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// 'main' takes in .so files for two versions of FT, the character size, and
// a font directory. It uses 'bitmap' and 'murmur3' to compare hashes for all
// glyphs in the font, using the base and test FT libraries, then renders
// differing glyphs as PNGs. A webpage is generated with a table of these
// glyphs.
#include "bitmap.h"
#include <dlfcn.h> // for dynamic linking
#include <math.h> // for glyph comparison
// a single 'entry' is related to a single charcode for a glyph, as well as
// a row in the generated html table
struct entry
{
char base_img[256]; // filename of base png
char test_img[256]; // filename of test png
char base_hash[33]; // base mm3 hash
char test_hash[33]; // test mm3 hash
double base_value; // comparison metric for base glyph
double test_value; // comparison metric for test glyph
double difference; // difference holding the distance between glyphs
};
void render(const char*, const char*, FT_UInt32, int, struct entry**, int*);
int compare(const void* e1, const void* e2);
void make_html(struct entry**, int* , const char*);
int main(int argc, char const *argv[])
{
const char* base_ft; // path of base ft
const char* test_ft; // path of test ft
FT_UInt32 size; // char size
const char* font; // path of font
int mode;
// create array of structs with size 1
struct entry* entries = malloc(1 * sizeof(struct entry));
int entries_len = 1;
if(argc != 5)
{
printf("Usage: %s <base ft.so> <test ft.so> <char size> <font>\n", argv[0]);
return 0;
}
base_ft = argv[1];
test_ft = argv[2];
size = atoi(argv[3]);
font = argv[4];
mode = 0; // base hashes
render(base_ft, font, size, mode, &entries, &entries_len);
mode = 1; // test hashes
render(test_ft, font, size, mode, &entries, &entries_len);
mode = 2; // base images for differing glyphs
render(test_ft, font, size, mode, &entries, &entries_len);
mode = 3; // test images for differing glyphs
render(test_ft, font, size, mode, &entries, &entries_len);
// quicksort array by decreasing difference
qsort(entries, entries_len, sizeof(struct entry), compare);
// generate HTML output
make_html(&entries, &entries_len, font);
// free array
free(entries);
}
// generate HTML output
void make_html(struct entry** entries, int* num, const char* font)
{
FILE *fp = fopen("index.html", "w");
if (fp == NULL)
{
printf("Error opening file.\n");
exit(1);
}
// TODO: refactor
fprintf(fp, "<!DOCTYPE html>\n<html>\n<head>\n<style>\nimg{image-rendering: optimizeSpeed;image-rendering: -moz-crisp-edges;image-rendering: -o-crisp-edges;image-rendering: -webkit-optimize-contrast;image-rendering: pixelated;image-rendering: optimize-contrast;-ms-interpolation-mode: nearest-neighbor;min-width:10%%}\ntable, th, td{\nborder: 1px solid black;\n}\n</style>\n</head>\n\n<body>\n");
fprintf(fp, "<p>%s</p>\n<table style=\"width:100%%\">", font);
fprintf(fp, "<tr><th>ID</th><th>Difference</th><th>Base glyph | Test glyph</th></tr>\n");
for (int i = 0; i < *num; ++i)
{
if ((*entries)[i].difference > 0){
fprintf(fp, "<tr><td>%d</td><td>%.2f</td><td><img src=\"%s\"</img> <img src=\"%s\"</img></td></tr>\n", i, (*entries)[i].difference, (*entries)[i].base_img, (*entries)[i].test_img);
}
}
fprintf(fp, "</table>\n</body>\n</html>");
fclose(fp);
}
// comparison function for quick sort
int compare (const void* e1, const void* e2)
{
struct entry *s1 = (struct entry *)e1;
struct entry *s2 = (struct entry *)e2;
int comp = (int)(s2->difference) - (int)(s1->difference);
return comp;
}
// multifunctional render function
void render(const char* ft_dir, const char* font, FT_UInt32 size, int mode, struct entry** entries, int* entries_len)
{
FT_Library library;
FT_Face face;
FT_GlyphSlot slot;
FT_Bitmap *bitmap;
FT_Error error;
int i;
// declare dynamically loaded functions
FT_Error (*ft_init_fun)(FT_Library*);
FT_Error (*ft_newface_fun)(FT_Library, const char*, FT_Long, FT_Face*);
FT_Error (*ft_setcharsize_fun)(FT_Face, FT_F26Dot6, FT_F26Dot6, FT_UInt,
FT_UInt);
FT_Error (*ft_loadglyph_fun)(FT_Face, FT_UInt, FT_Int32);
FT_Error (*ft_renderglyph_fun)(FT_GlyphSlot, FT_Render_Mode);
FT_Error (*ft_doneface_fun)(FT_Face);
FT_Error (*ft_donefreetype_fun)(FT_Library);
void (*ft_bitmapinit_fun)(FT_Bitmap*);
FT_Error (*ft_bitmapconvert_fun)(FT_Library, const FT_Bitmap*, FT_Bitmap,
FT_Int);
// dynamically load ft version specified by ft_dir
void* handle = dlopen(ft_dir, RTLD_LAZY | RTLD_LOCAL | RTLD_DEEPBIND);
if (!handle) {
fputs(dlerror(), stderr);
exit(1);
}
// error checking
dlerror();
// initialize dynamically loaded functions
*(void**)(&ft_init_fun) = dlsym(handle,"FT_Init_FreeType");
*(void**)(&ft_newface_fun) = dlsym(handle,"FT_New_Face");
*(void**)(&ft_setcharsize_fun) = dlsym(handle,"FT_Set_Char_Size");
*(void**)(&ft_loadglyph_fun) = dlsym(handle,"FT_Load_Glyph");
*(void**)(&ft_renderglyph_fun) = dlsym(handle,"FT_Render_Glyph");
*(void**)(&ft_doneface_fun) = dlsym(handle,"FT_Done_Face");
*(void**)(&ft_donefreetype_fun) = dlsym(handle,"FT_Done_FreeType");
*(void**)(&ft_bitmapinit_fun) = dlsym(handle,"FT_Bitmap_Init");
*(void**)(&ft_bitmapconvert_fun) = dlsym(handle,"FT_Bitmap_Convert");
// error checking
dlerror();
error = ft_init_fun(&library);
if (error)
{
printf("Error: library init");
}
error = ft_newface_fun(library, font, 0, &face);
if (error)
{
printf("Error: loading face");
}
error = ft_setcharsize_fun(face, size * 64, 0, 96, 0);
if (error)
{
printf("Error: setting char size");
}
slot = face->glyph;
// if 'images' folder doesn't exist, create it
struct stat st = {0};
if (stat("./images/", &st) == -1) {
mkdir("./images/", 0777);
}
// iterate over all glyphs in the font
for (i = 0; i < face->num_glyphs; ++i)
{
// if we've reached capacity of array, double array size
if (i == *entries_len)
{
*entries = realloc(*entries, (*entries_len * 2) * sizeof (struct entry));
entries = &(*entries);
*entries_len = *entries_len * 2;
}
// initially assume no difference between glyphs
(*entries)[i].difference = 0.0;
// if hashes are the same, move to the next glyph
if (((mode == 2) || (mode == 3)) &&
(strcmp((*entries)[i].base_hash, (*entries)[i].test_hash) == 0))
{
continue;
}
error = ft_loadglyph_fun(face, i, FT_LOAD_DEFAULT);
if (error)
{
printf("Error: loading glyph");
}
error = ft_renderglyph_fun(slot, FT_RENDER_MODE_NORMAL);
if (error)
{
printf("Error: rendering glyph");
}
bitmap = &slot->bitmap;
// calculates and stores hash for a glyph
if ((mode == 0) || (mode == 1))
{
HASH_128 * murmur = (HASH_128 *)malloc(sizeof(HASH_128));
murmur = Generate_Hash_x64_128(bitmap, murmur);
if (mode == 0)
{
sprintf((*entries)[i].base_hash, "%08x%08x%08x%08x",
murmur->hash[0], murmur->hash[1], murmur->hash[2], murmur->hash[3]);
}
else
{
sprintf((*entries)[i].test_hash, "%08x%08x%08x%08x",
murmur->hash[0], murmur->hash[1], murmur->hash[2], murmur->hash[3]);
}
} else { // if we're done hashing
// if glyph is empty, move to the next glyph
if (bitmap->width == 0 || bitmap->rows == 0)
{
continue;
}
// the glyphs have a different hash and are not empty so we generate a
// PNG for the glyph and calculate the difference between them
if (mode == 2)
{
Make_PNG(bitmap, "./images/base", i, 1);
sprintf((*entries)[i].base_img, "images/base_%d.png", i);
(*entries)[i].base_value = (double)(rand() % 1000);
} else if (mode == 3){
Make_PNG(bitmap, "./images/test", i, 1);
sprintf((*entries)[i].test_img, "images/test_%d.png", i);
(*entries)[i].test_value = (double)(rand() % 1000);
(*entries)[i].difference = fabs((*entries)[i].base_value - (*entries)[i].test_value);
}
}
}
error = ft_doneface_fun(face);
if (error)
{
printf("Error: freeing face");
}
error = ft_donefreetype_fun(library);
if (error)
{
printf("Error: freeing library");
}
dlclose(handle);
}
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