libstage: introduce stage_match_func_t

Preparation for adding stage_lookup_key() to search a stage
heirarchy by an opaque key the per-node functions know how to
compare against.

2 files changed, 12 insertions, 9 deletions

diff --git a/src/stage.c b/src/stage.c
index e6da788..10a7f0a 100644
--- a/src/stage.c
+++ b/src/stage.c
@@ -34,12 +34,13 @@ struct stage_t {
 
 	stage_render_func_t	*render;	/* render object */
 	stage_free_func_t	*free;		/* free object */
+	stage_match_func_t	*match;		/* match object against key */
 	void			*object;	/* object */
 };
 
 
 /* minimally initialize a stage to carry an object */
-static void _stage_set_object(stage_t *stage, const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func)
+static void _stage_set_object(stage_t *stage, const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func, stage_match_func_t *match_func)
 {
 	assert(stage);
 	assert(name);
@@ -47,12 +48,13 @@ static void _stage_set_object(stage_t *stage, const char *name, void *object, st
 	strncpy(stage->name, name, sizeof(stage->name));
 	stage->render = render_func;
 	stage->free = free_func;
+	stage->match = match_func;
 	stage->object = object;
 }
 
 
 /* allocate a stage, this purely creates a stage in isolation and assigns its associated name, object and functions */
-static stage_t * _stage_new(const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func)
+static stage_t * _stage_new(const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func, stage_match_func_t *match_func)
 {
 	stage_t	*stage;
 
@@ -64,7 +66,7 @@ static stage_t * _stage_new(const char *name, void *object, stage_render_func_t
 	for (int i = 0; i < STAGE_LAYERS_MAX; i++)
 		dll_init(&stage->layers[i]);
 
-	_stage_set_object(stage, name, object, render_func, free_func);
+	_stage_set_object(stage, name, object, render_func, free_func, match_func);
 
 	return stage;
 }
@@ -84,14 +86,14 @@ static void _stage_free(stage_t *stage)
 
 /* returns a new stage, attached at the specified layer under parent if supplied */
 /* layer has no effect when parent == NULL */
-stage_t * stage_new(stage_t *parent, int layer, const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func)
+stage_t * stage_new(stage_t *parent, int layer, const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func, stage_match_func_t *match_func)
 {
 	stage_t	*stage;
 
 	assert(parent || !layer);
 	assert(layer < STAGE_LAYERS_MAX);
 
-	stage = _stage_new(name, object, render_func, free_func);
+	stage = _stage_new(name, object, render_func, free_func, match_func);
 	if (!stage)
 		return NULL;
 
@@ -105,14 +107,14 @@ stage_t * stage_new(stage_t *parent, int layer, const char *name, void *object,
 
 
 /* replaces a given stage's object-related properties but otherwise keeping the existing state */
-void stage_replace(stage_t *stage, const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func)
+void stage_replace(stage_t *stage, const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func, stage_match_func_t *match_func)
 {
 	assert(stage);
 
 	if (stage->free)
 		stage->free(stage, stage->object);
 
-	_stage_set_object(stage, name, object, render_func, free_func);
+	_stage_set_object(stage, name, object, render_func, free_func, match_func);
 }
 
 
diff --git a/src/stage.h b/src/stage.h
index 59329d7..b273b7b 100644
--- a/src/stage.h
+++ b/src/stage.h
@@ -24,9 +24,10 @@ typedef struct stage_t stage_t;
 
 typedef void (stage_render_func_t)(const stage_t *stage, void *object, float alpha);
 typedef void (stage_free_func_t)(const stage_t *stage, void *object);
+typedef int (stage_match_func_t)(const stage_t *stage, void *object, void *key);
 
-stage_t * stage_new(stage_t *parent, int layer, const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func);
-void stage_replace(stage_t *stage, const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func);
+stage_t * stage_new(stage_t *parent, int layer, const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func, stage_match_func_t *match_func);
+void stage_replace(stage_t *stage, const char *name, void *object, stage_render_func_t *render_func, stage_free_func_t *free_func, stage_match_func_t *match_func);
 stage_t * stage_free(stage_t *stage);
 void stage_render(const stage_t *stage);
 void stage_clear(stage_t *stage);