string
-marked_up (list<StringText> subtitles, int target_height, float fade_factor)
+marked_up (list<StringText> subtitles, int target_height, float fade_factor, string font_name)
{
- string out;
+ auto constexpr pixels_to_1024ths_point = 72 * 1024 / 96;
- for (auto const& i: subtitles) {
- out += "<span ";
- if (i.italic()) {
- out += "style=\"italic\" ";
+ auto make_span = [target_height, fade_factor](StringText const& subtitle, string text, string extra_attribute) {
+ string span;
+ span += "<span ";
+ if (subtitle.italic()) {
+ span += "style=\"italic\" ";
}
- if (i.bold()) {
- out += "weight=\"bold\" ";
+ if (subtitle.bold()) {
+ span += "weight=\"bold\" ";
}
- if (i.underline()) {
- out += "underline=\"single\" ";
+ if (subtitle.underline()) {
+ span += "underline=\"single\" ";
}
- out += "size=\"" + dcp::raw_convert<string>(i.size_in_pixels(target_height) * 72 * 1024 / 96) + "\" ";
+ span += "size=\"" + dcp::raw_convert<string>(subtitle.size_in_pixels(target_height) * pixels_to_1024ths_point) + "\" ";
/* Between 1-65535 inclusive, apparently... */
- out += "alpha=\"" + dcp::raw_convert<string>(int(floor(fade_factor * 65534)) + 1) + "\" ";
- out += "color=\"#" + i.colour().to_rgb_string() + "\">";
- out += i.text();
- out += "</span>";
+ span += "alpha=\"" + dcp::raw_convert<string>(int(floor(fade_factor * 65534)) + 1) + "\" ";
+ span += "color=\"#" + subtitle.colour().to_rgb_string() + "\"";
+ if (!extra_attribute.empty()) {
+ span += " " + extra_attribute;
+ }
+ span += ">";
+ span += text;
+ span += "</span>";
+ return span;
+ };
+
+ string out;
+ for (auto const& i: subtitles) {
+ if (std::abs(i.space_before()) > dcp::SPACE_BEFORE_EPSILON) {
+ /* We need to insert some horizontal space into the layout. The only way I can find to do this
+ * is to write a " " with some special letter_spacing. As far as I can see, such a space will
+ * be written with letter_spacing either side. This means that to get a horizontal space x we
+ * need to write a " " with letter spacing (x - s) / 2, where s is the width of the " ".
+ */
+ auto layout = create_layout();
+ setup_layout(layout, font_name, make_span(i, " ", {}));
+ int space_width;
+ int dummy;
+ layout->get_pixel_size(space_width, dummy);
+ auto spacing = ((i.space_before() * i.size_in_pixels(target_height) - space_width) / 2) * pixels_to_1024ths_point;
+ out += make_span(i, " ", "letter_spacing=\"" + dcp::raw_convert<string>(spacing) + "\"");
+ }
+
+ out += make_span(i, i.text(), {});
}
return out;
auto const font_name = setup_font (first, fonts);
auto const fade_factor = calculate_fade_factor (first, time, frame_rate);
- auto const markup = marked_up (subtitles, target.height, fade_factor);
+ auto const markup = marked_up (subtitles, target.height, fade_factor, font_name);
auto layout = create_layout ();
setup_layout (layout, font_name, markup);
dcp::Size size;