Linux: Use libfontconfig directly instead of calling fc-match

There are apparently some linux systems out there with versions of
fontconfig that do not understanf the :charset query when passed to
fc-match. See #46

.travis.yml

@@ -12,7 +12,7 @@ matrix:
           addons:
             apt:
               packages:
-                - libfreetype6-dev
+                - libfontconfig1-dev
                 - libglew-dev
                 - libxi-dev
                 - libxrandr-dev
@@ -30,7 +30,7 @@ matrix:
           addons:
             apt:
               packages:
-                - libfreetype6-dev
+                - libfontconfig1-dev
                 - libglew-dev
                 - libxi-dev
                 - libxrandr-dev

kitty/data-types.c

@@ -40,6 +40,7 @@ static PyMethodDef module_methods[] = {
     {"read_bytes_dump", (PyCFunction)read_bytes_dump, METH_VARARGS, ""},
     {"wcwidth", (PyCFunction)wcwidth_wrap, METH_O, ""},
     {"change_wcwidth", (PyCFunction)change_wcwidth_wrap, METH_O, ""},
+    {"get_fontconfig_font", (PyCFunction)get_fontconfig_font, METH_VARARGS, ""},
     GLFW_FUNC_WRAPPERS
     {NULL, NULL, 0, NULL}        /* Sentinel */
 };
@@ -77,6 +78,7 @@ PyInit_fast_data_types(void) {
 #else
         if (!init_Face(m)) return NULL;
         if (!init_freetype_library(m)) return NULL;
+        if (!init_fontconfig_library(m)) return NULL;
 #endif
         PyModule_AddIntConstant(m, "BOLD", BOLD_SHIFT);
         PyModule_AddIntConstant(m, "ITALIC", ITALIC_SHIFT);

kitty/data-types.h

@@ -415,3 +415,5 @@ DECLARE_CH_SCREEN_HANDLER(linefeed)
 DECLARE_CH_SCREEN_HANDLER(carriage_return)
 
 bool init_freetype_library(PyObject*);
+bool init_fontconfig_library(PyObject*);
+PyObject *get_fontconfig_font(PyObject *self, PyObject *args);

kitty/fontconfig.c

@@ -0,0 +1,84 @@
+/*
+ * fontconfig.c
+ * Copyright (C) 2017 Kovid Goyal <kovid at kovidgoyal.net>
+ *
+ * Distributed under terms of the GPL3 license.
+ */
+
+#include "data-types.h"
+#include <fontconfig/fontconfig.h>
+
+PyObject*
+get_fontconfig_font(PyObject UNUSED *self, PyObject *args) {
+    char *family;
+    int bold, italic, allow_bitmapped_fonts, index = 0, hint_style=0, weight=0, slant=0;
+    double size_in_pts, dpi;
+    unsigned int character;
+    FcBool hinting, scalable, outline;
+    FcChar8 *path = NULL;
+    FcPattern *pat = NULL, *match = NULL;
+    FcResult result;
+    FcCharSet *charset = NULL;
+    PyObject *ans = NULL;
+
+    if (!PyArg_ParseTuple(args, "spppdId", &family, &bold, &italic, &allow_bitmapped_fonts, &size_in_pts, &character, &dpi)) return NULL;
+    pat = FcPatternCreate();
+    if (pat == NULL) return PyErr_NoMemory();
+
+#define AP(func, which, in, desc) if (!func(pat, which, in)) { PyErr_Format(PyExc_RuntimeError, "Failed to add %s to fontconfig patter", desc, NULL); goto end; }
+    AP(FcPatternAddString, FC_FAMILY, (const FcChar8*)family, "family");
+    if (!allow_bitmapped_fonts) {
+        AP(FcPatternAddBool, FC_OUTLINE, true, "outline");
+        AP(FcPatternAddBool, FC_SCALABLE, true, "scalable");
+    }
+    if (size_in_pts > 0) { AP(FcPatternAddDouble, FC_SIZE, size_in_pts, "size"); }
+    if (dpi > 0) { AP(FcPatternAddDouble, FC_DPI, dpi, "dpi"); }
+    if (bold) { AP(FcPatternAddInteger, FC_WEIGHT, FC_WEIGHT_BOLD, "weight"); }
+    if (italic) { AP(FcPatternAddInteger, FC_SLANT, FC_SLANT_ITALIC, "slant"); }
+    if (character > 0) {
+        charset = FcCharSetCreate();
+        if (charset == NULL) { PyErr_NoMemory(); goto end; }
+        if (!FcCharSetAddChar(charset, character)) { PyErr_SetString(PyExc_RuntimeError, "Failed to add character to fontconfig charset"); goto end; }
+        AP(FcPatternAddCharSet, FC_CHARSET, charset, "charset");
+    }
+#undef AP
+    FcConfigSubstitute(NULL, pat, FcMatchPattern);
+    FcDefaultSubstitute(pat);
+    match = FcFontMatch(NULL, pat, &result);
+    if (match == NULL) { PyErr_SetString(PyExc_KeyError, "FcFontMatch() failed"); goto end; }
+
+#define GI(func, which, out, desc) \
+    if (func(match, which, 0, & out) != FcResultMatch) { \
+        PyErr_Format(PyExc_RuntimeError, "Failed to get %s from match object", desc, NULL); goto end; \
+    }
+
+    GI(FcPatternGetString, FC_FILE, path, "file path");
+    GI(FcPatternGetInteger, FC_INDEX, index, "face index");
+    GI(FcPatternGetInteger, FC_WEIGHT, weight, "weight");
+    GI(FcPatternGetInteger, FC_SLANT, slant, "slant");
+    GI(FcPatternGetInteger, FC_HINT_STYLE, hint_style, "hint style");
+    GI(FcPatternGetBool, FC_HINTING, hinting, "hinting");
+    GI(FcPatternGetBool, FC_SCALABLE, scalable, "scalable");
+    GI(FcPatternGetBool, FC_OUTLINE, outline, "outline");
+#undef GI
+
+#define BP(x) (x ? Py_True : Py_False)
+    ans = Py_BuildValue("siiOOOii", path, index, hint_style, BP(hinting), BP(scalable), BP(outline), weight, slant);
+#undef BP
+
+end:
+    if (pat != NULL) FcPatternDestroy(pat);
+    if (match != NULL) FcPatternDestroy(match);
+    if (charset != NULL) FcCharSetDestroy(charset);
+    if (PyErr_Occurred()) return NULL;
+    return ans;
+}
+
+bool 
+init_fontconfig_library(PyObject UNUSED *m) {
+    if (!FcInit()) {
+        PyErr_SetString(PyExc_RuntimeError, "Failed to initialize the fontconfig library");
+        return false;
+    }
+    return true;
+}

kitty/fonts/fontconfig.py

@@ -7,7 +7,7 @@ import re
 import subprocess
 from collections import namedtuple
 
-from kitty.fast_data_types import Face
+from kitty.fast_data_types import Face, get_fontconfig_font
 
 
 def escape_family_name(name):
@@ -15,7 +15,8 @@ def escape_family_name(name):
 
 
 Font = namedtuple(
-    'Font', 'face hinting hintstyle bold italic scalable outline weight slant index'
+    'Font',
+    'face hinting hintstyle bold italic scalable outline weight slant index'
 )
 
 
@@ -27,10 +28,10 @@ def to_bool(x):
     return x.lower() == 'true'
 
 
-def get_font(
-    family,
-    bold,
-    italic,
+def get_font_subprocess(
+    family='monospace',
+    bold=False,
+    italic=False,
     allow_bitmaped_fonts=False,
     size_in_pts=None,
     character=None,
@@ -63,10 +64,34 @@ def get_font(
         path,
         to_bool(hinting),
         int(hintstyle), bold, italic,
-        to_bool(scalable), to_bool(outline), int(weight), int(slant), int(index)
+        to_bool(scalable),
+        to_bool(outline), int(weight), int(slant), int(index)
     )
 
 
+def get_font_lib(
+    family='monospace',
+    bold=False,
+    italic=False,
+    allow_bitmaped_fonts=False,
+    size_in_pts=None,
+    character=None,
+    dpi=None
+):
+    path, index, hintstyle, hinting, scalable, outline, weight, slant = get_fontconfig_font(
+        family, bold, italic, allow_bitmaped_fonts, size_in_pts or 0,
+        0 if character is None else ord(character[0]), dpi or 0
+    )
+
+    return Font(
+        path, hinting, hintstyle, bold, italic, scalable, outline, weight,
+        slant, index
+    )
+
+
+get_font = get_font_lib
+
+
 def find_font_for_character(
     family,
     char,

setup.py

@@ -106,8 +106,8 @@ def init_env(debug=False, asan=False):
     if isosx:
         font_libs = ['-framework', 'CoreText', '-framework', 'CoreGraphics']
     else:
-        cflags.extend(pkg_config('freetype2', '--cflags-only-I'))
-        font_libs = pkg_config('freetype2', '--libs')
+        cflags.extend(pkg_config('fontconfig', '--cflags-only-I'))
+        font_libs = pkg_config('fontconfig', '--libs')
     cflags.extend(pkg_config('glfw3', '--cflags-only-I'))
     ldflags.append('-shared')
     pylib = get_python_flags(cflags)
@@ -190,7 +190,7 @@ def option_parser():
 def find_c_files():
     ans, headers = [], []
     d = os.path.join(base, 'kitty')
-    exclude = {'freetype.c'} if isosx else {'core_text.m'}
+    exclude = {'freetype.c', 'fontconfig.c'} if isosx else {'core_text.m'}
     for x in os.listdir(d):
         ext = os.path.splitext(x)[1]
         if ext in ('.c', '.m') and os.path.basename(x) not in exclude: