1 files changed, 131 insertions, 0 deletions
diff --git a/xft.go b/xft.go
new file mode 100644
index 0000000..73ab52b
--- /dev/null
+++ b/xft.go
@@ -0,0 +1,131 @@
+package main
+
+/*
+#cgo pkg-config: xft xrender x11 fontconfig
+#include <stdlib.h>
+#include <X11/Xlib.h>
+#include <X11/extensions/Xrender.h>
+#include <X11/Xft/Xft.h>
+
+static Display *_dpy;
+static XftDraw *_drw;
+static XftFont *_ft;
+static Visual *_vis;
+static Colormap _cmap;
+static XftColor _fg;
+static int _scr;
+
+static int wm_xft_init(const char *pattern)
+{
+    int event_basep, error_basep;
+    _dpy = XOpenDisplay(NULL);
+    if (!_dpy)
+        return -1;
+    if (!XRenderQueryExtension(_dpy, &event_basep, &error_basep))
+        return -3;
+    XftInit(NULL);
+    _scr = DefaultScreen(_dpy);
+    _vis = DefaultVisual(_dpy, _scr);
+    _cmap = DefaultColormap(_dpy, _scr);
+    _ft = XftFontOpenName(_dpy, _scr, pattern);
+    if (!_ft)
+        return -2;
+    return 0;
+}
+
+static void wm_xft_setfg(unsigned int px)
+{
+    XRenderColor c;
+    c.red   = ((px >> 16) & 0xff) << 8;
+    c.green = ((px >> 8) & 0xff) << 8;
+    c.blue  = (px & 0xff) << 8;
+    c.alpha = 0xffff;
+    XftColorAllocValue(_dpy, _vis, _cmap, &c, &_fg);
+}
+
+static int wm_xft_width(const char *s, int n)
+{
+    XGlyphInfo gi;
+    XftTextExtentsUtf8(_dpy, _ft, (const FcChar8 *)s, n, &gi);
+    return gi.xOff;
+}
+
+static void wm_xft_draw(unsigned int win, int x, int y,
+                        const char *s, int n, unsigned int fg)
+{
+    if (!_dpy || !_ft || !win)
+        return;
+    if (!_drw)
+        _drw = XftDrawCreate(_dpy, (Drawable)win, _vis, _cmap);
+    if (!_drw)
+        return;
+    XftDrawChange(_drw, (Drawable)win);
+    wm_xft_setfg(fg);
+    XftDrawStringUtf8(_drw, &_fg, _ft, x, y, (const FcChar8 *)s, n);
+    XFlush(_dpy);
+}
+
+static int wm_xft_ascent(void)  { return _ft ? _ft->ascent : 0; }
+static int wm_xft_descent(void) { return _ft ? _ft->descent : 0; }
+*/
+import "C"
+
+import (
+	"unsafe"
+
+	"github.com/BurntSushi/xgb/xproto"
+)
+
+var xftOK bool
+
+func xftInit(pattern string) error {
+	cp := C.CString(pattern)
+	defer C.free(unsafe.Pointer(cp))
+
+	switch rc := int(C.wm_xft_init(cp)); rc {
+	case 0:
+		xftOK = true
+		return nil
+	case -1:
+		return errXftNoDisplay
+	case -2:
+		return errXftNoFont
+	default:
+		return errXftNoRender
+	}
+}
+
+var (
+	errXftNoDisplay = errXft("xft: cannot open display")
+	errXftNoFont    = errXft("xft: cannot load font pattern")
+	errXftNoRender  = errXft("xft: no RENDER extension")
+)
+
+type errXft string
+
+func (e errXft) Error() string { return string(e) }
+
+func xftTextWidth(s string) int {
+	if !xftOK {
+		return 0
+	}
+	cs := C.CString(s)
+	defer C.free(unsafe.Pointer(cs))
+	return int(C.wm_xft_width(cs, C.int(len(s))))
+}
+
+func xftDrawText(win xproto.Window, x, baseline int, s string, fg uint32) {
+	if !xftOK || win == 0 {
+		return
+	}
+	cs := C.CString(s)
+	defer C.free(unsafe.Pointer(cs))
+	C.wm_xft_draw(C.uint(win), C.int(x), C.int(baseline), cs, C.int(len(s)), C.uint(fg))
+}
+
+func xftMetrics() (ascent, descent int) {
+	if !xftOK {
+		return 0, 0
+	}
+	return int(C.wm_xft_ascent()), int(C.wm_xft_descent())
+}