From 75cbbd416551fdcc789ffd215e1121c8d129e732 Mon Sep 17 00:00:00 2001
From: P. J. McDermott <pj@pehjota.net>
Date: Tue, 30 Mar 2021 03:42:37 -0400
Subject: ball: Avoid double bouncing off points

---
diff --git a/src/ball.c b/src/ball.c
index 99415cc..2666a6e 100644
--- a/src/ball.c
+++ b/src/ball.c
@@ -112,6 +112,8 @@ void
 db_balls_collisions(struct db_ball *ball)
 {
 	struct db_map_line *line;
+	double              prev_col_x;
+	double              prev_col_y;
 	int                 line_x1;
 	int                 line_y1;
 	int                 line_x2;
@@ -122,6 +124,7 @@ db_balls_collisions(struct db_ball *ball)
 
 	/* Spinning balls shouldn't bounce off walls */
 	if (ball->sr == 0) {
+		prev_col_x = prev_col_y = -1;
 		for (line = db_map_get_lines(ball->map); line != NULL;
 				line = db_map_line_get_next(line)) {
 			db_map_line_get_coords(line, &line_x1, &line_y1,
@@ -131,8 +134,12 @@ db_balls_collisions(struct db_ball *ball)
 						line_x1, line_y1,
 						line_x2, line_y2,
 						&col_x, &col_y)){
+				if (col_x == prev_col_x || col_y == prev_col_y){
+					continue;
+				}
 				_db_ball_bounce(ball, col_x, col_y);
-				break;
+				prev_col_x = col_x;
+				prev_col_y = col_y;
 			}
 		}
 	}
--
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