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Diffstat (limited to 'pango2/pango-userfont.c')
| -rw-r--r-- | pango2/pango-userfont.c | 442 |
1 files changed, 442 insertions, 0 deletions
diff --git a/pango2/pango-userfont.c b/pango2/pango-userfont.c new file mode 100644 index 00000000..6bd4b20c --- /dev/null +++ b/pango2/pango-userfont.c @@ -0,0 +1,442 @@ +/* Pango2 + * + * 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-userfont-private.h" + +#include "pango-font-private.h" +#include "pango-font-metrics-private.h" +#include "pango-userface-private.h" +#include "pango-hbfamily-private.h" +#include "pango-impl-utils.h" +#include "pango-language-set-private.h" + +#include <hb-ot.h> + +/** + * Pango2UserFont: + * + * `Pango2UserFont` is a `Pango2Font` implementation that uses callbacks. + */ + +/* {{{ Pango2Font implementation */ + +struct _Pango2UserFontClass +{ + Pango2FontClass parent_class; +}; + +G_DEFINE_FINAL_TYPE (Pango2UserFont, pango2_user_font, PANGO2_TYPE_FONT) + +static void +pango2_user_font_init (Pango2UserFont *self G_GNUC_UNUSED) +{ +} + +static void +pango2_user_font_finalize (GObject *object) +{ + G_OBJECT_CLASS (pango2_user_font_parent_class)->finalize (object); +} + +static Pango2FontDescription * +pango2_user_font_describe (Pango2Font *font) +{ + Pango2FontDescription *desc; + + desc = pango2_font_face_describe (PANGO2_FONT_FACE (font->face)); + pango2_font_description_set_gravity (desc, font->gravity); + pango2_font_description_set_size (desc, font->size); + + return desc; +} + +static void +pango2_user_font_get_glyph_extents (Pango2Font *font, + Pango2Glyph glyph, + Pango2Rectangle *ink_rect, + Pango2Rectangle *logical_rect) +{ + hb_font_t *hb_font = pango2_font_get_hb_font (font); + hb_glyph_extents_t extents; + hb_direction_t direction; + hb_font_extents_t font_extents; + + direction = PANGO2_GRAVITY_IS_VERTICAL (font->gravity) + ? HB_DIRECTION_TTB + : HB_DIRECTION_LTR; + + hb_font_get_extents_for_direction (hb_font, direction, &font_extents); + + if (glyph == PANGO2_GLYPH_EMPTY || (glyph & PANGO2_GLYPH_UNKNOWN_FLAG)) + { + 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; + } + + hb_font_get_glyph_extents (hb_font, glyph, &extents); + + if (ink_rect) + { + Pango2Rectangle r; + + r.x = extents.x_bearing; + r.y = - extents.y_bearing; + r.width = extents.width; + r.height = - extents.height; + + switch (font->gravity) + { + case PANGO2_GRAVITY_AUTO: + case PANGO2_GRAVITY_SOUTH: + ink_rect->x = r.x; + ink_rect->y = r.y; + ink_rect->width = r.width; + ink_rect->height = r.height; + break; + case PANGO2_GRAVITY_NORTH: + ink_rect->x = - r.x; + ink_rect->y = - r.y; + ink_rect->width = - r.width; + ink_rect->height = - r.height; + break; + case PANGO2_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 PANGO2_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 (PANGO2_GRAVITY_IS_IMPROPER (font->gravity)) + { + Pango2Matrix matrix = (Pango2Matrix) PANGO2_MATRIX_INIT; + pango2_matrix_scale (&matrix, -1, -1); + pango2_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 (font->gravity) + { + case PANGO2_GRAVITY_AUTO: + case PANGO2_GRAVITY_SOUTH: + logical_rect->y = - extents.ascender; + logical_rect->width = h_advance; + break; + case PANGO2_GRAVITY_NORTH: + logical_rect->y = extents.descender; + logical_rect->width = h_advance; + break; + case PANGO2_GRAVITY_EAST: + logical_rect->y = - logical_rect->height / 2; + logical_rect->width = logical_rect->height; + break; + case PANGO2_GRAVITY_WEST: + logical_rect->y = - logical_rect->height / 2; + logical_rect->width = - logical_rect->height; + break; + default: + g_assert_not_reached (); + } + + if (PANGO2_GRAVITY_IS_IMPROPER (font->gravity)) + { + logical_rect->height = - logical_rect->height; + logical_rect->y = - logical_rect->y; + } + } +} + +static Pango2FontMetrics * +pango2_user_font_get_metrics (Pango2Font *font, + Pango2Language *language) +{ + hb_font_t *hb_font = pango2_font_get_hb_font (font); + Pango2FontMetrics *metrics; + hb_font_extents_t extents; + + metrics = pango2_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; + + metrics->underline_thickness = PANGO2_SCALE; + metrics->underline_position = - PANGO2_SCALE; + metrics->strikethrough_thickness = PANGO2_SCALE; + metrics->strikethrough_position = metrics->ascent / 2; + metrics->approximate_char_width = 0; /* FIXME */ + metrics->approximate_digit_width = 0; + + return metrics; +} + +static hb_bool_t +nominal_glyph_func (hb_font_t *hb_font, + void *font_data, + hb_codepoint_t unicode, + hb_codepoint_t *glyph, + void *user_data) +{ + Pango2Font *font = font_data; + Pango2UserFace *face = PANGO2_USER_FACE (font->face); + + return face->glyph_func (face, unicode, glyph, face->user_data); +} + +static hb_position_t +glyph_h_advance_func (hb_font_t *hb_font, + void *font_data, + hb_codepoint_t glyph, + void *user_data) +{ + Pango2Font *font = font_data; + Pango2UserFace *face = PANGO2_USER_FACE (font->face); + int size = font->size * font->dpi / 72.; + hb_position_t h_advance, v_advance; + hb_glyph_extents_t glyph_extents; + gboolean is_color; + + face->glyph_info_func (face, size, glyph, + &glyph_extents, + &h_advance, &v_advance, + &is_color, + face->user_data); + + return h_advance; +} + +static hb_bool_t +glyph_extents_func (hb_font_t *hb_font, + void *font_data, + hb_codepoint_t glyph, + hb_glyph_extents_t *extents, + void *user_data) +{ + Pango2Font *font = font_data; + Pango2UserFace *face = PANGO2_USER_FACE (font->face); + int size = font->size * font->dpi / 72.; + hb_position_t h_advance, v_advance; + gboolean is_color; + + face->glyph_info_func (face, size, glyph, + extents, + &h_advance, &v_advance, + &is_color, + face->user_data); + + if (PANGO2_GRAVITY_IS_IMPROPER (font->gravity)) + { + extents->x_bearing = - extents->x_bearing; + extents->y_bearing = - extents->y_bearing; + extents->width = - extents->width; + extents->height = - extents->height; + } + + return TRUE; +} + +static hb_bool_t +font_extents_func (hb_font_t *hb_font, + void *font_data, + hb_font_extents_t *extents, + void *user_data) +{ + Pango2Font *font = font_data; + Pango2UserFace *face = PANGO2_USER_FACE (font->face); + int size = font->size * font->dpi / 72.; + gboolean ret; + + ret = face->font_info_func (face, size, extents, face->user_data); + + if (PANGO2_GRAVITY_IS_IMPROPER (font->gravity)) + { + extents->ascender = - extents->ascender; + extents->descender = - extents->descender; + } + + return ret; +} + +static hb_font_t * +pango2_user_font_create_hb_font (Pango2Font *font) +{ + double x_scale, y_scale; + int size; + hb_blob_t *blob; + hb_face_t *hb_face; + hb_font_t *hb_font; + hb_font_funcs_t *funcs; + + blob = hb_blob_create ("", 0, HB_MEMORY_MODE_READONLY, NULL, NULL); + hb_face = hb_face_create (blob, 0); + hb_font = hb_font_create (hb_face); + + funcs = hb_font_funcs_create (); + + hb_font_funcs_set_nominal_glyph_func (funcs, nominal_glyph_func, NULL, NULL); + hb_font_funcs_set_glyph_h_advance_func (funcs, glyph_h_advance_func, NULL, NULL); + hb_font_funcs_set_glyph_extents_func (funcs, glyph_extents_func, NULL, NULL); + hb_font_funcs_set_font_h_extents_func (funcs, font_extents_func, NULL, NULL); + hb_font_funcs_set_font_v_extents_func (funcs, font_extents_func, NULL, NULL); + + hb_font_set_funcs (hb_font, funcs, font, NULL); + + hb_font_funcs_destroy (funcs); + hb_face_destroy (hb_face); + hb_blob_destroy (blob); + + size = font->size * font->dpi / 72.f; + x_scale = y_scale = 1; + + if (PANGO2_GRAVITY_IS_IMPROPER (font->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, font->size / PANGO2_SCALE); + + return hb_font; +} + +static void +pango2_user_font_class_init (Pango2UserFontClass *class) +{ + GObjectClass *object_class = G_OBJECT_CLASS (class); + Pango2FontClass *font_class = PANGO2_FONT_CLASS (class); + + object_class->finalize = pango2_user_font_finalize; + + font_class->describe = pango2_user_font_describe; + font_class->get_glyph_extents = pango2_user_font_get_glyph_extents; + font_class->get_metrics = pango2_user_font_get_metrics; + font_class->create_hb_font = pango2_user_font_create_hb_font; +} + +/* }}} */ + /* {{{ Public API */ + +/** + * pango2_user_font_new: + * @face: the `Pango2UserFace` to use + * @size: the desired size in points, scaled by `PANGO2_SCALE` + * @gravity: the gravity to use when rendering + * @dpi: the dpi used when rendering + * @ctm: (nullable): transformation matrix to use when rendering + * + * Creates a new `Pango2UserFont`. + * + * Returns: a newly created `Pango2UserFont` + */ +Pango2UserFont * +pango2_user_font_new (Pango2UserFace *face, + int size, + Pango2Gravity gravity, + float dpi, + const Pango2Matrix *ctm) +{ + Pango2UserFont *self; + Pango2Font *font; + + self = g_object_new (PANGO2_TYPE_USER_FONT, NULL); + + font = PANGO2_FONT (self); + + pango2_font_set_face (font, PANGO2_FONT_FACE (face)); + pango2_font_set_size (font, size); + pango2_font_set_dpi (font, dpi); + pango2_font_set_gravity (font, gravity); + pango2_font_set_ctm (font, ctm); + + return self; +} + +/** + * pango2_user_font_new_for_description: + * @face: the `Pango2UserFace` to use + * @description: a `Pango2FontDescription` + * @dpi: the dpi used when rendering + * @ctm: (nullable): transformation matrix to use when rendering + * + * Creates a new `Pango2UserFont` with size and gravity taken + * from a font description. + * + * Returns: a newly created `Pango2HbFont` + */ + +Pango2UserFont * +pango2_user_font_new_for_description (Pango2UserFace *face, + const Pango2FontDescription *description, + float dpi, + const Pango2Matrix *ctm) +{ + int size; + Pango2Gravity gravity; + + if (pango2_font_description_get_size_is_absolute (description)) + size = pango2_font_description_get_size (description) * 72. / dpi; + else + size = pango2_font_description_get_size (description); + + if ((pango2_font_description_get_set_fields (description) & PANGO2_FONT_MASK_GRAVITY) != 0 && + pango2_font_description_get_gravity (description) != PANGO2_GRAVITY_SOUTH) + gravity = pango2_font_description_get_gravity (description); + else + gravity = PANGO2_GRAVITY_AUTO; + + return pango2_user_font_new (face, size, gravity, dpi, ctm); +} + +/* }}} */ + +/* vim:set foldmethod=marker expandtab: */ |