Improve the packing algorithm

diff --git a/ttf2png.c b/ttf2png.c
index c77cd5889509248390bd80dbeee0606586719c96..ebc953022e20178d35a5f001a1c87ff3a5cf9ad1 100644 (file)
--- a/ttf2png.c
+++ b/ttf2png.c
@@ -465,13 +465,13 @@ void render_packed(Font *font)
 {
        unsigned i;
        unsigned area = 0;
-       unsigned last_h = 0xFFFF;
        char     *used_glyphs;
        char     *used_pixels;
        unsigned cx = 0, cy;
+       unsigned used_h = 0;
 
        for(i=0; i<font->n_glyphs; ++i)
-               area+=(font->glyphs[i].image.w+1)*(font->glyphs[i].image.h+1);
+               area += (font->glyphs[i].image.w+1)*(font->glyphs[i].image.h+1);
 
        for(font->image.w=1;; font->image.w<<=1)
        {
@@ -494,17 +494,24 @@ void render_packed(Font *font)
                unsigned x, y;
                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)
                {
                        cx = 0;
                        ++cy;
-                       last_h = 0xFFFF;
                        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;
+               }
+
                for(i=0; i<font->n_glyphs; ++i)
                {
                        Glyph *g;
@@ -515,7 +522,7 @@ void render_packed(Font *font)
                                unsigned score;
 
                                score = g->image.h+1;
-                               if(g->image.h==last_h)
+                               if(g->image.h==target_h)
                                        score *= g->image.w;
                                else
                                        score += g->image.w;
@@ -551,8 +558,11 @@ void render_packed(Font *font)
                        used_pixels[cx+x-1+(cy+y-1)*font->image.w] = 1;
                }
 
-               last_h = glyph->image.h;
+               if(cy+glyph->image.h>used_h)
+                       used_h = cy+glyph->image.h;
        }
+
+       font->image.h = round_to_pot(used_h);
 }
 
 int save_defs(const char *fn, const Font *font)