user-font-rescale.c [plain text]
#include "cairo-test.h"
#include <math.h>
#define BORDER 10
#define TEXT_SIZE 32
#define WIDTH (TEXT_SIZE * 13.75 + 2*BORDER)
#define HEIGHT ((TEXT_SIZE + 2*BORDER)*3 + BORDER)
#define TEXT "test of rescaled glyphs"
static const cairo_user_data_key_t rescale_font_closure_key;
struct rescaled_font {
cairo_font_face_t *substitute_font;
cairo_scaled_font_t *measuring_font;
unsigned long glyph_count;
unsigned long start;
double *desired_width;
double *rescale_factor;
};
static cairo_status_t
test_scaled_font_render_glyph (cairo_scaled_font_t *scaled_font,
unsigned long glyph,
cairo_t *cr,
cairo_text_extents_t *metrics)
{
cairo_font_face_t *user_font;
struct rescaled_font *r;
cairo_glyph_t cairo_glyph;
cairo_glyph.index = glyph;
cairo_glyph.x = 0;
cairo_glyph.y = 0;
user_font = cairo_scaled_font_get_font_face (scaled_font);
r = cairo_font_face_get_user_data (user_font, &rescale_font_closure_key);
cairo_set_font_face (cr, r->substitute_font);
if (glyph - r->start < r->glyph_count) {
cairo_matrix_t matrix;
if (isnan (r->rescale_factor[glyph - r->start])) {
double desired_width;
double actual_width;
cairo_text_extents_t extents;
cairo_scaled_font_glyph_extents (r->measuring_font,
&cairo_glyph, 1,
&extents);
desired_width = r->desired_width[glyph - r->start];
actual_width = extents.x_advance;
r->rescale_factor[glyph - r->start] = desired_width / actual_width;
}
cairo_get_font_matrix (cr, &matrix);
cairo_matrix_scale (&matrix, r->rescale_factor[glyph - r->start], 1.);
cairo_set_font_matrix (cr, &matrix);
}
cairo_show_glyphs (cr, &cairo_glyph, 1);
cairo_glyph_extents (cr, &cairo_glyph, 1, metrics);
return CAIRO_STATUS_SUCCESS;
}
static void
unichar_to_utf8 (uint32_t ucs4, char utf8[7])
{
int i, charlen, first;
if (ucs4 < 0x80) {
first = 0;
charlen = 1;
} else if (ucs4 < 0x800) {
first = 0xc0;
charlen = 2;
} else if (ucs4 < 0x10000) {
first = 0xe0;
charlen = 3;
} else if (ucs4 < 0x200000) {
first = 0xf0;
charlen = 4;
} else if (ucs4 < 0x4000000) {
first = 0xf8;
charlen = 5;
} else {
first = 0xfc;
charlen = 6;
}
for (i = charlen - 1; i > 0; --i) {
utf8[i] = (ucs4 & 0x3f) | 0x80;
ucs4 >>= 6;
}
utf8[0] = ucs4 | first;
utf8[charlen] = '\0';
}
static cairo_status_t
test_scaled_font_unicode_to_glyph (cairo_scaled_font_t *scaled_font,
unsigned long unicode,
unsigned long *glyph_index)
{
cairo_font_face_t *user_font;
struct rescaled_font *r;
int num_glyphs;
cairo_glyph_t *glyphs = NULL;
cairo_status_t status;
char utf8[7];
user_font = cairo_scaled_font_get_font_face (scaled_font);
unichar_to_utf8 (unicode, utf8);
r = cairo_font_face_get_user_data (user_font, &rescale_font_closure_key);
status = cairo_scaled_font_text_to_glyphs (r->measuring_font, 0, 0,
utf8, -1,
&glyphs, &num_glyphs,
NULL, NULL, NULL);
if (status)
return status;
*glyph_index = glyphs[0].index;
cairo_glyph_free (glyphs);
return CAIRO_STATUS_SUCCESS;
}
static void rescale_font_closure_destroy (void *data)
{
struct rescaled_font *r = data;
cairo_font_face_destroy (r->substitute_font);
cairo_scaled_font_destroy (r->measuring_font);
free (r->desired_width);
free (r->rescale_factor);
free (r);
}
static cairo_status_t
create_rescaled_font (cairo_font_face_t *substitute_font,
int glyph_start,
int glyph_count,
double *desired_width,
cairo_font_face_t **out)
{
cairo_font_face_t *user_font_face;
struct rescaled_font *r;
cairo_font_options_t *options;
cairo_status_t status;
cairo_matrix_t m;
unsigned long i;
user_font_face = cairo_user_font_face_create ();
cairo_user_font_face_set_render_glyph_func (user_font_face, test_scaled_font_render_glyph);
cairo_user_font_face_set_unicode_to_glyph_func (user_font_face, test_scaled_font_unicode_to_glyph);
r = xmalloc (sizeof (struct rescaled_font));
r->substitute_font = cairo_font_face_reference (substitute_font);
options = cairo_font_options_create ();
cairo_font_options_set_hint_style (options, CAIRO_HINT_STYLE_NONE);
cairo_font_options_set_hint_metrics (options, CAIRO_HINT_METRICS_OFF);
cairo_matrix_init_identity (&m);
r->measuring_font = cairo_scaled_font_create (r->substitute_font,
&m, &m,
options);
cairo_font_options_destroy (options);
r->start = glyph_start;
r->glyph_count = glyph_count;
r->desired_width = xcalloc (sizeof (double), r->glyph_count);
r->rescale_factor = xcalloc (sizeof (double), r->glyph_count);
for (i = 0; i < r->glyph_count; i++) {
r->desired_width[i] = desired_width[i];
r->rescale_factor[i] = cairo_test_NaN ();
}
status = cairo_font_face_set_user_data (user_font_face,
&rescale_font_closure_key,
r, rescale_font_closure_destroy);
if (status) {
rescale_font_closure_destroy (r);
cairo_font_face_destroy (user_font_face);
return status;
}
*out = user_font_face;
return CAIRO_STATUS_SUCCESS;
}
static cairo_status_t
get_user_font_face (cairo_font_face_t *substitute_font,
const char *text,
cairo_font_face_t *old,
cairo_font_face_t **out)
{
cairo_font_options_t *options;
cairo_matrix_t m;
cairo_scaled_font_t *measure;
int i;
double *widths;
int count;
int num_glyphs;
unsigned long min_index, max_index;
cairo_status_t status;
cairo_glyph_t *glyphs = NULL;
options = cairo_font_options_create ();
cairo_font_options_set_hint_style (options, CAIRO_HINT_STYLE_NONE);
cairo_font_options_set_hint_metrics (options, CAIRO_HINT_METRICS_OFF);
cairo_matrix_init_identity (&m);
measure = cairo_scaled_font_create (old, &m, &m, options);
status = cairo_scaled_font_text_to_glyphs (measure, 0, 0,
text, -1,
&glyphs, &num_glyphs,
NULL, NULL, NULL);
cairo_font_options_destroy (options);
if (status) {
cairo_scaled_font_destroy (measure);
return status;
}
max_index = glyphs[0].index;
min_index = glyphs[0].index;
for (i=0; i<num_glyphs; i++) {
if (glyphs[i].index < min_index)
min_index = glyphs[i].index;
if (glyphs[i].index > max_index)
max_index = glyphs[i].index;
}
count = max_index - min_index + 1;
widths = xcalloc (sizeof (double), count);
for (i=0; i<num_glyphs; i++) {
cairo_text_extents_t extents;
cairo_scaled_font_glyph_extents (measure, &glyphs[i], 1, &extents);
widths[glyphs[i].index - min_index] = extents.x_advance;
}
status = cairo_scaled_font_status (measure);
cairo_scaled_font_destroy (measure);
cairo_glyph_free (glyphs);
if (status == CAIRO_STATUS_SUCCESS) {
status = create_rescaled_font (substitute_font,
min_index, count, widths,
out);
}
free (widths);
return status;
}
static cairo_test_status_t
draw (cairo_t *cr, int width, int height)
{
cairo_font_extents_t font_extents;
cairo_text_extents_t extents;
cairo_font_face_t *rescaled;
cairo_font_face_t *old;
cairo_font_face_t *substitute;
const char text[] = TEXT;
cairo_status_t status;
cairo_set_source_rgb (cr, 1, 1, 1);
cairo_paint (cr);
cairo_select_font_face (cr,
CAIRO_TEST_FONT_FAMILY " Sans",
CAIRO_FONT_SLANT_NORMAL,
CAIRO_FONT_WEIGHT_NORMAL);
cairo_set_font_size (cr, TEXT_SIZE);
cairo_font_extents (cr, &font_extents);
cairo_text_extents (cr, text, &extents);
cairo_set_source_rgb (cr, 0, 0, 0);
cairo_move_to (cr, BORDER, BORDER + font_extents.ascent);
cairo_show_text (cr, text);
old = cairo_font_face_reference (cairo_get_font_face (cr));
cairo_select_font_face (cr,
CAIRO_TEST_FONT_FAMILY " Sans Mono",
CAIRO_FONT_SLANT_NORMAL,
CAIRO_FONT_WEIGHT_NORMAL);
substitute = cairo_get_font_face (cr);
status = get_user_font_face (substitute, text, old, &rescaled);
cairo_font_face_destroy (old);
if (status) {
return cairo_test_status_from_status (cairo_test_get_context (cr),
status);
}
cairo_set_font_face (cr, rescaled);
cairo_font_face_destroy (rescaled);
cairo_set_source_rgb (cr, 0, 0, 1);
cairo_move_to (cr, BORDER, BORDER + font_extents.height + 2*BORDER + font_extents.ascent);
cairo_show_text (cr, text);
cairo_select_font_face (cr,
CAIRO_TEST_FONT_FAMILY " Sans Mono",
CAIRO_FONT_SLANT_NORMAL,
CAIRO_FONT_WEIGHT_NORMAL);
cairo_set_source_rgb (cr, 0, 0, 1);
cairo_move_to (cr, BORDER, BORDER + 2*font_extents.height + 4*BORDER + font_extents.ascent);
cairo_show_text (cr, text);
return CAIRO_TEST_SUCCESS;
}
CAIRO_TEST (user_font_rescale,
"Tests drawing text with user defined widths",
"user-font, font",
NULL,
WIDTH, HEIGHT,
NULL, draw)