[user-font] Add a cairo_t argument to cairo_user_scaled_font_init_func_t

The init func does not actually need to draw anything, but having a cairo_t
similar to that passed to render_glyph is handy for computing font extents.
This is because cairo makes doing some things really hard (if not impossible)
without a cairo_t.

The user-font-proxy test case is a great example of how the added cairo_t
makes life much easier.

1 files changed, 35 insertions, 9 deletions

diff --git a/src/cairo-user-font.c b/src/cairo-user-font.c
index cb15ca43..bcc3cfab 100644
--- a/src/cairo-user-font.c
+++ b/src/cairo-user-font.c
@@ -74,6 +74,28 @@ typedef struct _cairo_user_scaled_font {
 
 /* #cairo_user_scaled_font_t */
 
+static cairo_t *
+_cairo_user_scaled_font_create_meta_context (cairo_user_scaled_font_t *scaled_font)
+{
+    cairo_content_t content;
+    cairo_surface_t *meta_surface;
+    cairo_t *cr;
+
+    content = scaled_font->base.options.antialias == CAIRO_ANTIALIAS_SUBPIXEL ?
+						     CAIRO_CONTENT_COLOR_ALPHA :
+						     CAIRO_CONTENT_ALPHA;
+
+    meta_surface = _cairo_meta_surface_create (content, -1, -1);
+    cr = cairo_create (meta_surface);
+    cairo_surface_destroy (meta_surface);
+
+    cairo_set_matrix (cr, &scaled_font->base.scale);
+    cairo_set_font_size (cr, 1.0);
+    cairo_set_font_options (cr, &scaled_font->base.options);
+
+    return cr;
+}
+
 static const cairo_scaled_font_backend_t cairo_user_scaled_font_backend;
 
 static cairo_int_status_t
@@ -89,17 +111,9 @@ _cairo_user_scaled_glyph_init (void			 *abstract_font,
 	cairo_user_font_face_t *face =
 	    (cairo_user_font_face_t *) scaled_font->base.font_face;
 	cairo_text_extents_t extents = scaled_font->default_glyph_extents;
-	cairo_content_t content = scaled_font->base.options.antialias == CAIRO_ANTIALIAS_SUBPIXEL ?
-									 CAIRO_CONTENT_COLOR_ALPHA :
-									 CAIRO_CONTENT_ALPHA;
 	cairo_t *cr;
 
-	meta_surface = _cairo_meta_surface_create (content, -1, -1);
-	cr = cairo_create (meta_surface);
-
-	cairo_set_matrix (cr, &scaled_font->base.scale);
-	cairo_set_font_size (cr, 1.0);
-	cairo_set_font_options (cr, &scaled_font->base.options);
+	cr = _cairo_user_scaled_font_create_meta_context (scaled_font);
 
 	if (face->scaled_font_methods.render_glyph)
 	    status = face->scaled_font_methods.render_glyph ((cairo_scaled_font_t *)scaled_font,
@@ -111,6 +125,8 @@ _cairo_user_scaled_glyph_init (void			 *abstract_font,
 	if (status == CAIRO_STATUS_SUCCESS)
 	    status = cairo_status (cr);
 
+	meta_surface = cairo_surface_reference (cairo_get_target (cr));
+
 	cairo_destroy (cr);
 
 	if (status) {
@@ -377,6 +393,8 @@ _cairo_user_font_face_scaled_font_create (void                        *abstract_
 
     if (status == CAIRO_STATUS_SUCCESS && font_face->scaled_font_methods.init != NULL) {
 
+	cairo_t *cr;
+
 	/* Lock the scaled_font mutex such that user doesn't accidentally try
          * to use it just yet. */
 	CAIRO_MUTEX_LOCK (user_scaled_font->base.mutex);
@@ -384,9 +402,17 @@ _cairo_user_font_face_scaled_font_create (void                        *abstract_
 	/* Give away fontmap lock such that user-font can use other fonts */
 	_cairo_scaled_font_register_placeholder_and_unlock_font_map (&user_scaled_font->base);
 
+	cr = _cairo_user_scaled_font_create_meta_context (user_scaled_font);
+
 	status = font_face->scaled_font_methods.init (&user_scaled_font->base,
+						      cr,
 						      &font_extents);
 
+	if (status == CAIRO_STATUS_SUCCESS)
+	    status = cairo_status (cr);
+
+	cairo_destroy (cr);
+
 	_cairo_scaled_font_unregister_placeholder_and_lock_font_map (&user_scaled_font->base);
 
 	CAIRO_MUTEX_UNLOCK (user_scaled_font->base.mutex);