[util/hb-view] Fix rendering with all combinations of negative scales

This commit is contained in:
Behdad Esfahbod 2015-04-09 15:52:26 -07:00
parent 69d5af9316
commit e8fd83932a
2 changed files with 48 additions and 46 deletions

View File

@ -26,69 +26,71 @@
#include "view-cairo.hh" #include "view-cairo.hh"
#include <assert.h>
void void
view_cairo_t::get_surface_size (cairo_scaled_font_t *scaled_font, view_cairo_t::render (const font_options_t *font_opts)
double *w, double *h)
{ {
cairo_font_extents_t font_extents;
cairo_scaled_font_extents (scaled_font, &font_extents);
bool vertical = HB_DIRECTION_IS_VERTICAL (direction); bool vertical = HB_DIRECTION_IS_VERTICAL (direction);
(vertical ? *w : *h) = (int) lines->len * (font_extents.height + view_options.line_space) - view_options.line_space; int vert = vertical ? 1 : 0;
(vertical ? *h : *w) = 0; int horiz = vertical ? 0 : 1;
int x_sign = font_opts->font_size_x < 0 ? -1 : +1;
int y_sign = font_opts->font_size_y < 0 ? -1 : +1;
cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts);
cairo_font_extents_t font_extents;
cairo_scaled_font_extents (scaled_font, &font_extents);
/* Looks like cairo doesn't negate the sign of font extents even if
* y_scale is negative. This is probably a bug, but that's the way
* it is, and we code for it. Assert, just in case this accidentally
* changes in the future (or is different on non-FreeType cairo font
* backends. */
assert (font_extents.height >= 0);
double leading = font_extents.height + view_options.line_space;
/* Calculate surface size. */
double w, h;
(vertical ? w : h) = (int) lines->len * leading - view_options.line_space;
(vertical ? h : w) = 0;
for (unsigned int i = 0; i < lines->len; i++) { for (unsigned int i = 0; i < lines->len; i++) {
helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i); helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i);
double x_advance, y_advance; double x_advance, y_advance;
line.get_advance (&x_advance, &y_advance); line.get_advance (&x_advance, &y_advance);
if (vertical) if (vertical)
*h = MAX (*h, y_advance); h = MAX (h, y_sign * y_advance);
else else
*w = MAX (*w, x_advance); w = MAX (w, x_sign * x_advance);
} }
*w += view_options.margin.l + view_options.margin.r; /* Create surface. */
*h += view_options.margin.t + view_options.margin.b; cairo_t *cr = helper_cairo_create_context (w + view_options.margin.l + view_options.margin.r,
} h + view_options.margin.t + view_options.margin.b,
&view_options, &output_options);
void
view_cairo_t::render (const font_options_t *font_opts)
{
cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts);
double w, h;
get_surface_size (scaled_font, &w, &h);
cairo_t *cr = helper_cairo_create_context (w, h, &view_options, &output_options);
cairo_set_scaled_font (cr, scaled_font); cairo_set_scaled_font (cr, scaled_font);
cairo_scaled_font_destroy (scaled_font);
draw (cr); /* Setup coordinate system. */
helper_cairo_destroy_context (cr);
}
void
view_cairo_t::draw (cairo_t *cr)
{
cairo_save (cr);
bool vertical = HB_DIRECTION_IS_VERTICAL (direction);
int v = vertical ? 1 : 0;
int h = vertical ? 0 : 1;
cairo_font_extents_t font_extents;
cairo_font_extents (cr, &font_extents);
cairo_translate (cr, view_options.margin.l, view_options.margin.t); cairo_translate (cr, view_options.margin.l, view_options.margin.t);
if (vertical) if (vertical)
cairo_translate (cr, font_extents.height * (lines->len + .5), 0); cairo_translate (cr,
w /* We stack lines right to left */
-font_extents.height * .5 /* "ascent" for vertical */,
y_sign < 0 ? h : 0);
else else
cairo_translate (cr, 0, -(font_extents.height - font_extents.ascent)); {
cairo_translate (cr,
x_sign < 0 ? w : 0,
y_sign < 0 ? font_extents.descent : font_extents.ascent);
}
/* Draw. */
cairo_translate (cr, +vert * leading, -horiz * leading);
for (unsigned int i = 0; i < lines->len; i++) for (unsigned int i = 0; i < lines->len; i++)
{ {
helper_cairo_line_t &l = g_array_index (lines, helper_cairo_line_t, i); helper_cairo_line_t &l = g_array_index (lines, helper_cairo_line_t, i);
if (i) cairo_translate (cr, -vert * leading, +horiz * leading);
cairo_translate (cr, v * -view_options.line_space, h * view_options.line_space);
cairo_translate (cr, v * -font_extents.height, h * font_extents.height);
if (view_options.annotate) { if (view_options.annotate) {
cairo_save (cr); cairo_save (cr);
@ -120,5 +122,7 @@ view_cairo_t::draw (cairo_t *cr)
cairo_show_glyphs (cr, l.glyphs, l.num_glyphs); cairo_show_glyphs (cr, l.glyphs, l.num_glyphs);
} }
cairo_restore (cr); /* Clean up. */
helper_cairo_destroy_context (cr);
cairo_scaled_font_destroy (scaled_font);
} }

View File

@ -95,8 +95,6 @@ struct view_cairo_t
view_options_t view_options; view_options_t view_options;
void render (const font_options_t *font_opts); void render (const font_options_t *font_opts);
void get_surface_size (cairo_scaled_font_t *scaled_font, double *w, double *h);
void draw (cairo_t *cr);
hb_direction_t direction; // Remove this, make segment_properties accessible hb_direction_t direction; // Remove this, make segment_properties accessible
GArray *lines; GArray *lines;