[pango/simple-fontmap: 2/17] Add PangoHbFont
- From: Matthias Clasen <matthiasc src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [pango/simple-fontmap: 2/17] Add PangoHbFont
- Date: Thu, 27 Jan 2022 06:06:39 +0000 (UTC)
commit 78c5ae40103040175b46fd5ecccf37db572062f7
Author: Matthias Clasen <mclasen redhat com>
Date: Fri Oct 29 19:19:31 2021 -0400
Add PangoHbFont
This is a simple wrapper around hb_font_t.
This is an attempt to make a font backend that does
not depend on platform specifics and can be used in
tests.
pango/meson.build | 2 +
pango/pango-hbfont-private.h | 56 +++
pango/pango-hbfont.c | 1047 ++++++++++++++++++++++++++++++++++++++++++
pango/pango-hbfont.h | 50 ++
pango/pango.h | 1 +
5 files changed, 1156 insertions(+)
---
diff --git a/pango/meson.build b/pango/meson.build
index ef498d6b..0c6e204a 100644
--- a/pango/meson.build
+++ b/pango/meson.build
@@ -37,6 +37,7 @@ pango_sources = [
'pango-hbface.c',
'pango-hbfamily.c',
'pango-generic-family.c',
+ 'pango-hbfont.c',
]
pango_headers = [
@@ -69,6 +70,7 @@ pango_headers = [
'pango-types.h',
'pango-utils.h',
'pango-hbface.h',
+ 'pango-hbfont.h',
]
pango_installed_headers = pango_headers + [ 'pango-version-macros.h' ]
diff --git a/pango/pango-hbfont-private.h b/pango/pango-hbfont-private.h
new file mode 100644
index 00000000..fea6162f
--- /dev/null
+++ b/pango/pango-hbfont-private.h
@@ -0,0 +1,56 @@
+/* Pango
+ *
+ * Copyright (C) 2021 Matthias Clasen
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#pragma once
+
+#include "pango-hbfont.h"
+#include "pango-hbface.h"
+#include <hb.h>
+
+typedef struct _HexBoxInfo HexBoxInfo;
+struct _HexBoxInfo
+{
+ PangoFont *font;
+ int rows;
+ double digit_width;
+ double digit_height;
+ double pad_x;
+ double pad_y;
+ double line_width;
+ double box_descent;
+ double box_height;
+};
+
+struct _PangoHbFont
+{
+ PangoFont parent_instance;
+
+ PangoHbFace *face;
+ int size; /* point size, scaled by PANGO_SCALE */
+ float dpi;
+ hb_feature_t *features;
+ unsigned int n_features;
+ hb_variation_t *variations;
+ unsigned int n_variations;
+ PangoGravity gravity;
+ PangoMatrix matrix;
+
+ HexBoxInfo *hex_box_info;
+};
diff --git a/pango/pango-hbfont.c b/pango/pango-hbfont.c
new file mode 100644
index 00000000..ccfb2e61
--- /dev/null
+++ b/pango/pango-hbfont.c
@@ -0,0 +1,1047 @@
+/* Pango
+ *
+ * Copyright (C) 2021 Matthias Clasen
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include "pango-hbfont-private.h"
+
+#include "pango-font-private.h"
+#include "pango-coverage-private.h"
+#include "pango-hbface-private.h"
+#include "pango-hbfamily-private.h"
+#include "pango-impl-utils.h"
+#include "pango-language-set-private.h"
+
+#include <hb-ot.h>
+
+/**
+ * PangoHbFont:
+ *
+ * `PangoHbFont` is a `PangoFont` implementation that wraps
+ * a `hb_font_t` object and implements all of the `PangoFont`
+ * functionality using HarfBuzz.
+ *
+ * In addition to a `PangoHbFace` and a size, a number of optional
+ * parameters can be tweaked when creating a `PangoHbFont`. First
+ * there are OpenType font features, which can be used to e.g.
+ * select Small Caps. If the face has variation axes, then
+ * coordinates for these axes can be provided. Finally, there are
+ * rendering parameters such as the dpi and the global transformation
+ * matrix.
+ */
+
+ /* {{{ Utilities */
+
+static int
+get_average_char_width (PangoFont *font,
+ const char *text)
+{
+ hb_font_t *hb_font = pango_font_get_hb_font (font);
+ int width = 0;
+
+ for (const char *p = text; *p; p = g_utf8_next_char (p))
+ {
+ gunichar wc;
+ hb_codepoint_t glyph;
+ PangoRectangle extents;
+
+ wc = g_utf8_get_char (p);
+ if (!hb_font_get_nominal_glyph (hb_font, wc, &glyph))
+ continue;
+
+ pango_font_get_glyph_extents (font, glyph, &extents, NULL);
+
+ width += extents.x + extents.width;
+ }
+
+ return width / pango_utf8_strwidth (text);
+}
+
+static void
+get_max_char_size (PangoFont *font,
+ const char *text,
+ int *width,
+ int *height)
+{
+ hb_font_t *hb_font = pango_font_get_hb_font (font);
+ int w = 0;
+ int h = 0;
+
+ for (const char *p = text; *p; p = g_utf8_next_char (p))
+ {
+ gunichar wc;
+ hb_codepoint_t glyph;
+ PangoRectangle extents;
+
+ wc = g_utf8_get_char (p);
+ if (!hb_font_get_nominal_glyph (hb_font, wc, &glyph))
+ continue;
+
+ pango_font_get_glyph_extents (font, glyph, &extents, NULL);
+
+ w = MAX (w, extents.x + extents.width);
+ h = MAX (h, extents.height);
+ }
+
+ if (width)
+ *width = w;
+
+ if (height)
+ *height = h;
+}
+
+static PangoFontMap *
+pango_hb_font_get_font_map (PangoFont *font)
+{
+ PangoHbFont *self = PANGO_HB_FONT (font);
+ PangoHbFamily *family = PANGO_HB_FAMILY (self->face->family);
+
+ return family->map;
+}
+
+static PangoVariant
+pango_variant_from_features (hb_feature_t *features,
+ unsigned int n_features)
+{
+ PangoVariant variant = PANGO_VARIANT_NORMAL;
+ gboolean all_caps = FALSE;
+
+ for (int i = 0; i < n_features; i++)
+ {
+ if (features[i].value != 1)
+ continue;
+
+ switch (features[i].tag)
+ {
+ case HB_TAG('s','m','c','p'):
+ if (all_caps)
+ variant = PANGO_VARIANT_ALL_SMALL_CAPS;
+ else
+ variant = PANGO_VARIANT_SMALL_CAPS;
+ break;
+ case HB_TAG('c','2','s','c'):
+ if (variant == PANGO_VARIANT_SMALL_CAPS)
+ variant = PANGO_VARIANT_ALL_SMALL_CAPS;
+ else
+ all_caps = TRUE;
+ break;
+ case HB_TAG('p','c','a','p'):
+ if (all_caps)
+ variant = PANGO_VARIANT_ALL_PETITE_CAPS;
+ else
+ variant = PANGO_VARIANT_PETITE_CAPS;
+ break;
+ case HB_TAG('c','2','p','c'):
+ if (variant == PANGO_VARIANT_PETITE_CAPS)
+ variant = PANGO_VARIANT_ALL_PETITE_CAPS;
+ else
+ all_caps = TRUE;
+ break;
+ case HB_TAG('u','n','i','c'):
+ variant = PANGO_VARIANT_UNICASE;
+ break;
+ case HB_TAG('t','i','t','l'):
+ variant = PANGO_VARIANT_TITLE_CAPS;
+ break;
+ default:
+ break;
+ }
+ }
+
+ return variant;
+}
+
+static void
+font_description_get_features (const PangoFontDescription *description,
+ hb_feature_t *features,
+ unsigned int length,
+ unsigned int *n_features)
+{
+
+#define ADD_FEATURE(name) \
+ features[*n_features].tag = HB_TAG (name[0], name[1], name[2], name[3]); \
+ features[*n_features].value = 1; \
+ features[*n_features].start = 0; \
+ features[*n_features].end = (unsigned int) -1; \
+ (*n_features)++
+
+ g_assert (length >= 2);
+
+ *n_features = 0;
+ switch (pango_font_description_get_variant (description))
+ {
+ case PANGO_VARIANT_SMALL_CAPS:
+ ADD_FEATURE ("smcp");
+ break;
+ case PANGO_VARIANT_ALL_SMALL_CAPS:
+ ADD_FEATURE ("smcp");
+ ADD_FEATURE ("c2sc");
+ break;
+ case PANGO_VARIANT_PETITE_CAPS:
+ ADD_FEATURE ("pcap");
+ break;
+ case PANGO_VARIANT_ALL_PETITE_CAPS:
+ ADD_FEATURE ("pcap");
+ ADD_FEATURE ("c2pc");
+ break;
+ case PANGO_VARIANT_UNICASE:
+ ADD_FEATURE ("unic");
+ break;
+ case PANGO_VARIANT_TITLE_CAPS:
+ ADD_FEATURE ("titl");
+ break;
+ case PANGO_VARIANT_NORMAL:
+ break;
+ default:
+ g_assert_not_reached ();
+ }
+
+#undef ADD_FEATURE
+}
+
+static unsigned int
+count_variations (const char *string)
+{
+ unsigned int n;
+ const char *p;
+
+ n = 1;
+ p = string;
+ while ((p = strchr (p, ',')) != NULL)
+ n++;
+
+ return n;
+}
+
+static void
+parse_variations (const char *str,
+ hb_variation_t *variations,
+ unsigned int length,
+ unsigned int *n_variations)
+{
+ const char *p;
+
+ *n_variations = 0;
+
+ p = str;
+ while (p && *p && *n_variations < length)
+ {
+ const char *end = strchr (p, ',');
+ if (hb_variation_from_string (p, end ? end - p: -1, &variations[*n_variations]))
+ (*n_variations)++;
+ p = end ? end + 1 : NULL;
+ }
+}
+
+static char *
+variations_to_string (hb_variation_t *variations,
+ unsigned int n_variations)
+{
+ GString *s;
+ char buf[128];
+
+ s = g_string_new ("");
+
+ for (unsigned int i = 0; i < n_variations; i++)
+ {
+ hb_variation_to_string (&variations[i], buf, sizeof (buf));
+ if (s->len > 0)
+ g_string_append_c (s, ',');
+ g_string_append (s, buf);
+ }
+
+ return g_string_free (s, FALSE);
+}
+
+static inline void
+replace_variation (hb_variation_t *values,
+ unsigned int *len,
+ const hb_variation_t *v)
+{
+ for (int i = 0; i < *len; i++)
+ {
+ if (values[i].tag == v->tag)
+ {
+ values[i].value = v->value;
+ return;
+ }
+ }
+
+ values[(*len)++] = *v;
+}
+
+static unsigned int
+merge_variations (const hb_variation_t *v1,
+ unsigned int l1,
+ const hb_variation_t *v2,
+ unsigned int l2,
+ hb_variation_t *v,
+ unsigned int l)
+{
+ unsigned int len = 0;
+
+ for (int i = 0; i < l1; i++)
+ replace_variation (v, &len, &v1[i]);
+
+ for (int i = 0; i < l2; i++)
+ replace_variation (v, &len, &v2[i]);
+
+ return len;
+}
+
+static inline void
+collect_variation (hb_variation_t *variation,
+ unsigned int n_axes,
+ hb_ot_var_axis_info_t *axes,
+ float *coords)
+{
+ for (int j = 0; j < n_axes; j++)
+ {
+ if (axes[j].tag == variation->tag)
+ {
+ coords[axes[j].axis_index] = variation->value;
+ break;
+ }
+ }
+}
+
+static inline void
+collect_variations (hb_variation_t *variations,
+ unsigned int n_variations,
+ unsigned int n_axes,
+ hb_ot_var_axis_info_t *axes,
+ float *coords)
+{
+ for (int i = 0; i < n_variations; i++)
+ collect_variation (&variations[i], n_axes, axes, coords);
+}
+
+/* }}} */
+/* {{{ hex box sizing */
+
+/* This code needs to stay in sync with the hexbox rendering code in pangocairo-render.c */
+static HexBoxInfo *
+create_hex_box_info (PangoHbFont *self)
+{
+ const char hexdigits[] = "0123456789ABCDEF";
+ hb_font_t *hb_font;
+ PangoFont *mini_font;
+ HexBoxInfo *hbi;
+ int rows;
+ double pad;
+ int width = 0;
+ int height = 0;
+ hb_font_extents_t font_extents;
+ double font_ascent, font_descent;
+ double mini_size;
+ PangoFontDescription *desc;
+ PangoContext *context;
+ PangoFontMap *map;
+
+ map = pango_hb_font_get_font_map (PANGO_FONT (self));
+
+ if (!map)
+ return NULL;
+
+ desc = pango_font_describe_with_absolute_size (PANGO_FONT (self));
+ hb_font = pango_font_get_hb_font (PANGO_FONT (self));
+
+ /* Create mini_font description */
+
+ /* We inherit most font properties for the mini font.
+ * Just change family and size, so you get bold
+ * hex digits in the hexbox for a bold font.
+ */
+
+ /* We should rotate the box, not glyphs */
+ pango_font_description_unset_fields (desc, PANGO_FONT_MASK_GRAVITY);
+
+ pango_font_description_set_family_static (desc, "monospace");
+
+ rows = 2;
+ mini_size = self->size / 2.2;
+
+ if (mini_size < 6.0)
+ {
+ rows = 1;
+ mini_size = MIN (MAX (self->size - 1, 0), 6.0);
+ }
+
+ pango_font_description_set_size (desc, mini_size);
+
+ /* Load mini_font */
+ context = pango_font_map_create_context (map);
+ pango_context_set_matrix (context, &self->matrix);
+ pango_context_set_language (context, pango_script_get_sample_language (PANGO_SCRIPT_LATIN));
+
+ mini_font = pango_font_map_load_font (map, context, desc);
+
+ g_object_unref (context);
+
+ pango_font_description_free (desc);
+
+ get_max_char_size (mini_font, hexdigits, &width, &height);
+
+ hb_font_get_extents_for_direction (hb_font, HB_DIRECTION_LTR, &font_extents);
+ font_ascent = font_extents.ascender / (double) PANGO_SCALE;
+ font_descent = - font_extents.descender / (double) PANGO_SCALE;
+
+ pad = (font_ascent + font_descent) / 43.;
+ pad = MIN (pad, mini_size / (double) PANGO_SCALE);
+
+ hbi = g_new (HexBoxInfo, 1);
+ hbi->font = mini_font;
+ hbi->rows = rows;
+
+ hbi->digit_width = width / (double) PANGO_SCALE;
+ hbi->digit_height = height / (double) PANGO_SCALE;
+
+ hbi->pad_x = pad;
+ hbi->pad_y = pad;
+
+ hbi->line_width = MIN (hbi->pad_x, hbi->pad_y);
+
+ hbi->box_height = 3 * hbi->pad_y + rows * (hbi->pad_y + hbi->digit_height);
+
+ if (rows == 1 || hbi->box_height <= font_ascent)
+ hbi->box_descent = 2 * hbi->pad_y;
+ else if (hbi->box_height <= font_ascent + font_descent - 2 * hbi->pad_y)
+ hbi->box_descent = 2 * hbi->pad_y + hbi->box_height - font_ascent;
+ else
+ hbi->box_descent = font_descent * hbi->box_height / (font_ascent + font_descent);
+
+ return hbi;
+}
+
+static void
+get_space_extents (PangoHbFont *self,
+ PangoRectangle *ink_rect,
+ PangoRectangle *logical_rect)
+{
+ hb_font_t *hb_font = pango_font_get_hb_font (PANGO_FONT (self));
+ int width;
+ hb_direction_t direction;
+ hb_font_extents_t font_extents;
+
+ direction = PANGO_GRAVITY_IS_VERTICAL (self->gravity)
+ ? HB_DIRECTION_TTB
+ : HB_DIRECTION_LTR;
+
+ hb_font_get_extents_for_direction (hb_font, direction, &font_extents);
+
+ /* See https://docs.microsoft.com/en-us/typography/develop/character-design-standards/whitespace */
+
+ width = self->size / 4;
+
+ if (ink_rect)
+ {
+ ink_rect->x = ink_rect->y = ink_rect->height = 0;
+ ink_rect->width = width;
+ }
+
+ if (logical_rect)
+ {
+ logical_rect->x = 0;
+ logical_rect->y = - font_extents.ascender;
+ logical_rect->height = font_extents.ascender - font_extents.descender;
+ logical_rect->width = width;
+ }
+}
+
+static void
+get_glyph_extents_missing (PangoHbFont *self,
+ PangoGlyph glyph,
+ PangoRectangle *ink_rect,
+ PangoRectangle *logical_rect)
+{
+ gunichar ch;
+ int rows, cols;
+ HexBoxInfo *hbi;
+
+ ch = glyph & ~PANGO_GLYPH_UNKNOWN_FLAG;
+
+ if (!self->hex_box_info)
+ self->hex_box_info = create_hex_box_info (self);
+
+ if (ch == 0x20 || ch == 0x2423)
+ {
+ get_space_extents (self, ink_rect, logical_rect);
+ return;
+ }
+
+ hbi = self->hex_box_info;
+
+ if (G_UNLIKELY (glyph == PANGO_GLYPH_INVALID_INPUT || ch > 0x10FFFF))
+ {
+ rows = hbi->rows;
+ cols = 1;
+ }
+ else if (pango_get_ignorable_size (ch, &rows, &cols))
+ {
+ /* We special-case ignorables when rendering hex boxes */
+ }
+ else
+ {
+ rows = hbi->rows;
+ cols = (ch > 0xffff ? 6 : 4) / rows;
+ }
+
+ if (ink_rect)
+ {
+ ink_rect->x = PANGO_SCALE * hbi->pad_x;
+ ink_rect->y = PANGO_SCALE * (hbi->box_descent - hbi->box_height);
+ ink_rect->width = PANGO_SCALE * (3 * hbi->pad_x + cols * (hbi->digit_width + hbi->pad_x));
+ ink_rect->height = PANGO_SCALE * hbi->box_height;
+ }
+
+ if (logical_rect)
+ {
+ logical_rect->x = 0;
+ logical_rect->y = PANGO_SCALE * (hbi->box_descent - (hbi->box_height + hbi->pad_y));
+ logical_rect->width = PANGO_SCALE * (5 * hbi->pad_x + cols * (hbi->digit_width + hbi->pad_x));
+ logical_rect->height = PANGO_SCALE * (hbi->box_height + 2 * hbi->pad_y);
+ }
+}
+
+ /* }}} */
+/* {{{ PangoFont implementation */
+
+struct _PangoHbFontClass
+{
+ PangoFontClass parent_class;
+};
+
+G_DEFINE_TYPE (PangoHbFont, pango_hb_font, PANGO_TYPE_FONT)
+
+static void
+pango_hb_font_init (PangoHbFont *self)
+{
+ self->gravity = PANGO_GRAVITY_AUTO;
+ self->matrix = (PangoMatrix) PANGO_MATRIX_INIT;
+}
+
+static void
+hex_box_info_destroy (HexBoxInfo *hex_box_info)
+{
+ g_object_unref (hex_box_info->font);
+ g_free (hex_box_info);
+}
+
+static void
+pango_hb_font_finalize (GObject *object)
+{
+ PangoHbFont *self = PANGO_HB_FONT (object);
+
+ g_object_unref (self->face);
+ g_free (self->variations);
+ g_clear_pointer (&self->hex_box_info, hex_box_info_destroy);
+
+ G_OBJECT_CLASS (pango_hb_font_parent_class)->finalize (object);
+}
+
+static PangoFontDescription *
+pango_hb_font_describe (PangoFont *font)
+{
+ PangoHbFont *self = PANGO_HB_FONT (font);
+ PangoFontDescription *desc;
+ PangoVariant variant;
+
+ desc = pango_font_face_describe (PANGO_FONT_FACE (self->face));
+ pango_font_description_set_gravity (desc, self->gravity);
+ variant = pango_variant_from_features (self->features, self->n_features);
+ if (variant != PANGO_VARIANT_NORMAL)
+ pango_font_description_set_variant (desc, variant);
+ if (self->n_variations > 0)
+ {
+ hb_variation_t *variations;
+ unsigned int n_variations;
+ char *str;
+
+ if (self->face->n_variations > 0)
+ {
+ variations = g_alloca (sizeof (hb_variation_t) * (self->n_variations + self->face->n_variations));
+ n_variations = merge_variations (self->face->variations, self->face->n_variations,
+ self->variations, self->n_variations,
+ variations, self->n_variations + self->face->n_variations);
+ }
+ else
+ {
+ variations = self->variations;
+ n_variations = self->n_variations;
+ }
+
+ str = variations_to_string (variations, n_variations);
+ pango_font_description_set_variations (desc, str);
+ g_free (str);
+ }
+ pango_font_description_set_size (desc, self->size);
+
+ return desc;
+}
+
+static PangoFontDescription *
+pango_hb_font_describe_absolute (PangoFont *font)
+{
+ PangoHbFont *self = PANGO_HB_FONT (font);
+ PangoFontDescription *desc;
+
+ desc = pango_hb_font_describe (font);
+ pango_font_description_set_absolute_size (desc, self->size * self->dpi / 72.);
+
+ return desc;
+}
+
+static PangoCoverage *
+pango_hb_font_get_coverage (PangoFont *font,
+ PangoLanguage *language G_GNUC_UNUSED)
+{
+ PangoHbFont *self = PANGO_HB_FONT (font);
+
+ return pango_coverage_new_for_hb_face (pango_hb_face_get_hb_face (self->face));
+}
+
+static void
+pango_hb_font_get_glyph_extents (PangoFont *font,
+ PangoGlyph glyph,
+ PangoRectangle *ink_rect,
+ PangoRectangle *logical_rect)
+{
+ PangoHbFont *self = PANGO_HB_FONT (font);
+ hb_font_t *hb_font = pango_font_get_hb_font (font);
+ hb_glyph_extents_t extents;
+ hb_direction_t direction;
+ hb_font_extents_t font_extents;
+
+ direction = PANGO_GRAVITY_IS_VERTICAL (self->gravity)
+ ? HB_DIRECTION_TTB
+ : HB_DIRECTION_LTR;
+
+ hb_font_get_extents_for_direction (hb_font, direction, &font_extents);
+
+ if (glyph == PANGO_GLYPH_EMPTY)
+ {
+ if (ink_rect)
+ ink_rect->x = ink_rect->y = ink_rect->width = ink_rect->height = 0;
+
+ if (logical_rect)
+ {
+ logical_rect->x = logical_rect->width = 0;
+ logical_rect->y = - font_extents.ascender;
+ logical_rect->height = font_extents.ascender - font_extents.descender;
+ }
+
+ return;
+ }
+ else if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
+ {
+ get_glyph_extents_missing (self, glyph, ink_rect, logical_rect);
+
+ return;
+ }
+
+ hb_font_get_glyph_extents (hb_font, glyph, &extents);
+
+ if (ink_rect)
+ {
+ PangoRectangle r;
+ PangoMatrix m = PANGO_MATRIX_INIT;
+
+ r.x = extents.x_bearing;
+ r.y = - extents.y_bearing;
+ r.width = extents.width;
+ r.height = - extents.height;
+
+ if (self->face->matrix)
+ {
+ m.xx = self->face->matrix->xx;
+ m.yx = - self->face->matrix->yx;
+ m.xy = - self->face->matrix->xy;
+ m.yy = self->face->matrix->yy;
+ }
+
+ pango_matrix_transform_rectangle (&m, &r);
+
+ switch (self->gravity)
+ {
+ case PANGO_GRAVITY_AUTO:
+ case PANGO_GRAVITY_SOUTH:
+ ink_rect->x = r.x;
+ ink_rect->y = r.y;
+ ink_rect->width = r.width;
+ ink_rect->height = r.height;
+ break;
+ case PANGO_GRAVITY_NORTH:
+ ink_rect->x = - r.x;
+ ink_rect->y = - r.y;
+ ink_rect->width = - r.width;
+ ink_rect->height = - r.height;
+ break;
+ case PANGO_GRAVITY_EAST:
+ ink_rect->x = r.y;
+ ink_rect->y = - r.x - r.width;
+ ink_rect->width = r.height;
+ ink_rect->height = r.width;
+ break;
+ case PANGO_GRAVITY_WEST:
+ ink_rect->x = - r.y - r.height;
+ ink_rect->y = r.x;
+ ink_rect->width = r.height;
+ ink_rect->height = r.width;
+ break;
+ default:
+ g_assert_not_reached ();
+ }
+
+ if (PANGO_GRAVITY_IS_IMPROPER (self->gravity))
+ {
+ PangoMatrix matrix = (PangoMatrix) PANGO_MATRIX_INIT;
+ pango_matrix_scale (&matrix, -1, -1);
+ pango_matrix_transform_rectangle (&matrix, ink_rect);
+ }
+ }
+
+ if (logical_rect)
+ {
+ hb_position_t h_advance;
+ hb_font_extents_t extents;
+
+ h_advance = hb_font_get_glyph_h_advance (hb_font, glyph);
+ hb_font_get_h_extents (hb_font, &extents);
+
+ logical_rect->x = 0;
+ logical_rect->height = extents.ascender - extents.descender;
+
+ switch (self->gravity)
+ {
+ case PANGO_GRAVITY_AUTO:
+ case PANGO_GRAVITY_SOUTH:
+ logical_rect->y = - extents.ascender;
+ logical_rect->width = h_advance;
+ break;
+ case PANGO_GRAVITY_NORTH:
+ logical_rect->y = extents.descender;
+ logical_rect->width = h_advance;
+ break;
+ case PANGO_GRAVITY_EAST:
+ logical_rect->y = - logical_rect->height / 2;
+ logical_rect->width = logical_rect->height;
+ break;
+ case PANGO_GRAVITY_WEST:
+ logical_rect->y = - logical_rect->height / 2;
+ logical_rect->width = - logical_rect->height;
+ break;
+ default:
+ g_assert_not_reached ();
+ }
+
+ if (PANGO_GRAVITY_IS_IMPROPER (self->gravity))
+ {
+ logical_rect->height = - logical_rect->height;
+ logical_rect->y = - logical_rect->y;
+ }
+ }
+}
+
+static PangoFontMetrics *
+pango_hb_font_get_metrics (PangoFont *font,
+ PangoLanguage *language)
+{
+ hb_font_t *hb_font = pango_font_get_hb_font (font);
+ PangoFontMetrics *metrics;
+ hb_font_extents_t extents;
+ hb_position_t position;
+
+ metrics = pango_font_metrics_new ();
+
+ hb_font_get_extents_for_direction (hb_font, HB_DIRECTION_LTR, &extents);
+
+ metrics->descent = - extents.descender;
+ metrics->ascent = extents.ascender;
+ metrics->height = extents.ascender - extents.descender + extents.line_gap;
+
+ if (hb_ot_metrics_get_position (hb_font, HB_OT_METRICS_TAG_UNDERLINE_SIZE, &position) && position != 0)
+ metrics->underline_thickness = position;
+ else
+ metrics->underline_thickness = PANGO_SCALE;
+
+ if (hb_ot_metrics_get_position (hb_font, HB_OT_METRICS_TAG_UNDERLINE_OFFSET, &position) && position != 0)
+ metrics->underline_position = position;
+ else
+ metrics->underline_position = - PANGO_SCALE;
+
+ if (hb_ot_metrics_get_position (hb_font, HB_OT_METRICS_TAG_STRIKEOUT_SIZE, &position) && position != 0)
+ metrics->strikethrough_thickness = position;
+ else
+ metrics->strikethrough_thickness = PANGO_SCALE;
+
+ if (hb_ot_metrics_get_position (hb_font, HB_OT_METRICS_TAG_STRIKEOUT_OFFSET, &position) && position != 0)
+ metrics->strikethrough_position = position;
+ else
+ metrics->strikethrough_position = metrics->ascent / 2;
+
+ metrics->approximate_char_width = get_average_char_width (font, pango_language_get_sample_string
(language));
+ get_max_char_size (font, "0123456789", &metrics->approximate_digit_width, NULL);
+
+ return metrics;
+}
+
+static hb_font_t *
+pango_hb_font_create_hb_font (PangoFont *font)
+{
+ PangoHbFont *self = PANGO_HB_FONT (font);
+ hb_face_t *hb_face;
+ hb_font_t *hb_font;
+ double x_scale, y_scale;
+ unsigned int n_axes;
+ hb_ot_var_axis_info_t *axes;
+ float *coords;
+ int size;
+
+ hb_face = pango_hb_face_get_hb_face (self->face);
+ hb_font = hb_font_create (hb_face);
+
+ size = self->size * self->dpi / 72.f;
+ x_scale = self->face->x_scale;
+ y_scale = self->face->y_scale;
+
+ if (PANGO_GRAVITY_IS_IMPROPER (self->gravity))
+ {
+ x_scale = - x_scale;
+ y_scale = - y_scale;
+ }
+
+ hb_font_set_scale (hb_font, size * x_scale, size * y_scale);
+ hb_font_set_ptem (hb_font, self->size / PANGO_SCALE);
+
+#if HB_VERSION_ATLEAST (3, 3, 0)
+ hb_font_set_synthetic_slant (hb_font, pango_matrix_get_slant_ratio (&self->face->matrix));
+#endif
+
+ if (self->face->instance_id >= 0)
+ hb_font_set_var_named_instance (hb_font, self->face->instance_id);
+
+ if (self->n_variations > 0 || self->face->n_variations > 0)
+ {
+ n_axes = hb_ot_var_get_axis_count (self->face->face);
+ axes = g_alloca (sizeof (hb_ot_var_axis_info_t) * n_axes);
+ coords = g_alloca (sizeof (float) * n_axes);
+
+ hb_ot_var_get_axis_infos (hb_face, 0, &n_axes, axes);
+
+ if (self->face->instance_id >= 0)
+ hb_ot_var_named_instance_get_design_coords (self->face->face, self->face->instance_id, &n_axes,
coords);
+ else
+ {
+ for (int i = 0; i < n_axes; i++)
+ coords[axes[i].axis_index] = axes[i].default_value;
+ }
+
+ collect_variations (self->face->variations, self->face->n_variations, n_axes, axes, coords);
+ collect_variations (self->variations, self->n_variations, n_axes, axes, coords);
+
+ hb_font_set_var_coords_design (hb_font, coords, n_axes);
+ }
+
+ return hb_font;
+}
+
+static gboolean
+pango_hb_font_has_char (PangoFont *font,
+ gunichar wc)
+{
+ hb_font_t *hb_font = pango_font_get_hb_font (font);
+ hb_codepoint_t glyph;
+
+ return hb_font_get_nominal_glyph (hb_font, wc, &glyph);
+}
+
+static PangoFontFace *
+pango_hb_font_get_face (PangoFont *font)
+{
+ PangoHbFont *self = PANGO_HB_FONT (font);
+
+ return PANGO_FONT_FACE (self->face);
+}
+
+static void
+pango_hb_font_get_matrix (PangoFont *font,
+ PangoMatrix *matrix)
+{
+ PangoHbFont *self = PANGO_HB_FONT (font);
+
+ if (self->face->matrix)
+ {
+ *matrix = *self->face->matrix;
+ pango_matrix_scale (matrix, self->face->x_scale, self->face->y_scale);
+ }
+ else
+ *matrix = (PangoMatrix) PANGO_MATRIX_INIT;
+}
+
+static void
+pango_hb_font_get_features (PangoFont *font,
+ hb_feature_t *features,
+ guint len,
+ guint *num_features)
+{
+ PangoHbFont *self = PANGO_HB_FONT (font);
+
+ *num_features = MIN (len, self->n_features);
+ memcpy (features, self->features, sizeof (hb_feature_t) * *num_features);
+}
+
+static void
+pango_hb_font_class_init (PangoHbFontClass *class)
+{
+ GObjectClass *object_class = G_OBJECT_CLASS (class);
+ PangoFontClass *font_class = PANGO_FONT_CLASS (class);
+ PangoFontClassPrivate *pclass;
+
+ object_class->finalize = pango_hb_font_finalize;
+
+ font_class->describe = pango_hb_font_describe;
+ font_class->describe_absolute = pango_hb_font_describe_absolute;
+ font_class->get_coverage = pango_hb_font_get_coverage;
+ font_class->get_glyph_extents = pango_hb_font_get_glyph_extents;
+ font_class->get_metrics = pango_hb_font_get_metrics;
+ font_class->get_font_map = pango_hb_font_get_font_map;
+ font_class->create_hb_font = pango_hb_font_create_hb_font;
+ font_class->get_features = pango_hb_font_get_features;
+
+ pclass = g_type_class_get_private ((GTypeClass *) class, PANGO_TYPE_FONT);
+
+ pclass->has_char = pango_hb_font_has_char;
+ pclass->get_face = pango_hb_font_get_face;
+ pclass->get_matrix = pango_hb_font_get_matrix;
+}
+
+/* }}} */
+ /* {{{ Public API */
+
+/**
+ * pango_hb_font_new:
+ * @face: the `PangoHbFace` to use
+ * @size: the desired size in points, scaled by `PANGO_SCALE`
+ * @features: (nullable) (array length=n_features): OpenType font features to use for this font
+ * @n_features: length of @features
+ * @variations: (nullable) (array length=n_variations): font variations to apply
+ * @n_variations: length of @variations
+ * @gravity: the gravity to use when rendering
+ * @dpi: the dpi used when rendering
+ * @matrix: (nullable): transformation matrix to use when rendering
+ *
+ * Creates a new `PangoHbFont`.
+ *
+ * Returns: a newly created `PangoHbFont`
+ *
+ * Since: 1.52
+ */
+PangoHbFont *
+pango_hb_font_new (PangoHbFace *face,
+ int size,
+ hb_feature_t *features,
+ unsigned int n_features,
+ hb_variation_t *variations,
+ unsigned int n_variations,
+ PangoGravity gravity,
+ float dpi,
+ const PangoMatrix *matrix)
+{
+ PangoHbFont *self;
+
+ self = g_object_new (PANGO_TYPE_HB_FONT, NULL);
+
+ self->face = g_object_ref (face);
+
+ self->size = size;
+ self->dpi = dpi;
+ self->features = g_memdup2 (features, sizeof (hb_feature_t) * n_features);
+ self->n_features = n_features;
+ self->variations = g_memdup2 (variations, sizeof (hb_variation_t) * n_variations);
+ self->n_variations = n_variations;
+ if (gravity != PANGO_GRAVITY_AUTO)
+ self->gravity = gravity;
+ if (matrix)
+ self->matrix = *matrix;
+
+ return self;
+}
+
+/**
+ * pango_hb_font_new_for_description:
+ * @face: the `PangoHbFace` to use
+ * @description: a `PangoFontDescription`
+ * @dpi: the dpi used when rendering
+ * @matrix: (nullable): transformation matrix to use when rendering
+ *
+ * Creates a new `PangoHbFont` with size, features, variations and
+ * gravity taken from a font description.
+ *
+ * Returns: a newly created `PangoHbFont`
+ *
+ * Since: 1.52
+ */
+PangoHbFont *
+pango_hb_font_new_for_description (PangoHbFace *face,
+ const PangoFontDescription *description,
+ float dpi,
+ const PangoMatrix *matrix)
+{
+ int size;
+ hb_feature_t features[10];
+ unsigned int n_features;
+ hb_variation_t *variations;
+ unsigned int n_variations;
+ unsigned int length;
+ PangoGravity gravity;
+ const char *str;
+
+ if (pango_font_description_get_size_is_absolute (description))
+ size = pango_font_description_get_size (description) * 72. / dpi;
+ else
+ size = pango_font_description_get_size (description);
+
+ font_description_get_features (description, features, G_N_ELEMENTS (features), &n_features);
+
+ if ((pango_font_description_get_set_fields (description) & PANGO_FONT_MASK_VARIATIONS) != 0)
+ {
+ str = pango_font_description_get_variations (description);
+ length = count_variations (str);
+ variations = g_alloca (sizeof (hb_variation_t) * length);
+ parse_variations (str, variations, length, &n_variations);
+ }
+ else
+ {
+ variations = NULL;
+ n_variations = 0;
+ }
+
+ if ((pango_font_description_get_set_fields (description) & PANGO_FONT_MASK_GRAVITY) != 0 &&
+ pango_font_description_get_gravity (description) != PANGO_GRAVITY_SOUTH)
+ gravity = pango_font_description_get_gravity (description);
+ else
+ gravity = PANGO_GRAVITY_AUTO;
+
+ return pango_hb_font_new (face, size, features, n_features, variations, n_variations, gravity, dpi,
matrix);
+}
+
+/* }}} */
+
+/* vim:set foldmethod=marker expandtab: */
diff --git a/pango/pango-hbfont.h b/pango/pango-hbfont.h
new file mode 100644
index 00000000..1c747d97
--- /dev/null
+++ b/pango/pango-hbfont.h
@@ -0,0 +1,50 @@
+/* Pango
+ *
+ * Copyright (C) 2021 Matthias Clasen
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#pragma once
+
+#include <pango/pango-types.h>
+#include <pango/pango-hbface.h>
+#include <hb.h>
+
+G_BEGIN_DECLS
+
+#define PANGO_TYPE_HB_FONT (pango_hb_font_get_type ())
+
+PANGO_AVAILABLE_IN_1_52
+G_DECLARE_FINAL_TYPE (PangoHbFont, pango_hb_font, PANGO, HB_FONT, PangoFont)
+
+PANGO_AVAILABLE_IN_1_52
+PangoHbFont * pango_hb_font_new (PangoHbFace *face,
+ int size,
+ hb_feature_t *features,
+ unsigned int n_features,
+ hb_variation_t *variations,
+ unsigned int
n_variations,
+ PangoGravity gravity,
+ float dpi,
+ const PangoMatrix *matrix);
+
+PANGO_AVAILABLE_IN_1_52
+PangoHbFont * pango_hb_font_new_for_description (PangoHbFace *face,
+ const PangoFontDescription *description,
+ float dpi,
+ const PangoMatrix *matrix);
+G_END_DECLS
diff --git a/pango/pango.h b/pango/pango.h
index 87036972..a1af0802 100644
--- a/pango/pango.h
+++ b/pango/pango.h
@@ -41,6 +41,7 @@
#include <pango/pango-glyph-item.h>
#include <pango/pango-gravity.h>
#include <pango/pango-hbface.h>
+#include <pango/pango-hbfont.h>
#include <pango/pango-item.h>
#include <pango/pango-language.h>
#include <pango/pango-layout.h>
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