From 01e2f6af97c858b810e834b53aa25c356b940a38 Mon Sep 17 00:00:00 2001
From: P. J. McDermott <pj@pehjota.net>
Date: Fri, 24 Dec 2021 04:52:13 -0500
Subject: char/enemy: Factor out collision check into jump

And replace the loop with tail recursion.
---
(limited to 'src')

diff --git a/src/char/enemy.c b/src/char/enemy.c
index 8bb2c4e..1e03567 100644
--- a/src/char/enemy.c
+++ b/src/char/enemy.c
@@ -178,8 +178,6 @@ mf_enemy_new(struct mf_maze *maze, int cell_width, int maze_size,
 {
 	struct mf_char  *c;
 	struct mf_enemy *e;
-	int              collide;
-	int              i;
 
 	mf_char_init(c, e, enemy);
 
@@ -206,39 +204,42 @@ mf_enemy_new(struct mf_maze *maze, int cell_width, int maze_size,
 	c->eyes_color.r = MF_COLOR_EEYE_R, c->eyes_color.g = MF_COLOR_EEYE_G;
 	c->eyes_color.b = MF_COLOR_EEYE_B, c->eyes_color.a = MF_COLOR_EEYE_A;
 
-	do {
-		collide = SDL_FALSE;
-		if (c->cur_x < maze_size * MF_ENEMY_MIN_DIST &&
-				c->cur_y < maze_size * MF_ENEMY_MIN_DIST) {
-			collide = SDL_TRUE;
-		} else {
-			for (i = 0; i < num_allies; ++i) {
-				if (allies[i] != NULL &&
-						c->cur_x == allies[i]->cur_x &&
-						c->cur_y == allies[i]->cur_y) {
-					collide = SDL_TRUE;
-				}
-			}
-		}
-		if (collide == SDL_TRUE) {
-			mf_enemy_random_jump(c, maze_size);
-		}
-	} while (collide == SDL_TRUE);
+	e->num_allies = num_allies;
+	e->allies     = allies;
+	e->waiting    = SDL_FALSE;
+
+	mf_enemy_random_jump(c, maze_size);
 
 	c->cur_dir = MF_CHAR_DIR_N_;
 	_mf_enemy_step(c);
 	c->cur_dir = c->new_dir;
 
-	e->num_allies = num_allies;
-	e->allies     = allies;
-	e->waiting    = SDL_FALSE;
-
 	return c;
 }
 
 void
 mf_enemy_random_jump(struct mf_char *c, int maze_size)
 {
-	c->cur_x = rand() / (RAND_MAX / maze_size);
-	c->cur_y = rand() / (RAND_MAX / maze_size);
+	struct mf_enemy *e       = (struct mf_enemy *) c;
+	int              collide;
+	int              i;
+
+	collide = SDL_FALSE;
+	if (c->cur_x < maze_size * MF_ENEMY_MIN_DIST &&
+			c->cur_y < maze_size * MF_ENEMY_MIN_DIST) {
+		collide = SDL_TRUE;
+	} else {
+		for (i = 0; i < e->num_allies; ++i) {
+			if (e->allies[i] != NULL &&
+					c->cur_x == e->allies[i]->cur_x &&
+					c->cur_y == e->allies[i]->cur_y) {
+				collide = SDL_TRUE;
+			}
+		}
+	}
+	if (collide == SDL_TRUE) {
+		c->cur_x = rand() / (RAND_MAX / maze_size);
+		c->cur_y = rand() / (RAND_MAX / maze_size);
+		mf_enemy_random_jump(c, maze_size);
+	}
 }
--
cgit v0.9.1