From 329e747da6ee89d4ed2de15ceacf68b932e56e80 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 14 Apr 2018 17:12:01 +0300
Subject: [PATCH] Make sure there code point ranges are in order

And that there are no overlapping ranges.  The grid rendering logic
depends on being able to determine the total range of code points from
the first and last converted glyph.
---
 ttf2png.c | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/ttf2png.c b/ttf2png.c
index 2a087ff..6224fc3 100644
--- a/ttf2png.c
+++ b/ttf2png.c
@@ -74,6 +74,8 @@ int convert_numeric_option(char, int);
 void convert_code_point_range(char, Range *);
 unsigned str_to_code_point(const char *, char **);
 void convert_size(char, unsigned *, unsigned *);
+void sort_and_compact_ranges(Range *, unsigned *);
+int range_cmp(const void *, const void *);
 unsigned round_to_pot(unsigned);
 void *alloc_image_data(size_t, size_t);
 int init_font(Font *, FT_Face, const Range *, unsigned, bool);
@@ -214,6 +216,7 @@ int main(int argc, char **argv)
 	}
 
 	font.size = size;
+	sort_and_compact_ranges(ranges, &n_ranges);
 	err = init_font(&font, face, ranges, n_ranges, autohinter);
 	if(err)
 		return 1;
@@ -404,6 +407,44 @@ void convert_size(char opt, unsigned *width, unsigned *height)
 	exit(1);
 }
 
+void sort_and_compact_ranges(Range *ranges, unsigned *n_ranges)
+{
+	unsigned i, j;
+
+	if(!*n_ranges)
+		return;
+
+	qsort(ranges, *n_ranges, sizeof(Range), &range_cmp);
+	for(i=0, j=1; j<*n_ranges; ++j)
+	{
+		if(ranges[i].last+1>=ranges[j].first)
+		{
+			if(ranges[j].last>ranges[i].last)
+				ranges[i].last = ranges[j].last;
+		}
+		else
+		{
+			++i;
+			if(i!=j)
+				ranges[i] = ranges[j];
+		}
+	}
+
+	*n_ranges = i+1;
+}
+
+int range_cmp(const void *p1, const void *p2)
+{
+	const Range *r1 = (const Range *)p1;
+	const Range *r2 = (const Range *)p2;
+	if(r1->first!=r2->first)
+		return (r1->first<r2->first ? -1 : 1);
+	else if(r1->last!=r2->last)
+		return (r1->last<r2->last ? -1 : 1);
+	else
+		return 0;
+}
+
 unsigned round_to_pot(unsigned n)
 {
 	n -= 1;
-- 
2.43.0