tests: Add a difficult node

This node has the Fira e glyph in various sizes,
to demonstrate clipping of text bounds.

demos/gtk-demo/font_features.c

@@ -746,7 +746,7 @@ update_display (void)
   if (do_waterfall)
     {
       waterfall = g_string_new ("");
-      int sizes[] = { 7, 8, 9, 10, 12, 14, 16, 20, 24, 30, 40, 50, 60, 70, 90 };
+      int sizes[] = { 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 20, 24, 30, 40, 50, 60, 70, 90 };
       start = 0;
       for (int i = 0; i < G_N_ELEMENTS (sizes); i++)
         {

gsk/gpu/gskgldevice.c

@@ -132,6 +132,47 @@ gsk_gl_device_make_current (GskGpuDevice *device)
   gdk_gl_context_make_current (gdk_display_get_gl_context (gsk_gpu_device_get_display (device)));
 }
 
+static void
+save_texture_to_png (GdkDisplay *display,
+                     int         texture_id,
+                     int         width,
+                     int         height,
+                     const char *filename)
+{
+  GdkGLTextureBuilder *builder;
+  GdkTexture *texture;
+
+  builder = gdk_gl_texture_builder_new ();
+  gdk_gl_texture_builder_set_context (builder, gdk_display_get_gl_context (display));
+  gdk_gl_texture_builder_set_id (builder, texture_id);
+  gdk_gl_texture_builder_set_width (builder, width);
+  gdk_gl_texture_builder_set_height (builder, height);
+
+  texture = gdk_gl_texture_builder_build (builder, NULL, NULL);
+  gdk_texture_save_to_png (texture, filename);
+
+  g_object_unref (texture);
+  g_object_unref (builder);
+}
+
+static void
+gsk_gl_device_end_frame (GskGpuDevice *device)
+{
+  GskGpuImage *image;
+  static int count = 0;
+  char *filename;
+
+  image = gsk_gpu_device_get_atlas_image (device);
+
+  filename = g_strdup_printf ("atlas%d.png", count++);
+  save_texture_to_png (gsk_gpu_device_get_display (device),
+                       gsk_gl_image_peek_texture (GSK_GL_IMAGE (image)),
+                       gsk_gpu_image_get_width (image),
+                       gsk_gpu_image_get_height (image),
+                       filename);
+  g_free (filename);
+}
+
 static void
 gsk_gl_device_finalize (GObject *object)
 {
@@ -159,6 +200,7 @@ gsk_gl_device_class_init (GskGLDeviceClass *klass)
   gpu_device_class->create_upload_image = gsk_gl_device_create_upload_image;
   gpu_device_class->create_download_image = gsk_gl_device_create_download_image;
   gpu_device_class->make_current = gsk_gl_device_make_current;
+  gpu_device_class->end_frame = gsk_gl_device_end_frame;
 
   object_class->finalize = gsk_gl_device_finalize;
 }
@@ -698,4 +740,3 @@ gsk_gl_device_find_gl_format (GskGLDevice      *self,
   /* fallbacks will always fallback to a supported format */
   g_assert_not_reached ();
 }
-

gsk/gpu/gskglimage.c

@@ -316,3 +316,9 @@ gsk_gl_image_steal_texture (GskGLImage *self)
 
   return self->texture_id;
 }
+
+GLuint
+gsk_gl_image_peek_texture (GskGLImage *self)
+{
+  return self->texture_id;
+}

gsk/gpu/gskglimageprivate.h

@@ -39,4 +39,7 @@ GLenum                  gsk_gl_image_get_gl_type                        (GskGLIm
 
 GLuint                  gsk_gl_image_steal_texture                      (GskGLImage             *self);
 
+GLuint                  gsk_gl_image_peek_texture                       (GskGLImage             *self);
+
+
 G_END_DECLS

gsk/gpu/gskgpudevice.c

@@ -907,7 +907,9 @@ gsk_gpu_device_lookup_glyph_image (GskGpuDevice           *self,
   gsize atlas_x, atlas_y, padding;
   float subpixel_x, subpixel_y;
   PangoFont *scaled_font;
+  cairo_antialias_t antialias;
   cairo_hint_metrics_t hint_metrics;
+  cairo_hint_style_t hint_style;
 
   cache = g_hash_table_lookup (priv->glyph_cache, &lookup);
   if (cache)
@@ -919,15 +921,8 @@ gsk_gpu_device_lookup_glyph_image (GskGpuDevice           *self,
       return cache->image;
     }
 
-  /* The combination of hint-style != none and hint-metrics == off
-   * leads to broken rendering with some fonts.
-   */
-  if (gsk_font_get_hint_style (font) != CAIRO_HINT_STYLE_NONE)
-    hint_metrics = CAIRO_HINT_METRICS_ON;
-  else
-    hint_metrics = CAIRO_HINT_METRICS_DEFAULT;
-
-  scaled_font = gsk_reload_font (font, scale, hint_metrics, CAIRO_HINT_STYLE_DEFAULT, CAIRO_ANTIALIAS_DEFAULT);
+  gsk_font_get_rendering (font, scale, &hint_metrics, &hint_style, &antialias);
+  scaled_font = gsk_reload_font (font, scale, hint_metrics, hint_style, antialias);
 
   subpixel_x = (flags & 3) / 4.f;
   subpixel_y = ((flags >> 2) & 3) / 4.f;
@@ -991,5 +986,12 @@ gsk_gpu_device_lookup_glyph_image (GskGpuDevice           *self,
   return cache->image;
 }
 
+void
+gsk_gpu_device_end_frame (GskGpuDevice *self)
+{
+  if (GSK_GPU_DEVICE_GET_CLASS (self))
+    GSK_GPU_DEVICE_GET_CLASS (self)->end_frame (self);
+}
+
 /* }}} */
 /* vim:set foldmethod=marker expandtab: */

gsk/gpu/gskgpudeviceprivate.h

@@ -42,7 +42,7 @@ struct _GskGpuDeviceClass
                                                                          gsize                   width,
                                                                          gsize                   height);
   void                  (* make_current)                                (GskGpuDevice           *self);
-
+  void                  (* end_frame)                                   (GskGpuDevice           *self);
 };
 
 GType                   gsk_gpu_device_get_type                         (void) G_GNUC_CONST;
@@ -99,6 +99,8 @@ GskGpuImage *           gsk_gpu_device_lookup_glyph_image               (GskGpuD
                                                                          graphene_point_t       *out_origin);
 
 
+void                    gsk_gpu_device_end_frame                        (GskGpuDevice           *self);
+
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GskGpuDevice, g_object_unref)
 
 G_END_DECLS

gsk/gpu/gskgpunodeprocessor.c

@@ -3008,6 +3008,9 @@ gsk_gpu_node_processor_add_glyph_node (GskGpuNodeProcessor *self,
   GskGpuImage *last_image;
   guint32 descriptor;
   const float inv_pango_scale = 1.f / PANGO_SCALE;
+  cairo_hint_metrics_t hint_metrics;
+  cairo_hint_style_t hint_style;
+  cairo_antialias_t antialias;
 
   if (self->opacity < 1.0 &&
       gsk_text_node_has_color_glyphs (node))
@@ -3016,6 +3019,17 @@ gsk_gpu_node_processor_add_glyph_node (GskGpuNodeProcessor *self,
       return;
     }
 
+  if (g_getenv ("DEBUG_TEXT_BOUNDS"))
+    {
+      GdkRGBA color;
+      GskRenderNode *c;
+
+      gdk_rgba_parse (&color, "yellow");
+      c = gsk_color_node_new (&color, &node->bounds);
+      gsk_gpu_node_processor_add_color_node (self, c);
+      gsk_render_node_unref (c);
+    }
+
   device = gsk_gpu_frame_get_device (self->frame);
 
   color = *gsk_text_node_get_color (node);
@@ -3030,7 +3044,8 @@ gsk_gpu_node_processor_add_glyph_node (GskGpuNodeProcessor *self,
   scale = MAX (graphene_vec2_get_x (&self->scale), graphene_vec2_get_y (&self->scale));
   inv_scale = 1.f / scale;
 
-  if (gsk_font_get_hint_style (font) != CAIRO_HINT_STYLE_NONE)
+  gsk_font_get_rendering (font, scale, &hint_metrics, &hint_style, &antialias);
+  if (hint_style != CAIRO_HINT_STYLE_NONE)
     {
       align_scale_x = scale * 4;
       align_scale_y = scale;
@@ -3128,6 +3143,9 @@ gsk_gpu_node_processor_create_glyph_pattern (GskGpuPatternWriter *self,
   float inv_align_scale_x, inv_align_scale_y;
   unsigned int flags_mask;
   const float inv_pango_scale = 1.f / PANGO_SCALE;
+  cairo_hint_metrics_t hint_metrics;
+  cairo_hint_style_t hint_style;
+  cairo_antialias_t antialias;
 
   if (gsk_text_node_has_color_glyphs (node))
     return FALSE;
@@ -3147,7 +3165,8 @@ gsk_gpu_node_processor_create_glyph_pattern (GskGpuPatternWriter *self,
   gsk_gpu_pattern_writer_append_rgba (self, gsk_text_node_get_color (node));
   gsk_gpu_pattern_writer_append_uint (self, num_glyphs);
 
-  if (gsk_font_get_hint_style (font) != CAIRO_HINT_STYLE_NONE)
+  gsk_font_get_rendering (font, scale, &hint_metrics, &hint_style, &antialias);
+  if (hint_style != CAIRO_HINT_STYLE_NONE)
     {
       align_scale_x = scale * 4;
       align_scale_y = scale;

gsk/gpu/gskgpurenderer.c

@@ -423,6 +423,7 @@ gsk_gpu_renderer_render (GskRenderer          *renderer,
   gsk_gpu_device_queue_gc (priv->device);
 
   gdk_draw_context_end_frame (priv->context);
+  gsk_gpu_device_end_frame (priv->device);
 
   g_clear_pointer (&render_region, cairo_region_destroy);
 }

gsk/gskprivate.c

@@ -25,11 +25,27 @@ gsk_ensure_resources (void)
   g_once (&register_resources_once, register_resources, NULL);
 }
 
+static cairo_font_options_t *font_options = NULL;
+
+static inline cairo_font_options_t *
+pango_font_get_cairo_font_options (PangoFont *font)
+{
+  cairo_scaled_font_t *sf;
+
+  if (G_UNLIKELY (font_options == NULL))
+    font_options = cairo_font_options_create ();
+
+  sf = pango_cairo_font_get_scaled_font (PANGO_CAIRO_FONT (font));
+  cairo_scaled_font_get_font_options (sf, font_options);
+
+  return font_options;
+}
+
 /*< private >
  * gsk_reload_font:
  * @font: a `PangoFont`
  * @scale: the scale to apply
- * @hint_metris: hint metrics to use or `CAIRO_HINT_METRICS_DEFAILT` to keep the
+ * @hint_metris: hint metrics to use or `CAIRO_HINT_METRICS_DEFAULT` to keep the
  *   hint metrics of the font unchanged
  * @hint_style: hint style to use or `CAIRO_HINT_STYLE_DEFAULT` to keep the
  *   hint style of @font unchanged
@@ -48,9 +64,8 @@ gsk_reload_font (PangoFont            *font,
                  cairo_hint_style_t    hint_style,
                  cairo_antialias_t     antialias)
 {
-  static cairo_font_options_t *options = NULL;
   static PangoContext *context = NULL;
-  cairo_scaled_font_t *sf;
+  cairo_font_options_t *options;
 
   /* These requests often come in sequentially so keep the result
    * around and re-use it if everything matches.
@@ -78,11 +93,7 @@ gsk_reload_font (PangoFont            *font,
   g_set_object (&last_font, font);
   g_clear_object (&last_result);
 
-  if (G_UNLIKELY (options == NULL))
-    options = cairo_font_options_create ();
-
-  sf = pango_cairo_font_get_scaled_font (PANGO_CAIRO_FONT (font));
-  cairo_scaled_font_get_font_options (sf, options);
+  options = pango_font_get_cairo_font_options (font);
 
   if (hint_metrics == CAIRO_HINT_METRICS_DEFAULT)
     hint_metrics = cairo_font_options_get_hint_metrics (options);
@@ -118,27 +129,103 @@ gsk_reload_font (PangoFont            *font,
   return g_object_ref (last_result);
 }
 
-/*< private >
- * gsk_font_get_hint_style:
- * @font: a `PangoFont`
- *
- * Get the hint style from the cairo font options.
- *
- * Returns: the hint style
- */
-cairo_hint_style_t
-gsk_font_get_hint_style (PangoFont *font)
+static inline double
+gsk_font_get_size (PangoFont *font)
 {
-  static cairo_font_options_t *options = NULL;
-  cairo_scaled_font_t *sf;
-  cairo_hint_style_t style;
+  PangoFontDescription *desc;
+  double size;
 
-  if (G_UNLIKELY (options == NULL))
-    options = cairo_font_options_create ();
+  desc = pango_font_describe_with_absolute_size (font);
 
-  sf = pango_cairo_font_get_scaled_font (PANGO_CAIRO_FONT (font));
-  cairo_scaled_font_get_font_options (sf, options);
-  style = cairo_font_options_get_hint_style (options);
+  size = pango_font_description_get_size (desc);
 
-  return style;
+  pango_font_description_free (desc);
+
+  return size / PANGO_SCALE;
+}
+
+/*< private >
+ * gsk_font_get_rendering:
+ * @font: a `PangoFont`
+ * @scale: the scale to use
+ * @hint_metrics: (out): return location for metrics hinting
+ * @hint_style: (out): return location for hint style
+ * @antialias: (out): return location for antialiasing
+ *
+ * Determines the font options to use for rendering with
+ * the font at the given scale.
+ */
+void
+gsk_font_get_rendering (PangoFont            *font,
+                        float                 scale,
+                        cairo_hint_metrics_t *hint_metrics,
+                        cairo_hint_style_t   *hint_style,
+                        cairo_antialias_t    *antialias)
+{
+  const cairo_font_options_t *options;
+
+  options = pango_font_get_cairo_font_options (font);
+
+  /* Keep this in sync with gtkwidget.c:update_pango_context */
+  if (cairo_font_options_get_antialias (options) == CAIRO_ANTIALIAS_GOOD)
+    {
+      double font_size;
+
+      font_size = gsk_font_get_size (font) * scale;
+
+      *antialias = CAIRO_ANTIALIAS_GRAY;
+      *hint_metrics = CAIRO_HINT_METRICS_OFF;
+
+      /* 31 pixels is equivalent to an 11 pt font at 200 dpi */
+      if (font_size > 31)
+        *hint_style = CAIRO_HINT_STYLE_NONE;
+      else
+        *hint_style = CAIRO_HINT_STYLE_SLIGHT;
+    }
+  else
+    {
+      *antialias = cairo_font_options_get_antialias (options);
+      *hint_metrics = cairo_font_options_get_hint_metrics (options);
+      *hint_style = cairo_font_options_get_hint_style (options);
+    }
+
+  /* The combination of hint-style != none and hint-metrics == off
+   * leads to broken rendering with some fonts.
+   */
+  if (*hint_style != CAIRO_HINT_STYLE_NONE)
+    *hint_metrics = CAIRO_HINT_METRICS_ON;
+}
+
+/*< private >
+ * gsk_font_get_extents:
+ * @font: a `PangoFont`
+ * @glyphs: a `PangoGlyphString`
+ * @ink_rect: (out): rectangle used to store the extents of the glyph
+ *   string as drawn
+ *
+ * Compute the ink extents of a glyph string.
+ *
+ * This is like [method@Pango.GlyphString.extents], but it provides
+ * unhinted extents.
+ */
+void
+gsk_font_get_extents (PangoFont        *font,
+                      PangoGlyphString *glyphs,
+                      PangoRectangle   *ink_rect)
+{
+  PangoFont *unhinted;
+
+  unhinted = gsk_reload_font (font, 1.0, CAIRO_HINT_METRICS_OFF,
+                                         CAIRO_HINT_STYLE_NONE,
+                                         CAIRO_ANTIALIAS_GRAY);
+
+  pango_glyph_string_extents (glyphs, unhinted, ink_rect, NULL);
+
+  /* Hack: Without this, cff fonts like Fira get clipped */
+  ink_rect->x -= 1024;
+  ink_rect->y -= 1024;
+  ink_rect->width += 2048;
+  ink_rect->height += 2048;
+
+  g_object_unref (unhinted);
 }

gsk/gskprivate.h

@@ -6,15 +6,22 @@
 
 G_BEGIN_DECLS
 
-void       gsk_ensure_resources  (void);
+void       gsk_ensure_resources          (void);
 
-PangoFont *gsk_reload_font (PangoFont            *font,
-                            float                 scale,
-                            cairo_hint_metrics_t  hint_metrics,
-                            cairo_hint_style_t    hint_style,
-                            cairo_antialias_t     antialias);
+PangoFont *gsk_reload_font               (PangoFont            *font,
+                                          float                 scale,
+                                          cairo_hint_metrics_t  hint_metrics,
+                                          cairo_hint_style_t    hint_style,
+                                          cairo_antialias_t     antialias);
 
-cairo_hint_style_t gsk_font_get_hint_style (PangoFont *font);
+void       gsk_font_get_rendering        (PangoFont            *font,
+                                          float                 scale,
+                                          cairo_hint_metrics_t *hint_metrics,
+                                          cairo_hint_style_t   *hint_style,
+                                          cairo_antialias_t    *antialias);
+
+void       gsk_font_get_extents          (PangoFont            *font,
+                                          PangoGlyphString     *glyphs,
+                                          PangoRectangle       *ink_rect);
 
 G_END_DECLS
-

gsk/gskrendernodeimpl.c

@@ -5825,7 +5825,7 @@ gsk_text_node_new (PangoFont              *font,
   PangoGlyphInfo *glyph_infos;
   int n;
 
-  pango_glyph_string_extents (glyphs, font, &ink_rect, NULL);
+  gsk_font_get_extents (font, glyphs, &ink_rect);
 
   /* Don't create nodes with empty bounds */
   if (ink_rect.width == 0 || ink_rect.height == 0)

gsk/gskrendernodeparser.c

@@ -2302,7 +2302,8 @@ parse_antialias (GtkCssParser *parser,
     return FALSE;
 
   if (*(cairo_antialias_t *) out != CAIRO_ANTIALIAS_NONE &&
-      *(cairo_antialias_t *) out != CAIRO_ANTIALIAS_GRAY)
+      *(cairo_antialias_t *) out != CAIRO_ANTIALIAS_GRAY &&
+      *(cairo_antialias_t *) out != CAIRO_ANTIALIAS_GOOD)
     {
       gtk_css_parser_error_value (parser, "Unsupported value for enum \"%s\"",
                                   g_type_name (CAIRO_GOBJECT_TYPE_ANTIALIAS));
@@ -3662,9 +3663,11 @@ gsk_text_node_serialize_font_options (GskRenderNode *node,
     append_enum_param (p, "hint-style", CAIRO_GOBJECT_TYPE_HINT_STYLE, hint_style);
 
   /* CAIRO_ANTIALIAS_NONE is the only value we ever emit here, since gray is the default,
-   * and we don't accept any other values.
+   * and we don't accept any other values. We do accept GOOD as GTK uses that to pass
+   * the gtk-font-rendering value down.
    */
-  if (antialias == CAIRO_ANTIALIAS_NONE)
+  if (antialias == CAIRO_ANTIALIAS_NONE ||
+      antialias == CAIRO_ANTIALIAS_GOOD)
     append_enum_param (p, "antialias", CAIRO_GOBJECT_TYPE_ANTIALIAS, antialias);
 
   /* CAIRO_HINT_METRICS_ON is the only value we ever emit here, since off is the default,

gtk/gtkwidget.c

@@ -6513,39 +6513,22 @@ gtk_widget_update_pango_context (GtkWidget        *widget,
   else
     {
       cairo_font_options_t *options;
-      double dpi = 96.;
-      GdkSurface *surface;
-
-      surface = gtk_widget_get_surface (widget);
-      if (surface)
-        {
-          GdkDisplay *display;
-          GdkMonitor *monitor;
-
-          display = gdk_surface_get_display (surface);
-          monitor = gdk_display_get_monitor_at_surface (display, surface);
-          if (monitor)
-            dpi = gdk_monitor_get_dpi (monitor);
-        }
 
       options = cairo_font_options_create ();
 
-      cairo_font_options_set_antialias (options, CAIRO_ANTIALIAS_GRAY);
+      /* HACK: Use CAIRO_ANTIALIAS_GOOD to communicate 'automatic' to gsk */
+      cairo_font_options_set_antialias (options, CAIRO_ANTIALIAS_GOOD);
 
-      if (dpi < 200.)
-        {
-          /* Not high-dpi. Prefer sharpness by enabling hinting */
-          cairo_font_options_set_hint_metrics (options, CAIRO_HINT_METRICS_ON);
-          cairo_font_options_set_hint_style (options, CAIRO_HINT_STYLE_SLIGHT);
-        }
-      else
-        {
-          /* High-dpi. Prefer precise positioning */
-          cairo_font_options_set_hint_metrics (options, CAIRO_HINT_METRICS_OFF);
-          cairo_font_options_set_hint_style (options, CAIRO_HINT_STYLE_NONE);
-        }
+      cairo_font_options_set_hint_style (options, CAIRO_HINT_STYLE_NONE);
+
+     /* Don't do any rounding during layout. In particular with fractional
+      * scaling, we want to avoid rounding to application pixels, since the
+      * may not align with the device pixel grid.
+      */
+      cairo_font_options_set_hint_metrics (options, CAIRO_HINT_METRICS_OFF);
 
       pango_context_set_round_glyph_positions (context, FALSE);
+
       pango_cairo_context_set_font_options (context, options);
 
       cairo_font_options_destroy (options);

tests/demo.node

@@ -0,0 +1,66 @@
+transform {
+  transform: scale(1);
+  child: container {
+
+    color {
+      color: white;
+      bounds: -5 -20 140 30;
+    }
+    text {
+      font: "Fira Sans Medium 21px";
+      glyphs: "e";
+      offset: -2 0;
+    }
+    text {
+      font: "Fira Sans Medium 20.5px";
+      glyphs: "e";
+      offset: 11 0;
+    }
+    text {
+      font: "Fira Sans Medium 20px";
+      glyphs: "e";
+      offset: 24 0;
+    }
+    text {
+      font: "Fira Sans Medium 19.5px";
+      glyphs: "e";
+      offset: 36 0;
+    }
+    text {
+      font: "Fira Sans Medium 19px";
+      glyphs: "e";
+      offset: 48 0;
+    }
+    text {
+      font: "Fira Sans Medium 18.5px";
+      glyphs: "e";
+      offset: 60 0;
+    }
+    text {
+      font: "Fira Sans Medium 18px";
+      glyphs: "e";
+      offset: 72 0;
+    }
+    text {
+      font: "Fira Sans Medium 17.5px";
+      glyphs: "e";
+      offset: 84 0;
+    }
+    text {
+      font: "Fira Sans Medium 17px";
+      glyphs: "e";
+      offset: 96 0;
+    }
+    text {
+      font: "Fira Sans Medium 16.5px";
+      glyphs: "e";
+      offset: 108 0;
+    }
+    text {
+      font: "Fira Sans Medium 16px";
+      glyphs: "e";
+      offset: 120 0;
+    }
+
+  }
+}