From 82896a389cdd43984a4f1cb73d7a262ad60f26be Mon Sep 17 00:00:00 2001
From: Ian C <ianc@noddybox.co.uk>
Date: Thu, 1 Nov 2018 12:44:48 +0000
Subject: Added firework demo.

---
 xd.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 131 insertions(+), 1 deletion(-)

diff --git a/xd.c b/xd.c
index 77b9247..68c147a 100644
--- a/xd.c
+++ b/xd.c
@@ -175,10 +175,11 @@ static void	GravityDemo(void);
 static void	SnowDemo(void);
 static void	RoadDemo(void);
 static void	CoasterDemo(void);
+static void	FireworkDemo(void);
 
 /* ---------------------------------------- GLOBAL VARS
 */
-#define NO_DEMOS	21
+#define NO_DEMOS	22
 
 static int		demo=NO_DEMOS-1;
 
@@ -291,6 +292,11 @@ static DemoInfo		demotbl[NO_DEMOS]=
 				CoasterDemo,
 				UsesPixmap
 			    },
+			    {
+				"Firework Demo",
+				FireworkDemo,
+				UsesPixmap
+			    },
 			};
 
 /* ---------------------------------------- X11 VARS
@@ -4917,4 +4923,128 @@ static void CoasterDemo(void)
 #undef COASTER_POLE
 
 
+/* ---------------------------------------- FIREWORK DEMO
+ */
+
+#define MAX_FIREWORKS	10
+#define FIREWORK_SPARKS	100
+#define FIREWORK_COL	4
+#define DY_ADJ		0.008
+
+static void FireworkDemo(void)
+{
+    static int init = FALSE;
+
+    typedef struct
+    {
+    	double	x,y;
+	double	dx,dy;
+	int	life;
+    } Spark;
+
+    typedef struct
+    {
+	int	alive;
+    	double	x,y;
+	double	dx,dy;
+	int	life;
+	Spark	spark[FIREWORK_SPARKS];
+    } Firework;
+
+    static Firework firework[MAX_FIREWORKS];
+    static int colour[FIREWORK_COL];
+
+    int f,r;
+
+    if (!init)
+    {
+	init=TRUE;
+
+	colour[0] = white;
+	colour[1] = GetCol(255, 128, 128);
+	colour[2] = GetCol(128, 255, 128);
+	colour[3] = GetCol(128, 128, 255);
+    }
+
+    Cls();
+
+    if (RND(100) > 95)
+    {
+    	for(f = 0; f < MAX_FIREWORKS && firework[f].alive; f++)
+	{
+	}
+
+	if (f < MAX_FIREWORKS)
+	{
+	    firework[f].alive = TRUE;
+	    firework[f].life = RND2(200, 100);
+	    firework[f].y = height;
+	    firework[f].x = RND2(width - 100, 100);
+	    firework[f].dx = (RND(200) / 100.0) - 1.0;
+	    firework[f].dy = -(RND(300) / 100.0);
+	}
+    }
+
+    for(f = 0; f < MAX_FIREWORKS; f++)
+    {
+    	if (firework[f].alive)
+	{
+	    if (firework[f].life > 0)
+	    {
+	    	firework[f].x += firework[f].dx;
+		firework[f].y += firework[f].dy;
+		firework[f].dy += DY_ADJ;
+		firework[f].life--;
+
+		FCircle(firework[f].x, firework[f].y, 2,
+			colour[RND(FIREWORK_COL)]);
+
+		if (firework[f].life == 0)
+		{
+		    for(r = 0; r < FIREWORK_SPARKS; r++)
+		    {
+		    	firework[f].spark[r].life = RND2(200, 150);
+			firework[f].spark[r].x = firework[f].x;
+			firework[f].spark[r].y = firework[f].y;
+			firework[f].spark[r].dx = (RND(300) / 100.0) - 1.5;
+			firework[f].spark[r].dy = (RND(300) / 100.0) - 1.5;
+		    }
+		}
+	    }
+	    else
+	    {
+		int all_dead = TRUE;
+
+	    	for(r = 0; r < FIREWORK_SPARKS; r++)
+		{
+		    if (firework[f].spark[r].life > 0)
+		    {
+		    	all_dead = FALSE;
+
+			firework[f].spark[r].x += firework[f].spark[r].dx;
+			firework[f].spark[r].y += firework[f].spark[r].dy;
+			firework[f].spark[r].dy += DY_ADJ;
+			firework[f].spark[r].life--;
+
+			Plot(firework[f].spark[r].x,
+			     firework[f].spark[r].y,
+			     colour[RND(FIREWORK_COL)]);
+		    }
+		}
+
+		if (all_dead)
+		{
+		    firework[f].alive = FALSE;
+		}
+	    }
+	}
+    }
+}
+
+#undef MAX_FIREWORKS
+#undef FIREWORK_SPARKS
+#undef FIREWORK_COL
+#undef DY_ADJ
+
+
 /* END OF FILE */
-- 
cgit v1.2.3