Adding files related to the `screenhack` API for X11 hacks.

[screensavers] / screenhack / xft.h

/* xscreensaver, Copyright (c) 2014-2015 Jamie Zawinski <jwz@jwz.org>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation.  No representations are made about the suitability of this
* software for any purpose.  It is provided "as is" without express or 
* implied warranty.
*/

/* Compatibility layer using XDrawString, XDrawString16() or Xutf8DrawString().
  This layer is used by X11 systems without Xft, and by MacOS / iOS.
*/

#ifndef __XSCREENSAVER_XFT_H__
#define __XSCREENSAVER_XFT_H__

/* The XGlyphInfo field names and values are, of course, arbitrarily
  different from XCharStruct for no sensible reason.  These macros
  translate between them.
*/

# define XGlyphInfo_to_XCharStruct(G,C) do {            \
   (C).lbearing  =  -(G).x;                            \
   (C).rbearing  =   (G).width - (G).x;                \
   (C).ascent    =   (G).y;                            \
   (C).descent   =   (G).height - (G).y;               \
   (C).width     =   (G).xOff;                         \
} while (0)

# define XCharStruct_to_XGlyphInfo(C,G) do {            \
   (G).x         =  -(C).lbearing;                     \
   (G).y         =   (C).ascent;                       \
   (G).xOff      =   (C).width;                        \
   (G).yOff      =   0;                                \
   (G).width     =   (C).rbearing - (C).lbearing;      \
   (G).height    =   (C).ascent   + (C).descent;       \
} while (0)

/* Xutf8TextExtents returns a bounding box in an XRectangle, which
  conveniently interprets everything in the opposite direction
  from XGlyphInfo!
*/
# define XCharStruct_to_XmbRectangle(C,R) do {          \
   (R).x         =   (C).lbearing;                     \
   (R).y         =  -(C).ascent;                       \
   (R).width     =   (C).rbearing - (C).lbearing;      \
   (R).height    =   (C).ascent   + (C).descent;       \
} while (0)

# define XmbRectangle_to_XCharStruct(R,C,ADV) do {      \
   (C).lbearing  =   (R).x;                            \
   (C).rbearing  =   (R).width + (R).x;                \
   (C).ascent    =  -(R).y;                            \
   (C).descent   =   (R).height + (R).y;               \
   (C).width     =   (ADV);                            \
} while (0)


# ifdef HAVE_XFT

#  include <X11/Xft/Xft.h>

# else  /* !HAVE_XFT -- the rest of the file */

# ifdef HAVE_COCOA
#  include "jwxyz.h"
#elif defined(HAVE_ANDROID)
#  include "jwxyz.h"
# else
#  include <X11/Xlib.h>
# endif

/* This doesn't seem to work right under X11.  See comment in xft.c. */
# ifndef HAVE_COCOA
#  undef HAVE_XUTF8DRAWSTRING
# endif


# ifndef _Xconst
#  define _Xconst const
# endif

typedef struct _XGlyphInfo {
 unsigned short width, height;     /* bounding box of the ink */
 short x, y;           /* distance from upper left of bbox to glyph origin. */
 short xOff, yOff;     /* distance from glyph origin to next origin. */
} XGlyphInfo;


typedef struct _XftFont {
 XFontStruct *xfont;
# ifdef HAVE_XUTF8DRAWSTRING
 XFontSet fontset;
# endif
 char *name;
 int ascent;
 int descent;
 int height;
} XftFont;

typedef struct {
 unsigned short   red;
 unsigned short   green;
 unsigned short   blue;
 unsigned short   alpha;
} XRenderColor;

typedef struct _XftColor {
 unsigned long pixel;
 XRenderColor color;
} XftColor;

typedef struct _XftDraw XftDraw;

typedef unsigned char FcChar8;


XftFont *XftFontOpenXlfd (Display *dpy, int screen, _Xconst char *xlfd);
#define XftFontOpenName XftFontOpenXlfd

void XftFontClose (Display *dpy, XftFont *font);

Bool XftColorAllocName (Display  *dpy,
                       _Xconst Visual *visual,
                       Colormap cmap,
                       _Xconst char *name,
                       XftColor *result);

Bool XftColorAllocValue (Display *dpy,
                        _Xconst Visual *visual,
                        Colormap cmap,
                        _Xconst XRenderColor *color,
                        XftColor *result);

void XftColorFree (Display *dpy,
                  Visual *visual,
                  Colormap cmap,
                  XftColor *color);

XftDraw *XftDrawCreate (Display   *dpy,
                       Drawable  drawable,
                       Visual    *visual,
                       Colormap  colormap);

void XftDrawDestroy (XftDraw *draw);

void
XftTextExtentsUtf8 (Display         *dpy,
                   XftFont         *pub,
                   _Xconst FcChar8 *string,
                   int             len,
                   XGlyphInfo      *extents);

void
XftDrawStringUtf8 (XftDraw          *draw,
                  _Xconst XftColor *color,
                  XftFont          *pub,
                  int              x,
                  int              y,
                  _Xconst FcChar8  *string,
                  int              len);

# endif /* !HAVE_XFT */

#endif /* __XSCREENSAVER_XFT_H__ */