[pango] pango-view: Add font options

[Matthias Clasen <matthiasc src gnome org>]

commit d31bb1c145737d6c75bd49995d322e5f52a651a0
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Jul 31 23:26:44 2019 -0400

    pango-view: Add font options
    
    Add commandline options for antialiasing,
    subpixel order and metrics hinting, so we
    can reproduce font rendering issues with
    pango-view.

 utils/viewer-pangocairo.c | 14 +++++++
 utils/viewer-render.c     | 94 ++++++++++++++++++++++++++++++++++++++++++++++-
 utils/viewer-render.h     | 26 +++++++++++++
 3 files changed, 132 insertions(+), 2 deletions(-)
---
diff --git a/utils/viewer-pangocairo.c b/utils/viewer-pangocairo.c
index 9054b9fe..f82bd72d 100644
--- a/utils/viewer-pangocairo.c
+++ b/utils/viewer-pangocairo.c
@@ -55,10 +55,24 @@ pangocairo_view_create (const PangoViewer *klass G_GNUC_UNUSED)
     {
       if (opt_hinting == HINT_NONE)
        cairo_font_options_set_hint_style (instance->font_options, CAIRO_HINT_STYLE_NONE);
+      else if (opt_hinting == HINT_SLIGHT ||
+               opt_hinting == HINT_AUTO)
+       cairo_font_options_set_hint_style (instance->font_options, CAIRO_HINT_STYLE_SLIGHT);
+      else if (opt_hinting == HINT_MEDIUM)
+       cairo_font_options_set_hint_style (instance->font_options, CAIRO_HINT_STYLE_MEDIUM);
       else if (opt_hinting == HINT_FULL)
        cairo_font_options_set_hint_style (instance->font_options, CAIRO_HINT_STYLE_FULL);
     }
 
+  if (opt_subpixel_order != SUBPIXEL_DEFAULT)
+    cairo_font_options_set_subpixel_order (instance->font_options, 
(cairo_subpixel_order_t)opt_subpixel_order);
+
+  if (opt_hint_metrics != HINT_METRICS_DEFAULT)
+    cairo_font_options_set_hint_metrics (instance->font_options, (cairo_hint_metrics_t)opt_hint_metrics);
+
+  if (opt_antialias != ANTIALIAS_DEFAULT)
+    cairo_font_options_set_antialias (instance->font_options, (cairo_antialias_t)opt_antialias);
+
   return instance;
 }
 
diff --git a/utils/viewer-render.c b/utils/viewer-render.c
index 8fd6cfaf..36cee596 100644
--- a/utils/viewer-render.c
+++ b/utils/viewer-render.c
@@ -60,6 +60,9 @@ PangoEllipsizeMode opt_ellipsize = PANGO_ELLIPSIZE_NONE;
 PangoGravity opt_gravity = PANGO_GRAVITY_SOUTH;
 PangoGravityHint opt_gravity_hint = PANGO_GRAVITY_HINT_NATURAL;
 HintMode opt_hinting = HINT_DEFAULT;
+HintMetrics opt_hint_metrics = HINT_METRICS_DEFAULT;
+SubpixelOrder opt_subpixel_order = SUBPIXEL_DEFAULT;
+Antialias opt_antialias = ANTIALIAS_DEFAULT;
 PangoWrapMode opt_wrap = PANGO_WRAP_WORD_CHAR;
 gboolean opt_wrap_set = FALSE;
 static const char *opt_pangorc = NULL; /* Unused */
@@ -443,6 +446,10 @@ parse_hinting (const char *name G_GNUC_UNUSED,
     opt_hinting = HINT_NONE;
   else if (strcmp (arg, "auto") == 0)
     opt_hinting = HINT_AUTO;
+  else if (strcmp (arg, "slight") == 0)
+    opt_hinting = HINT_SLIGHT;
+  else if (strcmp (arg, "medium") == 0)
+    opt_hinting = HINT_MEDIUM;
   else if (strcmp (arg, "full") == 0)
     opt_hinting = HINT_FULL;
   else
@@ -450,13 +457,90 @@ parse_hinting (const char *name G_GNUC_UNUSED,
       g_set_error(error,
                  G_OPTION_ERROR,
                  G_OPTION_ERROR_BAD_VALUE,
-                 "Argument for --hinting must be one of none/auto/full");
+                 "Argument for --hinting must be one of none/auto/slight/medium/full");
       ret = FALSE;
     }
 
   return ret;
 }
 
+static gboolean
+parse_subpixel_order (const char  *name,
+                      const char  *arg,
+                      gpointer     data,
+                      GError     **error)
+{
+  gboolean ret = TRUE;
+
+  if (strcmp (arg, "rgb") == 0)
+    opt_subpixel_order = SUBPIXEL_RGB;
+  else if (strcmp (arg, "bgr") == 0)
+    opt_subpixel_order = SUBPIXEL_BGR;
+  else if (strcmp (arg, "vrgb") == 0)
+    opt_subpixel_order = SUBPIXEL_VRGB;
+  else if (strcmp (arg, "vbgr") == 0)
+    opt_subpixel_order = SUBPIXEL_VBGR;
+  else
+    {
+      g_set_error (error,
+                  G_OPTION_ERROR,
+                  G_OPTION_ERROR_BAD_VALUE,
+                  "Argument for --subpixel-order must be one of rgb/bgr/vrgb/vbgr");
+      ret = FALSE;
+    }
+
+  return ret;
+}
+
+static gboolean
+parse_hint_metrics (const char  *name,
+                    const char  *arg,
+                    gpointer     data,
+                    GError     **error)
+{
+  gboolean ret = TRUE;
+
+  if (strcmp (arg, "on") == 0)
+    opt_hint_metrics = HINT_METRICS_ON;
+  else if (strcmp (arg, "off") == 0)
+    opt_hint_metrics = HINT_METRICS_OFF;
+  else
+    {
+      g_set_error (error,
+                  G_OPTION_ERROR,
+                  G_OPTION_ERROR_BAD_VALUE,
+                  "Argument for --hint-metrics must be one of on/off");
+      ret = FALSE;
+    }
+
+  return ret;
+}
+
+static gboolean
+parse_antialias (const char  *name,
+                 const char  *arg,
+                 gpointer     data,
+                 GError     **error)
+{
+  gboolean ret = TRUE;
+
+  if (strcmp (arg, "none") == 0)
+    opt_antialias = ANTIALIAS_NONE;
+  else if (strcmp (arg, "gray") == 0)
+    opt_antialias = ANTIALIAS_GRAY;
+  else if (strcmp (arg, "subpixel") == 0)
+    opt_antialias = ANTIALIAS_SUBPIXEL;
+  else
+    {
+      g_set_error (error,
+                  G_OPTION_ERROR,
+                  G_OPTION_ERROR_BAD_VALUE,
+                  "Argument for --antialias must be one of none/gray/subpixel");
+      ret = FALSE;
+    }
+
+  return ret;
+}
 static gboolean
 parse_wrap (const char *name,
            const char *arg,
@@ -711,7 +795,13 @@ parse_options (int argc, char *argv[])
     {"height",         0, 0, G_OPTION_ARG_INT,                         &opt_height,
      "Height in points (positive) or number of lines (negative) for ellipsizing", "+points/-numlines"},
     {"hinting",                0, 0, G_OPTION_ARG_CALLBACK,                    &parse_hinting,
-     "Hinting style",                                      "none/auto/full"},
+     "Hinting style",                                      "none/auto/slight/medium/full"},
+    {"antialias",       0, 0, G_OPTION_ARG_CALLBACK,                    &parse_antialias,
+     "Antialiasing",                                        "none/gray/subpixel"},
+    {"hint-metrics",    0, 0, G_OPTION_ARG_CALLBACK,                    &parse_hint_metrics,
+     "Hint metrics",                                        "on/off"},
+    {"subpixel-order",  0, 0, G_OPTION_ARG_CALLBACK,                    &parse_subpixel_order,
+     "Subpixel order",                                      "rgb/bgr/vrgb/vbgr"},
     {"indent",         0, 0, G_OPTION_ARG_INT,                         &opt_indent,
      "Width in points to indent paragraphs",                       "points"},
     {"spacing",                0, 0, G_OPTION_ARG_INT,                         &opt_spacing,
diff --git a/utils/viewer-render.h b/utils/viewer-render.h
index ade22986..bfb50e55 100644
--- a/utils/viewer-render.h
+++ b/utils/viewer-render.h
@@ -29,9 +29,32 @@ typedef enum {
   HINT_DEFAULT,
   HINT_NONE,
   HINT_AUTO,
+  HINT_SLIGHT,
+  HINT_MEDIUM,
   HINT_FULL
 } HintMode;
 
+typedef enum {
+  SUBPIXEL_DEFAULT,
+  SUBPIXEL_RGB,
+  SUBPIXEL_BGR,
+  SUBPIXEL_VRGB,
+  SUBPIXEL_VBGR
+} SubpixelOrder;
+
+typedef enum {
+  ANTIALIAS_DEFAULT,
+  ANTIALIAS_NONE,
+  ANTIALIAS_GRAY,
+  ANTIALIAS_SUBPIXEL
+} Antialias;
+
+typedef enum {
+  HINT_METRICS_DEFAULT,
+  HINT_METRICS_ON,
+  HINT_METRICS_OFF
+} HintMetrics;
+
 typedef void (*RenderCallback) (PangoLayout *layout,
                                int          x,
                                int          y,
@@ -81,6 +104,9 @@ extern const PangoViewer *opt_viewer;
 /* handled by backend-specific code */
 extern int opt_dpi;
 extern HintMode opt_hinting;
+extern SubpixelOrder opt_subpixel_order;
+extern Antialias opt_antialias;
+extern HintMetrics opt_hint_metrics;
 extern PangoColor opt_fg_color;
 extern guint16 opt_fg_alpha;
 extern gboolean opt_bg_set;