Fix incorrect preview of italic subtitles (#728).

This requires fonts to be configured with their italic versions so
that the italic font can be given to FontConfig and hence used to
render text.  Bold font configuration is also added here although
bold subtitles aren't yet supported.

1 files changed, 94 insertions, 37 deletions

diff --git a/src/lib/render_subtitles.cc b/src/lib/render_subtitles.cc
index f507238fb..9b5f585e5 100644
--- a/src/lib/render_subtitles.cc
+++ b/src/lib/render_subtitles.cc
@@ -22,6 +22,7 @@
 #include "image.h"
 #include "cross.h"
 #include "font.h"
+#include "dcpomatic_assert.h"
 #include <cairomm/cairomm.h>
 #include <pangomm.h>
 #include <boost/foreach.hpp>
@@ -39,23 +40,30 @@ using boost::shared_ptr;
 using boost::optional;
 
 static FcConfig* fc_config = 0;
-static list<pair<boost::filesystem::path, string> > fc_config_fonts;
+static list<pair<FontFiles, string> > fc_config_fonts;
 
+/** @param subtitles A list of subtitles that are all on the same line */
 static PositionImage
-render_subtitle (dcp::SubtitleString const & subtitle, list<shared_ptr<Font> > fonts, dcp::Size target)
+render_line (list<dcp::SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp::Size target)
 {
+	/* 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 (subtitle.aspect_adjust() - 1.0) > dcp::ASPECT_ADJUST_EPSILON) {
-		if (subtitle.aspect_adjust() < 1) {
-			xscale = max (0.25f, subtitle.aspect_adjust ());
+	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, subtitle.aspect_adjust ());
+			yscale = 1 / min (4.0f, subtitles.front().aspect_adjust ());
 		}
 	}
 
@@ -64,7 +72,7 @@ render_subtitle (dcp::SubtitleString const & subtitle, list<shared_ptr<Font> > f
 	*/
 
 	/* Basic guess on height... */
-	int height = subtitle.size() * target.height / (11 * 72);
+	int height = subtitles.front().size() * target.height / (11 * 72);
 	/* ...scaled... */
 	height *= yscale;
 	/* ...and add a bit more for luck */
@@ -87,22 +95,36 @@ render_subtitle (dcp::SubtitleString const & subtitle, list<shared_ptr<Font> > f
 		fc_config = FcConfigCreate ();
 	}
 
-	boost::filesystem::path font_file;
+	FontFiles font_files;
+
 	try {
-		font_file = shared_path () / "LiberationSans-Regular.ttf";
+		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) {
-		/* Hack: try the debian/ubuntu location if getting the shared path failed */
-		font_file = "/usr/share/fonts/truetype/liberation/LiberationSans-Regular.ttf";
+
+	}
+
+	/* Hack: try the debian/ubuntu locations if getting the shared path failed */
+
+	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() == subtitle.font() && i->file ()) {
-			font_file = i->file().get ();
+		if (i->id() == subtitles.front().font() && i->file(FontFiles::NORMAL)) {
+			font_files = i->files ();
 		}
 	}
 
-	list<pair<boost::filesystem::path, string> >::const_iterator existing = fc_config_fonts.begin ();
-	while (existing != fc_config_fonts.end() && existing->first != font_file) {
+	list<pair<FontFiles, string> >::const_iterator existing = fc_config_fonts.begin ();
+	while (existing != fc_config_fonts.end() && existing->first != font_files) {
 		++existing;
 	}
 
@@ -111,9 +133,16 @@ render_subtitle (dcp::SubtitleString const & subtitle, list<shared_ptr<Font> > f
 		font_name = existing->second;
 	} else {
 		/* Make this font available to DCP-o-matic */
-		FcConfigAppFontAddFile (fc_config, reinterpret_cast<FcChar8 const *> (font_file.string().c_str ()));
+		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_file.string().c_str(), static_cast<char *> (0));
+		FcPattern* pattern = FcPatternBuild (0, FC_FILE, FcTypeString, font_files.get(FontFiles::NORMAL).get().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);
 		if (font_set) {
@@ -137,7 +166,7 @@ render_subtitle (dcp::SubtitleString const & subtitle, list<shared_ptr<Font> > f
 		FcObjectSetDestroy (object_set);
 		FcPatternDestroy (pattern);
 
-		fc_config_fonts.push_back (make_pair (font_file, font_name));
+		fc_config_fonts.push_back (make_pair (font_files, font_name));
 	}
 
 	FcConfigSetCurrent (fc_config);
@@ -151,12 +180,29 @@ render_subtitle (dcp::SubtitleString const & subtitle, list<shared_ptr<Font> > f
 	/* Render the subtitle at the top left-hand corner of image */
 
 	Pango::FontDescription font (font_name);
-	font.set_absolute_size (subtitle.size_in_pixels (target.height) * PANGO_SCALE);
-	if (subtitle.italic ()) {
-		font.set_style (Pango::STYLE_ITALIC);
-	}
+	font.set_absolute_size (subtitles.front().size_in_pixels (target.height) * PANGO_SCALE);
 	layout->set_font_description (font);
-	layout->set_text (subtitle.text ());
+
+	string marked_up;
+	bool italic = false;
+	BOOST_FOREACH (dcp::SubtitleString const & i, subtitles) {
+		if (i.italic() != italic) {
+			if (i.italic()) {
+				marked_up += "<i>";
+			} else {
+				marked_up += "</i>";
+			}
+			italic = i.italic ();
+		}
+
+		marked_up += i.text ();
+	}
+
+	if (italic) {
+		marked_up += "</i>";
+	}
+
+	layout->set_markup (marked_up);
 
 	/* Compute fade factor */
 	/* XXX */
@@ -166,9 +212,9 @@ render_subtitle (dcp::SubtitleString const & subtitle, list<shared_ptr<Font> > f
 
 	context->scale (xscale, yscale);
 
-	if (subtitle.effect() == dcp::SHADOW) {
+	if (subtitles.front().effect() == dcp::SHADOW) {
 		/* Drop-shadow effect */
-		dcp::Colour const ec = subtitle.effect_colour ();
+		dcp::Colour const ec = subtitles.front().effect_colour ();
 		context->set_source_rgba (float(ec.r) / 255, float(ec.g) / 255, float(ec.b) / 255, fade_factor);
 		context->move_to (4, 4);
 		layout->add_to_cairo_context (context);
@@ -177,15 +223,15 @@ render_subtitle (dcp::SubtitleString const & subtitle, list<shared_ptr<Font> > f
 
 	/* The actual subtitle */
 
-	dcp::Colour const c = subtitle.colour ();
+	dcp::Colour const c = subtitles.front().colour ();
 	context->set_source_rgba (float(c.r) / 255, float(c.g) / 255, float(c.b) / 255, fade_factor);
 	context->move_to (0, 0);
 	layout->add_to_cairo_context (context);
 	context->fill ();
 
-	if (subtitle.effect() == dcp::BORDER) {
+	if (subtitles.front().effect() == dcp::BORDER) {
 		/* Border effect */
-		dcp::Colour ec = subtitle.effect_colour ();
+		dcp::Colour ec = subtitles.front().effect_colour ();
 		context->set_source_rgba (float(ec.r) / 255, float(ec.g) / 255, float(ec.b) / 255, fade_factor);
 		context->move_to (0, 0);
 		layout->add_to_cairo_context (context);
@@ -197,34 +243,34 @@ render_subtitle (dcp::SubtitleString const & subtitle, list<shared_ptr<Font> > f
 	layout->get_size (layout_width, layout_height);
 
 	int x = 0;
-	switch (subtitle.h_align ()) {
+	switch (subtitles.front().h_align ()) {
 	case dcp::HALIGN_LEFT:
 		/* h_position is distance between left of frame and left of subtitle */
-		x = subtitle.h_position() * target.width;
+		x = subtitles.front().h_position() * target.width;
 		break;
 	case dcp::HALIGN_CENTER:
 		/* h_position is distance between centre of frame and centre of subtitle */
-		x = (0.5 + subtitle.h_position()) * target.width - layout_width / (PANGO_SCALE * 2);
+		x = (0.5 + subtitles.front().h_position()) * target.width - layout_width / (PANGO_SCALE * 2);
 		break;
 	case dcp::HALIGN_RIGHT:
 		/* h_position is distance between right of frame and right of subtitle */
-		x = (1.0 - subtitle.h_position()) * target.width - layout_width / PANGO_SCALE;
+		x = (1.0 - subtitles.front().h_position()) * target.width - layout_width / PANGO_SCALE;
 		break;
 	}
 
 	int y = 0;
-	switch (subtitle.v_align ()) {
+	switch (subtitles.front().v_align ()) {
 	case dcp::VALIGN_TOP:
 		/* v_position is distance between top of frame and top of subtitle */
-		y = subtitle.v_position() * target.height;
+		y = subtitles.front().v_position() * target.height;
 		break;
 	case dcp::VALIGN_CENTER:
 		/* v_position is distance between centre of frame and centre of subtitle */
-		y = (0.5 + subtitle.v_position()) * target.height - layout_height / (PANGO_SCALE * 2);
+		y = (0.5 + subtitles.front().v_position()) * target.height - layout_height / (PANGO_SCALE * 2);
 		break;
 	case dcp::VALIGN_BOTTOM:
 		/* v_position is distance between bottom of frame and bottom of subtitle */
-		y = (1.0 - subtitle.v_position()) * target.height - layout_height / PANGO_SCALE;
+		y = (1.0 - subtitles.front().v_position()) * target.height - layout_height / PANGO_SCALE;
 		break;
 	}
 
@@ -234,9 +280,20 @@ render_subtitle (dcp::SubtitleString const & subtitle, list<shared_ptr<Font> > f
 list<PositionImage>
 render_subtitles (list<dcp::SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp::Size target)
 {
+	list<dcp::SubtitleString> pending;
 	list<PositionImage> images;
+
 	BOOST_FOREACH (dcp::SubtitleString const & i, subtitles) {
-		images.push_back (render_subtitle (i, fonts, target));
+		if (!pending.empty() && fabs (i.v_position() - pending.back().v_position()) > 1e-4) {
+			images.push_back (render_line (pending, fonts, target));
+			pending.clear ();
+		}
+		pending.push_back (i);
 	}
+
+	if (!pending.empty ()) {
+		images.push_back (render_line (pending, fonts, target));
+	}
+
 	return images;
 }