context
	viewport - window
		layer - z-order surface


struct ee_contextattr *ee_contextattr_create(void);
void ee_contextattr_destroy(struct ee_contextattr *);
int ee_contextattr_set_XXX(struct ee_contextattr *, int);
struct ee_context *ee_context_create(struct ee_contextattr *attr);
void ee_context_destroy(struct ee_context *);

struct ee_viewattr *ee_viewattr_create(void);
void ee_viewattr_destroy(struct ee_viewattr *);
int ee_viewattr_set_XXX(struct ee_viewattr *, int);
struct ee_view *ee_view_create(struct ee_context *, int width, int height, struct ee_viewattr *);
void ee_view_destroy(struct ee_view *);

struct ee_layerattr *ee_layerattr_create(void);
void ee_layerattr_destroy(struct ee_layerattr *);
int ee_layerattr_set_XXX(struct ee_layerattr *, int);
struct ee_view *ee_layer_create(struct ee_view *, int virt_width, int virt_height, struct ee_layerattr *);
void ee_layer_destroy(struct ee_layer *);
int ee_layer_move(struct ee_layer *, int x, int y, int width, int height);
int ee_layer_resize(struct ee_layer *, int virt_width, int virt_height);
int ee_layer_show(struct ee_layer *);