Perform color inversion and npot rounding in save_png

diff --git a/ttf2png.c b/ttf2png.c
index 84455554eb5c403bbe1c4329fa71b2998af9a4c0..6543a8d8a009b2de12f898c6effcb964707012b1 100644 (file)
--- a/ttf2png.c
+++ b/ttf2png.c
@@ -84,10 +84,10 @@ 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 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;
 
@@ -260,18 +260,13 @@ int main(int argc, char **argv)
        }
 
        if(pack)
-               err = render_packed(&font, margin, padding, npot);
+               err = render_packed(&font, margin, padding);
        else
-               err = render_grid(&font, cellw, cellh, cpl, seq, npot);
+               err = render_grid(&font, cellw, cellh, cpl, seq);
        if(err)
                return 1;
 
-       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 && !distfield));
+       err = save_png(out_fn, &font.image, (alpha && !distfield), (invert || distfield), npot);
        if(err)
                return 1;
 
@@ -789,7 +784,7 @@ int create_distance_field(const FT_Bitmap *bmp, Image *image, unsigned scale, un
        return 0;
 }
 
-int render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, bool seq, bool npot)
+int render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, bool seq)
 {
        unsigned i;
        int top = 0, bot = 0;
@@ -854,19 +849,15 @@ int render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, bool s
        last = font->glyphs[font->n_glyphs-1].code;
 
        font->image.w = cpl*cellw;
-       if(!npot)
-               font->image.w = round_to_pot(font->image.w);
        if(seq)
                font->image.h = (font->n_glyphs+cpl-1)/cpl*cellh;
        else
                font->image.h = (last-first+cpl)/cpl*cellh;
-       if(!npot)
-               font->image.h = round_to_pot(font->image.h);
 
        font->image.data = (unsigned char *)alloc_image_data(font->image.w, font->image.h);
        if(!font->image.data)
                return -1;
-       memset(font->image.data, 255, font->image.w*font->image.h);
+       memset(font->image.data, 0, font->image.w*font->image.h);
 
        for(i=0; i<font->n_glyphs; ++i)
        {
@@ -895,14 +886,14 @@ int render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, bool s
                {
                        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;
 }
 
-int render_packed(Font *font, unsigned margin, unsigned padding, bool npot)
+int render_packed(Font *font, unsigned margin, unsigned padding)
 {
        unsigned i;
        size_t area = 0;
@@ -943,7 +934,7 @@ int render_packed(Font *font, unsigned margin, unsigned padding, bool npot)
        font->image.data = (unsigned char *)alloc_image_data(font->image.w, font->image.h);
        if(!font->image.data)
                return -1;
-       memset(font->image.data, 255, font->image.w*font->image.h);
+       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 = (char *)malloc(font->n_glyphs);
@@ -1014,7 +1005,7 @@ int render_packed(Font *font, unsigned margin, unsigned padding, bool npot)
                {
                        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(x=0; x<glyph->image.w+2*padding; ++x)
                {
@@ -1031,8 +1022,6 @@ int render_packed(Font *font, unsigned margin, unsigned padding, bool npot)
        /* Trim the image to the actually used size, in case the original estimate
        was too pessimistic. */
        font->image.h = used_h;
-       if(!npot)
-               font->image.h = round_to_pot(font->image.h);
 
        free(used_glyphs);
        free(used_pixels);
@@ -1075,15 +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;
        png_struct *pngs;
        png_info *pngi;
-       png_byte **rows;
-       unsigned i;
-       png_byte *data2 = NULL;
+       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;
@@ -1111,38 +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);
-       rows = (png_byte **)malloc(image->h*sizeof(png_byte *));
+       png_write_info(pngs, pngi);
+       row = (png_byte *)malloc(w*(1+alpha));
        if(alpha)
        {
-               data2 = (png_byte *)alloc_image_data(image->w*2, image->h);
-               if(!data2)
-                       return -1;
-               for(i=0; i<image->w*image->h; ++i)
+               for(x=0; x<w; ++x)
+               {
+                       row[x*2] = 255;
+                       row[x*2+1] = flip_bits;
+               }
+               for(y=0; y<image->h; ++y)
                {
-                       data2[i*2] = 255;
-                       data2[i*2+1] = 255-image->data[i];
+                       for(x=0; x<image->w; ++x)
+                               row[x*2+1] = *src++^flip_bits;
+                       png_write_row(pngs, row);
                }
-               for(i=0; i<image->h; ++i)
-                       rows[i] = (png_byte *)(data2+i*image->w*2);
-               color = PNG_COLOR_TYPE_GRAY_ALPHA;
+
+               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);
-       free(rows);
-       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);