/* Tabs Widget for XEmacs.
    Copyright (C) 1999 Edward A. Falk

 This file is part of XEmacs.

XEmacs is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.

XEmacs is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs.  If not, see <http://www.gnu.org/licenses/>. */

/* Synched up with: Gcs.c 1.7 */

 /* #### This code is duplicated many times within lwlib and XEmacs. It
    should be modularised. */

/*
 * Gcs.c - Utility functions to allocate GCs.
 *
 * Author: Edward A. Falk
 *	   falk@falconer.vip.best.com
 *
 * Date: Sept 29, 1998
 */

/* Functions:
 *
 * GC AllocFgGC(w, fg, font)
 *	Return a GC with foreground set as specified.
 *	If font is None, then the returned GC is allocated with font specified
 *	as a "don't care" value.
 *
 * GC
 * AllocBackgroundGC(w, font)
 *	Return a GC with the foreground set to the widget's background color.
 *
 * GC
 * AllocGreyGC(w, fg, font, contrast, be_nice_to_cmap)
 *	Widget	w ;
 *	Pixel	fg ;
 *	Font	font ;
 *	int	contrast ;
 *	int	be_nice_to_cmap ;
 *
 *	Return a GC suitable for rendering a widget in its "inactive" color.
 *	Normally returns a GC with a color somewhere between the widget's
 *	background color and the specified foreground. If font is None, then
 *	the returned GC is allocated with font specified as "don't care".
 *	If be_nice_to_cmap is True, the returned GC is created using a 50%
 *	dither instead of a new color.
 *
 *
 * GC
 * AllocShadeGC(w, fg, bg, font, contrast, be_nice_to_cmap)
 *	Widget	w ;
 *	Pixel	fg, bg ;
 *	Font	font ;
 *	int	contrast ;
 *	int	be_nice_to_cmap ;
 *
 *	Return a GC suitable for rendering in a shade somewhere between
 *	bg and fg, as determined by contrast (0 = bg, 100 = fg)
 *	If font is None, then the returned GC is allocated with
 *	font specified as "don't care".  If be_nice_to_cmap
 *	is True, the returned GC is created using a 50% dither
 *	instead of a new color.
 *
 *
 * GC
 * AllocTopShadowGC(w, contrast, be_nice_to_cmap)
 *	Return a GC suitable for rendering the "top shadow" decorations of
 *	a widget.  Returns a GC with foreground computed from widget's
 *	background color and contrast.  If be_nice_to_cmap is True, the
 *	returned GC will use a foreground color of white.  If widget depth
 *	is 1, this function will use a foreground color of black.
 *
 * GC
 * AllocBotShadowGC(w, contrast, be_nice_to_cmap)
 *	Return a GC suitable for rendering the "bottom shadow" decorations
 *	of a widget. Returns a GC with foreground computed from widget's
 *	background color and contrast. If be_nice_to_cmap is True, the
 *	returned GC will use a foreground color of black.
 *
 * GC
 * AllocArmGC(w, contrast, be_nice_to_cmap)
 *	Return a GC suitable for rendering the "armed" decorations of a
 *	widget. This GC would typically be used to fill in the widget's
 *	background. Returns a GC with foreground computed from widget's
 *	background color and contrast.  If be_nice_to_cmap is True, the
 *	returned GC will use a foreground color of black and a 50% dither.
 *
 *
 * void
 * Draw3dBox(w, x,y,wid,hgt,s, topgc, botgc)
 *	Utility function.  Draws a raised shadow box with outside dimensions
 *	as specified by x,y,wid,hgt and shadow width specified by s.
 *	A lowered shadow box may be generated by swapping topgc and botgc.
 *
 */

#include	<config.h>
#include	<stdio.h>

#include	<X11/Xlib.h>
#include	<X11/IntrinsicP.h>
#include	<X11/StringDefs.h>
#include	<X11/Xmu/Drawing.h>
#include	<X11/Xmu/Misc.h>
#include	"xlwgcs.h"

	/* Color & GC allocation.
	 *
	 * Frame widgets use the following graphics contexts:
	 *
	 *  Foreground		tab label text drawn this way
	 *  Insensitive Fg	foreground color greyed out.
	 *  Background		frame background color
	 *  Top shadow		upper-left highlight around widget
	 *  Bottom shadow	lower-right highlight around widget
	 *  Arm shadow		button pressed and ready to be released
	 *
	 *
	 * GC's are defined as follows, depending on attributes and
	 * window depth:
	 *
	 * Monochrome:
	 *	Foreground = foreground color attribute or BlackPixel()
	 *	Grey = Foreground color + 50% dither
	 *	Background = background color attribute or WhitePixel()
	 *	top shadow = foreground
	 *	bottom shadow = foreground
	 *	arm shadow = (what?)
	 *
	 * Color, beNiceToColormap=true:
	 *	Foreground = foreground color attribute or BlackPixel()
	 *	Grey = Foreground color + 50% dither
	 *	Background = background color attribute or WhitePixel()
	 *	top shadow = white
	 *	bottom shadow = black
	 *	arm shadow = (what?)
	 *
	 * Color, beNiceToColormap=false:
	 *	Foreground = foreground color attribute or BlackPixel()
	 *	Grey = (foreground color + background color)/2
	 *	Background = background color attribute or WhitePixel()
	 *	top shadow = background * 1.2
	 *	bottom shadow = background * .6
	 *	arm shadow = background * .8
	 *
	 * Special cases:
	 *	If background is white,   ??
	 *	if background is black,   ??
	 *
	 *
	 * If the widget's background is solid white or solid black,
	 * this code just picks some numbers.  (The choice is designed
	 * to be compatible with ThreeD interface.)
	 */



#if	NeedFunctionPrototypes
static	Pixmap	getDitherPixmap(Widget, int contrast) ;
#else
static	Pixmap	getDitherPixmap() ;
#endif

	/* return a GC with the specified foreground and optional font */

GC
AllocFgGC(Widget w, Pixel fg, Font font)
{
	XGCValues	values ;
	unsigned long	vmask, dcmask ;

	values.foreground = fg ;
	values.font = font ;

	if( font != None ) {
	  vmask = GCForeground|GCFont ;
	  dcmask = GCSubwindowMode|GCDashOffset|
		GCDashList|GCArcMode|GCBackground|GCGraphicsExposures ;
	} else {
	  vmask = GCForeground ;
	  dcmask = GCFont|GCSubwindowMode|GCDashOffset|
		GCDashList|GCArcMode|GCBackground|GCGraphicsExposures ;
	}

	return XtAllocateGC(w, w->core.depth, vmask, &values, 0L, dcmask) ;
}


	/* return gc with widget background color as the foreground */

GC
AllocBackgroundGC(Widget w, Font font)
{
	return AllocFgGC(w, w->core.background_pixel, font) ;
}


	/* Allocate an "inactive" GC.  Color is grey (possibly via
	 * dither pattern).
	 */

GC
AllocGreyGC(Widget w, Pixel fg, Font font, int contrast, Bool be_nice_to_cmap)
{
	return AllocShadeGC(w, fg, w->core.background_pixel,
		font, contrast, be_nice_to_cmap) ;
}


	/* Allocate a GC somewhere between two colors.  */

GC
AllocShadeGC(Widget w, Pixel fg, Pixel bg, Font font,
	     int contrast, Bool be_nice_to_cmap)
{
	XGCValues	values ;
	unsigned long	vmask, dcmask ;

	values.foreground = fg ;
	values.background = bg ;
	values.font = font ;

	if( font != None ) {
	  vmask = GCForeground|GCFont ;
	  dcmask = GCSubwindowMode|GCDashOffset|
		GCDashList|GCArcMode|GCGraphicsExposures ;
	} else {
	  vmask = GCForeground;
	  dcmask = GCFont|GCSubwindowMode|GCDashOffset|
		GCDashList|GCArcMode|GCGraphicsExposures ;
	}
	if( be_nice_to_cmap || w->core.depth == 1)
	{
	  if( contrast <= 5 )
	    values.foreground = bg ;
	  else if( contrast >= 95 )
	    values.foreground = fg ;
	  else {
	    vmask |= GCBackground|GCStipple|GCFillStyle ;
	    values.fill_style = FillOpaqueStippled ;
	    values.stipple = getDitherPixmap(w, contrast) ;
	  }

	  return XtAllocateGC(w, w->core.depth, vmask, &values, 0L, dcmask) ;
	} else {
	  dcmask |= GCBackground ;
	  values.foreground = AllocGreyPixel(w, fg, bg, contrast) ;
	  return XtAllocateGC(w, w->core.depth, vmask, &values, 0L, dcmask) ;
	}
}

	/* return top-shadow gc. */

GC
AllocTopShadowGC(Widget w, int contrast, Bool be_nice_to_cmap)
{
	Screen		*scr = XtScreen (w);
	XGCValues	values ;

	if( w->core.depth == 1 )
	  values.foreground = BlackPixelOfScreen(scr) ;
	else if( be_nice_to_cmap )
	  values.foreground = WhitePixelOfScreen(scr) ;
	else
	  values.foreground = AllocShadowPixel(w, 100+contrast) ;

	return XtAllocateGC(w, w->core.depth,
	    GCForeground, &values,
	    0L,
	    GCBackground|GCFont|GCSubwindowMode|GCGraphicsExposures|
		GCDashOffset|GCDashList|GCArcMode) ;
}

	/* return bottom-shadow gc. */

GC
AllocBotShadowGC(Widget w, int contrast, Bool be_nice_to_cmap)
{
	Screen		*scr = XtScreen (w);
	XGCValues	values ;

	if( w->core.depth == 1 || be_nice_to_cmap )
	  values.foreground = BlackPixelOfScreen(scr) ;
	else
	  values.foreground = AllocShadowPixel(w, 100-contrast) ;

	return XtAllocateGC(w, w->core.depth,
	    GCForeground, &values,
	    0L,
	    GCBackground|GCFont|GCSubwindowMode|GCGraphicsExposures|
		GCDashOffset|GCDashList|GCArcMode) ;
}

	/* return arm-shadow gc. */

GC
AllocArmGC(Widget w, int contrast, Bool be_nice_to_cmap)
{
	Screen		*scr = XtScreen (w);
	XGCValues	values ;

	/* Not clear exactly what we should do here.  Take a look at
	 * Xaw3d to see what they do.
	 */
	if( w->core.depth == 1 || be_nice_to_cmap )
	{
	  values.background = w->core.background_pixel ;
	  if( values.background == BlackPixelOfScreen(scr) )
	    values.foreground = WhitePixelOfScreen(scr) ;
	  else
	    values.foreground = BlackPixelOfScreen(scr) ;
	  values.fill_style = FillStippled ;
	  values.stipple = XmuCreateStippledPixmap(XtScreen(w), 1L, 0L, 1) ;

	  return XtAllocateGC(w, w->core.depth,
	      GCForeground|GCBackground|GCStipple|GCFillStyle,
	      &values, 0L,
	      GCFont|GCSubwindowMode|GCGraphicsExposures|
		  GCDashOffset|GCDashList|GCArcMode) ;
	} else {
	  values.foreground = AllocShadowPixel(w, 100-contrast) ;
	  return XtAllocateGC(w, w->core.depth,
	      GCForeground, &values,
	      0L,
	      GCBackground|GCFont|GCSubwindowMode|GCGraphicsExposures|
		  GCDashOffset|GCDashList|GCArcMode) ;
	}
}


Pixel
AllocShadowPixel(Widget w, int scale)
{
	XColor	get_c, set_c ;
	Display	*dpy = XtDisplay(w) ;
	Screen	*scr = XtScreen(w) ;
	Colormap cmap ;
	Pixel	maxColor ;

	cmap = w->core.colormap ;

	get_c.pixel = w->core.background_pixel ;
	if( get_c.pixel == WhitePixelOfScreen(scr)  ||
	    get_c.pixel == BlackPixelOfScreen(scr) )
	{
	  /* what we *ought* to do is choose gray75 as the base color,
	   * or perhaps gray83.  Instead, we choose colors that are
	   * the same as ThreeD would choose.
	   */
	  if( scale > 100 )	scale = 200 - scale ;
	  set_c.red = set_c.green = set_c.blue = 65535*scale/100 ;
	}
	else
	{
	  XQueryColor(dpy, cmap, &get_c) ;
	  /* adjust scale so that brightest component does not
	   * exceed 65535; otherwise hue would change.
	   */
	  if( scale > 100 ) {
	    maxColor = Max(get_c.red, Max(get_c.green, get_c.blue)) ;
	    if( scale*maxColor > 65535*100 )
	      scale = 65535*100/maxColor ;
	  }
	  set_c.red = scale * get_c.red / 100 ;
	  set_c.green = scale * get_c.green / 100 ;
	  set_c.blue = scale * get_c.blue / 100 ;
	}
	set_c.flags = DoRed | DoGreen | DoBlue ;
	if( XAllocColor(dpy, cmap, &set_c) )
	  return set_c.pixel ;
	else if( scale > 100 )
	  return WhitePixelOfScreen(scr) ;
	else
	  return BlackPixelOfScreen(scr) ;
}


	/* Allocate a pixel partway between foreground and background */


Pixel
AllocGreyPixel(Widget w, Pixel fg, Pixel bg, int scale)
{
  XColor	get_cf, get_cb ;
  Display	*dpy = XtDisplay(w) ;
  Colormap cmap ;

  cmap = w->core.colormap ;

  get_cf.pixel = fg ;
  get_cb.pixel = bg ;

  XQueryColor(dpy, cmap, &get_cf) ;
  XQueryColor(dpy, cmap, &get_cb) ;

  return AllocGreyPixelC(w, &get_cf, &get_cb, scale) ;
}



	/* Allocate a pixel partway between foreground and background */


Pixel
AllocGreyPixelC(Widget w, XColor *fg, XColor *bg, int scale)
{
  XColor	set_c ;
  Display	*dpy = XtDisplay(w) ;
  int		r,g,b ;
  Colormap	cmap = w->core.colormap ;

  r = (fg->red * scale +   bg->red * (100-scale)) / 100 ;
  g = (fg->green * scale + bg->green * (100-scale)) / 100 ;
  b = (fg->blue * scale +  bg->blue * (100-scale)) / 100 ;

  if( scale > 100 || scale < 0 )	/* look out for overflow */
  {
    int minc, maxc ;
    maxc = Max(r, Max(g,b)) ;
    minc = Min(r, Min(g,b)) ;
    if( maxc > 65535 )
    {
      maxc /= 16 ;
      r = r*(65535/16) / maxc ;
      g = g*(65535/16) / maxc ;
      b = b*(65535/16) / maxc ;
    }
    if( minc < 0 )
    {
      r = Max(r,0) ;
      g = Max(g,0) ;
      b = Max(b,0) ;
    }
  }

  set_c.red = r ; set_c.green = g ; set_c.blue = b ;
  set_c.flags = DoRed | DoGreen | DoBlue ;
  (void)XAllocColor(dpy, cmap, &set_c) ;
  return set_c.pixel ;
}





	/* draw a 3-d box */

void
Draw3dBox(Widget w, int x, int y, int wid, int hgt, int s, GC topgc, GC botgc)
{
	Display		*dpy = XtDisplay(w) ;
	Window		win = XtWindow(w) ;

	if( s == 0 ) return ;

	if( s == 1 ) {
	  XDrawLine(dpy,win,botgc, x,y+hgt-1, x+wid-1,y+hgt-1) ;
	  XDrawLine(dpy,win,botgc, x+wid-1,y, x+wid-1,y+hgt-1) ;
	  XDrawLine(dpy,win,topgc, x,y, x,y+hgt-1) ;
	  XDrawLine(dpy,win,topgc, x,y, x+wid-1,y) ;
	}
	else
	{
	  XPoint pts[6] ;

	  /* bottom-right shadow */
	  pts[0].x = x ;	pts[0].y = y + hgt ;
	  pts[1].x = s ;	pts[1].y = -s ;
	  pts[2].x = wid-2*s ;	pts[2].y = 0 ;
	  pts[3].x = 0 ;	pts[3].y = -(hgt-2*s) ;
	  pts[4].x = s ;	pts[4].y = -s ;
	  pts[5].x = 0 ;	pts[5].y = hgt ;
	  XFillPolygon(dpy,win,botgc, pts,6, Nonconvex,CoordModePrevious) ;

	  /* top-left shadow */
	  pts[0].x = x ;	pts[0].y = y ;
	  pts[1].x = wid ;	pts[1].y = 0 ;
	  pts[2].x = -s ;	pts[2].y = s ;
	  pts[3].x = -wid+2*s ;	pts[3].y = 0 ;
	  pts[4].x = 0 ;	pts[4].y = hgt-2*s ;
	  pts[5].x = -s ;	pts[5].y = s ;
	  XFillPolygon(dpy,win,topgc, pts,6, Nonconvex,CoordModePrevious) ;
	}
}

static	unsigned char screen0[2] = {0,0} ;
static	unsigned char screen25[2] = {0,0xaa} ;
static	unsigned char screen75[2] = {0xaa,0xff} ;
static	unsigned char screen100[2] = {0xff,0xff} ;

static	Pixmap
getDitherPixmap(Widget w, int contrast)
{
	Display	*dpy = XtDisplay(w) ;
	Window	win = XtWindow(w) ;

	if( contrast <= 5 )
	  return XCreateBitmapFromData(dpy,win, (char *)screen0, 2,2) ;
	else if( contrast <= 37 )
	  return XCreateBitmapFromData(dpy,win, (char *)screen25, 2,2) ;
	else if( contrast <= 62 )
	  return XmuCreateStippledPixmap(XtScreen(w), 1L, 0L, 1) ;
	else if( contrast <= 95 )
	  return XCreateBitmapFromData(dpy,win, (char *)screen75, 2,2) ;
	else
	  return XCreateBitmapFromData(dpy,win, (char *)screen100, 2,2) ;
}