From 875c3cf912367151fa81aab04b05b809bf3b7f6d Mon Sep 17 00:00:00 2001
From: Ian C <ianc@noddybox.co.uk>
Date: Thu, 8 Nov 2018 13:17:28 +0000
Subject: Added rain demo.

---
 xd.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 111 insertions(+), 1 deletion(-)

diff --git a/xd.c b/xd.c
index 638aa2f..600850b 100644
--- a/xd.c
+++ b/xd.c
@@ -176,10 +176,11 @@ static void	SnowDemo(void);
 static void	RoadDemo(void);
 static void	CoasterDemo(void);
 static void	FireworkDemo(void);
+static void	RainDemo(void);
 
 /* ---------------------------------------- GLOBAL VARS
 */
-#define NO_DEMOS	22
+#define NO_DEMOS	23
 
 static int		demo=NO_DEMOS-1;
 
@@ -297,6 +298,11 @@ static DemoInfo		demotbl[NO_DEMOS]=
 				FireworkDemo,
 				UsesPixmap
 			    },
+			    {
+				"Rain Demo",
+				RainDemo,
+				UsesPixmap
+			    },
 			};
 
 /* ---------------------------------------- X11 VARS
@@ -350,6 +356,8 @@ static void		LineP(XPoint *p1,XPoint *p2,int col);
 static void		Plot(int x,int y,int col);
 static void		Circle(int x,int y,int r,int col);
 static void		FCircle(int x,int y,int r,int col);
+static void		Ellipse(int x,int y,int rx,int ry,int col);
+static void		FEllipse(int x,int y,int rx,int ry,int col);
 static void		Print(int x,int y,int col,char *fmt,...);
 static void		Rect(int x,int y,int w,int h,int col);
 static void		FRect(int x,int y,int w,int h,int col);
@@ -747,6 +755,32 @@ static void FCircle(int x,int y,int r,int col)
 }
 
 
+static void Ellipse(int x,int y,int rx,int ry,int col)
+{
+    if (rx < 1 && ry < 1)
+    {
+	Plot(x,y,col);
+	return;
+    }
+
+    SetCol(col);
+    XDrawArc(disp,pix,gc,x-rx,y-ry,rx*2,ry*2,0,64*360);
+}
+
+
+static void FEllipse(int x,int y,int rx,int ry,int col)
+{
+    if (rx < 1 && ry < 1)
+    {
+	Plot(x,y,col);
+	return;
+    }
+
+    SetCol(col);
+    XFillArc(disp,pix,gc,x-rx,y-ry,rx*2,ry*2,0,64*360);
+}
+
+
 static void Print(int x,int y,int col,char *fmt,...)
 {
     char s[1024];
@@ -5047,4 +5081,80 @@ static void FireworkDemo(void)
 #undef DY_ADJ
 
 
+/* ---------------------------------------- RAIN DEMO
+ */
+
+#define MAX_DROPS	40
+#define MAX_RADIUS	40
+
+static void RainDemo(void)
+{
+    static int init = FALSE;
+
+    typedef struct
+    {
+	int	alive;
+    	int	x,y;
+	int	r;
+	int	life;
+    } Drop;
+
+    static Drop drop[MAX_DROPS];
+
+    int f;
+
+    if (!init)
+    {
+	init=TRUE;
+    }
+
+    Cls();
+
+    if (RND(100) > 95)
+    {
+    	for(f = 0; f < MAX_DROPS && drop[f].alive; f++)
+	{
+	}
+
+	if (f < MAX_DROPS)
+	{
+	    drop[f].alive = TRUE;
+	    drop[f].life = RND2(height-20, height/2);
+	    drop[f].y = 0;
+	    drop[f].r = 0;
+	    drop[f].x = RND(width);
+	}
+    }
+
+    for(f = 0; f < MAX_DROPS; f++)
+    {
+    	if (drop[f].alive)
+	{
+	    if (drop[f].life > 0)
+	    {
+		drop[f].y++;
+		drop[f].life--;
+
+		FCircle(drop[f].x, drop[f].y, 3, blue);
+		Line(drop[f].x, drop[f].y, drop[f].x, drop[f].y - 5, blue);
+	    }
+	    else
+	    {
+	    	if (drop[f].r < MAX_RADIUS)
+		{
+		    drop[f].r++;
+		    Ellipse(drop[f].x, drop[f].y, drop[f].r, drop[f].r/3, blue);
+		}
+		else
+		{
+		    drop[f].alive = FALSE;
+		}
+	    }
+	}
+    }
+}
+
+#undef MAX_DROPS
+
+
 /* END OF FILE */
-- 
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