X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=ttf2png.c;h=5e6e351328e30b78f0b641ec867cda66d8313351;hb=887d2514f9c7e57898cec5d598cd2a3bcd9ce757;hp=e890e33643084f7784c8d23e280555c425e8fec4;hpb=2bd053c9c2207a7c0afa2defee10568fde2e7c50;p=ttf2png.git

diff --git a/ttf2png.c b/ttf2png.c
index e890e33..5e6e351 100644
--- a/ttf2png.c
+++ b/ttf2png.c
@@ -78,9 +78,12 @@ 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);
-int init_glyphs(Font *, FT_Face, const Range *, bool);
+int init_font(Font *, FT_Face, const Range *, unsigned, bool, unsigned);
+int init_glyphs(Font *, FT_Face, const Range *, bool, 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, bool);
 int render_packed(Font *, unsigned, unsigned, bool);
 int save_defs(const char *, const Font *);
@@ -105,6 +108,7 @@ int main(int argc, char **argv)
 	unsigned margin = 0;
 	unsigned padding = 1;
 	bool npot = 0;
+	unsigned distfield = 0;
 
 	FT_Library freetype;
 	FT_Face face;
@@ -123,7 +127,7 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
-	while((i = getopt(argc, argv, "r:s:l:c:o:atvh?ed:pim:n:f")) != -1)
+	while((i = getopt(argc, argv, "r:s:l:c:o:atvh?ed:pim:n:gf:")) != -1)
 	{
 		switch(i)
 		{
@@ -174,9 +178,12 @@ int main(int argc, char **argv)
 		case 'n':
 			padding = convert_numeric_option('n', 0);
 			break;
-		case 'f':
+		case 'g':
 			npot = 1;
 			break;
+		case 'f':
+			distfield = convert_numeric_option('f', 1);
+			break;
 		}
 	}
 	if(!strcmp(out_fn, "-"))
@@ -213,7 +220,7 @@ int main(int argc, char **argv)
 		printf("Glyphs:    %ld\n", face->num_glyphs);
 	}
 
-	err = FT_Set_Pixel_Sizes(face, 0, size);
+	err = FT_Set_Pixel_Sizes(face, 0, (distfield ? size*distfield : size));
 	if(err)
 	{
 		fprintf(stderr, "Couldn't set size\n");
@@ -231,7 +238,7 @@ int main(int argc, char **argv)
 		sort_and_compact_ranges(ranges, &n_ranges);
 
 	font.size = size;
-	err = init_font(&font, face, ranges, n_ranges, autohinter);
+	err = init_font(&font, face, ranges, n_ranges, autohinter, distfield);
 	if(err)
 		return 1;
 
@@ -248,12 +255,12 @@ int main(int argc, char **argv)
 	if(err)
 		return 1;
 
-	if(invert)
+	if(invert || distfield)
 	{
 		for(i=0; (unsigned)i<font.image.w*font.image.h; ++i)
 			font.image.data[i] = 255-font.image.data[i];
 	}
-	err = save_png(out_fn, &font.image, alpha);
+	err = save_png(out_fn, &font.image, (alpha && !distfield));
 	if(err)
 		return 1;
 
@@ -295,7 +302,8 @@ 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"
+		"  -g  Allow non-power-of-two result\n"
+		"  -f  Create a distance field texture\n"
 		"  -d  File name for writing glyph definitions\n"
 		"  -h  Print this message\n");
 }
@@ -497,13 +505,14 @@ void *alloc_image_data(size_t a, size_t b)
 	return ptr;
 }
 
-int init_font(Font *font, FT_Face face, const Range *ranges, unsigned n_ranges, bool autohinter)
+int init_font(Font *font, FT_Face face, const Range *ranges, unsigned n_ranges, bool autohinter, unsigned distfield)
 {
 	unsigned i, j;
 	unsigned size = 0;
+	int scale = (distfield>0 ? distfield : 1);
 
-	font->ascent = (face->size->metrics.ascender+63)/64;
-	font->descent = (face->size->metrics.descender-63)/64;
+	font->ascent = (face->size->metrics.ascender/scale+63)/64;
+	font->descent = (face->size->metrics.descender/scale-63)/64;
 
 	if(verbose>=1)
 	{
@@ -514,7 +523,7 @@ int init_font(Font *font, FT_Face face, const Range *ranges, unsigned n_ranges,
 	font->n_glyphs = 0;
 	font->glyphs = NULL;
 	for(i=0; i<n_ranges; ++i)
-		if(init_glyphs(font, face, &ranges[i], autohinter))
+		if(init_glyphs(font, face, &ranges[i], autohinter, distfield))
 			return -1;
 
 	if(verbose>=1)
@@ -543,7 +552,7 @@ int init_font(Font *font, FT_Face face, const Range *ranges, unsigned n_ranges,
 				kern = &font->kerning[font->n_kerning++];
 				kern->left_code = font->glyphs[i].code;
 				kern->right_code = font->glyphs[j].code;
-				kern->distance = (kerning.x+32)/64;
+				kern->distance = (kerning.x/scale+32)/64;
 			}
 		}
 
@@ -553,10 +562,11 @@ int init_font(Font *font, FT_Face face, const Range *ranges, unsigned n_ranges,
 	return 0;
 }
 
-int init_glyphs(Font *font, FT_Face face, const Range *range, bool autohinter)
+int init_glyphs(Font *font, FT_Face face, const Range *range, bool autohinter, unsigned distfield)
 {
 	unsigned i, j;
 	unsigned size = font->n_glyphs;
+	int scale = (distfield>0 ? distfield : 1);
 
 	for(i=range->first; i<=range->last; ++i)
 	{
@@ -572,7 +582,7 @@ int init_glyphs(Font *font, FT_Face face, const Range *range, bool autohinter)
 		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)
 		{
@@ -592,7 +602,7 @@ int init_glyphs(Font *font, FT_Face face, const Range *range, bool autohinter)
 
 				printf(" (%s)", utf8);
 			}
-			printf(": glyph %u, size %dx%d\n", n, bmp->width, bmp->rows);
+			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)
@@ -610,15 +620,26 @@ int init_glyphs(Font *font, FT_Face face, const Range *range, bool autohinter)
 		glyph = &font->glyphs[font->n_glyphs++];
 		glyph->index = n;
 		glyph->code = i;
-		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;
+		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(copy_bitmap(bmp, &glyph->image))
-			return -1;
+		if(distfield)
+		{
+			unsigned margin = 3;
+
+			glyph->offset_x -= margin;
+			glyph->offset_y -= margin;
+			create_distance_field(bmp, &glyph->image, distfield, margin);
+		}
+		else
+		{
+			if(copy_bitmap(bmp, &glyph->image))
+				return -1;
+		}
 	}
 
 	return 0;
@@ -671,6 +692,100 @@ int copy_bitmap(const FT_Bitmap *bmp, Image *image)
 	return 0;
 }
 
+unsigned sqrti(unsigned num)
+{
+	unsigned result = num;
+	while(result*result>num)
+	{
+		unsigned diff = result*result-num;
+		if(diff<result)
+			break;
+
+		result -= (diff+result)/(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)*0x7F/range;
+}
+
+int create_distance_field(const FT_Bitmap *bmp, Image *image, unsigned scale, unsigned margin)
+{
+	unsigned x, y;
+	Image base_image;
+
+	if(!bmp->width || !bmp->rows)
+	{
+		image->w = 0;
+		image->h = 0;
+		image->data = NULL;
+		return 0;
+	}
+
+	if(copy_bitmap(bmp, &base_image))
+		return -1;
+
+	image->w = (base_image.w-1)/scale+2*margin+1;
+	image->h = (base_image.h-1)/scale+2*margin+1;
+	image->data = (unsigned char *)malloc(image->w*image->h);
+	if(!image->data)
+	{
+		fprintf(stderr, "Cannot allocate %d bytes of memory for glyph\n", image->w*image->h);
+		free(base_image.data);
+		return -1;
+	}
+
+	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, bool npot)
 {
 	unsigned i;
@@ -805,18 +920,18 @@ int render_packed(Font *font, unsigned margin, unsigned padding, bool npot)
 		area = a;
 	}
 
-	/* Find an image size that's no higher than wide, allowing for some
-	imperfections in the packing. */
+	/* Find an image size that's approximately square. */
 	for(font->image.w=1;; font->image.w<<=1)
 	{
 		if(font->image.w<=margin*2)
 			continue;
-		font->image.h = (area*5/4)/(font->image.w-margin*2)+margin*2;
+		font->image.h = area/(font->image.w-margin*2)+margin*2;
 		if(font->image.h<=font->image.w)
 			break;
 	}
-	if(!npot)
-		font->image.h = round_to_pot(font->image.h);
+
+	/* 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