xlib_playground

commit c4a76674993d7e0915aa88ace813459c2e966d5a
parent a20b34d8e11f276e4d2c206ad94a383e97881226
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Tue, 10 Jan 2023 14:16:55 +0900

clean

Diffstat:
M
ex9/object.c
 | 
28
++++++++++++++++++----------

1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/ex9/object.c b/ex9/object.c
@@ -9,6 +9,16 @@ static int test_collision_rr(struct Object *, struct Object *);
 static void rect_next_tick(struct Object *, long);
 static void rect_handle_collision_mf(struct Object *, struct Object *);
 
+/*
+ * Pair of two objects with their distance.
+ * Used by lhandle_collision();
+ */
+struct LLD {
+	struct Object *o0;
+	struct Object *o1;
+	float dist;
+};
+
 struct Object *
 create_object(enum object_type t, uint32_t color,
               float px, float py, float vx, float vy, float ax, float ay,
@@ -220,12 +230,7 @@ olqsortx(struct List *p)
 	lqsort(p, (int (*)(void *, void *))&olcmpx);
 }
 
-struct LLD {
-	struct Object *o0;
-	struct Object *o1;
-	float dist;
-};
-int
+static int
 lldcmpdst(struct LLD *p, struct LLD *q)
 {
 	if (p->dist < q->dist)
@@ -235,7 +240,8 @@ lldcmpdst(struct LLD *p, struct LLD *q)
 	else
 		return 1;
 }
-void
+
+static void
 lldprint(struct LLD *p)
 {
 	printf("{");
@@ -244,6 +250,7 @@ lldprint(struct LLD *p)
 	oprint(p->o1);
 	printf(", %2.0f}", p->dist);
 }
+
 /*
  * The order of list o will be changed.
  */
@@ -254,14 +261,15 @@ lhandle_collision(struct List *p)
 	struct List *stack, *tmp;
 	stack = NULL;
 	for (; p != NULL; p = p->next) {
-		// if p doesn't have intersection with an item in the stack
+		// If p doesn't have intersection with an item in the stack
+		// Checking only against the first object suffices because stack is sorted.
 		if (stack != NULL &&
 			((struct Object *)stack->item)->p.x +
 			((struct Object *)stack->item)->body.rectangle.w <=
 			((struct Object *)p->item)->p.x) {
-			// handle collision among the items in the stack.
+			// Handle collision among the items in the stack.
 			// LLD: {struct Object *o0, struct Object *o1, float dist}
-			// sort LLD according to dist.
+			// Sort LLD according to dist.
 			struct List *lld, *tmplld;
 			struct List *s, *t;
 			lld = NULL;