epub: Put font fallback chain in fz_font.

fz_encode_character_with_fallback finds the first font in the fallback
chain that has the glyph encoded, and if none do then try to encode
a bullet character.

4 files changed, 67 insertions, 102 deletions

diff --git a/source/fitz/font.c b/source/fitz/font.c
index 0350674f..bdfee584 100644
--- a/source/fitz/font.c
+++ b/source/fitz/font.c
@@ -120,14 +120,14 @@ fz_drop_font(fz_context *ctx, fz_font *font)
 	if (!fz_drop_imp(ctx, font, &font->refs))
 		return;
 
-	free_resources(ctx, font);
+	fz_drop_font(ctx, font->fallback);
+
 	if (font->t3lists)
 	{
+		free_resources(ctx, font);
 		for (i = 0; i < 256; i++)
-		{
 			if (font->t3lists[i])
 				fz_drop_display_list(ctx, font->t3lists[i]);
-		}
 		fz_free(ctx, font->t3procs);
 		fz_free(ctx, font->t3lists);
 		fz_free(ctx, font->t3widths);
@@ -1366,3 +1366,33 @@ fz_encode_character(fz_context *ctx, fz_font *font, int ucs)
 	}
 	return ucs;
 }
+
+int
+fz_encode_character_with_fallback(fz_context *ctx, fz_font *first_font, int ucs, fz_font **out_font)
+{
+	fz_font *font;
+
+	for (font = first_font; font; font = font->fallback)
+	{
+		int gid = fz_encode_character(ctx, font, ucs);
+		if (gid > 0)
+		{
+			*out_font = font;
+			return gid;
+		}
+	}
+
+	ucs = 0x25CF; /* bullet */
+	for (font = first_font; font; font = font->fallback)
+	{
+		int gid = fz_encode_character(ctx, font, ucs);
+		if (gid > 0)
+		{
+			*out_font = font;
+			return gid;
+		}
+	}
+
+	*out_font = first_font;
+	return 0;
+}
diff --git a/source/html/css-apply.c b/source/html/css-apply.c
index f7884504..45fa7713 100644
--- a/source/html/css-apply.c
+++ b/source/html/css-apply.c
@@ -1161,7 +1161,6 @@ fz_apply_css_style(fz_context *ctx, fz_html_font_set *set, fz_css_style *style,
 		const char *font_style = string_from_property(match, "font-style", "normal");
 		const char *font_weight = string_from_property(match, "font-weight", "normal");
 		style->font = fz_load_html_font(ctx, set, font_family, font_variant, font_style, font_weight);
-		style->fallback = fz_load_html_fallback_font(ctx, set);
 	}
 }
 
diff --git a/source/html/html-font.c b/source/html/html-font.c
index e9c17719..4b138162 100644
--- a/source/html/html-font.c
+++ b/source/html/html-font.c
@@ -12,6 +12,23 @@ static const char *font_names[16] =
 };
 
 fz_font *
+fz_load_html_fallback_font(fz_context *ctx, fz_html_font_set *set)
+{
+	if (!set->fallback)
+	{
+		unsigned char *data;
+		unsigned int size;
+		int index;
+
+		data = pdf_lookup_substitute_cjk_font(ctx, FZ_ADOBE_GB_1, 0, 0, &size, &index);
+		if (!data)
+			fz_throw(ctx, FZ_ERROR_GENERIC, "cannot load fallback font");
+		set->fallback = fz_new_font_from_memory(ctx, "fallback", data, size, index, 0);
+	}
+	return set->fallback;
+}
+
+fz_font *
 fz_load_html_font(fz_context *ctx, fz_html_font_set *set,
 	const char *family, const char *variant, const char *style, const char *weight)
 {
@@ -30,28 +47,12 @@ fz_load_html_font(fz_context *ctx, fz_html_font_set *set,
 		if (!data)
 			fz_throw(ctx, FZ_ERROR_GENERIC, "cannot load html font: %s", font_names[idx]);
 		set->fonts[idx] = fz_new_font_from_memory(ctx, font_names[idx], data, size, 0, 1);
+		set->fonts[idx]->fallback = fz_load_html_fallback_font(ctx, set);
 	}
 
 	return set->fonts[idx];
 }
 
-fz_font *
-fz_load_html_fallback_font(fz_context *ctx, fz_html_font_set *set)
-{
-	if (!set->fallback)
-	{
-		unsigned char *data;
-		unsigned int size;
-		int index;
-
-		data = pdf_lookup_substitute_cjk_font(ctx, FZ_ADOBE_GB_1, 0, 0, &size, &index);
-		if (!data)
-			fz_throw(ctx, FZ_ERROR_GENERIC, "cannot load fallback font");
-		set->fallback = fz_new_font_from_memory(ctx, "fallback", data, size, index, 0);
-	}
-	return set->fallback;
-}
-
 fz_html_font_set *fz_new_html_font_set(fz_context *ctx)
 {
 	return fz_malloc_struct(ctx, fz_html_font_set);
diff --git a/source/html/html-layout.c b/source/html/html-layout.c
index 6366f5cc..36995c34 100644
--- a/source/html/html-layout.c
+++ b/source/html/html-layout.c
@@ -538,6 +538,7 @@ static void measure_image(fz_context *ctx, fz_html_flow *node, float max_w, floa
 
 static void measure_word(fz_context *ctx, fz_html_flow *node, float em)
 {
+	fz_font *font;
 	const char *s;
 	int c, g;
 	float w;
@@ -552,16 +553,8 @@ static void measure_word(fz_context *ctx, fz_html_flow *node, float em)
 	while (*s)
 	{
 		s += fz_chartorune(&c, s);
-		g = fz_encode_character(ctx, node->style->font, c);
-		if (g)
-		{
-			w += fz_advance_glyph(ctx, node->style->font, g) * em;
-		}
-		else
-		{
-			g = fz_encode_character(ctx, node->style->fallback, c);
-			w += fz_advance_glyph(ctx, node->style->fallback, g) * em;
-		}
+		g = fz_encode_character_with_fallback(ctx, node->style->font, c, &font);
+		w += fz_advance_glyph(ctx, font, g) * em;
 	}
 	node->w = w;
 	node->em = em;
@@ -906,6 +899,7 @@ static float layout_block(fz_context *ctx, fz_html *box, fz_html *top, float em,
 
 static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float page_bot, fz_device *dev, const fz_matrix *ctm)
 {
+	fz_font *font;
 	fz_html_flow *node;
 	fz_text *text;
 	fz_matrix trm;
@@ -949,27 +943,9 @@ static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float p
 				{
 					t += fz_chartorune(&c, t);
 					if (node->mirror)
-					{
 						c = ucdn_mirror(c);
-					}
-					g = fz_encode_character(ctx, node->style->font, c);
-					if (g)
-					{
-						w += fz_advance_glyph(ctx, node->style->font, g) * node->em;
-					}
-					else
-					{
-						g = fz_encode_character(ctx, node->style->fallback, c);
-						if (g)
-						{
-							w += fz_advance_glyph(ctx, node->style->fallback, g) * node->em;
-						}
-						else
-						{
-							g = fz_encode_character(ctx, node->style->font, 0x25CF); /* bullet */
-							w += fz_advance_glyph(ctx, node->style->font, g) * node->em;
-						}
-					}
+					g = fz_encode_character_with_fallback(ctx, node->style->font, c, &font);
+					w += fz_advance_glyph(ctx, font, g) * node->em;
 				}
 
 				trm.e += w;
@@ -977,33 +953,11 @@ static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float p
 				{
 					s += fz_chartorune(&c, s);
 					if (node->mirror)
-					{
 						c = ucdn_mirror(c);
-					}
-					g = fz_encode_character(ctx, node->style->font, c);
-					if (g)
-					{
-						trm.e -= fz_advance_glyph(ctx, node->style->font, g) * node->em;
-						if (node->style->visibility == V_VISIBLE)
-							fz_add_text(ctx, text, node->style->font, 0, &trm, g, c);
-					}
-					else
-					{
-						g = fz_encode_character(ctx, node->style->fallback, c);
-						if (g)
-						{
-							trm.e -= fz_advance_glyph(ctx, node->style->fallback, g) * node->em;
-							if (node->style->visibility == V_VISIBLE)
-								fz_add_text(ctx, text, node->style->fallback, 0, &trm, g, c);
-						}
-						else
-						{
-							trm.e -= fz_advance_glyph(ctx, node->style->font, g) * node->em;
-							g = fz_encode_character(ctx, node->style->font, 0x25CF); /* bullet */
-							if (node->style->visibility == V_VISIBLE)
-								fz_add_text(ctx, text, node->style->font, 0, &trm, g, c);
-						}
-					}
+					g = fz_encode_character_with_fallback(ctx, node->style->font, c, &font);
+					trm.e -= fz_advance_glyph(ctx, font, g) * node->em;
+					if (node->style->visibility == V_VISIBLE)
+						fz_add_text(ctx, text, font, 0, &trm, g, c);
 				}
 				trm.e += w;
 			}
@@ -1012,30 +966,10 @@ static void draw_flow_box(fz_context *ctx, fz_html *box, float page_top, float p
 				while (*s)
 				{
 					s += fz_chartorune(&c, s);
-					g = fz_encode_character(ctx, node->style->font, c);
-					if (g)
-					{
-						if (node->style->visibility == V_VISIBLE)
-							fz_add_text(ctx, text, node->style->font, 0, &trm, g, c);
-						trm.e += fz_advance_glyph(ctx, node->style->font, g) * node->em;
-					}
-					else
-					{
-						g = fz_encode_character(ctx, node->style->fallback, c);
-						if (g)
-						{
-							if (node->style->visibility == V_VISIBLE)
-								fz_add_text(ctx, text, node->style->fallback, 0, &trm, g, c);
-							trm.e += fz_advance_glyph(ctx, node->style->fallback, g) * node->em;
-						}
-						else
-						{
-							g = fz_encode_character(ctx, node->style->font, 0x25CF); /* bullet */
-							if (node->style->visibility == V_VISIBLE)
-								fz_add_text(ctx, text, node->style->font, 0, &trm, g, c);
-							trm.e += fz_advance_glyph(ctx, node->style->font, g) * node->em;
-						}
-					}
+					g = fz_encode_character_with_fallback(ctx, node->style->font, c, &font);
+					if (node->style->visibility == V_VISIBLE)
+						fz_add_text(ctx, text, font, 0, &trm, g, c);
+					trm.e += fz_advance_glyph(ctx, font, g) * node->em;
 				}
 			}
 
@@ -1181,6 +1115,7 @@ static fz_html_flow *find_list_mark_anchor(fz_context *ctx, fz_html *box)
 
 static void draw_list_mark(fz_context *ctx, fz_html *box, float page_top, float page_bot, fz_device *dev, const fz_matrix *ctm, int n)
 {
+	fz_font *font;
 	fz_text *text;
 	fz_matrix trm;
 	fz_html_flow *line;
@@ -1219,7 +1154,7 @@ static void draw_list_mark(fz_context *ctx, fz_html *box, float page_top, float
 	while (*s)
 	{
 		s += fz_chartorune(&c, s);
-		g = fz_encode_character(ctx, box->style.font, c);
+		g = fz_encode_character_with_fallback(ctx, box->style.font, c, &font);
 		w += fz_advance_glyph(ctx, box->style.font, g) * box->em;
 	}