/*
- Copyright (C) 2014-2016 Carl Hetherington <cth@carlh.net>
+ Copyright (C) 2014-2021 Carl Hetherington <cth@carlh.net>
This file is part of DCP-o-matic.
*/
-#include "render_text.h"
-#include "types.h"
-#include "image.h"
+
#include "cross.h"
-#include "font.h"
#include "dcpomatic_assert.h"
+#include "font.h"
+#include "image.h"
+#include "render_text.h"
+#include "types.h"
+#include "util.h"
#include <dcp/raw_convert.h>
+#include <dcp/warnings.h>
#include <fontconfig/fontconfig.h>
#include <cairomm/cairomm.h>
+LIBDCP_DISABLE_WARNINGS
#include <pangomm.h>
-#ifndef DCPOMATIC_HAVE_SHOW_IN_CAIRO_CONTEXT
+LIBDCP_ENABLE_WARNINGS
#include <pango/pangocairo.h>
-#endif
-#include <boost/foreach.hpp>
#include <boost/algorithm/string.hpp>
#include <iostream>
-using std::list;
+
+using std::cerr;
using std::cout;
-using std::string;
-using std::min;
+using std::list;
+using std::make_pair;
+using std::make_shared;
using std::max;
+using std::min;
using std::pair;
-using std::cerr;
-using std::make_pair;
-using boost::shared_ptr;
-using boost::optional;
-using boost::algorithm::replace_all;
+using std::shared_ptr;
+using std::string;
+using namespace dcpomatic;
+
+
+static FcConfig* fc_config = nullptr;
+static list<pair<boost::filesystem::path, string>> fc_config_fonts;
+
+
+/** Create a Pango layout using a dummy context which we can use to calculate the size
+ * of the text we will render. Then we can transfer the layout over to the real context
+ * for the actual render.
+ */
+static Glib::RefPtr<Pango::Layout>
+create_layout()
+{
+ auto c_font_map = pango_cairo_font_map_new ();
+ DCPOMATIC_ASSERT (c_font_map);
+ auto font_map = Glib::wrap (c_font_map);
+ auto c_context = pango_font_map_create_context (c_font_map);
+ DCPOMATIC_ASSERT (c_context);
+ auto context = Glib::wrap (c_context);
+ return Pango::Layout::create (context);
+}
+
+
+static void
+setup_layout (Glib::RefPtr<Pango::Layout> layout, string font_name, string markup)
+{
+ layout->set_alignment (Pango::ALIGN_LEFT);
+ Pango::FontDescription font (font_name);
+ layout->set_font_description (font);
+ layout->set_markup (markup);
+}
-static FcConfig* fc_config = 0;
-static list<pair<FontFiles, string> > fc_config_fonts;
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;
- BOOST_FOREACH (StringText 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>(lrintf(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() + "\">";
+ 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 t = i.text();
- replace_all(t, "&", "&");
- out += t;
+ 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 += "</span>";
+ out += make_span(i, i.text(), {});
}
return out;
}
+
static void
set_source_rgba (Cairo::RefPtr<Cairo::Context> context, dcp::Colour colour, float fade_factor)
{
context->set_source_rgba (float(colour.r) / 255, float(colour.g) / 255, float(colour.b) / 255, fade_factor);
}
-/** @param subtitles A list of subtitles that are all on the same line,
- * at the same time and with the same fade in/out.
- */
-static PositionImage
-render_line (list<StringText> subtitles, list<shared_ptr<Font> > fonts, dcp::Size target, DCPTime time, int frame_rate)
-{
- /* XXX: this method can only handle italic / bold changes mid-line,
- nothing else yet.
- */
-
- DCPOMATIC_ASSERT (!subtitles.empty ());
-
- /* Calculate x and y scale factors. These are only used to stretch
- the font away from its normal aspect ratio.
- */
- float xscale = 1;
- float yscale = 1;
- if (fabs (subtitles.front().aspect_adjust() - 1.0) > dcp::ASPECT_ADJUST_EPSILON) {
- if (subtitles.front().aspect_adjust() < 1) {
- xscale = max (0.25f, subtitles.front().aspect_adjust ());
- yscale = 1;
- } else {
- xscale = 1;
- yscale = 1 / min (4.0f, subtitles.front().aspect_adjust ());
- }
- }
-
- /* Make an empty bitmap as wide as target and at
- least tall enough for this subtitle.
- */
- int largest = 0;
- BOOST_FOREACH (dcp::SubtitleString const & i, subtitles) {
- largest = max (largest, i.size());
- }
- /* Basic guess on height... */
- int height = largest * target.height / (11 * 72);
- /* ...scaled... */
- height *= yscale;
- /* ...and add a bit more for luck */
- height += target.height / 11;
-
- /* FFmpeg BGRA means first byte blue, second byte green, third byte red, fourth byte alpha */
- shared_ptr<Image> image (new Image (AV_PIX_FMT_BGRA, dcp::Size (target.width, height), false));
+static shared_ptr<Image>
+create_image (dcp::Size size)
+{
+ /* FFmpeg BGRA means first byte blue, second byte green, third byte red, fourth byte alpha.
+ * This must be COMPACT as we're using it with Cairo::ImageSurface::create
+ */
+ auto image = make_shared<Image>(AV_PIX_FMT_BGRA, size, Image::Alignment::COMPACT);
image->make_black ();
+ return image;
+}
+
-#ifdef DCPOMATIC_HAVE_FORMAT_STRIDE_FOR_WIDTH
- Cairo::RefPtr<Cairo::ImageSurface> surface = Cairo::ImageSurface::create (
+static Cairo::RefPtr<Cairo::ImageSurface>
+create_surface (shared_ptr<Image> image)
+{
+ /* XXX: I don't think it's guaranteed that format_stride_for_width will return a stride without any padding,
+ * so it's lucky that this works.
+ */
+ DCPOMATIC_ASSERT (image->alignment() == Image::Alignment::COMPACT);
+ DCPOMATIC_ASSERT (image->pixel_format() == AV_PIX_FMT_BGRA);
+ return Cairo::ImageSurface::create (
image->data()[0],
Cairo::FORMAT_ARGB32,
image->size().width,
/* Cairo ARGB32 means first byte blue, second byte green, third byte red, fourth byte alpha */
Cairo::ImageSurface::format_stride_for_width (Cairo::FORMAT_ARGB32, image->size().width)
);
-#else
- /* Centos 5 does not have Cairo::ImageSurface::format_stride_for_width, so just use width * 4
- which I hope is safe (if slow)
- */
- Cairo::RefPtr<Cairo::ImageSurface> surface = Cairo::ImageSurface::create (
- image->data()[0],
- Cairo::FORMAT_ARGB32,
- image->size().width,
- image->size().height,
- image->size().width * 4
- );
-#endif
+}
- Cairo::RefPtr<Cairo::Context> context = Cairo::Context::create (surface);
+static string
+setup_font (StringText const& subtitle, list<shared_ptr<Font>> const& fonts)
+{
if (!fc_config) {
- fc_config = FcConfigCreate ();
- }
-
- FontFiles font_files;
-
- try {
- font_files.set (FontFiles::NORMAL, shared_path () / "LiberationSans-Regular.ttf");
- font_files.set (FontFiles::ITALIC, shared_path () / "LiberationSans-Italic.ttf");
- font_files.set (FontFiles::BOLD, shared_path () / "LiberationSans-Bold.ttf");
- } catch (boost::filesystem::filesystem_error& e) {
-
+ fc_config = FcInitLoadConfig ();
}
- /* Hack: try the debian/ubuntu locations if getting the shared path failed */
+ auto font_file = default_font_file ();
- if (!font_files.get(FontFiles::NORMAL) || !boost::filesystem::exists(font_files.get(FontFiles::NORMAL).get())) {
- font_files.set (FontFiles::NORMAL, "/usr/share/fonts/truetype/liberation/LiberationSans-Regular.ttf");
- }
- if (!font_files.get(FontFiles::ITALIC) || !boost::filesystem::exists(font_files.get(FontFiles::ITALIC).get())) {
- font_files.set (FontFiles::ITALIC, "/usr/share/fonts/truetype/liberation/LiberationSans-Italic.ttf");
- }
- if (!font_files.get(FontFiles::BOLD) || !boost::filesystem::exists(font_files.get(FontFiles::BOLD).get())) {
- font_files.set (FontFiles::BOLD, "/usr/share/fonts/truetype/liberation/LiberationSans-Bold.ttf");
- }
-
- BOOST_FOREACH (shared_ptr<Font> i, fonts) {
- if (i->id() == subtitles.front().font() && i->file(FontFiles::NORMAL)) {
- font_files = i->files ();
+ for (auto i: fonts) {
+ if (i->id() == subtitle.font() && i->file()) {
+ font_file = i->file().get();
}
}
- list<pair<FontFiles, string> >::const_iterator existing = fc_config_fonts.begin ();
- while (existing != fc_config_fonts.end() && existing->first != font_files) {
+ auto existing = fc_config_fonts.cbegin ();
+ while (existing != fc_config_fonts.end() && existing->first != font_file) {
++existing;
}
font_name = existing->second;
} else {
/* Make this font available to DCP-o-matic */
- for (int i = 0; i < FontFiles::VARIANTS; ++i) {
- if (font_files.get(static_cast<FontFiles::Variant>(i))) {
- FcConfigAppFontAddFile (
- fc_config,
- reinterpret_cast<FcChar8 const *> (font_files.get(static_cast<FontFiles::Variant>(i)).get().string().c_str())
- );
- }
- }
-
- FcPattern* pattern = FcPatternBuild (
- 0, FC_FILE, FcTypeString, font_files.get(FontFiles::NORMAL).get().string().c_str(), static_cast<char *> (0)
+ FcConfigAppFontAddFile (fc_config, reinterpret_cast<FcChar8 const *>(font_file.string().c_str()));
+ auto pattern = FcPatternBuild (
+ 0, FC_FILE, FcTypeString, font_file.string().c_str(), static_cast<char *>(0)
);
- FcObjectSet* object_set = FcObjectSetBuild (FC_FAMILY, FC_STYLE, FC_LANG, FC_FILE, static_cast<char *> (0));
- FcFontSet* font_set = FcFontList (fc_config, pattern, object_set);
+ auto object_set = FcObjectSetBuild (FC_FAMILY, FC_STYLE, FC_LANG, FC_FILE, static_cast<char *> (0));
+ auto font_set = FcFontList (fc_config, pattern, object_set);
if (font_set) {
for (int i = 0; i < font_set->nfont; ++i) {
FcPattern* font = font_set->fonts[i];
FcObjectSetDestroy (object_set);
FcPatternDestroy (pattern);
- fc_config_fonts.push_back (make_pair (font_files, font_name));
+ fc_config_fonts.push_back (make_pair(font_file, font_name));
}
FcConfigSetCurrent (fc_config);
+ return font_name;
+}
- Glib::RefPtr<Pango::Layout> layout = Pango::Layout::create (context);
-
- layout->set_alignment (Pango::ALIGN_LEFT);
-
- context->set_line_width (1);
- /* Compute fade factor */
+static float
+calculate_fade_factor (StringText const& first, DCPTime time, int frame_rate)
+{
float fade_factor = 1;
/* Round the fade start/end to the nearest frame start. Otherwise if a subtitle starts just after
the start of a frame it will be faded out.
*/
- DCPTime const fade_in_start = DCPTime::from_seconds(subtitles.front().in().as_seconds()).round(frame_rate);
- DCPTime const fade_in_end = fade_in_start + DCPTime::from_seconds (subtitles.front().fade_up_time().as_seconds ());
- DCPTime const fade_out_end = DCPTime::from_seconds (subtitles.front().out().as_seconds()).round(frame_rate);
- DCPTime const fade_out_start = fade_out_end - DCPTime::from_seconds (subtitles.front().fade_down_time().as_seconds ());
+ auto const fade_in_start = DCPTime::from_seconds(first.in().as_seconds()).round(frame_rate);
+ auto const fade_in_end = fade_in_start + DCPTime::from_seconds (first.fade_up_time().as_seconds ());
if (fade_in_start <= time && time <= fade_in_end && fade_in_start != fade_in_end) {
fade_factor *= DCPTime(time - fade_in_start).seconds() / DCPTime(fade_in_end - fade_in_start).seconds();
}
- if (fade_out_start <= time && time <= fade_out_end && fade_out_start != fade_out_end) {
- fade_factor *= 1 - DCPTime(time - fade_out_start).seconds() / DCPTime(fade_out_end - fade_out_start).seconds();
- }
- if (time < fade_in_start || time > fade_out_end) {
+
+ if (time < fade_in_start) {
fade_factor = 0;
}
- /* Render the subtitle at the top left-hand corner of image */
-
- Pango::FontDescription font (font_name);
- layout->set_font_description (font);
- layout->set_markup (marked_up (subtitles, target.height, fade_factor));
-
- context->scale (xscale, yscale);
- layout->update_from_cairo_context (context);
-
- /* Shuffle the subtitle over very slightly if it has a border so that the left-hand
- side of the first character's border is not cut off.
- */
- int const x_offset = subtitles.front().effect() == dcp::BORDER ? (target.width / 600.0) : 0;
- /* Move down a bit so that accents on capital letters can be seen */
- int const y_offset = target.height / 100.0;
+ /* first.out() may be zero if we don't know when this subtitle will finish. We can only think about
+ * fading out if we _do_ know when it will finish.
+ */
+ if (first.out() != dcp::Time()) {
+ auto const fade_out_end = DCPTime::from_seconds (first.out().as_seconds()).round(frame_rate);
+ auto const fade_out_start = fade_out_end - DCPTime::from_seconds(first.fade_down_time().as_seconds());
- if (subtitles.front().effect() == dcp::SHADOW) {
- /* Drop-shadow effect */
- set_source_rgba (context, subtitles.front().effect_colour(), fade_factor);
- context->move_to (x_offset + 4, y_offset + 4);
- layout->add_to_cairo_context (context);
- context->fill ();
- }
-
- if (subtitles.front().effect() == dcp::BORDER) {
- /* Border effect; stroke the subtitle with a large (arbitrarily chosen) line width */
- set_source_rgba (context, subtitles.front().effect_colour(), fade_factor);
- context->set_line_width (subtitles.front().outline_width * target.width / 2048.0);
- context->set_line_join (Cairo::LINE_JOIN_ROUND);
- context->move_to (x_offset, y_offset);
- layout->add_to_cairo_context (context);
- context->stroke ();
+ if (fade_out_start <= time && time <= fade_out_end && fade_out_start != fade_out_end) {
+ fade_factor *= 1 - DCPTime(time - fade_out_start).seconds() / DCPTime(fade_out_end - fade_out_start).seconds();
+ }
+ if (time > fade_out_end) {
+ fade_factor = 0;
+ }
}
- /* The actual subtitle */
+ return fade_factor;
+}
- context->set_line_width (0);
- context->move_to (x_offset, y_offset);
-#ifdef DCPOMATIC_HAVE_SHOW_IN_CAIRO_CONTEXT
- layout->show_in_cairo_context (context);
-#else
- pango_cairo_show_layout (context->cobj(), layout->gobj());
-#endif
-
- int layout_width;
- int layout_height;
- layout->get_pixel_size (layout_width, layout_height);
- layout_width *= xscale;
- layout_height *= yscale;
+static int
+x_position (StringText const& first, int target_width, int layout_width)
+{
int x = 0;
- switch (subtitles.front().h_align ()) {
- case dcp::HALIGN_LEFT:
+ switch (first.h_align()) {
+ case dcp::HAlign::LEFT:
/* h_position is distance between left of frame and left of subtitle */
- x = subtitles.front().h_position() * target.width;
+ x = first.h_position() * target_width;
break;
- case dcp::HALIGN_CENTER:
+ case dcp::HAlign::CENTER:
/* h_position is distance between centre of frame and centre of subtitle */
- x = (0.5 + subtitles.front().h_position()) * target.width - layout_width / 2;
+ x = (0.5 + first.h_position()) * target_width - layout_width / 2;
break;
- case dcp::HALIGN_RIGHT:
+ case dcp::HAlign::RIGHT:
/* h_position is distance between right of frame and right of subtitle */
- x = (1.0 - subtitles.front().h_position()) * target.width - layout_width;
+ x = (1.0 - first.h_position()) * target_width - layout_width;
break;
}
+ return x;
+}
+
+
+static int
+y_position (StringText const& first, int target_height, int layout_height)
+{
int y = 0;
- switch (subtitles.front().v_align ()) {
- case dcp::VALIGN_TOP:
+ switch (first.v_align()) {
+ case dcp::VAlign::TOP:
/* SMPTE says that v_position is the distance between top
of frame and top of subtitle, but this doesn't always seem to be
the case in practice; Gunnar Ásgeirsson's Dolby server appears
- to put VALIGN_TOP subs with v_position as the distance between top
+ to put VAlign::TOP subs with v_position as the distance between top
of frame and bottom of subtitle.
*/
- y = subtitles.front().v_position() * target.height - layout_height;
+ y = first.v_position() * target_height - layout_height;
break;
- case dcp::VALIGN_CENTER:
+ case dcp::VAlign::CENTER:
/* v_position is distance between centre of frame and centre of subtitle */
- y = (0.5 + subtitles.front().v_position()) * target.height - layout_height / 2;
+ y = (0.5 + first.v_position()) * target_height - layout_height / 2;
break;
- case dcp::VALIGN_BOTTOM:
+ case dcp::VAlign::BOTTOM:
/* v_position is distance between bottom of frame and bottom of subtitle */
- y = (1.0 - subtitles.front().v_position()) * target.height - layout_height;
+ y = (1.0 - first.v_position()) * target_height - layout_height;
break;
}
- return PositionImage (image, Position<int> (max (0, x), max (0, y)));
+ return y;
+}
+
+
+/** @param subtitles A list of subtitles that are all on the same line,
+ * at the same time and with the same fade in/out.
+ */
+static PositionImage
+render_line (list<StringText> subtitles, list<shared_ptr<Font>> fonts, dcp::Size target, DCPTime time, int frame_rate)
+{
+ /* XXX: this method can only handle italic / bold changes mid-line,
+ nothing else yet.
+ */
+
+ DCPOMATIC_ASSERT (!subtitles.empty ());
+ auto const& first = subtitles.front ();
+
+ 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, font_name);
+ auto layout = create_layout ();
+ setup_layout (layout, font_name, markup);
+ dcp::Size size;
+ layout->get_pixel_size (size.width, size.height);
+
+ /* Calculate x and y scale factors. These are only used to stretch
+ the font away from its normal aspect ratio.
+ */
+ float x_scale = 1;
+ float y_scale = 1;
+ if (fabs (first.aspect_adjust() - 1.0) > dcp::ASPECT_ADJUST_EPSILON) {
+ if (first.aspect_adjust() < 1) {
+ x_scale = max (0.25f, first.aspect_adjust ());
+ y_scale = 1;
+ } else {
+ x_scale = 1;
+ y_scale = 1 / min (4.0f, first.aspect_adjust ());
+ }
+ }
+
+ auto const border_width = first.effect() == dcp::Effect::BORDER ? (first.outline_width * target.width / 2048.0) : 0;
+ size.width += 2 * ceil (border_width);
+ size.height += 2 * ceil (border_width);
+
+ size.width *= x_scale;
+ size.height *= y_scale;
+
+ /* Shuffle the subtitle over by the border width (if we have any) so it's not cut off */
+ int const x_offset = ceil (border_width);
+ /* Move down a bit so that accents on capital letters can be seen */
+ int const y_offset = target.height / 100.0;
+
+ size.width += x_offset;
+ size.height += y_offset;
+
+ auto image = create_image (size);
+ auto surface = create_surface (image);
+ auto context = Cairo::Context::create (surface);
+
+ context->set_line_width (1);
+ context->scale (x_scale, y_scale);
+ layout->update_from_cairo_context (context);
+
+ if (first.effect() == dcp::Effect::SHADOW) {
+ /* Drop-shadow effect */
+ set_source_rgba (context, first.effect_colour(), fade_factor);
+ context->move_to (x_offset + 4, y_offset + 4);
+ layout->add_to_cairo_context (context);
+ context->fill ();
+ }
+
+ if (first.effect() == dcp::Effect::BORDER) {
+ /* Border effect */
+ set_source_rgba (context, first.effect_colour(), fade_factor);
+ context->set_line_width (border_width);
+ context->set_line_join (Cairo::LINE_JOIN_ROUND);
+ context->move_to (x_offset, y_offset);
+ layout->add_to_cairo_context (context);
+ context->stroke ();
+ }
+
+ /* The actual subtitle */
+
+ set_source_rgba (context, first.colour(), fade_factor);
+
+ context->move_to (x_offset, y_offset);
+ layout->add_to_cairo_context (context);
+ context->fill ();
+
+ context->set_line_width (0.5);
+ context->move_to (x_offset, y_offset);
+ layout->add_to_cairo_context (context);
+ context->stroke ();
+
+ int const x = x_position (first, target.width, size.width);
+ int const y = y_position (first, target.height, size.height);
+ return PositionImage (image, Position<int>(max (0, x), max(0, y)));
}
+
/** @param time Time of the frame that these subtitles are going on.
+ * @param target Size of the container that this subtitle will end up in.
* @param frame_rate DCP frame rate.
*/
list<PositionImage>
-render_text (list<StringText> subtitles, list<shared_ptr<Font> > fonts, dcp::Size target, DCPTime time, int frame_rate)
+render_text (list<StringText> subtitles, list<shared_ptr<Font>> fonts, dcp::Size target, DCPTime time, int frame_rate)
{
list<StringText> pending;
list<PositionImage> images;
- BOOST_FOREACH (StringText const & i, subtitles) {
- if (!pending.empty() && fabs (i.v_position() - pending.back().v_position()) > 1e-4) {
+ for (auto const& i: subtitles) {
+ if (!pending.empty() && (i.v_align() != pending.back().v_align() || fabs(i.v_position() - pending.back().v_position()) > 1e-4)) {
images.push_back (render_line (pending, fonts, target, time, frame_rate));
pending.clear ();
}
pending.push_back (i);
}
- if (!pending.empty ()) {
+ if (!pending.empty()) {
images.push_back (render_line (pending, fonts, target, time, frame_rate));
}