Read 'post' table to determine if font is monospaced. Fix string width computation. Fix overflow glyph.baseline

main.c

@@ -98,6 +98,7 @@ struct font_directory {
     u32 glyf_offset;
     u32 hmtx_offset;
     u32 maxp_offset;
+    u32 post_offset;
     
     u32 cvt_offset;
     u32 cvt_size;
@@ -191,6 +192,7 @@ struct ttf_font {
     
     s16 *cvt;
     int cmap_format;
+    int is_monospace;
     
     struct font_directory dir;
     struct ttf_function *functions;
@@ -646,11 +648,7 @@ render_utf_string(struct ttf_font font, int px_size, u32 *pixels, u32 width, wch
             
             render_glyph(g, px_size, &lines, scale, pixels, width, offset_x + g.lsb * scale, offset_y);
             
-#if 1
-            offset_x += round_f32(scale * g.advance);
-#else
-            offset_x += px_size * 2;
-#endif
+            offset_x += ceil_f32(scale * g.advance);
             
             free(lines.data);
         } else {
@@ -732,23 +730,23 @@ main(int argc, char **argv)
         //render_utf_string(font, 18, pixels, width, L"The quick brown fox jumps over the lazy dog", 100, 150);
         //render_utf_string(font, 12, pixels, width, L"This text is seriously small", 100, at); at += 12;
         //render_utf_string(font, 13, pixels, width, L"This text is seriously small", 100, at); at += 13;
-        //render_utf_string(font, 14, pixels, width, L"This text is seriously small", 100, at); at += 14;
+        render_utf_string(font, 14, pixels, width, L"This text is seriously small", 100, at); at += 14;
         //render_utf_string(font, 15, pixels, width, L"This text is seriously small", 100, at); at += 14;
-        render_utf_string(font, 20, pixels, width, L"result = XCreateImage(display, visinfo.visual, visinfo.depth, ZPixmap, 0, hc_vram, width, height, pixel_bits, 0);", 100, at); at += 20;
-        render_utf_string(font, 24, pixels, width, L"The quick brown fox jumps over the lazy dog", 100, at); at += 24;
+        render_utf_string(font, 26, pixels, width, L"memset(pixels, 0x00, width * height * 4);", 10, at); at += 24;
+        render_utf_string(font, 24, pixels, width, L"The quick brown fox jumps over the lazy dog", 10, at); at += 24;
         
-        wchar_t *string1 = L"iiiiiiiiil";
+        wchar_t *string1 = L"iiiiiiiiiiiiiiiiiii";
         wchar_t *string2 = L"something-some";
         wchar_t *string3 = L"MORE MORE";
         
         int w1 = get_string_width(&font, 32, string1, wcslen(string1));
         int w2 = get_string_width(&font, 32, string2, wcslen(string2));
         
-        render_utf_string(font, 32, pixels, width, string1, 100, at); 
-        render_utf_string(font, 32, pixels, width, string2, 100 + w1, at);
-        render_utf_string(font, 32, pixels, width, string3, 100 + w1 + w2, at);
+        render_utf_string(font, 32, pixels, width, string1, 10, at); 
+        render_utf_string(font, 32, pixels, width, string2, 10 + w1, at);
+        render_utf_string(font, 32, pixels, width, string3, 10 + w1 + w2, at);
         at += 80;
-        render_utf_string(font, 80, pixels, width, L"~!@#$%^&*()_+;:,./\\|", 100, at);
+        render_utf_string(font, 80, pixels, width, L"~!@#$%^&*()_+;:,./\\||||", 10, at);
         
         XPutImage(display, window, default_gc, xwindow_buffer, 0, 0, 0, 0, width, height);
         

ttf2.c

@@ -1453,9 +1453,11 @@ get_hmtx(struct ttf_font *font, u32 glyph_index, struct glyph *dest)
 {
     struct font_buffer font_file = font->file;
     
-    // TODO: monospaced font only has one record
-    
-    font_file.offset = font->dir.hmtx_offset + glyph_index * 4;
+    if (font->is_monospace) {
+        font_file.offset = font->dir.hmtx_offset;
+    } else {
+        font_file.offset = font->dir.hmtx_offset + glyph_index * 4;
+    }
     
     dest->advance = read_be16(&font_file);
     dest->lsb = read_be16s(&font_file);
@@ -1472,11 +1474,9 @@ get_string_width(struct ttf_font *font, int px_size, wchar_t *string, int length
         u16 codepoint = string[i];
         u32 glyph_index = get_glyph_index(font, codepoint);
         get_hmtx(font, glyph_index, &g);
-        result += g.advance;
+        result += ceil_f32(scale * g.advance); // NOTE(aolo2): ceil each time because that's what the rasterizing code does
     }
     
-    result = ceil_f32(result * scale);
-    
     return(result);
 }
 
@@ -1588,6 +1588,11 @@ read_font_directory(struct font_buffer *file)
                 result.hhea_offset = offset;
                 break;
             }
+            
+            case 0x706f7374: {
+                /* post */
+                result.post_offset = offset;
+            }
         }
     }
     
@@ -1652,6 +1657,17 @@ read_cvt(struct ttf_font *font, struct font_buffer *font_file, struct font_direc
     iterate_instructions(font, font_file, font_dir.prep_offset, font_dir.prep_size, state);
 }
 
+static void
+read_post(struct font_directory font_dir, struct ttf_font *font)
+{
+    if (font_dir.post_offset) {
+        font->is_monospace = be32(font->file.data + font_dir.post_offset + 12);
+    } else {
+        printf("Warning: font file doesn't have a 'post' table. Assuming font is proportional\n");
+        font->is_monospace = 0;
+    }
+}
+
 static struct ttf_font
 parse_ttf_file(char *filename, char *fontname)
 {
@@ -1667,6 +1683,7 @@ parse_ttf_file(char *filename, char *fontname)
     result.cvt = (s16 *) (font_file.data + font_dir.cvt_offset);
     
     read_head(font_dir, &result);
+    read_post(font_dir, &result);
     read_maxp(font_dir, &result);
     read_cmap(font_dir, &result);
     read_hhea(font_dir, &result);