From 3ea6caa46577f716fa0e5cb46574469c44ee74ed Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 14 Apr 2018 17:20:02 +0300
Subject: [PATCH] Add a flag for non-power-of-two images

---
 Readme    |  5 +++++
 ttf2png.c | 36 ++++++++++++++++++++++++------------
 2 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/Readme b/Readme
index 9d10f6c..946c9b7 100644
--- a/Readme
+++ b/Readme
@@ -69,6 +69,10 @@ Command-line options
     Control the amount of padding between glyphs.  The default is 1 pixel.
     Only used with -p.
 
+  -f
+    Allow the resulting image to have a non-power-of-two size.  By default the
+    image size is rounded up to a power of two for maximum compatibility.
+
   -d
     File name to write glyph definitions.  See the section below for details.
 
@@ -139,6 +143,7 @@ Changelog
 next
 - Alternate ways of specifying code point ranges
 - Multiple code point ranges can be specified
+- Option to generate non-power-of-two images
 
 1.1
 - Controllable margin and padding in packed mode
diff --git a/ttf2png.c b/ttf2png.c
index 236fe9e..e39c328 100644
--- a/ttf2png.c
+++ b/ttf2png.c
@@ -80,8 +80,8 @@ unsigned round_to_pot(unsigned);
 void *alloc_image_data(size_t, size_t);
 int init_font(Font *, FT_Face, const Range *, unsigned, bool);
 int init_glyphs(Font *, FT_Face, const Range *, bool);
-int render_grid(Font *, unsigned, unsigned, unsigned, bool);
-int render_packed(Font *, unsigned, unsigned);
+int render_grid(Font *, unsigned, unsigned, unsigned, bool, bool);
+int render_packed(Font *, unsigned, unsigned, bool);
 int save_defs(const char *, const Font *);
 int save_png(const char *, const Image *, char);
 
@@ -103,6 +103,7 @@ int main(int argc, char **argv)
 	bool pack = 0;
 	unsigned margin = 0;
 	unsigned padding = 1;
+	bool npot = 0;
 
 	FT_Library freetype;
 	FT_Face face;
@@ -121,7 +122,7 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	while((i = getopt(argc, argv, "r:s:l:c:o:atvh?ed:pim:n:")) != -1)
+	while((i = getopt(argc, argv, "r:s:l:c:o:atvh?ed:pim:n:f")) != -1)
 	{
 		switch(i)
 		{
@@ -172,6 +173,9 @@ int main(int argc, char **argv)
 		case 'n':
 			padding = convert_numeric_option('n', 0);
 			break;
+		case 'f':
+			npot = 1;
+			break;
 		}
 	}
 	if(!strcmp(out_fn, "-"))
@@ -237,9 +241,9 @@ int main(int argc, char **argv)
 	}
 
 	if(pack)
-		err = render_packed(&font, margin, padding);
+		err = render_packed(&font, margin, padding, npot);
 	else
-		err = render_grid(&font, cellw, cellh, cpl, seq);
+		err = render_grid(&font, cellw, cellh, cpl, seq, npot);
 	if(err)
 		return 1;
 
@@ -289,6 +293,7 @@ void usage(void)
 		"  -p  Pack the glyphs tightly instead of in a grid\n"
 		"  -m  Margin around image edges (packed mode only) [0]\n"
 		"  -n  Padding between glyphs (packed mode only) [1]\n"
+		"  -f  Allow non-power-of-two result\n"
 		"  -d  File name for writing glyph definitions\n"
 		"  -h  Print this message\n");
 }
@@ -634,7 +639,7 @@ int init_glyphs(Font *font, FT_Face face, const Range *range, bool autohinter)
 	return 0;
 }
 
-int render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, bool seq)
+int render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, bool seq, bool npot)
 {
 	unsigned i;
 	int top = 0, bot = 0;
@@ -698,11 +703,15 @@ int render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, bool s
 		first -= first%cpl;
 	last = font->glyphs[font->n_glyphs-1].code;
 
-	font->image.w = round_to_pot(cpl*cellw);
+	font->image.w = cpl*cellw;
+	if(!npot)
+		font->image.w = round_to_pot(font->image.w);
 	if(seq)
-		font->image.h = round_to_pot((font->n_glyphs+cpl-1)/cpl*cellh);
+		font->image.h = (font->n_glyphs+cpl-1)/cpl*cellh;
 	else
-		font->image.h = round_to_pot((last-first+cpl)/cpl*cellh);
+		font->image.h = (last-first+cpl)/cpl*cellh;
+	if(!npot)
+		font->image.h = round_to_pot(font->image.h);
 
 	font->image.data = (char *)alloc_image_data(font->image.w, font->image.h);
 	if(!font->image.data)
@@ -743,7 +752,7 @@ int render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, bool s
 	return 0;
 }
 
-int render_packed(Font *font, unsigned margin, unsigned padding)
+int render_packed(Font *font, unsigned margin, unsigned padding, bool npot)
 {
 	unsigned i;
 	size_t area = 0;
@@ -774,7 +783,8 @@ int render_packed(Font *font, unsigned margin, unsigned padding)
 		if(font->image.h<=font->image.w)
 			break;
 	}
-	font->image.h = round_to_pot(font->image.h);
+	if(!npot)
+		font->image.h = round_to_pot(font->image.h);
 
 	/* Allocate arrays for storing the image and keeping track of used pixels and
 	glyphs.  Since glyphs are rectangular and the image is filled starting from
@@ -870,7 +880,9 @@ int render_packed(Font *font, unsigned margin, unsigned padding)
 
 	/* Trim the image to the actually used size, in case the original estimate
 	was too pessimistic. */
-	font->image.h = round_to_pot(used_h);
+	font->image.h = used_h;
+	if(!npot)
+		font->image.h = round_to_pot(font->image.h);
 
 	free(used_glyphs);
 	free(used_pixels);
-- 
2.43.0