add some notes and skeleton for scene abstraction

src/shader.h

@@ -54,6 +54,7 @@ struct GLVertexAttrib
 	char* name;
 };
 
+// TODO: add a note explaining usage when we implement complex entities
 struct GLBufferToAttribMapping
 {
 	GLVertexAttrib* attrib;
@@ -86,6 +87,8 @@ struct GLBuffer
 	GLuint id;
 	GLenum target;
 	GLenum data_type;
+	// FIXME: we should initialize both of these to UINT_MAX because '0' is a
+	// 	valid location and index
 	GLuint location; // NOTE: if used as backing for vertex attribute
 	GLuint binding_idx; // NOTE: if used as backing from uniform buffer object
 	char* name;

src/tangerine.h

@@ -72,6 +72,32 @@ struct RenderGroup
 	char* name;
 };
 
+#if 0
+struct Scene
+{
+	MemoryArena* rg_arena;
+	u32 num_render_groups;
+	u32 max_render_groups;
+	RenderGroup* render_groups;
+
+	u32 num_point_lights;
+	u32 max_point_lights;
+	PointLight* p_lights;
+
+	u32 num_d_lights;
+	u32 max_d_lights;
+	DirectionalLight* d_lights;
+
+	u32 num_spot_lights;
+	u32 max_spot_lights;
+	SpotLight* s_lights;
+
+	Node root_node;
+
+	Camera cam;
+};
+#endif
+
 struct GLClearColor
 {
 	GLfloat R;