fontselect: automatically read metadata from font file if needed

4 files changed, 76 insertions, 77 deletions

diff --git a/libass/ass_coretext.c b/libass/ass_coretext.c
index 42259bb..8002d8b 100644
--- a/libass/ass_coretext.c
+++ b/libass/ass_coretext.c
@@ -126,8 +126,7 @@ static char *get_name(CTFontDescriptorRef fontd, CFStringRef attr)
     return ret;
 }
 
-static bool get_font_info_ct(ASS_Library *lib, FT_Library ftlib,
-                             CTFontDescriptorRef fontd,
+static bool get_font_info_ct(CTFontDescriptorRef fontd,
                              char **path_out,
                              ASS_FontProviderMetaData *info)
 {
@@ -139,29 +138,19 @@ static bool get_font_info_ct(ASS_Library *lib, FT_Library ftlib,
     }
 
     char *ps_name = get_name(fontd, kCTFontNameAttribute);
+    info->postscript_name = ps_name;
     if (!ps_name)
         return false;
 
     char *family_name = get_name(fontd, kCTFontFamilyNameAttribute);
-    if (!family_name) {
-        free(ps_name);
+    info->extended_family = family_name;
+    if (!family_name)
         return false;
-    }
-
-    bool got_info =
-        ass_get_font_info(lib, ftlib, path, ps_name, -1, family_name, info);
-    free(ps_name);
 
-    if (got_info)
-        info->extended_family = family_name;
-    else
-        free(family_name);
-
-    return got_info;
+    return true;
 }
 
-static void process_descriptors(ASS_Library *lib, FT_Library ftlib,
-                                ASS_FontProvider *provider, CFArrayRef fontsd)
+static void process_descriptors(ASS_FontProvider *provider, CFArrayRef fontsd)
 {
     if (!fontsd)
         return;
@@ -172,20 +161,11 @@ static void process_descriptors(ASS_Library *lib, FT_Library ftlib,
         int index = -1;
 
         char *path = NULL;
-        if (get_font_info_ct(lib, ftlib, fontd, &path, &meta)) {
+        if (get_font_info_ct(fontd, &path, &meta)) {
             CFRetain(fontd);
             ass_font_provider_add_font(provider, &meta, path, index, (void*)fontd);
         }
 
-        for (int j = 0; j < meta.n_family; j++)
-            free(meta.families[j]);
-
-        for (int j = 0; j < meta.n_fullname; j++)
-            free(meta.fullnames[j]);
-
-        free(meta.families);
-        free(meta.fullnames);
-
         free(meta.postscript_name);
         free(meta.extended_family);
 
@@ -196,8 +176,6 @@ static void process_descriptors(ASS_Library *lib, FT_Library ftlib,
 static void match_fonts(void *priv, ASS_Library *lib, ASS_FontProvider *provider,
                         char *name)
 {
-    FT_Library ftlib = priv;
-
     CFStringRef cfname =
         CFStringCreateWithCString(NULL, name, kCFStringEncodingUTF8);
     if (!cfname)
@@ -256,7 +234,7 @@ static void match_fonts(void *priv, ASS_Library *lib, ASS_FontProvider *provider
     if (!fontsd)
         goto cleanup;
 
-    process_descriptors(lib, ftlib, provider, fontsd);
+    process_descriptors(provider, fontsd);
 
 cleanup:
     SAFE_CFRelease(fontsd);
@@ -329,5 +307,5 @@ ASS_FontProvider *
 ass_coretext_add_provider(ASS_Library *lib, ASS_FontSelector *selector,
                           const char *config, FT_Library ftlib)
 {
-    return ass_font_provider_new(selector, &coretext_callbacks, ftlib);
+    return ass_font_provider_new(selector, &coretext_callbacks, NULL);
 }
diff --git a/libass/ass_font.c b/libass/ass_font.c
index 9dc8772..a7ee576 100644
--- a/libass/ass_font.c
+++ b/libass/ass_font.c
@@ -203,8 +203,13 @@ FT_Face ass_face_stream(ASS_Library *lib, FT_Library ftlib, const char *name,
     FT_Face face;
     int error = FT_Open_Face(ftlib, &args, index, &face);
     if (error) {
-        ass_msg(lib, MSGL_WARN,
-                "Error opening memory font: '%s'", name);
+        if (name) {
+            ass_msg(lib, MSGL_WARN,
+                    "Error opening memory font: '%s'", name);
+        } else {
+            ass_msg(lib, MSGL_WARN,
+                    "Error opening memory font");
+        }
         return NULL;
     }
 
diff --git a/libass/ass_fontselect.c b/libass/ass_fontselect.c
index 670156e..68a4407 100644
--- a/libass/ass_fontselect.c
+++ b/libass/ass_fontselect.c
@@ -358,23 +358,6 @@ error:
     return false;
 }
 
-bool ass_get_font_info(ASS_Library *lib, FT_Library ftlib, const char *path,
-                       const char *postscript_name, int index,
-                       const char *fallback_family_name,
-                       ASS_FontProviderMetaData *info)
-{
-    FT_Face face = ass_face_open(lib, ftlib, path, postscript_name, index);
-    if (!face)
-        return false;
-
-    bool ret = get_font_info(ftlib, face, fallback_family_name, info);
-    if (ret)
-        info->postscript_name = strdup(info->postscript_name);
-    FT_Done_Face(face);
-
-    return ret;
-}
-
 /**
  * \brief Free the dynamically allocated fields of metadata
  * created by get_font_info.
@@ -382,16 +365,17 @@ bool ass_get_font_info(ASS_Library *lib, FT_Library ftlib, const char *path,
  */
 static void free_font_info(ASS_FontProviderMetaData *meta)
 {
-    int i;
-
-    for (i = 0; i < meta->n_family; i++)
-        free(meta->families[i]);
-
-    for (i = 0; i < meta->n_fullname; i++)
-        free(meta->fullnames[i]);
+    if (meta->families) {
+        for (int i = 0; i < meta->n_family; i++)
+            free(meta->families[i]);
+        free(meta->families);
+    }
 
-    free(meta->families);
-    free(meta->fullnames);
+    if (meta->fullnames) {
+        for (int i = 0; i < meta->n_fullname; i++)
+            free(meta->fullnames[i]);
+        free(meta->fullnames);
+    }
 }
 
 /**
@@ -411,7 +395,48 @@ ass_font_provider_add_font(ASS_FontProvider *provider,
     int i;
     int weight, slant, width;
     ASS_FontSelector *selector = provider->parent;
-    ASS_FontInfo *info;
+    ASS_FontInfo *info = NULL;
+    ASS_FontProviderMetaData implicit_meta = {0};
+
+    if (!meta->n_family) {
+        FT_Face face;
+        if (provider->funcs.get_font_index)
+            index = provider->funcs.get_font_index(data);
+        if (!path) {
+            ASS_FontStream stream = {
+                .func = provider->funcs.get_data,
+                .priv = data,
+            };
+            // This name is only used in an error message, so use
+            // our best name but don't panic if we don't have any.
+            // Prefer PostScript name because it is unique.
+            const char *name = meta->postscript_name ?
+                meta->postscript_name : meta->extended_family;
+            face = ass_face_stream(selector->library, selector->ftlibrary,
+                                   name, &stream, index);
+        } else {
+            face = ass_face_open(selector->library, selector->ftlibrary,
+                                 path, meta->postscript_name, index);
+        }
+        if (!face)
+            goto error;
+        if (!get_font_info(selector->ftlibrary, face, meta->extended_family,
+                           &implicit_meta)) {
+            FT_Done_Face(face);
+            goto error;
+        }
+        if (implicit_meta.postscript_name) {
+            implicit_meta.postscript_name =
+                strdup(implicit_meta.postscript_name);
+            if (!implicit_meta.postscript_name) {
+                FT_Done_Face(face);
+                goto error;
+            }
+        }
+        FT_Done_Face(face);
+        implicit_meta.extended_family = meta->extended_family;
+        meta = &implicit_meta;
+    }
 
 #if 0
     int j;
@@ -511,7 +536,11 @@ ass_font_provider_add_font(ASS_FontProvider *provider,
     return true;
 
 error:
-    ass_font_provider_free_fontinfo(info);
+    if (info)
+        ass_font_provider_free_fontinfo(info);
+
+    free_font_info(&implicit_meta);
+    free(implicit_meta.postscript_name);
 
     if (provider->funcs.destroy_font)
         provider->funcs.destroy_font(data);
diff --git a/libass/ass_fontselect.h b/libass/ass_fontselect.h
index 50c1968..522c729 100644
--- a/libass/ass_fontselect.h
+++ b/libass/ass_fontselect.h
@@ -171,6 +171,9 @@ typedef struct font_provider_funcs {
 /*
  * Basic font metadata. All strings must be encoded with UTF-8.
  * At minimum one family is required.
+ * If no family names are present, ass_font_provider_add_font
+ * will open the font file and read metadata from there,
+ * replacing everything but extended_family.
  */
 struct ass_font_provider_meta_data {
     /**
@@ -280,22 +283,6 @@ ass_font_provider_add_font(ASS_FontProvider *provider,
                            int index, void *data);
 
 /**
- * \brief Read a font's parameters
- * \param lib a FT_Library to use (need not be the global one)
- * \param path the path to the font file to read
- * \param postscript_name the PS name of the specific face to read (set either this or index)
- * \param index the face index to read, or -1 if not applicable
- * \param fallback_family_name family name from outside source, used as last resort
- * \param info the struct to store results into
- * \return success
- *
- */
-bool ass_get_font_info(ASS_Library *lib, FT_Library ftlib, const char *path,
-                       const char *postscript_name, int index,
-                       const char *fallback_family_name,
-                       ASS_FontProviderMetaData *info);
-
-/**
  * \brief Free font provider and associated fonts.
  * \param provider the font provider
  *