Eliminate some nested loops from the packing algorithm

[ttf2png.git] / ttf2png.c

diff --git a/ttf2png.c b/ttf2png.c
index c77cd5889509248390bd80dbeee0606586719c96..3685b5a106d9e3f9641051b13df4dfaa8ac5aeb1 100644 (file)
--- a/ttf2png.c
+++ b/ttf2png.c
@@ -362,14 +362,6 @@ void render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, int s
        unsigned first, last;
        unsigned maxw = 0, maxh = 0;
 
-       for(i=1;; i<<=1)
-       {
-               first = font->glyphs[0].code&~(i-1);
-               last = first+i-1;
-               if(last>=font->glyphs[font->n_glyphs-1].code)
-                       break;
-       }
-
        for(i=0; i<font->n_glyphs; ++i)
        {
                int y;
@@ -410,21 +402,21 @@ void render_grid(Font *font, unsigned cellw, unsigned cellh, unsigned cpl, int s
 
        if(cpl==0)
        {
-               unsigned count = (seq ? font->n_glyphs : last-first+1);
                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;
                }
        }
 
+       first = font->glyphs[0].code;
+       if(!seq)
+               first -= first%cpl;
+       last = font->glyphs[font->n_glyphs-1].code;
+
        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;
-       else
-               font->image.h = (last-first+cpl)/cpl*cellh;
-       font->image.h = round_to_pot(font->image.h);
+       font->image.h = round_to_pot((last-first+cpl)/cpl*cellh);
 
        font->image.data = (char *)malloc(font->image.w*font->image.h);
        memset(font->image.data, 255, font->image.w*font->image.h);
@@ -465,13 +457,13 @@ void render_packed(Font *font)
 {
        unsigned i;
        unsigned area = 0;
-       unsigned last_h = 0xFFFF;
        char     *used_glyphs;
-       char     *used_pixels;
+       unsigned *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)
        {
@@ -483,8 +475,8 @@ void render_packed(Font *font)
 
        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_pixels = (unsigned *)malloc(font->image.w*sizeof(unsigned));
+       memset(used_pixels, 0, font->image.w*sizeof(unsigned));
        used_glyphs = (char *)malloc(font->n_glyphs);
        memset(used_glyphs, 0, font->n_glyphs);
 
@@ -494,16 +486,20 @@ 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); ++cx)
+                       if(used_pixels[cx]-cy-1>target_h)
+                               target_h = used_pixels[cx]-cy-1;
 
-               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(w=0; (cx+w<font->image.w && used_pixels[cx+w]<=cy); ++w) ;
 
                for(i=0; i<font->n_glyphs; ++i)
                {
@@ -515,7 +511,7 @@ 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;
@@ -544,15 +540,19 @@ void render_packed(Font *font)
                                continue;
                        font->image.data[cx+x+(cy+y)*font->image.w] = 255-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; ++x)
                {
-                       if(cx+x<1 || cx+x>font->image.w || cy+y<1 || cy+y>font->image.h)
+                       if(cx+x<1 || cx+x>font->image.w)
                                continue;
-                       used_pixels[cx+x-1+(cy+y-1)*font->image.w] = 1;
+                       if(used_pixels[cx+x-1]<cy+glyph->image.h+1)
+                               used_pixels[cx+x-1] = cy+glyph->image.h+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)