From 30bb703ff3185f9c9c05cfbd67f0d008ea4c29bb Mon Sep 17 00:00:00 2001
From: P. J. McDermott <pj@pehjota.net>
Date: Sat, 27 Mar 2021 16:20:58 -0400
Subject: ball, map: Convert to left-hand rule

The SDL coordinate system has a negative orientation (the positive
y-axis points down).  It's easier to not fight it.
---
diff --git a/src/ball.c b/src/ball.c
index 3230628..ccdccec 100644
--- a/src/ball.c
+++ b/src/ball.c
@@ -59,7 +59,7 @@ db_ball_new(int x, int y, int r, int a, int d, int sr, double s,
 		ball->cx = x;
 		ball->cy = y;
 		ball->x  = x + cos(a * (M_PI / 180)) * sr;
-		ball->y  = y - sin(a * (M_PI / 180)) * sr;
+		ball->y  = y + sin(a * (M_PI / 180)) * sr;
 	}
 	ball->r        = r;
 	ball->a        = a;
@@ -81,11 +81,11 @@ db_balls_move(struct db_ball *ball)
 {
 	if (ball->sr == 0) {
 		ball->x += cos(ball->a * (M_PI / 180));
-		ball->y -= sin(ball->a * (M_PI / 180));
+		ball->y += sin(ball->a * (M_PI / 180));
 	} else {
 		ball->a += ball->d * ball->s;
 		ball->x  = ball->cx + cos(ball->a * (M_PI / 180)) * ball->sr;
-		ball->y  = ball->cy - sin(ball->a * (M_PI / 180)) * ball->sr;
+		ball->y  = ball->cy + sin(ball->a * (M_PI / 180)) * ball->sr;
 		db_dbg("Spinning ball angle %f (speed %f, direction %d)",
 				ball->a, ball->s, ball->d);
 	}
diff --git a/src/map.c b/src/map.c
index 7eb4ddb..add4c3e 100644
--- a/src/map.c
+++ b/src/map.c
@@ -440,7 +440,6 @@ _db_tmx_object_property_start(void *pv, const char *name, const char **attr)
 			free(p_type);
 			db_dbg("              Object speed: %f px/s",
 					map->obj_s);
-			map->obj_s /= map->fr;  /* Convert px/s to px/f */
 		} else if (strcmp(p_name, "direction") == 0) {
 			db_xml_get_string_attr(p, attr, "value", &dir, 1);
 			if (strcmp(dir, "lr") == 0) {
@@ -458,12 +457,12 @@ _db_tmx_object_property_start(void *pv, const char *name, const char **attr)
 						"random");
 			} else if (strcmp(dir, "cw") == 0) {
 				map->obj_a = rand() / (RAND_MAX / 360);
-				map->obj_d = -1;
+				map->obj_d =  1;
 				db_dbg("              Object direction: "
 						"clockwise");
 			} else if (strcmp(dir, "ccw") == 0) {
 				map->obj_a = rand() / (RAND_MAX / 360);
-				map->obj_d =  1;
+				map->obj_d = -1;
 				db_dbg("              Object direction: "
 						"counter-clockwise");
 			}
--
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