Add Stars wallpaper to graphics demos

src/Demo/Graphics/WallPaperStars.CC

@@ -0,0 +1,62 @@
+/*
+	You "Zenith include" this because you want the wallpaper
+	routine to stay in mem even if this task is killed.
+*/
+
+#define NUM_STARS	GR_WIDTH * GR_HEIGHT / 2160
+// Derived from ratio for 600 for 1440x900
+
+class Star
+{
+	U16 x, y;
+
+} wall_stars[NUM_STARS];
+
+U0 (*old_wall_paper)(CTask *task);
+
+U0 WallPaperStars(CTask *task)
+{
+	I64 i;
+	CDC *dc = DCAlias(gr.dc2, task);
+
+	dc->color = YELLOW;
+
+	for (i = 0; i < NUM_STARS; i++)
+	{
+		GrPlot(dc, wall_stars[i].x, wall_stars[i].y);
+
+		if (++wall_stars[i].y > GR_HEIGHT)
+		{
+			wall_stars[i].y = 0;
+			wall_stars[i].x = RandU16 % GR_WIDTH;
+		}
+	}
+
+	//Uncomment the following if you wish. Will draw the old wallpaper over this one.
+	//old_wall_paper(task);
+
+	task->text_attr = WHITE << 4 + WHITE;
+
+}
+
+U0 WallInit()
+{
+	I64 i;
+
+	if (Fs != zenith_task)
+	{
+		"\nMust be Zenith Included. (SHIFT-F5 / RightClick->Zenith Include) \n";
+		return;
+	}
+	old_wall_paper=gr.fp_wall_paper;
+
+	for (i = 0; i < NUM_STARS; i++)
+	{
+		wall_stars[i].x = RandU16 % GR_WIDTH;
+		wall_stars[i].y = RandU16 % GR_HEIGHT;
+	}
+
+	gr.fp_wall_paper = &WallPaperStars;
+}
+
+WallInit;