fdo-mirrors/cairo
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/cairo/cairo.git synced 2025-12-31 17:10:15 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

Changes the sign of extents->descent to match win32 backend and the conventional convention.

Browse source 
Document cairo_font_extents_t.
This commit is contained in:
Owen Taylor 2005-05-02 14:20:07 +00:00
parent 7dbd1f4401
commit e227a10685
3 changed files with 53 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
ChangeLog
View file

@ -1,3 +1,11 @@
2005-05-02 Owen Taylor <otaylor@redhat.com>
* src/cairo-ft-font.c (_cairo_ft_scaled_font_font_extents): Changes the
sign of extents->descent to match win32 backend and the conventional
convention.
* src/cairo.h: Document cairo_font_extents_t.
2005-04-28 Owen Taylor <otaylor@redhat.com>
* src/cairo-surface.c src/cairoint.h: Add _cairo_surface_begin/end

2
src/cairo-ft-font.c
View file

@ -936,7 +936,7 @@ _cairo_ft_scaled_font_font_extents (void *abstract_font,
* user space
*/
extents->ascent = DOUBLE_FROM_26_6(metrics->ascender) / scaled_font->unscaled->y_scale;
extents->descent = DOUBLE_FROM_26_6(metrics->descender) / scaled_font->unscaled->y_scale;
extents->descent = DOUBLE_FROM_26_6(- metrics->descender) / scaled_font->unscaled->y_scale;
extents->height = DOUBLE_FROM_26_6(metrics->height) / scaled_font->unscaled->y_scale;
extents->max_x_advance = DOUBLE_FROM_26_6(metrics->max_advance) / scaled_font->unscaled->x_scale;

47
src/cairo.h
View file

@ -616,10 +616,10 @@ typedef struct {
* after drawing these glyphs. Will typically be zero except
* for vertical text layout as found in East-Asian languages.
*
* The #cairo_text_extents_t< structure stores the extents of a single
* The #cairo_text_extents_t structure stores the extents of a single
* glyph or a string of glyphs in user-space coordinates. Because text
* extents are in user-space coordinates, they don't scale along with
* the current transformation matrix. If you call
* extents are in user-space coordinates, they are mostly, but not
* entirely, independent of the current transformation matrix. If you call
* <literal>cairo_scale(cr, 2.0, 2.0)</literal>, text will
* be drawn twice as big, but the reported text extents will not be
* doubled. They will change slightly due to hinting (so you can't
@ -635,6 +635,47 @@ typedef struct {
double y_advance;
} cairo_text_extents_t;
/**
* cairo_font_extents_t:
* @ascent: the distance that the font extends above the baseline.
* Note that this is not always exactly equal to the maximum
* of the extents of all the glyphs in the font, but rather
* is picked to express the font designer's intent as to
* how the font should align with elements above it.
* @descent: the distance that the font extends below the baseline.
* This value is positive for typical fonts that include
* portions below the baseline. Note that this is not always
* exactly equal to the maximum of the extents of all the
* glyphs in the font, but rather is picked to express the
* font designer's intent as to how the the font should
* align with elements below it.
* @height: the recommended vertical distance between baselines when
* setting consecutive lines of text with the font. This
* is greater than @ascent+@descent by a
* quantity known as the <firstterm>line spacing</firstterm>
* or <firstterm>external leading</firstterm>. When space
* is at a premium, most fonts can be set with only
* a distance of @ascent+@descent between lines.
* @max_x_advance: the maximum distance in the X direction that
* the the origin is advanced for any glyph in the font.
* @max_y_advance: the maximum distance in the Y direction that
* the the origin is advanced for any glyph in the font.
* this will be zero for normal fonts used for horizontal
* writing. (The scripts of East Asia are sometimes written
* vertically.)
*
* The #cairo_text_extents_t structure stores metric information for
* a font. Values are given in the current user-space coordinate
* system.
*
* Because font metrics are in user-space coordinates, they are
* mostly, but not entirely, independent of the current transformation
* matrix. If you call <literal>cairo_scale(cr, 2.0, 2.0)</literal>,
* text will be drawn twice as big, but the reported text extents will
* not be doubled. They will change slightly due to hinting (so you
* can't assume that metrics are independent of the transformation
* matrix), but otherwise will remain unchanged.
*/
typedef struct {
double ascent;
double descent;