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Diffstat (limited to 'pango2/pango-font.c')
| -rw-r--r-- | pango2/pango-font.c | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/pango2/pango-font.c b/pango2/pango-font.c new file mode 100644 index 00000000..cdf2fc42 --- /dev/null +++ b/pango2/pango-font.c @@ -0,0 +1,478 @@ +/* Pango2 + * fonts.c: + * + * Copyright (C) 1999 Red Hat Software + * + * 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 <stdlib.h> +#include <math.h> +#include <string.h> + +#include <gio/gio.h> + +#include "pango-types.h" +#include "pango-font-private.h" +#include "pango-font-metrics-private.h" +#include "pango-fontmap-private.h" +#include "pango-impl-utils.h" + +#include <hb-gobject.h> + +/** + * Pango2Font: + * + * A `Pango2Font` is used to represent a font in a + * rendering-system-independent manner. + */ + +/* }}} */ +/* {{{ Pango2Font implementation */ + +enum { + PROP_FACE = 1, + PROP_HB_FONT, + PROP_SIZE, + PROP_DPI, + PROP_GRAVITY, + N_PROPERTIES +}; + +static GParamSpec *properties[N_PROPERTIES] = { NULL, }; + +G_DEFINE_ABSTRACT_TYPE (Pango2Font, pango2_font, G_TYPE_OBJECT) + +static void +pango2_font_finalize (GObject *object) +{ + Pango2Font *font = PANGO2_FONT (object); + + g_object_unref (font->face); + hb_font_destroy (font->hb_font); + + G_OBJECT_CLASS (pango2_font_parent_class)->finalize (object); +} + +static void +pango2_font_get_property (GObject *object, + guint property_id, + GValue *value, + GParamSpec *pspec) +{ + Pango2Font *font = PANGO2_FONT (object); + + switch (property_id) + { + case PROP_FACE: + g_value_set_object (value, font->face); + break; + + case PROP_HB_FONT: + g_value_set_boxed (value, pango2_font_get_hb_font (font)); + break; + + case PROP_SIZE: + g_value_set_int (value, font->size); + break; + + case PROP_DPI: + g_value_set_float (value, font->dpi); + break; + + case PROP_GRAVITY: + g_value_set_enum (value, font->gravity); + break; + + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec); + } +} + +static gboolean +pango2_font_default_is_hinted (Pango2Font *font) +{ + return FALSE; +} + +static void +pango2_font_default_get_scale_factors (Pango2Font *font, + double *x_scale, + double *y_scale) +{ + *x_scale = *y_scale = 1.0; +} + +static void +pango2_font_default_get_transform (Pango2Font *font, + Pango2Matrix *matrix) +{ + *matrix = (Pango2Matrix) PANGO2_MATRIX_INIT; +} + +static void +pango2_font_class_init (Pango2FontClass *class G_GNUC_UNUSED) +{ + GObjectClass *object_class = G_OBJECT_CLASS (class); + + object_class->finalize = pango2_font_finalize; + object_class->get_property = pango2_font_get_property; + + class->is_hinted = pango2_font_default_is_hinted; + class->get_scale_factors = pango2_font_default_get_scale_factors; + class->get_transform = pango2_font_default_get_transform; + + /** + * Pango2Font:face: (attributes org.gtk.Property.get=pango2_font_get_face) + * + * The face to which the font belongs. + */ + properties[PROP_FACE] = + g_param_spec_object ("face", NULL, NULL, PANGO2_TYPE_FONT_FACE, + G_PARAM_READABLE | G_PARAM_STATIC_STRINGS); + + /** + * Pango2Font:hb-font: (attributes org.gtk.Property.get=pango2_font_get_hb_font) + * + * A `hb_font_t` object backing this font. + */ + properties[PROP_HB_FONT] = + g_param_spec_boxed ("hb-font", NULL, NULL, HB_GOBJECT_TYPE_FONT, + G_PARAM_READABLE | G_PARAM_STATIC_STRINGS); + + /** + * Pango2Font:size: (attributes org.gtk.Property.get=pango2_font_get_size) + * + * The size of the font, scaled by `PANGO2_SCALE`. + */ + properties[PROP_SIZE] = + g_param_spec_int ("size", NULL, NULL, 0, G_MAXINT, 0, + G_PARAM_READABLE | G_PARAM_STATIC_STRINGS); + + /** + * Pango2Font:dpi: + * + * The resolution at which the font is rendered. + * + * The pixel size of the font is computed as + * + * size * dpi / 72. + */ + properties[PROP_DPI] = + g_param_spec_float ("dpi", NULL, NULL, 0, G_MAXFLOAT, 96.0, + G_PARAM_READABLE | G_PARAM_STATIC_STRINGS); + + /** + * Pango2Font:gravity: (attributes org.gtk.Property.get=pango2_font_get_gravity) + * + * The gravity of the font. + */ + properties[PROP_GRAVITY] = + g_param_spec_enum ("gravity", NULL, NULL, PANGO2_TYPE_GRAVITY, + PANGO2_GRAVITY_AUTO, + G_PARAM_READABLE | G_PARAM_STATIC_STRINGS); + + g_object_class_install_properties (object_class, N_PROPERTIES, properties); +} + +static void +pango2_font_init (Pango2Font *font) +{ + font->gravity = PANGO2_GRAVITY_AUTO; + font->ctm = (Pango2Matrix) PANGO2_MATRIX_INIT; +} + +/* }}} */ +/* {{{ Private API */ + +/*< private > + * pango2_font_get_transform: + * @font: a `Pango2Font` + * @matrix: the matrix to fill in + * + * Gets the matrix for the transformation from 'font space' to 'user space'. + */ +void +pango2_font_get_transform (Pango2Font *font, + Pango2Matrix *matrix) +{ + PANGO2_FONT_GET_CLASS (font)->get_transform (font, matrix); +} + +/*< private > + * pango2_font_is_hinted: + * @font: a `Pango2Font` + * + * Gets whether this font is hinted. + * + * Returns: %TRUE if @font is hinted + */ +gboolean +pango2_font_is_hinted (Pango2Font *font) +{ + return PANGO2_FONT_GET_CLASS (font)->is_hinted (font); +} + +/*< private > + * pango2_font_get_scale_factors: + * @font: a `Pango2Font` + * @x_scale: return location for X scale + * @y_scale: return location for Y scale + * + * Gets the font scale factors of the ctm for this font. + * + * The ctm is the matrix set on the context that this font was + * loaded for. + */ +void +pango2_font_get_scale_factors (Pango2Font *font, + double *x_scale, + double *y_scale) +{ + PANGO2_FONT_GET_CLASS (font)->get_scale_factors (font, x_scale, y_scale); +} + +/* }}} */ +/* {{{ Public API */ + +/** + * pango2_font_describe: + * @font: a `Pango2Font` + * + * Returns a description of the font, with font size set in points. + * + * Use [method@Pango2.Font.describe_with_absolute_size] if you want + * the font size in device units. + * + * Return value: a newly-allocated `Pango2FontDescription` object. + */ +Pango2FontDescription * +pango2_font_describe (Pango2Font *font) +{ + g_return_val_if_fail (font != NULL, NULL); + + return PANGO2_FONT_GET_CLASS (font)->describe (font); +} + +/** + * pango2_font_describe_with_absolute_size: + * @font: a `Pango2Font` + * + * Returns a description of the font, with absolute font size set + * in device units. + * + * Use [method@Pango2.Font.describe] if you want the font size in points. + * + * Return value: a newly-allocated `Pango2FontDescription` object. + */ +Pango2FontDescription * +pango2_font_describe_with_absolute_size (Pango2Font *font) +{ + Pango2FontDescription *desc; + + g_return_val_if_fail (font != NULL, NULL); + + desc = pango2_font_describe (font); + pango2_font_description_set_absolute_size (desc, font->size * font->dpi / 72.); + + return desc; +} + +/** + * pango2_font_get_glyph_extents: + * @font: (nullable): a `Pango2Font` + * @glyph: the glyph index + * @ink_rect: (out) (optional): rectangle used to store the extents of the glyph as drawn + * @logical_rect: (out) (optional): rectangle used to store the logical extents of the glyph + * + * Gets the logical and ink extents of a glyph within a font. + * + * The coordinate system for each rectangle has its origin at the + * base line and horizontal origin of the character with increasing + * coordinates extending to the right and down. The macros PANGO2_ASCENT(), + * PANGO2_DESCENT(), PANGO2_LBEARING(), and PANGO2_RBEARING() can be used to convert + * from the extents rectangle to more traditional font metrics. The units + * of the rectangles are in 1/PANGO2_SCALE of a device unit. + * + * If @font is %NULL, this function gracefully sets some sane values in the + * output variables and returns. + */ +void +pango2_font_get_glyph_extents (Pango2Font *font, + Pango2Glyph glyph, + Pango2Rectangle *ink_rect, + Pango2Rectangle *logical_rect) +{ + if (G_UNLIKELY (!font)) + { + if (ink_rect) + { + ink_rect->x = PANGO2_SCALE; + ink_rect->y = - (PANGO2_UNKNOWN_GLYPH_HEIGHT - 1) * PANGO2_SCALE; + ink_rect->height = (PANGO2_UNKNOWN_GLYPH_HEIGHT - 2) * PANGO2_SCALE; + ink_rect->width = (PANGO2_UNKNOWN_GLYPH_WIDTH - 2) * PANGO2_SCALE; + } + if (logical_rect) + { + logical_rect->x = 0; + logical_rect->y = - PANGO2_UNKNOWN_GLYPH_HEIGHT * PANGO2_SCALE; + logical_rect->height = PANGO2_UNKNOWN_GLYPH_HEIGHT * PANGO2_SCALE; + logical_rect->width = PANGO2_UNKNOWN_GLYPH_WIDTH * PANGO2_SCALE; + } + return; + } + + PANGO2_FONT_GET_CLASS (font)->get_glyph_extents (font, glyph, ink_rect, logical_rect); +} + +/** + * pango2_font_get_metrics: + * @font: (nullable): a `Pango2Font` + * @language: (nullable): language tag used to determine which script + * to get the metrics for, or %NULL to indicate to get the metrics for + * the entire font. + * + * Gets overall metric information for a font. + * + * Since the metrics may be substantially different for different scripts, + * a language tag can be provided to indicate that the metrics should be + * retrieved that correspond to the script(s) used by that language. + * + * If @font is %NULL, this function gracefully sets some sane values in the + * output variables and returns. + * + * Return value: a `Pango2FontMetrics` object. The caller must call + * [method@Pango2.FontMetrics.free] when finished using the object. + */ +Pango2FontMetrics * +pango2_font_get_metrics (Pango2Font *font, + Pango2Language *language) +{ + if (G_UNLIKELY (!font)) + { + Pango2FontMetrics *metrics = pango2_font_metrics_new (); + + metrics->ascent = PANGO2_SCALE * PANGO2_UNKNOWN_GLYPH_HEIGHT; + metrics->descent = 0; + metrics->height = 0; + metrics->approximate_char_width = PANGO2_SCALE * PANGO2_UNKNOWN_GLYPH_WIDTH; + metrics->approximate_digit_width = PANGO2_SCALE * PANGO2_UNKNOWN_GLYPH_WIDTH; + metrics->underline_position = -PANGO2_SCALE; + metrics->underline_thickness = PANGO2_SCALE; + metrics->strikethrough_position = PANGO2_SCALE * PANGO2_UNKNOWN_GLYPH_HEIGHT / 2; + metrics->strikethrough_thickness = PANGO2_SCALE; + + return metrics; + } + + return PANGO2_FONT_GET_CLASS (font)->get_metrics (font, language); +} + +/** + * pango2_font_get_face: + * @font: a `Pango2Font` + * + * Gets the `Pango2FontFace` to which the font belongs. + * + * Returns: (transfer none): the `Pango2FontFace` + */ +Pango2FontFace * +pango2_font_get_face (Pango2Font *font) +{ + g_return_val_if_fail (PANGO2_IS_FONT (font), NULL); + + return font->face; +} + +/** + * pango2_font_get_hb_font: + * @font: a `Pango2Font` + * + * Get a `hb_font_t` object backing this font. + * + * Note that the objects returned by this function are cached + * and immutable. If you need to make changes to the `hb_font_t`, + * use [hb_font_create_sub_font()](https://harfbuzz.github.io/harfbuzz-hb-font.html#hb-font-create-sub-font). + * + * Returns: (transfer none) (nullable): the `hb_font_t` object + * backing the font + */ +hb_font_t * +pango2_font_get_hb_font (Pango2Font *font) +{ + g_return_val_if_fail (PANGO2_IS_FONT (font), NULL); + + if (!font->hb_font) + { + font->hb_font = PANGO2_FONT_GET_CLASS (font)->create_hb_font (font); + hb_font_make_immutable (font->hb_font); + } + + return font->hb_font; +} + +/** + * pango2_font_get_size: + * @font: a `Pango2Font` + * + * Returns the size of the font, scaled by `PANGO2_SCALE`. + * + * Return value: the size of the font + */ +int +pango2_font_get_size (Pango2Font *font) +{ + g_return_val_if_fail (PANGO2_IS_FONT (font), 0); + + return font->size; +} + +/** + * pango2_font_get_absolute_size: + * @font: a `Pango2Font` + * + * Returns the pixel size of the font, scaled by `PANGO2_SCALE`. + * + * Return value: the pixel size of the font + */ +double +pango2_font_get_absolute_size (Pango2Font *font) +{ + g_return_val_if_fail (PANGO2_IS_FONT (font), 0.); + + return font->size * font->dpi / 72.; +} + +/** + * pango2_font_get_gravity: + * @font: a `Pango2Font` + * + * Returns the gravity of the font. + * + * Return value: the gravity of the font + */ +Pango2Gravity +pango2_font_get_gravity (Pango2Font *font) +{ + g_return_val_if_fail (PANGO2_IS_FONT (font), PANGO2_GRAVITY_SOUTH); + + return font->gravity; +} + +/* }}} */ + +/* vim:set foldmethod=marker expandtab: */ |