From 98b9f36db18a5702a1c85421e8b0f71e73d1177e Mon Sep 17 00:00:00 2001
From: P. J. McDermott <pj@pehjota.net>
Date: Tue, 30 Mar 2021 04:23:20 -0400
Subject: ball: Collide with balls before lines

Seems to fix an issue of a ball getting stuck on a line when colliding
with both a line and a ball in the same frame.
---
diff --git a/src/ball.c b/src/ball.c
index 4dc0ab0..923994e 100644
--- a/src/ball.c
+++ b/src/ball.c
@@ -111,6 +111,9 @@ _db_ball_bounce(struct db_ball *ball, double col_x, double col_y)
 void
 db_balls_collisions(struct db_ball *ball)
 {
+	struct db_ball     *other;
+	double              col_x;
+	double              col_y;
 	struct db_map_line *line;
 	double              prev_col_x;
 	double              prev_col_y;
@@ -118,9 +121,19 @@ db_balls_collisions(struct db_ball *ball)
 	int                 line_y1;
 	int                 line_x2;
 	int                 line_y2;
-	double              col_x;
-	double              col_y;
-	struct db_ball     *other;
+
+	/* Spinning balls shouldn't collide with any other balls */
+	if (ball->sr == 0) {
+		for (other = ball->next; other != NULL; other = other->next) {
+			if (other->sr == 0 && db_col_pt_cir_cir(
+						 ball->x,  ball->y,  ball->r,
+						other->x, other->y, other->r,
+						&col_x, &col_y)) {
+				_db_ball_bounce(ball , col_x, col_y);
+				_db_ball_bounce(other, col_x, col_y);
+			}
+		}
+	}
 
 	/* Spinning balls shouldn't bounce off walls */
 	if (ball->sr == 0) {
@@ -144,19 +157,6 @@ db_balls_collisions(struct db_ball *ball)
 		}
 	}
 
-	/* Spinning balls shouldn't collide with any other balls */
-	if (ball->sr == 0) {
-		for (other = ball->next; other != NULL; other = other->next) {
-			if (other->sr == 0 && db_col_pt_cir_cir(
-						 ball->x,  ball->y,  ball->r,
-						other->x, other->y, other->r,
-						&col_x, &col_y)) {
-				_db_ball_bounce(ball , col_x, col_y);
-				_db_ball_bounce(other, col_x, col_y);
-			}
-		}
-	}
-
 	if (ball->next != NULL) {
 		db_balls_collisions(ball->next);
 	}
--
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