ref: 9eaba52cafcac7c2f3bfc72d7be1f15893196be1
dir: /DoConfig/fltk/src/fl_font_xft.cxx/
//
// "$Id$"
//
// Xft font code for the Fast Light Tool Kit (FLTK).
//
// Copyright 2001-2016 Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
// file is missing or damaged, see the license at:
//
// http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
//
// Draw fonts using Keith Packard's Xft library to provide anti-
// aliased text. Yow!
//
// Many thanks to Carl for making the original version of this.
//
// This font code only requires libXft to work. Contrary to popular
// belief there is no need to have FreeType, or the Xrender extension
// available to use this code. You will just get normal Xlib fonts
// (Xft calls them "core" fonts) The Xft algorithms for choosing
// these is about as good as the FLTK ones (I hope to fix it so it is
// exactly as good...), plus it can cache its results and share them
// between programs, so using this should be a win in all cases. Also
// it should be obvious by comparing this file and fl_font_x.cxx that
// it is a lot easier to program with Xft than with Xlib.
//
// Also, Xft supports UTF-8 text rendering directly, which will allow
// us to support UTF-8 on all platforms more easily.
//
// To actually get antialiasing you need the following:
//
// 1. You have XFree86 4
// 2. You have the XRender extension
// 3. Your X device driver supports the render extension
// 4. You have libXft
// 5. Your libXft has FreeType2 support compiled in
// 6. You have the FreeType2 library
//
// Distributions that have XFree86 4.0.3 or later should have all of this...
//
// Unlike some other Xft packages, I tried to keep this simple and not
// to work around the current problems in Xft by making the "patterns"
// complicated. I believe doing this defeats our ability to improve Xft
// itself. You should edit the ~/.xftconfig file to "fix" things, there
// are several web pages of information on how to do this.
//
#ifndef FL_DOXYGEN
#include <X11/Xft/Xft.h>
#include <math.h>
#define USE_OVERLAY 0
// The predefined fonts that FLTK has:
static Fl_Fontdesc built_in_table[] = {
#if 1
{" sans"},
{"Bsans"},
{"Isans"},
{"Psans"},
{" mono"},
{"Bmono"},
{"Imono"},
{"Pmono"},
{" serif"},
{"Bserif"},
{"Iserif"},
{"Pserif"},
{" symbol"},
{" screen"},
{"Bscreen"},
{" zapf dingbats"},
#else
{" helvetica"},
{"Bhelvetica"},
{"Ihelvetica"},
{"Phelvetica"},
{" courier"},
{"Bcourier"},
{"Icourier"},
{"Pcourier"},
{" times"},
{"Btimes"},
{"Itimes"},
{"Ptimes"},
{" symbol"},
{" lucidatypewriter"},
{"Blucidatypewriter"},
{" zapf dingbats"},
#endif
};
Fl_Fontdesc* fl_fonts = built_in_table;
Fl_XFont_On_Demand fl_xfont;
void *fl_xftfont = 0;
//static const char* fl_encoding_ = "iso8859-1";
static const char* fl_encoding_ = "iso10646-1";
static void fl_xft_font(Fl_Xlib_Graphics_Driver *driver, Fl_Font fnum, Fl_Fontsize size, int angle) {
if (fnum==-1) { // special case to stop font caching
driver->Fl_Graphics_Driver::font(0, 0);
return;
}
Fl_Font_Descriptor* f = driver->font_descriptor();
if (fnum == driver->Fl_Graphics_Driver::font() && size == driver->size() && f && f->angle == angle)
return;
driver->Fl_Graphics_Driver::font(fnum, size);
Fl_Fontdesc *font = fl_fonts + fnum;
// search the fontsizes we have generated already
for (f = font->first; f; f = f->next) {
if (f->size == size && f->angle == angle)// && !strcasecmp(f->encoding, fl_encoding_))
break;
}
if (!f) {
f = new Fl_Font_Descriptor(font->name, size, angle);
f->next = font->first;
font->first = f;
}
driver->font_descriptor(f);
#if XFT_MAJOR < 2
fl_xfont = f->font->u.core.font;
#else
fl_xfont = NULL; // invalidate
#endif // XFT_MAJOR < 2
fl_xftfont = (void*)f->font;
}
void Fl_Xlib_Graphics_Driver::font(Fl_Font fnum, Fl_Fontsize size) {
fl_xft_font(this,fnum,size,0);
}
static XftFont* fontopen(const char* name, Fl_Fontsize size, bool core, int angle) {
// Check: does it look like we have been passed an old-school XLFD fontname?
bool is_xlfd = false;
int hyphen_count = 0;
int comma_count = 0;
unsigned len = strlen(name);
if (len > 512) len = 512; // ensure we are not passed an unbounded font name
for(unsigned idx = 0; idx < len; idx++) {
if(name[idx] == '-') hyphen_count++; // check for XLFD hyphens
if(name[idx] == ',') comma_count++; // are there multiple names?
}
if(hyphen_count >= 14) is_xlfd = true; // Not a robust check, but good enough?
fl_open_display();
if(!is_xlfd) { // Not an XLFD - open as a XFT style name
XftFont *the_font = NULL; // the font we will return;
XftPattern *fnt_pat = XftPatternCreate(); // the pattern we will use for matching
int slant = XFT_SLANT_ROMAN;
int weight = XFT_WEIGHT_MEDIUM;
/* This "converts" FLTK-style font names back into "regular" names, extracting
* the BOLD and ITALIC codes as it does so - all FLTK font names are prefixed
* by 'I' (italic) 'B' (bold) 'P' (bold italic) or ' ' (regular) modifiers.
* This gives a fairly limited font selection ability, but is retained for
* compatibility reasons. If you really need a more complex choice, you are best
* calling Fl::set_fonts(*) then selecting the font by font-index rather than by
* name anyway. Probably.
* If you want to load a font who's name does actually begin with I, B or P, you
* MUST use a leading space OR simply use lowercase for the name...
*/
/* This may be efficient, but it is non-obvious. */
switch (*name++) {
case 'I': slant = XFT_SLANT_ITALIC; break; // italic
case 'P': slant = XFT_SLANT_ITALIC; // bold-italic (falls-through)
case 'B': weight = XFT_WEIGHT_BOLD; break; // bold
case ' ': break; // regular
default: name--; // no prefix, restore name
}
if(comma_count) { // multiple comma-separated names were passed
char *local_name = strdup(name); // duplicate the full name so we can edit the copy
char *curr = local_name; // points to first name in string
char *nxt; // next name in string
do {
nxt = strchr(curr, ','); // find comma separator
if (nxt) {
*nxt = 0; // terminate first name
nxt++; // first char of next name
}
// Add the current name to the match pattern
XftPatternAddString(fnt_pat, XFT_FAMILY, curr);
if(nxt) curr = nxt; // move onto next name (if it exists)
// Now do a cut-down version of the FLTK name conversion.
// NOTE: we only use the slant and weight of the first name,
// subsequent names we ignore this for... But we still need to do the check.
switch (*curr++) {
case 'I': break; // italic
case 'P': // bold-italic (falls-through)
case 'B': break; // bold
case ' ': break; // regular
default: curr--; // no prefix, restore name
}
comma_count--; // decrement name sections count
} while (comma_count >= 0);
free(local_name); // release our local copy of font names
}
else { // single name was passed - add it directly
XftPatternAddString(fnt_pat, XFT_FAMILY, name);
}
// Construct a match pattern for the font we want...
XftPatternAddInteger(fnt_pat, XFT_WEIGHT, weight);
XftPatternAddInteger(fnt_pat, XFT_SLANT, slant);
XftPatternAddDouble (fnt_pat, XFT_PIXEL_SIZE, (double)size);
XftPatternAddString (fnt_pat, XFT_ENCODING, fl_encoding_);
// rotate font if angle!=0
if (angle !=0) {
XftMatrix m;
XftMatrixInit(&m);
XftMatrixRotate(&m,cos(M_PI*angle/180.),sin(M_PI*angle/180.));
XftPatternAddMatrix (fnt_pat, XFT_MATRIX,&m);
}
if (core) {
XftPatternAddBool(fnt_pat, XFT_CORE, FcTrue);
XftPatternAddBool(fnt_pat, XFT_RENDER, FcFalse);
}
XftPattern *match_pat; // the best available match on the system
XftResult match_result; // the result of our matching attempt
// query the system to find a match for this font
match_pat = XftFontMatch(fl_display, fl_screen, fnt_pat, &match_result);
#if 0 // the XftResult never seems to get set to anything... abandon this code?
switch(match_result) { // how good a match is this font for our request?
case XftResultMatch:
puts("Object exists with the specified ID");
break;
case XftResultTypeMismatch:
puts("Object exists, but the type does not match");
break;
case XftResultNoId:
puts("Object exists, but has fewer values than specified");
break;
case FcResultOutOfMemory:
puts("FcResult: Malloc failed");
break;
case XftResultNoMatch:
puts("Object does not exist at all");
break;
default:
printf("Invalid XftResult status %d \n", match_result);
break;
}
#endif
#if 0 // diagnostic to print the "full name" of the font we matched. This works.
FcChar8 *picked_name = FcNameUnparse(match_pat);
printf("Match: %s\n", picked_name);
free(picked_name);
#endif
// open the matched font
if (match_pat) the_font = XftFontOpenPattern(fl_display, match_pat);
if (!match_pat || !the_font) {
// last chance, just open any font in the right size
the_font = XftFontOpen (fl_display, fl_screen,
XFT_FAMILY, XftTypeString, "sans",
XFT_SIZE, XftTypeDouble, (double)size,
NULL);
XftPatternDestroy(fnt_pat);
if (!the_font) {
Fl::error("Unable to find fonts. Check your FontConfig configuration.\n");
exit(1);
}
return the_font;
}
#if 0 // diagnostic to print the "full name" of the font we actually opened. This works.
FcChar8 *picked_name2 = FcNameUnparse(the_font->pattern);
printf("Open : %s\n", picked_name2);
free(picked_name2);
#endif
XftPatternDestroy(fnt_pat);
// XftPatternDestroy(match_pat); // FontConfig will destroy this resource for us. We must not!
return the_font;
}
else { // We were passed a font name in XLFD format
/* OksiD's X font code could handle being passed a comma separated list
* of XLFD's. It then attempted to find which font was "best" from this list.
* But XftFontOpenXlfd can not do this, so if a list is passed, we just
* terminate it at the first comma.
* A "better" solution might be to use XftXlfdParse() on each of the passed
* XLFD's to construct a "super-pattern" that incorporates attributes from all
* XLFD's and use that to perform a XftFontMatch(). Maybe...
*/
char *local_name = strdup(name);
if(comma_count) { // This means we were passed multiple XLFD's
char *pc = strchr(local_name, ',');
*pc = 0; // terminate the XLFD at the first comma
}
XftFont *the_font = XftFontOpenXlfd(fl_display, fl_screen, local_name);
free(local_name);
#if 0 // diagnostic to print the "full name" of the font we actually opened. This works.
puts("Font Opened"); fflush(stdout);
FcChar8 *picked_name2 = FcNameUnparse(the_font->pattern);
printf("Open : %s\n", picked_name2); fflush(stdout);
free(picked_name2);
#endif
return the_font;
}
} // end of fontopen
Fl_Font_Descriptor::Fl_Font_Descriptor(const char* name, Fl_Fontsize fsize, int fangle) {
// encoding = fl_encoding_;
size = fsize;
angle = fangle;
#if HAVE_GL
listbase = 0;
#endif // HAVE_GL
font = fontopen(name, fsize, false, angle);
}
Fl_Font_Descriptor::~Fl_Font_Descriptor() {
if (this == fl_graphics_driver->font_descriptor()) fl_graphics_driver->font_descriptor(NULL);
// XftFontClose(fl_display, font);
}
/* decodes the input UTF-8 string into a series of wchar_t characters.
n is set upon return to the number of characters.
Don't deallocate the returned memory.
*/
static const wchar_t *utf8reformat(const char *str, int& n)
{
static const wchar_t empty[] = {0};
static wchar_t *buffer;
static int lbuf = 0;
int newn;
if (n == 0) return empty;
newn = fl_utf8towc(str, n, (wchar_t*)buffer, lbuf);
if (newn >= lbuf) {
lbuf = newn + 100;
if (buffer) free(buffer);
buffer = (wchar_t*)malloc(lbuf * sizeof(wchar_t));
n = fl_utf8towc(str, n, (wchar_t*)buffer, lbuf);
} else {
n = newn;
}
return buffer;
}
static void utf8extents(Fl_Font_Descriptor *desc, const char *str, int n, XGlyphInfo *extents)
{
memset(extents, 0, sizeof(XGlyphInfo));
const wchar_t *buffer = utf8reformat(str, n);
#ifdef __CYGWIN__
XftTextExtents16(fl_display, desc->font, (XftChar16 *)buffer, n, extents);
#else
XftTextExtents32(fl_display, desc->font, (XftChar32 *)buffer, n, extents);
#endif
}
int Fl_Xlib_Graphics_Driver::height() {
if (font_descriptor()) return font_descriptor()->font->ascent + font_descriptor()->font->descent;
else return -1;
}
int Fl_Xlib_Graphics_Driver::descent() {
if (font_descriptor()) return font_descriptor()->font->descent;
else return -1;
}
double Fl_Xlib_Graphics_Driver::width(const char* str, int n) {
if (!font_descriptor()) return -1.0;
XGlyphInfo i;
utf8extents(font_descriptor(), str, n, &i);
return i.xOff;
}
/*double fl_width(uchar c) {
return fl_graphics_driver->width((const char *)(&c), 1);
}*/
static double fl_xft_width(Fl_Font_Descriptor *desc, FcChar32 *str, int n) {
if (!desc) return -1.0;
XGlyphInfo i;
XftTextExtents32(fl_display, desc->font, str, n, &i);
return i.xOff;
}
double Fl_Xlib_Graphics_Driver::width(unsigned int c) {
return fl_xft_width(font_descriptor(), (FcChar32 *)(&c), 1);
}
void Fl_Xlib_Graphics_Driver::text_extents(const char *c, int n, int &dx, int &dy, int &w, int &h) {
if (!font_descriptor()) {
w = h = 0;
dx = dy = 0;
return;
}
XGlyphInfo gi;
utf8extents(font_descriptor(), c, n, &gi);
w = gi.width;
h = gi.height;
dx = -gi.x;
dy = -gi.y;
} // fl_text_extents
/* This code is used (mainly by opengl) to get a bitmapped font. The
* original XFT-1 code used XFT's "core" fonts methods to load an XFT
* font that was actually a X-bitmap font, that could then be readily
* used with GL. But XFT-2 does not provide that ability, and there
* is no easy method to use an XFT font directly with GL. So...
*/
# if XFT_MAJOR > 1
// This function attempts, on XFT2 systems, to find a suitable "core" Xfont
// for GL or other bitmap font needs (we dont have an XglUseXftFont(...) function.)
// There's probably a better way to do this. I can't believe it is this hard...
// Anyway... This code attempts to make an XLFD out of the fltk-style font
// name it is passed, then tries to load that font. Surprisingly, this quite
// often works - boxes that have XFT generally also have a fontserver that
// can serve TTF and other fonts to X, and so the font name that fltk makes
// from the XFT name often also "exists" as an "core" X font...
// If this code fails to load the requested font, it falls back through a
// series of tried 'n tested alternatives, ultimately resorting to what the
// original fltk code did.
// NOTE: On my test boxes (FC6, FC7, FC8, ubuntu8.04, 9.04, 9.10) this works
// well for the fltk "built-in" font names.
static XFontStruct* load_xfont_for_xft2(Fl_Graphics_Driver *driver) {
XFontStruct* xgl_font = 0;
int size = driver->size();
int fnum = driver->font();
const char *wt_med = "medium";
const char *wt_bold = "bold";
const char *weight = wt_med; // no specifc weight requested - accept any
char slant = 'r'; // regular non-italic by default
char xlfd[128]; // we will put our synthetic XLFD in here
char *pc = strdup(fl_fonts[fnum].name); // what font were we asked for?
const char *name = pc; // keep a handle to the original name for freeing later
// Parse the "fltk-name" of the font
switch (*name++) {
case 'I': slant = 'i'; break; // italic
case 'P': slant = 'i'; // bold-italic (falls-through)
case 'B': weight = wt_bold; break; // bold
case ' ': break; // regular
default: name--; // no prefix, restore name
}
// first, we do a query with no prefered size, to see if the font exists at all
snprintf(xlfd, 128, "-*-%s-%s-%c-*--*-*-*-*-*-*-*-*", name, weight, slant); // make up xlfd style name
xgl_font = XLoadQueryFont(fl_display, xlfd);
if(xgl_font) { // the face exists, but can we get it in a suitable size?
XFreeFont(fl_display, xgl_font); // release the non-sized version
snprintf(xlfd, 128, "-*-%s-%s-%c-*--*-%d-*-*-*-*-*-*", name, weight, slant, (size*10));
xgl_font = XLoadQueryFont(fl_display, xlfd); // attempt to load the font at the right size
}
//puts(xlfd);
// try alternative names
if (!xgl_font) {
if (!strcmp(name, "sans")) {
name = "helvetica";
} else if (!strcmp(name, "mono")) {
name = "courier";
} else if (!strcmp(name, "serif")) {
name = "times";
} else if (!strcmp(name, "screen")) {
name = "lucidatypewriter";
} else if (!strcmp(name, "dingbats")) {
name = "zapf dingbats";
}
snprintf(xlfd, 128, "-*-*%s*-%s-%c-*--*-%d-*-*-*-*-*-*", name, weight, slant, (size*10));
xgl_font = XLoadQueryFont(fl_display, xlfd);
}
free(pc); // release our copy of the font name
// if we have nothing loaded, try a generic proportional font
if(!xgl_font) {
snprintf(xlfd, 128, "-*-helvetica-*-%c-*--*-%d-*-*-*-*-*-*", slant, (size*10));
xgl_font = XLoadQueryFont(fl_display, xlfd);
}
// If that still didn't work, try courier with resquested weight and slant
if(!xgl_font && weight != wt_med) {
snprintf(xlfd, 128, "-*-courier*-%s-%c-*--*-%d-*-*-*-*-*-*", weight, slant, (size*10));
xgl_font = XLoadQueryFont(fl_display, xlfd);
}
// If that still didn't work, try this instead
if(!xgl_font) {
snprintf(xlfd, 128, "-*-courier*-medium-%c-*--*-%d-*-*-*-*-*-*", slant, (size*10));
xgl_font = XLoadQueryFont(fl_display, xlfd);
}
//printf("glf: %d\n%s\n%s\n", size, xlfd, fl_fonts[fl_font_].name);
//if(xgl_font) puts("ok");
// Last chance fallback - this usually loads something...
if (!xgl_font) xgl_font = XLoadQueryFont(fl_display, "fixed");
return xgl_font;
} // end of load_xfont_for_xft2
# endif
static XFontStruct* fl_xxfont(Fl_Graphics_Driver *driver) {
# if XFT_MAJOR > 1
// kludge! XFT 2 and later does not provide core fonts for us to use with GL
// try to load a bitmap X font instead
static XFontStruct* xgl_font = 0;
static int glsize = 0;
static int glfont = -1;
// Do we need to load a new font?
if ((!xgl_font) || (glsize != driver->size()) || (glfont != driver->font())) {
// create a dummy XLFD for some font of the appropriate size...
if (xgl_font) XFreeFont(fl_display, xgl_font); // font already loaded, free it - this *might* be a Bad Idea
glsize = driver->size(); // record current font size
glfont = driver->font(); // and face
xgl_font = load_xfont_for_xft2(driver);
}
return xgl_font;
# else // XFT-1 provides a means to load a "core" font directly
if (driver->font_descriptor()->font->core) {
return driver->font_descriptor()->font->u.core.font; // is the current font a "core" font? If so, use it.
}
static XftFont* xftfont;
if (xftfont) XftFontClose (fl_display, xftfont);
xftfont = fontopen(fl_fonts[driver->font()].name, driver->size(), true, 0); // else request XFT to load a suitable "core" font instead.
return xftfont->u.core.font;
# endif // XFT_MAJOR > 1
}
XFontStruct* Fl_XFont_On_Demand::value() {
if (!ptr) ptr = fl_xxfont(fl_graphics_driver);
return ptr;
}
#if USE_OVERLAY
// Currently Xft does not work with colormapped visuals, so this probably
// does not work unless you have a true-color overlay.
extern bool fl_overlay;
extern Colormap fl_overlay_colormap;
extern XVisualInfo* fl_overlay_visual;
#endif
// For some reason Xft produces errors if you destroy a window whose id
// still exists in an XftDraw structure. It would be nice if this is not
// true, a lot of junk is needed to try to stop this:
static XftDraw* draw_;
static Window draw_window;
#if USE_OVERLAY
static XftDraw* draw_overlay;
static Window draw_overlay_window;
#endif
void fl_destroy_xft_draw(Window id) {
if (id == draw_window)
XftDrawChange(draw_, draw_window = fl_message_window);
#if USE_OVERLAY
if (id == draw_overlay_window)
XftDrawChange(draw_overlay, draw_overlay_window = fl_message_window);
#endif
}
void Fl_Xlib_Graphics_Driver::draw(const char *str, int n, int x, int y) {
if ( !this->font_descriptor() ) {
this->font(FL_HELVETICA, FL_NORMAL_SIZE);
}
#if USE_OVERLAY
XftDraw*& draw_ = fl_overlay ? draw_overlay : ::draw_;
if (fl_overlay) {
if (!draw_)
draw_ = XftDrawCreate(fl_display, draw_overlay_window = fl_window,
fl_overlay_visual->visual, fl_overlay_colormap);
else //if (draw_overlay_window != fl_window)
XftDrawChange(draw_, draw_overlay_window = fl_window);
} else
#endif
if (!draw_)
draw_ = XftDrawCreate(fl_display, draw_window = fl_window,
fl_visual->visual, fl_colormap);
else //if (draw_window != fl_window)
XftDrawChange(draw_, draw_window = fl_window);
Region region = fl_clip_region();
if (region && XEmptyRegion(region)) return;
XftDrawSetClip(draw_, region);
// Use fltk's color allocator, copy the results to match what
// XftCollorAllocValue returns:
XftColor color;
color.pixel = fl_xpixel(Fl_Graphics_Driver::color());
uchar r,g,b; Fl::get_color(Fl_Graphics_Driver::color(), r,g,b);
color.color.red = ((int)r)*0x101;
color.color.green = ((int)g)*0x101;
color.color.blue = ((int)b)*0x101;
color.color.alpha = 0xffff;
const wchar_t *buffer = utf8reformat(str, n);
#ifdef __CYGWIN__
XftDrawString16(draw_, &color, font_descriptor()->font, x, y, (XftChar16 *)buffer, n);
#else
XftDrawString32(draw_, &color, font_descriptor()->font, x, y, (XftChar32 *)buffer, n);
#endif
}
void Fl_Xlib_Graphics_Driver::draw(int angle, const char *str, int n, int x, int y) {
fl_xft_font(this, this->Fl_Graphics_Driver::font(), this->size(), angle);
this->draw(str, n, (int)x, (int)y);
fl_xft_font(this, this->Fl_Graphics_Driver::font(), this->size(), 0);
}
static void fl_drawUCS4(Fl_Graphics_Driver *driver, const FcChar32 *str, int n, int x, int y) {
#if USE_OVERLAY
XftDraw*& draw_ = fl_overlay ? draw_overlay : ::draw_;
if (fl_overlay) {
if (!draw_)
draw_ = XftDrawCreate(fl_display, draw_overlay_window = fl_window,
fl_overlay_visual->visual, fl_overlay_colormap);
else //if (draw_overlay_window != fl_window)
XftDrawChange(draw_, draw_overlay_window = fl_window);
} else
#endif
if (!draw_)
draw_ = XftDrawCreate(fl_display, draw_window = fl_window,
fl_visual->visual, fl_colormap);
else //if (draw_window != fl_window)
XftDrawChange(draw_, draw_window = fl_window);
Region region = fl_clip_region();
if (region && XEmptyRegion(region)) return;
XftDrawSetClip(draw_, region);
// Use fltk's color allocator, copy the results to match what
// XftCollorAllocValue returns:
XftColor color;
color.pixel = fl_xpixel(driver->color());
uchar r,g,b; Fl::get_color(driver->color(), r,g,b);
color.color.red = ((int)r)*0x101;
color.color.green = ((int)g)*0x101;
color.color.blue = ((int)b)*0x101;
color.color.alpha = 0xffff;
XftDrawString32(draw_, &color, driver->font_descriptor()->font, x, y, (FcChar32 *)str, n);
}
void Fl_Xlib_Graphics_Driver::rtl_draw(const char* c, int n, int x, int y) {
#if defined(__GNUC__)
// FIXME: warning Need to improve this XFT right to left draw function
#endif /*__GNUC__*/
// This actually draws LtoR, but aligned to R edge with the glyph order reversed...
// but you can't just byte-rev a UTF-8 string, that isn't valid.
// You can reverse a UCS4 string though...
int num_chars, wid, utf_len = strlen(c);
FcChar8 *u8 = (FcChar8 *)c;
FcBool valid = FcUtf8Len(u8, utf_len, &num_chars, &wid);
if (!valid)
{
// badly formed Utf-8 input string
return;
}
if (num_chars < n) n = num_chars; // limit drawing to usable characters in input array
FcChar32 *ucs_txt = new FcChar32[n+1];
FcChar32* pu;
int out, sz;
ucs_txt[n] = 0;
out = n-1;
while ((out >= 0) && (utf_len > 0))
{
pu = &ucs_txt[out];
sz = FcUtf8ToUcs4(u8, pu, utf_len);
utf_len = utf_len - sz;
u8 = u8 + sz;
out = out - 1;
}
// Now we have a UCS4 version of the input text, reversed, in ucs_txt
int offs = (int)fl_xft_width(font_descriptor(), ucs_txt, n);
fl_drawUCS4(this, ucs_txt, n, (x-offs), y);
delete[] ucs_txt;
}
#endif
//
// End of "$Id$"
//