X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=ttf2png.c;h=76c2e0d96d7330fa530fe00d842b42eca40573e7;hb=HEAD;hp=ebc953022e20178d35a5f001a1c87ff3a5cf9ad1;hpb=096d2b648330013d13d42cf3efe414f7860d6e77;p=ttf2png.git

diff --git a/ttf2png.c b/ttf2png.c
index ebc9530..76c2e0d 100644
--- a/ttf2png.c
+++ b/ttf2png.c
@@ -1,6 +1,6 @@
 /*
 ttf2png - True Type Font to PNG converter
-Copyright (c) 2004-2008 Mikko Rasa
+Copyright (c) 2004-2021 Mikko Rasa, Mikkosoft Productions
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -28,59 +28,95 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 typedef struct sImage
 {
 	unsigned w, h;
-	char     *data;
+	unsigned char *data;
+	unsigned border;
 } Image;
 
 typedef struct sGlyph
 {
+	unsigned index;
 	unsigned code;
-	Image    image;
+	Image image;
 	unsigned x, y;
-	int      offset_x;
-	int      offset_y;
-	int      advance;
+	int offset_x;
+	int offset_y;
+	int advance;
 } Glyph;
 
+typedef struct sKerning
+{
+	Glyph *left_glyph;
+	Glyph *right_glyph;
+	int distance;
+} Kerning;
+
 typedef struct sFont
 {
 	unsigned size;
-	int      ascent;
-	int      descent;
+	int ascent;
+	int descent;
 	unsigned n_glyphs;
-	Glyph    *glyphs;
-	Image    image;
+	Glyph *glyphs;
+	unsigned n_kerning;
+	Kerning *kerning;
+	Image image;
 } Font;
 
+typedef struct sRange
+{
+	unsigned first;
+	unsigned last;
+} Range;
+
+typedef unsigned char bool;
+
+void usage(void);
+int convert_numeric_option(char, int);
+void convert_code_point_range(char, Range *);
+int 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 usage();
-void init_font(Font *, FT_Face, unsigned, unsigned, int);
-void render_grid(Font *, unsigned, unsigned, unsigned, int);
-void render_packed(Font *);
+int init_image(Image *, size_t, size_t);
+int init_font(Font *, FT_Face, const Range *, unsigned, bool, unsigned, unsigned);
+int init_glyphs(Font *, FT_Face, const Range *, bool, unsigned, unsigned);
+int copy_bitmap(const FT_Bitmap *, Image *);
+unsigned sqrti(unsigned);
+unsigned find_distance_to_edge(const Image *, int, int, unsigned);
+int create_distance_field(const FT_Bitmap *, Image *, unsigned, unsigned);
+int render_grid(Font *, unsigned, unsigned, unsigned, bool);
+int render_packed(Font *, unsigned, unsigned);
 int save_defs(const char *, const Font *);
-int save_png(const char *, const Image *, char);
+int save_png(const char *, const Image *, bool, bool, bool);
 
 char verbose = 0;
 
 int main(int argc, char **argv)
 {
 	char *fn;
-	int  begin = 0;
-	int  end = 255;
-	int  size = 10;
-	int  cpl = 0;
-	int  cellw = 0;
-	int  cellh = 0;
-	char autohinter = 0;
-	char seq = 0;
-	char alpha = 0;
-	char invert = 0;
-	char pack = 0;
+	Range *ranges = NULL;
+	unsigned n_ranges = 0;
+	unsigned size = 10;
+	unsigned cpl = 0;
+	unsigned cellw = 0;
+	unsigned cellh = 0;
+	bool autohinter = 0;
+	bool seq = 0;
+	bool alpha = 0;
+	bool invert = 0;
+	bool pack = 0;
+	unsigned margin = 0;
+	unsigned padding = 1;
+	bool npot = 0;
+	unsigned distfield = 0;
+	unsigned border = 0;
 
 	FT_Library freetype;
-	FT_Face    face;
+	FT_Face face;
 
-	int  err;
-	int  i;
+	int err;
+	int i;
 
 	char *out_fn = "font.png";
 	char *def_fn = NULL;
@@ -93,63 +129,22 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	while((i = getopt(argc, argv, "r:s:l:c:o:atvh?ed:pi")) != -1)
+	while((i = getopt(argc, argv, "r:s:l:c:o:atvh?ed:pim:n:gf:b:")) != -1)
 	{
-		char *ptr;
-		int  temp;
 		switch(i)
 		{
 		case 'r':
-			if(!strcmp(optarg, "all"))
-			{
-				begin = 0;
-				end = 0x110000;
-			}
-			else
-			{
-				if(!isdigit(optarg[0]))
-					temp = -1;
-				else
-				{
-					temp = strtol(optarg, &ptr, 0);
-					if(ptr[0]!=',' || !isdigit(ptr[1]))
-						temp = -1;
-				}
-				if(temp<0)
-				{
-					printf("Not a valid range: %s\n", optarg);
-					exit(1);
-				}
-				else
-				{
-					begin = temp;
-					end = strtol(ptr+1, NULL, 0);
-				}
-			}
+			ranges = (Range *)realloc(ranges, (++n_ranges)*sizeof(Range));
+			convert_code_point_range('r', &ranges[n_ranges-1]);
 			break;
 		case 's':
-			size = strtol(optarg, NULL, 0);
+			size = convert_numeric_option('s', 1);
 			break;
 		case 'l':
-			cpl = strtol(optarg, NULL, 0);
+			cpl = convert_numeric_option('l', 1);
 			break;
 		case 'c':
-			if(!strcmp(optarg, "auto"))
-			{
-				cellw = 0;
-				cellh = 0;
-			}
-			else if(!strcmp(optarg, "autorect"))
-			{
-				cellw = 0;
-				cellh = 1;
-			}
-			else
-			{
-				cellw = strtol(optarg, &ptr, 0);
-				if(ptr[0]=='x' && isdigit(ptr[1]))
-					cellh = strtol(ptr+1, NULL, 0);
-			}
+			convert_size('c', &cellw, &cellh);
 			break;
 		case 'o':
 			out_fn = optarg;
@@ -179,6 +174,21 @@ int main(int argc, char **argv)
 		case 'i':
 			invert = 1;
 			break;
+		case 'm':
+			margin = convert_numeric_option('m', 0);
+			break;
+		case 'n':
+			padding = convert_numeric_option('n', 0);
+			break;
+		case 'g':
+			npot = 1;
+			break;
+		case 'f':
+			distfield = convert_numeric_option('f', 1);
+			break;
+		case 'b':
+			border = convert_numeric_option('b', 1);
+			break;
 		}
 	}
 	if(!strcmp(out_fn, "-"))
@@ -215,6 +225,14 @@ int main(int argc, char **argv)
 		printf("Glyphs:    %ld\n", face->num_glyphs);
 	}
 
+	font.size = size;
+	if(distfield)
+	{
+		if(!border)
+			border = sqrti(font.size);
+		size *= distfield;
+	}
+
 	err = FT_Set_Pixel_Sizes(face, 0, size);
 	if(err)
 	{
@@ -222,25 +240,46 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	font.size = size;
-	init_font(&font, face, begin, end, autohinter);
-	if(pack)
-		render_packed(&font);
+	if(!n_ranges)
+	{
+		ranges = malloc(sizeof(Range));
+		ranges[0].first = 0;
+		ranges[0].last = 255;
+		n_ranges = 1;
+	}
 	else
-		render_grid(&font, cellw, cellh, cpl, seq);
-	if(invert)
+		sort_and_compact_ranges(ranges, &n_ranges);
+
+	err = init_font(&font, face, ranges, n_ranges, autohinter, distfield, border);
+	if(err)
+		return 1;
+
+	if(!font.n_glyphs)
 	{
-		for(i=0; i<font.image.w*font.image.h; ++i)
-			font.image.data[i] = 255-font.image.data[i];
+		fprintf(stderr, "No glyphs found in the requested range\n");
+		return 1;
 	}
-	save_png(out_fn, &font.image, alpha);
+
+	if(pack)
+		err = render_packed(&font, margin, padding);
+	else
+		err = render_grid(&font, cellw, cellh, cpl, seq);
+	if(err)
+		return 1;
+
+	err = save_png(out_fn, &font.image, (alpha && !distfield), (invert || distfield), npot);
+	if(err)
+		return 1;
+
 	if(def_fn)
 		save_defs(def_fn, &font);
 
-	for(i=0; i<font.n_glyphs; ++i)
+	for(i=0; (unsigned)i<font.n_glyphs; ++i)
 		free(font.glyphs[i].image.data);
 	free(font.glyphs);
+	free(font.kerning);
 	free(font.image.data);
+	free(ranges);
 
 	FT_Done_Face(face);
 	FT_Done_FreeType(freetype);
@@ -248,6 +287,196 @@ int main(int argc, char **argv)
 	return 0;
 }
 
+void usage(void)
+{
+	printf("ttf2png 2.0 - True Type Font to PNG converter\n"
+		"Copyright (c) 2004-2021  Mikko Rasa, Mikkosoft Productions\n"
+		"Distributed under the GNU General Public License\n\n");
+
+	printf("Usage: ttf2png [options] <TTF file>\n\n");
+
+	printf("Accepted options (default values in [brackets])\n"
+		"  -r  Range of code points to convert [0,255]\n"
+		"  -s  Font size to use, in pixels [10]\n"
+		"  -l  Number of glyphs to put in one line [auto]\n"
+		"  -c  Glyph cell size, in pixels (grid mode only) [auto]\n"
+		"  -o  Output file name (or - for stdout) [font.png]\n");
+	printf("  -a  Force autohinter\n"
+		"  -t  Render glyphs to alpha channel\n"
+		"  -i  Invert colors of the glyphs\n"
+		"  -v  Increase the level of verbosity\n"
+		"  -e  Use cells in sequence, without gaps (grid mode only)\n"
+		"  -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"
+		"  -g  Allow non-power-of-two result\n");
+	printf("  -f  Create a distance field texture\n"
+		"  -b  Specify distance field border zone width\n"
+		"  -d  File name for writing glyph definitions\n"
+		"  -h  Print this message\n");
+}
+
+int convert_numeric_option(char opt, int min_value)
+{
+	int value;
+	char *ptr;
+
+	value = strtol(optarg, &ptr, 0);
+	if(value<min_value || *ptr)
+	{
+		printf("Invalid option argument in -%c %s\n", opt, optarg);
+		exit(1);
+	}
+
+	return value;
+}
+
+void convert_code_point_range(char opt, Range *range)
+{
+	int value;
+	char *ptr;
+
+	if(!strcmp(optarg, "all"))
+	{
+		range->first = 0;
+		range->last = 0x10FFFF;
+		return;
+	}
+
+	value = str_to_code_point(optarg, &ptr);
+	if(value>=0 && *ptr==',')
+	{
+		range->first = value;
+		value = str_to_code_point(ptr+1, &ptr);
+		if(value>=(int)range->first && !*ptr)
+		{
+			range->last = value;
+			return;
+		}
+	}
+
+	printf("Invalid option argument in -%c %s\n", opt, optarg);
+	exit(1);
+}
+
+int str_to_code_point(const char *nptr, char **endptr)
+{
+	if(nptr[0]=='U' && nptr[1]=='+')
+		return strtoul(nptr+2, endptr, 16);
+	else if(nptr[0]&0x80)
+	{
+		unsigned bytes;
+		unsigned code;
+		unsigned i;
+
+		if(endptr)
+			*endptr = (char *)nptr;
+
+		for(bytes=1; (bytes<4 && (nptr[0]&(0x80>>bytes))); ++bytes)
+			if((nptr[bytes]&0xC0)!=0x80)
+				return -1;
+		if(bytes<2)
+			return -1;
+
+		code = nptr[0]&(0x3F>>bytes);
+		for(i=1; i<bytes; ++i)
+			code = (code<<6)|(nptr[i]&0x3F);
+
+		if(endptr)
+			*endptr = (char *)nptr+bytes;
+
+		return code;
+	}
+	else if(isdigit(nptr[0]))
+		return strtoul(nptr, endptr, 0);
+	else
+	{
+		if(endptr)
+			*endptr = (char *)nptr+1;
+		return *nptr;
+	}
+}
+
+void convert_size(char opt, unsigned *width, unsigned *height)
+{
+	int value;
+	char *ptr;
+
+	if(!strcmp(optarg, "auto"))
+	{
+		*width = 0;
+		*height = 0;
+		return;
+	}
+	else if(!strcmp(optarg, "autorect"))
+	{
+		*width = 0;
+		*height = 1;
+		return;
+	}
+
+	value = strtol(optarg, &ptr, 0);
+	if(value>0)
+	{
+		*width = value;
+		if(*ptr=='x')
+		{
+			value = strtol(ptr+1, &ptr, 0);
+			if(value>0 && !*ptr)
+			{
+				*height = value;
+				return;
+			}
+		}
+		else if(!*ptr)
+		{
+			*height = *width;
+			return;
+		}
+	}
+
+	printf("Invalid option argument in -%c %s\n", opt, optarg);
+	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;
@@ -260,35 +489,43 @@ unsigned round_to_pot(unsigned n)
 	return n+1;
 }
 
-void usage()
+int init_image(Image *image, size_t w, size_t h)
 {
-	printf("ttf2png - True Type Font to PNG converter\n"
-		"Copyright (c) 2004-2008  Mikko Rasa, Mikkosoft Productions\n"
-		"Distributed under the GNU General Public License\n\n"
-		"Usage: ttf2png [options] <TTF file>\n\n"
-		"Accepted options (default values in [brackets])\n"
-		"  -r  Range of characters to convert in the format low,high [0,255]\n"
-		"  -s  Font size to use, in pixels [10]\n"
-		"  -l  Number of characters to put in one line [auto]\n"
-		"  -c  Character cell size, in pixels [auto]\n"
-		"  -o  Output file name (or - for stdout) [font.png]\n"
-		"  -a  Force autohinter\n"
-		"  -t  Render font to alpha channel\n"
-		"  -i  Invert colors of the glyphs\n"
-		"  -v  Increase the level of verbosity\n"
-		"  -e  Use cells in sequence, rather than by code\n"
-		"  -p  Pack the glyphs tightly instead of in a grid\n"
-		"  -d  Write a definition to the given file\n"
-		"  -h  Print this message\n");
+	size_t s;
+
+	image->w = w;
+	image->h = h;
+	image->data = NULL;
+	image->border = 0;
+
+	if(!image->w || !image->h)
+		return 0;
+
+	s = w*h;
+	if(s/h!=w)
+	{
+		fprintf(stderr, "Cannot allocate memory for a %dx%d image\n", image->w, image->h);
+		return -1;
+	}
+
+	image->data = malloc(s);
+	if(!image->data)
+	{
+		fprintf(stderr, "Cannot allocate memory for a %dx%d image\n", image->w, image->h);
+		return -1;
+	}
+
+	return 0;
 }
 
-void init_font(Font *font, FT_Face face, unsigned first, unsigned last, int autohinter)
+int init_font(Font *font, FT_Face face, const Range *ranges, unsigned n_ranges, bool autohinter, unsigned distfield, unsigned border)
 {
-	unsigned i;
+	unsigned i, j;
 	unsigned size = 0;
+	int scale = (distfield>0 ? distfield : 1);
 
-	font->ascent = (face->size->metrics.ascender+63)>>6;
-	font->descent = (face->size->metrics.descender+63)>>6;
+	font->ascent = (face->size->metrics.ascender/scale+63)/64;
+	font->descent = (face->size->metrics.descender/scale-63)/64;
 
 	if(verbose>=1)
 	{
@@ -298,13 +535,58 @@ void init_font(Font *font, FT_Face face, unsigned first, unsigned last, int auto
 
 	font->n_glyphs = 0;
 	font->glyphs = NULL;
-	for(i=first; i<=last; ++i)
+	for(i=0; i<n_ranges; ++i)
+		if(init_glyphs(font, face, &ranges[i], autohinter, distfield, border))
+			return -1;
+
+	if(verbose>=1)
+		printf("Loaded %u glyphs\n", font->n_glyphs);
+
+	font->n_kerning = 0;
+	font->kerning = NULL;
+	for(i=0; i<font->n_glyphs; ++i) for(j=0; j<font->n_glyphs; ++j)
+		if(j!=i)
+		{
+			FT_Vector kerning;
+			FT_Get_Kerning(face, font->glyphs[i].index, font->glyphs[j].index, FT_KERNING_DEFAULT, &kerning);
+
+			/* FreeType documentation says that vertical kerning is practically
+			never used, so we ignore it. */
+			if(kerning.x)
+			{
+				Kerning *kern;
+
+				if(font->n_kerning>=size)
+				{
+					size += 16;
+					font->kerning = (Kerning *)realloc(font->kerning, size*sizeof(Kerning));
+				}
+
+				kern = &font->kerning[font->n_kerning++];
+				kern->left_glyph = &font->glyphs[i];
+				kern->right_glyph = &font->glyphs[j];
+				kern->distance = (kerning.x/scale+32)/64;
+			}
+		}
+
+	if(verbose>=1)
+		printf("Loaded %d kerning pairs\n", font->n_kerning);
+
+	return 0;
+}
+
+int init_glyphs(Font *font, FT_Face face, const Range *range, bool autohinter, unsigned distfield, unsigned border)
+{
+	unsigned i, j;
+	unsigned size = font->n_glyphs;
+	int scale = (distfield>0 ? distfield : 1);
+
+	for(i=range->first; i<=range->last; ++i)
 	{
-		unsigned  n;
+		unsigned n;
 		FT_Bitmap *bmp = &face->glyph->bitmap;
-		int       x, y;
-		int       flags = 0;
-		Glyph     *glyph;
+		int flags = 0;
+		Glyph *glyph;
 
 		n = FT_Get_Char_Index(face, i);
 		if(!n)
@@ -313,14 +595,32 @@ void init_font(Font *font, FT_Face face, unsigned first, unsigned last, int auto
 		if(autohinter)
 			flags |= FT_LOAD_FORCE_AUTOHINT;
 		FT_Load_Glyph(face, n, flags);
-		FT_Render_Glyph(face->glyph, FT_RENDER_MODE_NORMAL);
+		FT_Render_Glyph(face->glyph, (distfield ? FT_RENDER_MODE_MONO : FT_RENDER_MODE_NORMAL));
 
 		if(verbose>=2)
-			printf("  Char %u: glyph %u, size %dx%d\n", i, n, bmp->width, bmp->rows);
+		{
+			printf("  Code point U+%04X", i);
+			if(i>=0x20 && i<0x7F)
+				printf(" (%c)", i);
+			else if(i>=0xA0 && i<=0x10FFFF)
+			{
+				char utf8[5];
+				unsigned bytes;
 
-		if(bmp->pixel_mode!=FT_PIXEL_MODE_GRAY)
+				for(bytes=2; i>>(1+bytes*5); ++bytes) ;
+				for(j=0; j<bytes; ++j)
+					utf8[j] = 0x80 | ((i>>((bytes-j-1)*6))&0x3F);
+				utf8[0] |= 0xF0<<(4-bytes);
+				utf8[j] = 0;
+
+				printf(" (%s)", utf8);
+			}
+			printf(": glyph %u, size %dx%d\n", n, bmp->width/scale, bmp->rows/scale);
+		}
+
+		if(bmp->pixel_mode!=FT_PIXEL_MODE_GRAY && bmp->pixel_mode!=FT_PIXEL_MODE_MONO)
 		{
-			fprintf(stderr, "Warning: Glyph %u skipped, not grayscale\n", n);
+			fprintf(stderr, "Warning: Glyph %u skipped, incompatible pixel mode\n", n);
 			continue;
 		}
 
@@ -331,45 +631,152 @@ void init_font(Font *font, FT_Face face, unsigned first, unsigned last, int auto
 		}
 
 		glyph = &font->glyphs[font->n_glyphs++];
+		glyph->index = n;
 		glyph->code = i;
-		glyph->image.w = bmp->width;
-		glyph->image.h = bmp->rows;
-		glyph->image.data = (char *)malloc(bmp->width*bmp->rows);
-		glyph->offset_x = face->glyph->bitmap_left;
-		glyph->offset_y = face->glyph->bitmap_top-bmp->rows;
-		glyph->advance = (int)(face->glyph->advance.x+32)/64;
-
-		if(bmp->pitch<0)
+		glyph->offset_x = (int)(face->glyph->bitmap_left+scale/2)/scale;
+		glyph->offset_y = (int)(face->glyph->bitmap_top-bmp->rows+scale/2)/scale;
+		glyph->advance = (int)(face->glyph->advance.x/scale+32)/64;
+
+		/* Copy the glyph image since FreeType uses a global buffer, which would
+		be overwritten by the next glyph.  Negative pitch means the scanlines
+		start from the bottom. */
+		if(distfield)
 		{
-			for(y=0; y<bmp->rows; ++y) for(x=0; x<bmp->width; ++x)
-				glyph->image.data[x+(glyph->image.h-1-y)*glyph->image.w] = bmp->buffer[x-y*bmp->pitch];
+			glyph->offset_x -= border;
+			glyph->offset_y -= border;
+			create_distance_field(bmp, &glyph->image, distfield, border);
 		}
 		else
 		{
-			for(y=0; y<bmp->rows; ++y) for(x=0; x<bmp->width; ++x)
-				glyph->image.data[x+y*glyph->image.w] = bmp->buffer[x+y*bmp->pitch];
+			if(copy_bitmap(bmp, &glyph->image))
+				return -1;
 		}
 	}
 
-	if(verbose>=1)
-		printf("Loaded %u glyphs\n", font->n_glyphs);
+	return 0;
 }
 
-void render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, int seq)
+int copy_bitmap(const FT_Bitmap *bmp, Image *image)
 {
-	unsigned i;
-	int      top = 0, bot = 0;
-	unsigned first, last;
-	unsigned maxw = 0, maxh = 0;
+	unsigned x, y;
+	unsigned char *src;
+	unsigned char *dst;
 
-	for(i=1;; i<<=1)
+	if(init_image(image, bmp->width, bmp->rows))
+		return -1;
+	if(!image->w || !image->h)
+		return 0;
+
+	if(bmp->pitch<0)
+		src = bmp->buffer+(bmp->rows-1)*-bmp->pitch;
+	else
+		src = bmp->buffer;
+	dst = image->data;
+
+	for(y=0; y<bmp->rows; ++y)
 	{
-		first = font->glyphs[0].code&~(i-1);
-		last = first+i-1;
-		if(last>=font->glyphs[font->n_glyphs-1].code)
-			break;
+		if(bmp->pixel_mode==FT_PIXEL_MODE_MONO)
+		{
+			for(x=0; x<bmp->width; ++x)
+				dst[x] = ((src[x/8]&(0x80>>(x%8))) ? 0xFF : 0x00);
+		}
+		else
+		{
+			for(x=0; x<bmp->width; ++x)
+				dst[x] = src[x];
+		}
+
+		src += bmp->pitch;
+		dst += image->w;
 	}
 
+	return 0;
+}
+
+unsigned sqrti(unsigned num)
+{
+	unsigned result = (num>0xFFFF ? 0xFFFF : 0x100);
+	while(result && result*result>=result+num)
+		result -= (result*result+result-num)/(result*2);
+
+	return result;
+}
+
+unsigned find_distance_to_edge(const Image *image, int origin_x, int origin_y, unsigned range)
+{
+	unsigned i, j;
+	int x, y;
+	unsigned char origin_pixel = 0;
+	unsigned closest = range*range;
+
+	if(origin_x>=0 && (unsigned)origin_x<image->w && origin_y>=0 && (unsigned)origin_y<image->h)
+		origin_pixel = image->data[origin_x+origin_y*image->w];
+
+	x = origin_x-1;
+	y = origin_y-1;
+	for(i=1; (i<range && i*i<=closest); ++i, --x, --y) for(j=0; j<4; ++j)
+	{
+		unsigned k;
+		int dx = (j==0 ? 1 : j==2 ? -1 : 0);
+		int dy = (j==1 ? 1 : j==3 ? -1 : 0);
+
+		for(k=0; k<i*2; ++k, x+=dx, y+=dy)
+		{
+			unsigned char pixel = 0;
+			if(x>=0 && (unsigned)x<image->w && y>=0 && (unsigned)y<image->h)
+				pixel = image->data[x+y*image->w];
+				
+			if((pixel^origin_pixel)&0x80)
+			{
+				unsigned d = 2*i*i + k*k - 2*k*i;
+				if(d<closest)
+					closest = d;
+			}
+		}
+	}
+
+	return sqrti(closest*0x3F01)/range;
+}
+
+int create_distance_field(const FT_Bitmap *bmp, Image *image, unsigned scale, unsigned margin)
+{
+	unsigned x, y;
+	Image base_image;
+
+	if(init_image(image, (bmp->width+scale-1)/scale+2*margin, (bmp->rows+scale-1)/scale+2*margin))
+		return -1;
+	if(!image->w || !image->h)
+		return 0;
+
+	if(copy_bitmap(bmp, &base_image))
+		return -1;
+
+	image->border = margin;
+	for(y=0; y<image->h; ++y) for(x=0; x<image->w; ++x)
+	{
+		int bx = (x-margin)*scale+scale/2;
+		int by = (y-margin)*scale+scale/2;
+		unsigned char pixel = find_distance_to_edge(&base_image, bx, by, margin*scale);
+		if(bx>=0 && (unsigned)bx<base_image.w && by>=0 && (unsigned)by<base_image.h)
+			pixel |= base_image.data[bx+by*base_image.w]&0x80;
+		if(!(pixel&0x80))
+			pixel = 0x80-pixel;
+		image->data[x+y*image->w] = pixel;
+	}
+
+	free(base_image.data);
+
+	return 0;
+}
+
+int render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, bool seq)
+{
+	unsigned i;
+	int top = 0, bot = 0;
+	unsigned first, n_cells;
+	unsigned maxw = 0, maxh = 0;
+
+	/* Find extremes of the glyph images. */
 	for(i=0; i<font->n_glyphs; ++i)
 	{
 		int y;
@@ -387,6 +794,7 @@ void render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, int s
 
 	if(cellw==0)
 	{
+		/* Establish a large enough cell to hold all glyphs in the range. */
 		int square = (cellh==cellw);
 		cellw = maxw;
 		cellh = top-bot;
@@ -404,35 +812,39 @@ void render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, int s
 		printf("Max size:  %u x %u\n", maxw, maxh);
 		printf("Y range:   [%d %d]\n", bot, top);
 		printf("Cell size: %u x %u\n", cellw, cellh);
-		if(maxw>cellw || top-bot>cellh)
+		if(maxw>cellw || (unsigned)(top-bot)>cellh)
 			fprintf(stderr, "Warning: character size exceeds cell size\n");
 	}
 
 	if(cpl==0)
 	{
-		unsigned count = (seq ? font->n_glyphs : last-first+1);
+		/* Determine number of characters per line, trying to fit all the glyphs
+		in a square image. */
 		for(i=1;; i<<=1)
 		{
 			cpl = i/cellw;
-			if(cpl>0 && (count+cpl-1)/cpl*cellh<=cpl*cellw)
+			if(cpl>0 && font->n_glyphs/cpl*cellh<=cpl*cellw)
 				break;
 		}
 	}
 
-	font->image.w = round_to_pot(cpl*cellw);
-	if(seq && font->n_glyphs<last-first+1)
-		font->image.h = (font->n_glyphs+cpl-1)/cpl*cellh;
+	first = font->glyphs[0].code;
+	if(seq)
+		n_cells = font->n_glyphs;
 	else
-		font->image.h = (last-first+cpl)/cpl*cellh;
-	font->image.h = round_to_pot(font->image.h);
+	{
+		first -= first%cpl;
+		n_cells = font->glyphs[font->n_glyphs-1].code+1-first;
+	}
 
-	font->image.data = (char *)malloc(font->image.w*font->image.h);
-	memset(font->image.data, 255, font->image.w*font->image.h);
+	if(init_image(&font->image, cpl*cellw, (n_cells+cpl-1)/cpl*cellh))
+		return -1;
+	memset(font->image.data, 0, font->image.w*font->image.h);
 
 	for(i=0; i<font->n_glyphs; ++i)
 	{
-		Glyph    *glyph;
-		int      ci, cx, cy;
+		Glyph *glyph;
+		unsigned ci, cx, cy;
 		unsigned x, y;
 
 		glyph = &font->glyphs[i];
@@ -454,64 +866,86 @@ void render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, int s
 
 		for(y=0; y<glyph->image.h; ++y) for(x=0; x<glyph->image.w; ++x)
 		{
-			if(cx+x<0 || cx+x>=font->image.w || cy+y<0 || cy+y>=font->image.h)
+			if(cx+x>=font->image.w || cy+y>=font->image.h)
 				continue;
-			font->image.data[cx+x+(cy+y)*font->image.w] = 255-glyph->image.data[x+y*glyph->image.w];
+			font->image.data[cx+x+(cy+y)*font->image.w] = glyph->image.data[x+y*glyph->image.w];
 		}
 	}
+
+	return 0;
 }
 
-void render_packed(Font *font)
+int render_packed(Font *font, unsigned margin, unsigned padding)
 {
 	unsigned i;
-	unsigned area = 0;
-	char     *used_glyphs;
-	char     *used_pixels;
-	unsigned cx = 0, cy;
+	size_t area = 0;
+	bool *used_glyphs;
+	unsigned *used_pixels;
+	unsigned cx = margin, cy;
 	unsigned used_h = 0;
 
+	/* Compute the total area occupied by glyphs and padding. */
 	for(i=0; i<font->n_glyphs; ++i)
-		area += (font->glyphs[i].image.w+1)*(font->glyphs[i].image.h+1);
+	{
+		size_t a = area+(font->glyphs[i].image.w+padding)*(font->glyphs[i].image.h+padding);
+		if(a<area)
+		{
+			fprintf(stderr, "Overflow in counting total glyph area\n");
+			return -1;
+		}
+		area = a;
+	}
 
+	/* Find an image size that's approximately square. */
 	for(font->image.w=1;; font->image.w<<=1)
 	{
-		font->image.h = (area*5/4)/font->image.w;
+		if(font->image.w<=margin*2)
+			continue;
+		font->image.h = area/(font->image.w-margin*2)+margin*2;
 		if(font->image.h<=font->image.w)
 			break;
 	}
-	font->image.h = round_to_pot(font->image.h);
 
-	font->image.data = (char *)malloc(font->image.w*font->image.h);
-	memset(font->image.data, 255, font->image.w*font->image.h);
-	used_pixels = (char *)malloc(font->image.w*font->image.h);
-	memset(used_pixels, 0, font->image.w*font->image.h);
-	used_glyphs = (char *)malloc(font->n_glyphs);
+	/* Add some extra space to accommodate packing imperfections. */
+	font->image.h = font->image.h*3/2;
+
+	/* 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
+	the top, it's enough to track the number of used pixels at the top of each
+	column. */
+	if(init_image(&font->image, font->image.w, font->image.h))
+		return -1;
+	memset(font->image.data, 0, font->image.w*font->image.h);
+	used_pixels = (unsigned *)malloc(font->image.w*sizeof(unsigned));
+	memset(used_pixels, 0, font->image.w*sizeof(unsigned));
+	used_glyphs = (bool *)malloc(font->n_glyphs);
 	memset(used_glyphs, 0, font->n_glyphs);
 
-	for(cy=0; cy<font->image.h;)
+	for(cy=margin; cy+margin<font->image.h;)
 	{
 		unsigned w;
 		unsigned x, y;
-		Glyph    *glyph = NULL;
+		Glyph *glyph = NULL;
 		unsigned best_score = 0;
 		unsigned target_h = 0;
 
-		for(; (cx<font->image.w && used_pixels[cx+cy*font->image.w]); ++cx) ;
-		if(cx>=font->image.w)
+		/* Find the leftmost free pixel on this row.  Also record the lowest
+		extent of glyphs to the left of the free position. */
+		for(; (cx+margin<font->image.w && used_pixels[cx]>cy); ++cx)
+			if(used_pixels[cx]-cy-padding>target_h)
+				target_h = used_pixels[cx]-cy-padding;
+
+		if(cx+margin>=font->image.w)
 		{
-			cx = 0;
+			cx = margin;
 			++cy;
 			continue;
 		}
-		for(w=0; (cx+w<font->image.w && !used_pixels[cx+w+cy*font->image.w]); ++w) ;
 
-		for(x=0; x<cx; ++x)
-		{
-			for(y=0; (cy+y+1<font->image.h && used_pixels[cx-x+(cy+y+1)*font->image.w]); ++y) ;
-			if(y>target_h)
-				target_h = y;
-		}
+		/* Count the free pixel at this position. */
+		for(w=0; (cx+w+margin<font->image.w && used_pixels[cx+w]<=cy); ++w) ;
 
+		/* Find a suitable glyph to put here. */
 		for(i=0; i<font->n_glyphs; ++i)
 		{
 			Glyph *g;
@@ -521,7 +955,10 @@ void render_packed(Font *font)
 			{
 				unsigned score;
 
-				score = g->image.h+1;
+				/* Prefer glyphs that would reach exactly as low as the ones left
+				of here.  This aims to create a straight edge at the bottom for
+				lining up further glyphs. */
+				score = g->image.h+padding;
 				if(g->image.h==target_h)
 					score *= g->image.w;
 				else
@@ -547,27 +984,35 @@ void render_packed(Font *font)
 
 		for(y=0; y<glyph->image.h; ++y) for(x=0; x<glyph->image.w; ++x)
 		{
-			if(cx+x<0 || cx+x>=font->image.w || cy+y<0 || cy+y>=font->image.h)
+			if(cx+x>=font->image.w || cy+y>=font->image.h)
 				continue;
-			font->image.data[cx+x+(cy+y)*font->image.w] = 255-glyph->image.data[x+y*glyph->image.w];
+			font->image.data[cx+x+(cy+y)*font->image.w] = glyph->image.data[x+y*glyph->image.w];
 		}
-		for(y=0; y<glyph->image.h+2; ++y) for(x=0; x<glyph->image.w+2; ++x)
+		for(x=0; x<glyph->image.w+2*padding; ++x)
 		{
-			if(cx+x<1 || cx+x>font->image.w || cy+y<1 || cy+y>font->image.h)
+			if(cx+x<padding || cx+x>=font->image.w+padding)
 				continue;
-			used_pixels[cx+x-1+(cy+y-1)*font->image.w] = 1;
+			if(used_pixels[cx+x-padding]<cy+glyph->image.h+padding)
+				used_pixels[cx+x-padding] = cy+glyph->image.h+padding;
 		}
 
-		if(cy+glyph->image.h>used_h)
-			used_h = cy+glyph->image.h;
+		if(cy+glyph->image.h+margin>used_h)
+			used_h = cy+glyph->image.h+margin;
 	}
 
-	font->image.h = round_to_pot(used_h);
+	/* Trim the image to the actually used size, in case the original estimate
+	was too pessimistic. */
+	font->image.h = used_h;
+
+	free(used_glyphs);
+	free(used_pixels);
+
+	return 0;
 }
 
 int save_defs(const char *fn, const Font *font)
 {
-	FILE     *out;
+	FILE *out;
 	unsigned i;
 
 	out = fopen(fn, "w");
@@ -577,11 +1022,41 @@ int save_defs(const char *fn, const Font *font)
 		return -1;
 	}
 
-	fprintf(out, "%d %d %d %d %d\n", font->image.w, font->image.h, font->size, font->ascent, font->descent);
+	fprintf(out, "# Image/font info:\n");
+	fprintf(out, "# width height size ascent descent\n");
+	fprintf(out, "font %d %d %d %d %d\n", font->image.w, font->image.h, font->size, font->ascent, font->descent);
+
+	fprintf(out, "\n# Code point mapping:\n");
+	fprintf(out, "# code index\n");
+	for(i=0; i<font->n_glyphs; ++i)
+	{
+		const Glyph *g = &font->glyphs[i];
+		fprintf(out, "code %u %u\n", g->code, g->index);
+	}
+
+	fprintf(out, "\n# Metrics info:\n");
+	fprintf(out, "# index width height offset_x offset_y advance\n");
+	for(i=0; i<font->n_glyphs; ++i)
+	{
+		const Glyph *g = &font->glyphs[i];
+		int b = g->image.border;
+		fprintf(out, "metrics %u %u %u %d %d %d\n", g->index, g->image.w-2*b, g->image.h-2*b, g->offset_x+b, g->offset_y+b, g->advance);
+	}
+
+	fprintf(out, "\n# Glyph info:\n");
+	fprintf(out, "# index x y width height border\n");
 	for(i=0; i<font->n_glyphs; ++i)
 	{
 		const Glyph *g = &font->glyphs[i];
-		fprintf(out, "%u %u %u %u %u %d %d %d\n", g->code, g->x, g->y, g->image.w, g->image.h, g->offset_x, g->offset_y, g->advance);
+		fprintf(out, "glyph %u %u %u %u %u %u\n", g->index, g->x, g->y, g->image.w, g->image.h, g->image.border);
+	}
+
+	fprintf(out, "\n# Kerning info:\n");
+	fprintf(out, "# left right distance\n");
+	for(i=0; i<font->n_kerning; ++i)
+	{
+		const Kerning *k = &font->kerning[i];
+		fprintf(out, "kern %u %u %d\n", k->left_glyph->index, k->right_glyph->index, k->distance);
 	}
 
 	fclose(out);
@@ -589,15 +1064,17 @@ int save_defs(const char *fn, const Font *font)
 	return 0;
 }
 
-int save_png(const char *fn, const Image *image, char alpha)
+int save_png(const char *fn, const Image *image, bool alpha, bool invert, bool npot)
 {
-	FILE       *out;
+	FILE *out;
 	png_struct *pngs;
-	png_info   *pngi;
-	png_byte   *rows[image->h];
-	int        i;
-	png_byte   *data2;
-	int        color;
+	png_info *pngi;
+	unsigned w, h;
+	png_byte *row;
+	unsigned x, y;
+	int color;
+	unsigned flip_bits = (invert==alpha ? 0xFF : 0x00);
+	unsigned char *src = image->data;
 
 	if(!strcmp(fn, "-"))
 		out = stdout;
@@ -625,34 +1102,53 @@ int save_png(const char *fn, const Image *image, char alpha)
 		return -1;
 	}
 
+	w = (npot ? image->w : round_to_pot(image->w));
+	h = (npot ? image->h : round_to_pot(image->h));
+	color = (alpha ? PNG_COLOR_TYPE_GRAY_ALPHA : PNG_COLOR_TYPE_GRAY);
+	png_set_IHDR(pngs, pngi, w, h, 8, color, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
 	png_init_io(pngs, out);
+	png_write_info(pngs, pngi);
+	row = (png_byte *)malloc(w*(1+alpha));
 	if(alpha)
 	{
-		data2 = (png_byte *)malloc(image->w*image->h*2);
-		for(i=0; i<image->w*image->h; ++i)
+		for(x=0; x<w; ++x)
 		{
-			data2[i*2] = 255;
-			data2[i*2+1] = 255-image->data[i];
+			row[x*2] = 255;
+			row[x*2+1] = flip_bits;
 		}
-		for(i=0; i<image->h; ++i)
-			rows[i] = (png_byte *)(data2+i*image->w*2);
-		color = PNG_COLOR_TYPE_GRAY_ALPHA;
+		for(y=0; y<image->h; ++y)
+		{
+			for(x=0; x<image->w; ++x)
+				row[x*2+1] = *src++^flip_bits;
+			png_write_row(pngs, row);
+		}
+
+		for(x=0; x<w; ++x)
+			row[x*2+1] = 0;
 	}
 	else
 	{
-		for(i=0; i<image->h; ++i)
-			rows[i] = (png_byte *)(image->data+i*image->w);
-		color = PNG_COLOR_TYPE_GRAY;
+		memset(row+image->w, flip_bits, w-image->w);
+		for(y=0; y<image->h; ++y)
+		{
+			for(x=0; x<image->w; ++x)
+				row[x] = *src++^flip_bits;
+			png_write_row(pngs, row);
+		}
+
+		memset(row, flip_bits, w);
 	}
-	png_set_IHDR(pngs, pngi, image->w, image->h, 8, color, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
-	png_set_rows(pngs, pngi, rows);
-	png_write_png(pngs, pngi, PNG_TRANSFORM_IDENTITY, NULL);
+
+	for(; y<h; ++y)
+		png_write_row(pngs, row);
+
+	png_write_end(pngs, pngi);
 	png_destroy_write_struct(&pngs, &pngi);
-	if(alpha)
-		free(data2);
+	free(row);
 
 	if(verbose)
-		printf("Saved %dx%d PNG image to %s\n", image->w, image->h, fn);
+		printf("Saved %dx%d PNG image to %s\n", w, h, fn);
 
 	fclose(out);