fdo-mirrors/cairo
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/cairo/cairo.git synced 2026-04-07 00:40:35 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

[user-font] Cache extent-space scale in the scaled font

Browse source
This commit is contained in:
Behdad Esfahbod 2008-05-28 20:20:46 -04:00
parent abdf04c671
commit b0796bf200
1 changed files with 46 additions and 24 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

70
src/cairo-user-font.c
View file

@ -59,6 +59,16 @@ typedef struct _cairo_user_scaled_font {
cairo_scaled_font_t base;
cairo_text_extents_t default_glyph_extents;
/* space to compute extents in, and factors to convert back to user space */
cairo_matrix_t extent_scale;
double extent_x_scale;
double extent_y_scale;
/* multiplier for metrics hinting */
double snap_x_scale;
double snap_y_scale;
} cairo_user_scaled_font_t;
/* #cairo_user_scaled_font_t */
@ -117,41 +127,22 @@ _cairo_user_scaled_glyph_init (void *abstract_font,
if (extents.width == 0.) {
/* Compute extents.x/y/width/height from meta_surface, in font space */
cairo_matrix_t matrix;
double fixed_scale, x_scale, y_scale;
cairo_box_t bbox;
double x1, y1, x2, y2;
double x_scale, y_scale;
cairo_surface_t *null_surface = _cairo_null_surface_create (cairo_surface_get_content (meta_surface));
cairo_surface_t *analysis_surface = _cairo_analysis_surface_create (null_surface, -1, -1);
cairo_surface_destroy (null_surface);
/* compute a normalized version of font scale matrix to compute
* extents in. This is to minimize error caused by the cairo_fixed_t
* representation. */
matrix = scaled_font->base.scale_inverse;
status = _cairo_matrix_compute_scale_factors (&matrix, &x_scale, &y_scale, 1);
if (status)
return status;
/* since glyphs are pretty much 1.0x1.0, we can reduce error by
* scaling to a larger square. say, 1024.x1024. */
fixed_scale = 1024.;
x_scale /= fixed_scale;
y_scale /= fixed_scale;
if (x_scale == 0) x_scale = 1. / fixed_scale;
if (y_scale == 0) y_scale = 1. / fixed_scale;
cairo_matrix_scale (&matrix, 1. / x_scale, 1. / y_scale);
_cairo_analysis_surface_set_ctm (analysis_surface, &matrix);
_cairo_analysis_surface_set_ctm (analysis_surface, &scaled_font->extent_scale);
status = _cairo_meta_surface_replay (meta_surface, analysis_surface);
_cairo_analysis_surface_get_bounding_box (analysis_surface, &bbox);
cairo_surface_destroy (analysis_surface);
_cairo_box_to_doubles (&bbox, &x1, &y1, &x2, &y2);
x_scale = scaled_font->extent_x_scale;
y_scale = scaled_font->extent_y_scale;
extents.x_bearing = x1 * x_scale;
extents.y_bearing = y1 * y_scale;
extents.width = (x2 - x1) * x_scale;
@ -342,7 +333,38 @@ _cairo_user_font_face_scaled_font_create (void *abstract_
return status;
}
if (font_face->scaled_font_methods.init != NULL) {
/* compute a normalized version of font scale matrix to compute
* extents in. This is to minimize error caused by the cairo_fixed_t
* representation. */
{
double fixed_scale, x_scale, y_scale;
user_scaled_font->extent_scale = user_scaled_font->base.scale_inverse;
status = _cairo_matrix_compute_scale_factors (&user_scaled_font->extent_scale,
&x_scale, &y_scale,
1);
if (status == CAIRO_STATUS_SUCCESS) {
if (x_scale == 0) x_scale = 1.;
if (y_scale == 0) y_scale = 1.;
user_scaled_font->snap_x_scale = x_scale;
user_scaled_font->snap_y_scale = y_scale;
/* since glyphs are pretty much 1.0x1.0, we can reduce error by
* scaling to a larger square. say, 1024.x1024. */
fixed_scale = 1024.;
x_scale /= fixed_scale;
y_scale /= fixed_scale;
cairo_matrix_scale (&user_scaled_font->extent_scale, 1. / x_scale, 1. / y_scale);
user_scaled_font->extent_x_scale = x_scale;
user_scaled_font->extent_y_scale = y_scale;
}
}
if (status == CAIRO_STATUS_SUCCESS && font_face->scaled_font_methods.init != NULL) {
/* Lock the scaled_font mutex such that user doesn't accidentally try
* to use it just yet. */