#include	<stdio.h>
#include	<Xm/MainW.h>
#include	<Xm/DrawingA.h>
#include	<Xm/RowColumn.h>
#include	<Xm/CascadeB.h>
#include	<Xm/PushB.h>
#include	<Xm/Scale.h>

#define	WinWidth	600
#define	WinHeight	400
#define	PointSize	2
#define	NPoints		50

XtAppContext	app_con;
Widget	app_sh, draw;
Boolean	Running = False;

String	fallback_resources[] = {
	"*FontList:     *-helvetica-bold-r-*-140-75-*",
	"*background:   grey90",
	"*.main.commandWindowLocation: XmCOMMAND_BELOW_WORKSPACE",
	"*.field.background: black",
	"*.field.foreground: white",
	"*.command.marginWidth: 0",
	"*.command.marginHeight: 0",
	"*.command.spacing: 0",
	"*.nvalue.titleString: N",
	"*.nvalue.minimum: 1",
	"*.nvalue.maximum: 500",
	"*.ivalue.titleString: initial value",
	"*.ivalue.maximum: 1000",
	"*.ivalue.decimalPoints: 3",
	"*.mvalue.titleString: minimum alpha",
	"*.mvalue.minimum: 1000",
	"*.mvalue.maximum: 3990",
	"*.mvalue.decimalPoints: 3",
	"*.White.background: white","*.Yellow.background: yellow",
	"*.Cyan.background: cyan","*.Magenta.background: magenta",
	"*.Green.background: green","*.Red.background: red",
	NULL
};
Display	*dpy = NULL;
GC	gc;
Window	win;
Pixmap pmap;
Pixel	fg, bg;

int	N = 300;
double	A0 = 0.2;
double	AlphaMin = 2.5;

void setup_draw_info()
{
	dpy = XtDisplay(app_sh);
	gc = DefaultGC(dpy,0);
	win = XtWindow(draw);
	pmap = XCreatePixmap(dpy,win,WinWidth,WinHeight,DefaultDepth(dpy,0));
	XtVaGetValues(draw,XmNforeground,&fg,XmNbackground,&bg,NULL);
	XSetForeground(dpy,gc,bg);
	XFillRectangle(dpy,pmap,gc,0,0,WinWidth,WinHeight);
	XSetForeground(dpy,gc,fg);
}
void draw_one(n) int n;
{
	int	x, y, xx, i;
	double	alpha, a;
	for (x = 0; x < WinWidth; x ++) {
		alpha = x * (4.-AlphaMin) / WinWidth + AlphaMin;
		for (a = A0, i = 0; i < N-1; i ++)
			a = (1. - a) * a * alpha;
		for (i = 0; i < n; i ++) {
			a = (1. - a) * a * alpha;
			y = WinHeight-1 - (int)(a * WinHeight) - PointSize/2;
			xx = x - PointSize/2;
			XFillRectangle(dpy,win,gc,xx,y,PointSize,PointSize);
			XFillRectangle(dpy,pmap,gc,xx,y,PointSize,PointSize);
		}
	}
}
void RedisplayCB(w,cl,cd) Widget w; XtPointer cl,cd;
{
	XmDrawingAreaCallbackStruct *d = (XmDrawingAreaCallbackStruct *)cd;
	XExposeEvent	*e = &(d->event->xexpose);
	XCopyArea(dpy,pmap,win,gc,e->x,e->y,e->width,e->height,e->x,e->y);
}
void QuitCB(w,cl,cd) Widget w; XtPointer cl,cd; { exit(0);}
void ClearCB(w,cl,cd) Widget w; XtPointer cl,cd;
{
	XClearWindow(dpy,win);
	XSetForeground(dpy,gc,bg);
	XFillRectangle(dpy,pmap,gc,0,0,WinWidth,WinHeight);
	XSetForeground(dpy,gc,fg);
}
void RedrawCB(w,cl,cd) Widget w; XtPointer cl,cd; { draw_one(1); }
void DrawManyCB(w,cl,cd) Widget w; XtPointer cl,cd; { draw_one(NPoints); }
void ColorCB(w,cl,cd) Widget w; XtPointer cl,cd;
{
	XtVaGetValues(w,XmNbackground,&fg,NULL);
	XSetForeground(dpy,gc,fg);
}
void ValueCB(w,cl,cd) Widget w; XtPointer cl,cd;
{
	XmScaleCallbackStruct	*cs = (XmScaleCallbackStruct *)cd;
	*((double *)cl) = cs->value * 0.001;
	draw_one(1);
}
void NValueCB(w,cl,cd) Widget w; XtPointer cl,cd;
{
	XmScaleCallbackStruct	*cs = (XmScaleCallbackStruct *)cd;
	N = cs->value;
	draw_one(1);
}
main(argc,argv)
int	argc;
char	*argv[];
{
	Widget	main_win, menu_bar, menu, button, command, scale;
	Arg	args[8];
	int	n;
	char	**p;
	static	char	*cols[] = {"White","Yellow","Cyan","Magenta",
		"Green","Red",NULL};
	app_sh = XtAppInitialize(&app_con,"Branch",NULL,0,
		&argc,argv,fallback_resources,NULL,0);
	XtSetArg(args[0],XmNshowSeparator,True);
	XtManageChild(main_win=XmCreateMainWindow(app_sh,"main",args,1));
	XtManageChild(menu_bar=XmCreateMenuBar(main_win,"bar",NULL,0));
	XtManageChild(button=XmCreateCascadeButton(menu_bar,"Quit",NULL,0));
	XtAddCallback(button,XmNactivateCallback,QuitCB,NULL);
	XtManageChild(button=XmCreateCascadeButton(menu_bar,"Clear",NULL,0));
	XtAddCallback(button,XmNactivateCallback,ClearCB,NULL);
	XtManageChild(button=XmCreateCascadeButton(menu_bar,"Draw",NULL,0));
	XtAddCallback(button,XmNactivateCallback,RedrawCB,NULL);
	XtManageChild(button=XmCreateCascadeButton(menu_bar,"Draw many",NULL,0));
	XtAddCallback(button,XmNactivateCallback,DrawManyCB,NULL);
	menu = XmCreatePulldownMenu(menu_bar,"ColorMenu",NULL,0);
	for (p = cols; *p; p ++) {
		XtManageChild(button=XmCreatePushButton(menu,*p,NULL,0));
		XtAddCallback(button,XmNactivateCallback,ColorCB,NULL);
	}
	XtSetArg(args[0],XmNsubMenuId,menu);
	XtManageChild(XmCreateCascadeButton(menu_bar,"Color",args,1));
	XtSetArg(args[0],XmNorientation,XmVERTICAL);
	XtManageChild(command=XmCreateRowColumn(main_win,"command",args,1));
	XtSetArg(args[0],XmNorientation,XmHORIZONTAL);
	XtSetArg(args[1],XmNshowValue,True);
	XtSetArg(args[2],XmNvalue,N);
	XtManageChild(scale=XmCreateScale(command,"nvalue",args,3));
	XtAddCallback(scale,XmNvalueChangedCallback,NValueCB,NULL);
	XtSetArg(args[2],XmNvalue,(int)(A0*1000));
	XtManageChild(scale=XmCreateScale(command,"ivalue",args,3));
	XtAddCallback(scale,XmNvalueChangedCallback,
		ValueCB,(XtPointer)(&A0));
	XtSetArg(args[2],XmNvalue,(int)(AlphaMin*1000));
	XtManageChild(scale=XmCreateScale(command,"mvalue",args,3));
	XtAddCallback(scale,XmNvalueChangedCallback,
		ValueCB,(XtPointer)(&AlphaMin));
	XtSetArg(args[0],XmNwidth,WinWidth);
	XtSetArg(args[1],XmNheight,WinHeight);
	XtManageChild(draw=XmCreateDrawingArea(main_win,"field",args,2));
	XtVaSetValues(main_win,XmNcommandWindow,command,
		XmNworkWindow,draw,NULL);
	XtRealizeWidget(app_sh);
	setup_draw_info(draw);
	XtAddCallback(draw,XmNexposeCallback,RedisplayCB,NULL);
	XtAppMainLoop(app_con);
}