adding more docs

engine/include/gf_type/core.h

@@ -32,6 +32,12 @@
  * @var gf_engine_t::draw
  * @brief Draw part
  * @todo Create gf_client_t and move draw there
+ *
+ * @var gf_engine_t::log
+ * @brief Log output
+ * @note Default is `stderr`
+ * @warning This is `NULL` when logger is using graphical console
+ * @warning Destroying engien instance **does not** `fclose` this
  */
 GF_DECLARE_TYPE(engine, {
 	gf_physics_t* physics;

engine/include/gf_type/graphic.h

@@ -1,3 +1,9 @@
+/**
+ * @file gf_type/graphic.h
+ * @~english
+ * @brief Type definitions related to graphic interface
+ */
+
 #ifndef __GF_TYPE_GRAPHIC_H__
 #define __GF_TYPE_GRAPHIC_H__
 
@@ -11,6 +17,23 @@
 
 /* Standard */
 
+/**
+ * @struct gf_color_t
+ * @~english
+ * @brief Color
+ *
+ * @var gf_color_t::r
+ * @brief Red
+ *
+ * @var gf_color_t::g
+ * @brief Green
+ *
+ * @var gf_color_t::b
+ * @brief Blue
+ *
+ * @var gf_color_t::a
+ * @brief Alpha
+ */
 GF_DECLARE_TYPE(color, {
 	double r;
 	double g;

engine/include/gf_type/version.h

@@ -18,7 +18,7 @@
 /* Standard */
 
 /**
- * @typedef gf_version_t
+ * @struct gf_version_t
  * @~english
  * @brief Version
  *