Start work on rendering text for CSDs

kitty/data-types.c

@@ -216,6 +216,7 @@ extern bool init_cocoa(PyObject *module);
 extern bool init_macos_process_info(PyObject *module);
 #else
 extern bool init_freetype_library(PyObject*);
+extern bool init_freetype_render_ui_text(PyObject*);
 #endif
 
 
@@ -253,6 +254,7 @@ PyInit_fast_data_types(void) {
     if (!init_freetype_library(m)) return NULL;
     if (!init_fontconfig_library(m)) return NULL;
     if (!init_desktop(m)) return NULL;
+    if (!init_freetype_render_ui_text(m)) return NULL;
 #endif
     if (!init_fonts(m)) return NULL;
 

kitty/fontconfig.c

@@ -168,6 +168,31 @@ end:
     if (charset != NULL) FcCharSetDestroy(charset);
 }
 
+const char*
+file_path_for_font(const char *family, bool bold, bool italic) {
+    const char *ans = NULL;
+    FcPattern *match = NULL;
+    FcPattern *pat = FcPatternCreate();
+    if (pat == NULL) { PyErr_NoMemory(); return NULL; }
+    if (family && strlen(family) > 0) AP(FcPatternAddString, FC_FAMILY, (const FcChar8*)family, "family");
+    if (bold) { AP(FcPatternAddInteger, FC_WEIGHT, FC_WEIGHT_BOLD, "weight"); }
+    if (italic) { AP(FcPatternAddInteger, FC_SLANT, FC_SLANT_ITALIC, "slant"); }
+    FcResult result;
+    FcConfigSubstitute(NULL, pat, FcMatchPattern);
+    FcDefaultSubstitute(pat);
+    match = FcFontMatch(NULL, pat, &result);
+    if (match == NULL) { PyErr_SetString(PyExc_KeyError, "FcFontMatch() failed"); goto end; }
+    FcChar8 *out;
+    if (FcPatternGetString(pat, FC_FILE, 0, &out) != FcResultMatch) { PyErr_SetString(PyExc_ValueError, "No path found in fontconfig result"); goto end; }
+    ans = strdup((char*)out);
+    if (!ans) { PyErr_NoMemory(); goto end; }
+end:
+    if (match != NULL) FcPatternDestroy(match);
+    if (pat != NULL) FcPatternDestroy(pat);
+    return ans;
+}
+
+
 static PyObject*
 fc_match(PyObject UNUSED *self, PyObject *args) {
     char *family = NULL;

kitty/fonts.h

@@ -50,3 +50,8 @@ right_shift_canvas(pixel *canvas, size_t width, size_t height, size_t amt) {
         zero_at_ptr_count(src, amt);
     }
 }
+
+
+#ifndef __APPLE__
+const char* file_path_for_font(const char *family, bool bold, bool italic);
+#endif

kitty/freetype_render_ui_text.c

@@ -0,0 +1,31 @@
+/*
+ * freetype_render_ui_text.c
+ * Copyright (C) 2021 Kovid Goyal <kovid at kovidgoyal.net>
+ *
+ * Distributed under terms of the GPL3 license.
+ */
+
+#include "data-types.h"
+#include "fonts.h"
+
+static PyObject*
+path_for_font(PyObject *self UNUSED, PyObject *args) {
+    const char *family = NULL; int bold = 0, italic = 0;
+    if (!PyArg_ParseTuple(args, "|zpp", &family, &bold, &italic)) return NULL;
+    const char *ans = file_path_for_font(family, bold, italic);
+    if (!ans) return NULL;
+    return PyUnicode_FromString(ans);
+}
+
+static PyMethodDef module_methods[] = {
+    METHODB(path_for_font, METH_VARARGS),
+
+    {NULL, NULL, 0, NULL}        /* Sentinel */
+};
+
+
+bool
+init_freetype_render_ui_text(PyObject *module) {
+    if (PyModule_AddFunctions(module, module_methods) != 0) return false;
+    return true;
+}

setup.py

@@ -669,7 +669,11 @@ def compile_c_extension(
 def find_c_files() -> Tuple[List[str], List[str]]:
     ans, headers = [], []
     d = 'kitty'
-    exclude = {'fontconfig.c', 'freetype.c', 'desktop.c'} if is_macos else {'core_text.m', 'cocoa_window.m', 'macos_process_info.c'}
+    exclude = {
+        'fontconfig.c', 'freetype.c', 'desktop.c', 'freetype_render_ui_text.c'
+    } if is_macos else {
+        'core_text.m', 'cocoa_window.m', 'macos_process_info.c'
+    }
     for x in sorted(os.listdir(d)):
         ext = os.path.splitext(x)[1]
         if ext in ('.c', '.m') and os.path.basename(x) not in exclude: