bool PangoFontInfo::GetSpacingProperties(const string& utf8_char,
int* x_bearing, int* x_advance) const {
// Convert to equivalent PangoFont structure
PangoFont* font = ToPangoFont();
// Find the glyph index in the font for the supplied utf8 character.
int total_advance = 0;
int min_bearing = 0;
// Handle multi-unicode strings by reporting the left-most position of the
// x-bearing, and right-most position of the x-advance if the string were to
// be rendered.
const UNICHAR::const_iterator it_begin = UNICHAR::begin(utf8_char.c_str(),
utf8_char.length());
const UNICHAR::const_iterator it_end = UNICHAR::end(utf8_char.c_str(),
utf8_char.length());
for (UNICHAR::const_iterator it = it_begin; it != it_end; ++it) {
PangoGlyph glyph_index = pango_fc_font_get_glyph(
reinterpret_cast<PangoFcFont*>(font), *it);
if (!glyph_index) {
// Glyph for given unicode character doesn't exist in font.
return false;
}
// Find the ink glyph extents for the glyph
PangoRectangle ink_rect, logical_rect;
pango_font_get_glyph_extents(font, glyph_index, &ink_rect, &logical_rect);
pango_extents_to_pixels(&ink_rect, NULL);
pango_extents_to_pixels(&logical_rect, NULL);
int bearing = total_advance + PANGO_LBEARING(ink_rect);
if (it == it_begin || bearing < min_bearing) {
min_bearing = bearing;
}
total_advance += PANGO_RBEARING(logical_rect);
}
*x_bearing = min_bearing;
*x_advance = total_advance;
return true;
}
void render_glyph(
cairo_t* cr,
PangoFontDescription* font_desc,
PangoFont* font,
const guint code_point,
const size_t cell_x,
const size_t cell_y,
const size_t cell_size,
const double tex_size,
const int ascent,
const int descent,
std::ostream& bgm_out
)
{
PangoLayout *layout = pango_cairo_create_layout(cr);
char str[6] = {'\0'};
size_t len = 0;
oglplus::aux::ConvertCodePointToUTF8(code_point, str, len);
pango_layout_set_font_description(layout, font_desc);
pango_layout_set_text(layout, str, len);
const int baseline = pango_layout_get_baseline(layout);
const double inv_ps = 1.0 / double(PANGO_SCALE);
const double font_size = ascent+descent;
PangoRectangle ink_rect, log_rect;
pango_layout_get_extents(
layout,
&ink_rect,
&log_rect
);
// code point number
bgm_out << code_point << std::endl;
// hex representation of the number
bgm_out << std::hex
<< "0x"
<< code_point
<< std::dec
<< std::endl;
// the utf-8 sequence
bgm_out << "'" << str << "'" << std::endl;
//
// vertex[0] logical rectangle metrics
//
// Left bearing (x)
bgm_out << PANGO_LBEARING(log_rect)/font_size << std::endl;
// Right bearing (x+width)
bgm_out << PANGO_RBEARING(log_rect)/font_size << std::endl;
// Ascent
bgm_out << (baseline-log_rect.y)/font_size << std::endl;
// Descent
bgm_out << (log_rect.height+log_rect.y-baseline)/font_size << std::endl;
//
// vertex[1] ink rectangle metrics
//
// Left bearing (x)
bgm_out << PANGO_LBEARING(ink_rect)/font_size << std::endl;
// Right bearing (x+width)
bgm_out << PANGO_RBEARING(ink_rect)/font_size << std::endl;
// Ascent
bgm_out << (baseline-ink_rect.y)/font_size << std::endl;
// Descent
bgm_out << (ink_rect.y+ink_rect.height-baseline)/font_size << std::endl;
//
// vertex[2] texture coordinates
//
// Origin X
bgm_out << (cell_x*cell_size+ink_rect.x*inv_ps)/tex_size << std::endl;
// Origin Y
bgm_out << 1.0-(cell_y*cell_size+baseline*inv_ps)/tex_size << std::endl;
// Width
bgm_out << ((ink_rect.width)*inv_ps)/tex_size << std::endl;
// Height
bgm_out << ((ink_rect.height)*inv_ps)/tex_size << std::endl;
// separating newline
bgm_out << std::endl;
cairo_new_path(cr);
cairo_move_to(cr, cell_x*cell_size, cell_y*cell_size);
cairo_set_line_width(cr, 0.5);
pango_cairo_update_layout(cr, layout);
pango_cairo_layout_path(cr, layout);
cairo_fill(cr);
g_object_unref(layout);
}
static void
draw_string(DiaRenderer *self,
const char *text,
Point *pos, Alignment alignment,
Color *color)
{
DiaCairoRenderer *renderer = DIA_CAIRO_RENDERER (self);
int len = strlen(text);
DIAG_NOTE(g_message("draw_string(%d) %f,%f %s",
len, pos->x, pos->y, text));
if (len < 1) return; /* shouldn't this be handled by Dia's core ? */
cairo_set_source_rgba (renderer->cr, color->red, color->green, color->blue, 1.0);
#ifdef HAVE_PANGOCAIRO_H
cairo_save (renderer->cr);
/* alignment calculation done by pangocairo? */
pango_layout_set_alignment (renderer->layout, alignment == ALIGN_CENTER ? PANGO_ALIGN_CENTER :
alignment == ALIGN_RIGHT ? PANGO_ALIGN_RIGHT : PANGO_ALIGN_LEFT);
pango_layout_set_text (renderer->layout, text, len);
{
PangoLayoutIter *iter = pango_layout_get_iter(renderer->layout);
int bline = pango_layout_iter_get_baseline(iter);
/* although we give the alignment above we need to adjust the start point */
PangoRectangle extents;
int shift;
pango_layout_iter_get_line_extents (iter, NULL, &extents);
shift = alignment == ALIGN_CENTER ? PANGO_RBEARING(extents)/2 :
alignment == ALIGN_RIGHT ? PANGO_RBEARING(extents) : 0;
cairo_move_to (renderer->cr, pos->x - (double)shift / PANGO_SCALE, pos->y - (double)bline / PANGO_SCALE);
pango_layout_iter_free (iter);
}
/* does this hide bug #341481? */
pango_cairo_update_context (renderer->cr, pango_layout_get_context (renderer->layout));
pango_layout_context_changed (renderer->layout);
pango_cairo_show_layout (renderer->cr, renderer->layout);
cairo_restore (renderer->cr);
#else
/* using the 'toy API' */
{
cairo_text_extents_t extents;
double x = 0, y = 0;
cairo_set_source_rgba (renderer->cr, color->red, color->green, color->blue, 1.0);
cairo_text_extents (renderer->cr,
text,
&extents);
y = pos->y; /* ?? */
switch (alignment) {
case ALIGN_LEFT:
x = pos->x;
break;
case ALIGN_CENTER:
x = pos->x - extents.width / 2 + +extents.x_bearing;
break;
case ALIGN_RIGHT:
x = pos->x - extents.width + extents.x_bearing;
break;
}
cairo_move_to (renderer->cr, x, y);
cairo_show_text (renderer->cr, text);
}
#endif
DIAG_STATE(renderer->cr)
}
