From a4d2b83d29a78d171deb2c6447369d94e752f2cb Mon Sep 17 00:00:00 2001
From: P. J. McDermott <pjm@nac.net>
Date: Tue, 21 May 2013 18:57:11 -0400
Subject: Make balls move.

---
diff --git a/Makefile.am b/Makefile.am
index efe5a40..93192a9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -7,4 +7,4 @@ cursespong_SOURCES = \
 cursespong_CFLAGS = \
 	$(GCC_CFLAGS)
 cursespong_LDADD = \
-	-lcurses
+	-lm -lcurses
diff --git a/src/ball.c b/src/ball.c
index 91c2995..3515b68 100644
--- a/src/ball.c
+++ b/src/ball.c
@@ -1,10 +1,11 @@
 #include <stdlib.h>
+#include <math.h>
 #include <curses.h>
 
 #include "ball.h"
 
 struct ball *
-new_ball(float x, float y)
+new_ball(float x, float y, float speed, float dir)
 {
 	struct ball *b;
 
@@ -15,6 +16,8 @@ new_ball(float x, float y)
 
 	b->x = x;
 	b->y = y;
+	b->speed = speed;
+	b->dir = dir;
 
 	return b;
 }
@@ -34,7 +37,8 @@ clear_ball(struct ball *b)
 void
 update_ball(struct ball *b)
 {
-	++b;
+	b->x += cosf(b->dir) * b->speed;
+	b->y += sinf(b->dir) * b->speed;
 }
 
 void
diff --git a/src/ball.h b/src/ball.h
index 232d2e3..bf96d3a 100644
--- a/src/ball.h
+++ b/src/ball.h
@@ -9,10 +9,12 @@ static const float BALL_START_Y_NORMAL = 12;
 struct ball {
 	float x;
 	float y;
+	float speed;
+	float dir;
 	struct ball *next;
 };
 
-struct ball *new_ball(float x, float y);
+struct ball *new_ball(float x, float y, float speed, float dir);
 void free_ball(struct ball *b);
 void clear_ball(struct ball *b);
 void update_ball(struct ball *b);
diff --git a/src/game.c b/src/game.c
index 7169fc3..013c0a4 100644
--- a/src/game.c
+++ b/src/game.c
@@ -122,7 +122,7 @@ update_game(struct game *g)
 	}
 
 	while (g->cur_balls < g->min_balls) {
-		b = new_ball(BALL_START_X_NORMAL, BALL_START_Y_NORMAL);
+		b = new_ball(BALL_START_X_NORMAL, BALL_START_Y_NORMAL, 1, 0.f);
 		b->next = g->balls_head;
 		g->balls_head = b;
 		++g->cur_balls;
--
cgit v0.9.1