeIter gfx_get_node_child(const SceneNode*);
+
+/// Get the iterator's next sibling node.
+NodeIter gfx_get_next_child(NodeIter);
+
+/// Get a scene node from the iterator.
+const SceneNode* gfx_get_iter_node(NodeIter);
+
+/// Get the node's (local) transform.
+mat4 gfx_get_node_transform(const SceneNode*);
+
+/// Get the node's global transform.
+mat4 gfx_get_node_global_transform(const SceneNode*);
+
+// -----------------------------------------------------------------------------
+// Setters.
+// -----------------------------------------------------------------------------
+
 /// Set the node's parent.
 ///
 /// Pass in null to unwire from the existing parent, if one exists.
@@ -93,11 +147,5 @@ void gfx_set_node_rotation(SceneNode*, const quat* rotation);
 /// Set the node's rotation.
 void gfx_set_node_rotation_mat(SceneNode*, const mat4* rotation);
 
-/// Get the node's (local) transform.
-mat4 gfx_get_node_transform(const SceneNode*);
-
-/// Get the node's global transform.
-mat4 gfx_get_node_global_transform(const SceneNode*);
-
 /// Log the node's hierarchy.
 void gfx_log_node_hierarchy(const SceneNode*);
diff --git a/gfx/src/scene/node.c b/gfx/src/scene/node.c
index 760951b..ea0f19d 100644
--- a/gfx/src/scene/node.c
+++ b/gfx/src/scene/node.c
@@ -227,10 +227,69 @@ NodeType gfx_get_node_type(const SceneNode* node) {
   return node->type;
 }
 
+#define NODE_GET(node, field, expected_type) \
+  {                                          \
+    assert(node);                            \
+    assert(node->type == expected_type);     \
+    return mem_get_##field(node->field);     \
+  }
+
 Anima* gfx_get_node_anima(const SceneNode* node) {
+  NODE_GET(node, anima, AnimaNode);
+}
+
+SceneCamera* gfx_get_node_camera(const SceneNode* node) {
+  NODE_GET(node, camera, CameraNode);
+}
+
+Joint* gfx_get_node_joint(const SceneNode* node) {
+  NODE_GET(node, joint, JointNode);
+}
+
+Light* gfx_get_node_light(const SceneNode* node) {
+  NODE_GET(node, light, LightNode);
+}
+
+SceneObject* gfx_get_node_object(const SceneNode* node) {
+  NODE_GET(node, object, ObjectNode);
+}
+
+NodeIter gfx_get_node_child(const SceneNode* node) {
   assert(node);
-  assert(node->type == AnimaNode);
-  return mem_get_anima(node->anima);
+  return (NodeIter)node->child.val;
+}
+
+NodeIter gfx_get_next_child(NodeIter it) {
+  if (!it) {
+    return it;
+  }
+  const SceneNode* cur_child  = mem_get_node((node_idx){.val = it});
+  const node_idx   next_child = cur_child->next;
+  return (NodeIter)next_child.val;
+}
+
+const SceneNode* gfx_get_iter_node(NodeIter it) {
+  if (!it) {
+    return 0;
+  }
+  return mem_get_node((node_idx){.val = it});
+}
+
+mat4 gfx_get_node_transform(const SceneNode* node) {
+  assert(node);
+  return node->transform;
+}
+
+mat4 gfx_get_node_global_transform(const SceneNode* node) {
+  assert(node);
+  mat4     transform    = node->transform;
+  node_idx parent_index = node->parent;
+  while (parent_index.val != 0) {
+    const SceneNode* parent = mem_get_node(parent_index);
+    transform               = mat4_mul(parent->transform, transform);
+    parent_index            = parent->parent;
+  }
+  return transform;
 }
 
 void gfx_set_node_parent(SceneNode* child, SceneNode* parent) {
@@ -263,23 +322,6 @@ void gfx_set_node_rotation_mat(SceneNode* node, const mat4* rotation) {
   mat4_set_3x3(&node->transform, *rotation);
 }
 
-mat4 gfx_get_node_transform(const SceneNode* node) {
-  assert(node);
-  return node->transform;
-}
-
-mat4 gfx_get_node_global_transform(const SceneNode* node) {
-  assert(node);
-  mat4     transform    = node->transform;
-  node_idx parent_index = node->parent;
-  while (parent_index.val != 0) {
-    const SceneNode* parent = mem_get_node(parent_index);
-    transform               = mat4_mul(parent->transform, transform);
-    parent_index            = parent->parent;
-  }
-  return transform;
-}
-
 static const char* get_node_type_str(NodeType type) {
   switch (type) {
   case LogicalNode: