More work on text rendering

kitty/fontconfig.c

@@ -10,6 +10,7 @@
 #include "fonts.h"
 #include <fontconfig/fontconfig.h>
 #include "emoji.h"
+#include "freetype_render_ui_text.h"
 #ifndef FC_COLOR
 #define FC_COLOR "color"
 #endif
@@ -168,28 +169,36 @@ end:
     if (charset != NULL) FcCharSetDestroy(charset);
 }
 
-const char*
-file_path_for_font(const char *family, bool bold, bool italic) {
-    const char *ans = NULL;
+bool
+information_for_font_family(const char *family, bool bold, bool italic, FontConfigFace *ans) {
+    memset(ans, 0, sizeof(FontConfigFace));
     FcPattern *match = NULL;
     FcPattern *pat = FcPatternCreate();
-    if (pat == NULL) { PyErr_NoMemory(); return NULL; }
+    bool ok = false;
+    if (pat == NULL) { PyErr_NoMemory(); return ok; }
     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);
+    /* printf("fc_match = %s\n", FcNameUnparse(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; }
+#define g(func, prop, output) if (func(match, prop, 0, &output) != FcResultMatch) { PyErr_SetString(PyExc_ValueError, "No " #prop " found in fontconfig match result"); goto end; }
+    g(FcPatternGetString, FC_FILE, out);
+    g(FcPatternGetInteger, FC_INDEX, ans->index);
+    g(FcPatternGetInteger, FC_HINT_STYLE, ans->hintstyle);
+    g(FcPatternGetBool, FC_HINTING, ans->hinting);
+#undef g
+    ans->path = strdup((char*)out);
+    if (!ans->path) { PyErr_NoMemory(); goto end; }
+    ok = true;
 end:
     if (match != NULL) FcPatternDestroy(match);
     if (pat != NULL) FcPatternDestroy(pat);
-    return ans;
+    return ok;
 }
 
 

kitty/fonts.h

@@ -50,8 +50,3 @@ 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.c

@@ -252,6 +252,15 @@ face_from_descriptor(PyObject *descriptor, FONTS_DATA_HANDLE fg) {
     return (PyObject*)self;
 }
 
+FT_Face
+native_face_from_path(const char *path, int index) {
+    int error;
+    FT_Face ans;
+    error = FT_New_Face(library, path, index, &ans);
+    if (error) { set_freetype_error("Failed to load face, with error:", error); return NULL; }
+    return ans;
+}
+
 PyObject*
 face_from_path(const char *path, int index, FONTS_DATA_HANDLE fg) {
     Face *ans = (Face*)Face_Type.tp_alloc(&Face_Type, 0);

kitty/freetype_render_ui_text.c

@@ -5,16 +5,54 @@
  * Distributed under terms of the GPL3 license.
  */
 
-#include "data-types.h"
-#include "fonts.h"
+#include "freetype_render_ui_text.h"
+#include <hb.h>
+#include <hb-ft.h>
+
+typedef struct FamilyInformation {
+    char *name;
+    bool bold, italic;
+} FamilyInformation;
+
+FT_Face main_face = NULL;
+FontConfigFace main_face_information = {0};
+FamilyInformation main_face_family = {0};
+
+
+static void
+cleanup(void) {
+    if (main_face) FT_Done_Face(main_face);
+    main_face = NULL;
+    free(main_face_information.path); main_face_information.path = NULL;
+    free(main_face_family.name);
+    memset(&main_face_family, 0, sizeof(FamilyInformation));
+}
+
+void
+set_main_face_family(const char *family, bool bold, bool italic) {
+    cleanup();
+    main_face_family.name = strdup(family);
+    main_face_family.bold = bold; main_face_family.italic = italic;
+}
+
+static bool
+ensure_state(void) {
+    if (main_face) return false;
+    if (!information_for_font_family(main_face_family.name, main_face_family.bold, main_face_family.italic, &main_face_information)) return false;
+    main_face = native_face_from_path(main_face_information.path, main_face_information.index);
+    return !!main_face;
+}
 
 static PyObject*
 path_for_font(PyObject *self UNUSED, PyObject *args) {
+    (void)ensure_state;
     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);
+    FontConfigFace f;
+    if (!information_for_font_family(family, bold, italic, &f)) return NULL;
+    PyObject *ret = Py_BuildValue("{ss si si si}", "path", f.path, "index", f.index, "hinting", f.hinting, "hintstyle", f.hintstyle);
+    free(f.path);
+    return ret;
 }
 
 static PyMethodDef module_methods[] = {
@@ -27,5 +65,9 @@ static PyMethodDef module_methods[] = {
 bool
 init_freetype_render_ui_text(PyObject *module) {
     if (PyModule_AddFunctions(module, module_methods) != 0) return false;
+    if (Py_AtExit(cleanup) != 0) {
+        PyErr_SetString(PyExc_RuntimeError, "Failed to register the fontconfig library at exit handler");
+        return false;
+    }
     return true;
 }

kitty/freetype_render_ui_text.h

@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2021 Kovid Goyal <kovid at kovidgoyal.net>
+ *
+ * Distributed under terms of the GPL3 license.
+ */
+
+#pragma once
+
+#include "data-types.h"
+#include <hb-ft.h>
+
+typedef struct FontConfigFace {
+    char *path;
+    int index;
+    int hinting;
+    int hintstyle;
+} FontConfigFace;
+
+bool information_for_font_family(const char *family, bool bold, bool italic, FontConfigFace *ans);
+FT_Face native_face_from_path(const char *path, int index);
+
+
+void set_main_face_family(const char *family, bool bold, bool italic);