Refactor asteroid generation

game.c

@@ -19,6 +19,12 @@
 #define ASTEROID_OMG_JITTER 0.005
 #define INIT_ASTEROIDS 8
 
+#define ASTEROID_SMALL 0.05
+#define ASTEROID_MEDIUM 0.1
+#define ASTEROID_LARGE 0.15
+#define ASTEROID_R_JITTER 0.02
+#define ASTEROID_MIN_DIST 0.5
+
 #define LIN_PWR 0.0001
 #define ROT_PWR 0.002
 
@@ -48,11 +54,6 @@ typedef struct {
 	uint8_t flags;
 } shape_t;
 
-typedef enum {
-	ASTEROID_SMALL,
-	ASTEROID_MEDIUM,
-	ASTEROID_LARGE,
-} asteroid_size_t;
 
 static const vec2_t ship_verts[] = {
 	{ 0.0, 0.11 },
@@ -124,63 +125,52 @@ static void shoot()
 	memcpy(s->verts, shot_verts, sizeof(shot_verts));
 }
 
-static void gen_asteroid_shape(asteroid_size_t size, shape_t *out)
+static entity_t *gen_asteroid(float r_mean)
-{
-	float r_mean, r_jitter;
-	switch (size) {
-	case ASTEROID_SMALL:
-		r_mean = 0.05;
-		r_jitter = 0.02;
-		break;
-	case ASTEROID_MEDIUM:
-		r_mean = 0.1;
-		r_jitter = 0.02;
-		break;
-	case ASTEROID_LARGE:
-		r_mean = 0.15;
-		r_jitter = 0.05;
-	}
-
-	const unsigned n
-		= ASTEROID_MIN_VERTS + rng_uint32() % (ASTEROID_VERT_RANGE);
-	out->vert_count = n;
-
-	const float da = 2.0f * PI / n;
-	for (unsigned i = 0; i < n; ++i) {
-		const float r = r_mean + rng_plusminus() * r_jitter;
-		const float a
-		    = i * da + ASTEROID_A_JITTER * rng_plusminus() * da / 2;
-		out->verts[i] = (vec2_t) { r * cosf(a), r * sinf(a) };
-	}
-}
-
-static void add_asteroid()
 {
 	unsigned id;
 	entity_t *e = add_entity(&id);
 	e->wrap = true;
-	e->pos.y = rng_plusminus();
-	e->pos.x = aspect * rng_plusminus();
-	e->vel = (vec2_t) {
-		ASTEROID_VEL_JITTER * rng_plusminus(),
-		ASTEROID_VEL_JITTER * rng_plusminus(),
-	};
-	e->omg = ASTEROID_OMG_JITTER * rng_plusminus();
 
 	shape_t *s = add_shape(id, nullptr);
 	s->visible = true;
 	s->flags = WRAP | CONNECT;
 
-	asteroid_size_t size;
+	const unsigned n
-	const float r = rng_canon();
+	    = ASTEROID_MIN_VERTS + rng_uint32() % ASTEROID_VERT_RANGE;
-	if (r < 0.2)
+	s->vert_count = n;
-		size = ASTEROID_SMALL;
-	else if (r < 0.5)
-		size = ASTEROID_MEDIUM;
-	else
-		size = ASTEROID_LARGE;
 
-	gen_asteroid_shape(size, s);
+	const float da = 2.0f * PI / n;
+	for (unsigned i = 0; i < n; ++i) {
+		const float r = r_mean + rng_plusminus() * ASTEROID_R_JITTER;
+		const float a
+		    = i * da + ASTEROID_A_JITTER * rng_plusminus() * da / 2;
+		s->verts[i] = (vec2_t) { r * cosf(a), r * sinf(a) };
+	}
+
+	return e;
+}
+
+static void add_asteroid()
+{
+	float r;
+	const float rnd = rng_canon();
+	if (rnd < 0.2)
+		r = ASTEROID_SMALL;
+	else if (rnd < 0.6)
+		r = ASTEROID_MEDIUM;
+	else
+		r = ASTEROID_LARGE;
+
+	entity_t *e = gen_asteroid(r);
+	do {
+		e->pos.y = rng_plusminus();
+		e->pos.x = aspect * rng_plusminus();
+	} while (vec2_len(e->pos) < ASTEROID_MIN_DIST);
+	e->vel = (vec2_t) {
+		ASTEROID_VEL_JITTER * rng_plusminus(),
+		ASTEROID_VEL_JITTER * rng_plusminus(),
+	};
+	e->omg = ASTEROID_OMG_JITTER * rng_plusminus();
 }
 
 static void remove_shape(unsigned id)