/* The following function stolen from XeTeX_ext.c */
static hb_tag_t
read_tag_with_param(const char* cp, int* param)
{
const char* cp2;
hb_tag_t tag;
int i;
cp2 = cp;
while (*cp2 && (*cp2 != ':') && (*cp2 != ';') && (*cp2 != ',') && (*cp2 != '='))
++cp2;
tag = hb_tag_from_string(cp, cp2 - cp);
cp = cp2;
if (*cp == '=') {
int neg = 0;
++cp;
if (*cp == '-') {
++neg;
++cp;
}
while (*cp >= '0' && *cp <= '9') {
*param = *param * 10 + *cp - '0';
++cp;
}
if (neg)
*param = -(*param);
}
return tag;
}
static bool
parse_feature_tag (const char **pp, const char *end, hb_feature_t *feature)
{
parse_space (pp, end);
char quote = 0;
if (*pp < end && (**pp == '\'' || **pp == '"'))
{
quote = **pp;
(*pp)++;
}
const char *p = *pp;
while (*pp < end && ISALNUM(**pp))
(*pp)++;
if (p == *pp || *pp - p > 4)
return false;
feature->tag = hb_tag_from_string (p, *pp - p);
if (quote)
{
/* CSS expects exactly four bytes. And we only allow quotations for
* CSS compatibility. So, enforce the length. */
if (*pp - p != 4)
return false;
if (*pp == end || **pp != quote)
return false;
(*pp)++;
}
return true;
}
XeTeXLayoutEngine
createLayoutEngine(PlatformFontRef fontRef, XeTeXFont font, hb_tag_t script, char *language,
hb_feature_t* features, int nFeatures, char **shapers, uint32_t rgbValue,
float extend, float slant, float embolden)
{
XeTeXLayoutEngine result = new XeTeXLayoutEngine_rec;
result->fontRef = fontRef;
result->font = (XeTeXFontInst*)font;
result->script = script;
result->features = features;
result->ShaperList = shapers;
result->shaper = NULL;
result->nFeatures = nFeatures;
result->rgbValue = rgbValue;
result->extend = extend;
result->slant = slant;
result->embolden = embolden;
result->hbBuffer = hb_buffer_create();
// For Graphite fonts treat the language as BCP 47 tag, for OpenType we
// treat it as a OT language tag for backward compatibility with pre-0.9999
// XeTeX.
if (getReqEngine() == 'G')
result->language = hb_language_from_string(language, -1);
else
result->language = hb_ot_tag_to_language(hb_tag_from_string(language, -1));
free(language);
return result;
}
static hb_feature_t* scan_feature_string(const char* cp1, int* ret) {
hb_feature_t* features = NULL;
hb_tag_t tag;
int nFeatures = 0;
const char* cp2;
const char* cp3;
while (*cp1) {
if ((*cp1 == ':') || (*cp1 == ';') || (*cp1 == ','))
++cp1;
while ((*cp1 == ' ') || (*cp1 == '\t')) /* skip leading whitespace */
++cp1;
if (*cp1 == 0) /* break if end of string */
break;
cp2 = cp1;
while (*cp2 && (*cp2 != ':') && (*cp2 != ';') && (*cp2 != ','))
++cp2;
if (*cp1 == '+') {
int param = 0;
tag = read_tag_with_param(cp1 + 1, ¶m);
features = realloc(features, (nFeatures + 1) * sizeof(hb_feature_t));
features[nFeatures].tag = tag;
features[nFeatures].start = 0;
features[nFeatures].end = (unsigned int) -1;
if (param >= 0)
param++;
features[nFeatures].value = param;
nFeatures++;
goto next_option;
}
if (*cp1 == '-') {
++cp1;
tag = hb_tag_from_string(cp1, cp2 - cp1);
features = realloc(features, (nFeatures + 1) * sizeof(hb_feature_t));
features[nFeatures].tag = tag;
features[nFeatures].start = 0;
features[nFeatures].end = (unsigned int) -1;
features[nFeatures].value = 0;
nFeatures++;
goto next_option;
}
bad_option:
//fontfeaturewarning(cp1, cp2 - cp1, 0, 0);
next_option:
cp1 = cp2;
}
*ret = nFeatures;
return features;
}
int shape (lua_State *L) {
const char * text = luaL_checkstring(L, 1);
FT_Face face = lua_touserdata(L, 2);
const char * script = luaL_checkstring(L, 3);
const char * direction_s = luaL_checkstring(L, 4);
const char * lang = luaL_checkstring(L, 5);
double point_size = luaL_checknumber(L, 6);
const char * featurestring = luaL_checkstring(L, 7);
hb_segment_properties_t segment_props;
hb_shape_plan_t *shape_plan;
hb_direction_t direction;
hb_feature_t* features;
int nFeatures = 0;
unsigned int glyph_count = 0;
hb_font_t *hb_ft_font;
hb_face_t *hb_ft_face;
hb_buffer_t *buf;
hb_glyph_info_t *glyph_info;
hb_glyph_position_t *glyph_pos;
unsigned int j;
features = scan_feature_string(featurestring, &nFeatures);
if (!strcasecmp(direction_s,"RTL"))
direction = HB_DIRECTION_RTL;
else if (!strcasecmp(direction_s,"TTB"))
direction = HB_DIRECTION_TTB;
else
direction = HB_DIRECTION_LTR;
hb_ft_font = hb_ft_font_create(face, NULL);
hb_face_t* hbFace = hb_font_get_face(hb_ft_font);
buf = hb_buffer_create();
hb_buffer_add_utf8(buf, text, strlen(text), 0, strlen(text));
hb_buffer_set_script(buf, hb_tag_from_string(script, strlen(script)));
hb_buffer_set_direction(buf, direction);
hb_buffer_set_language(buf, hb_language_from_string(lang,strlen(lang)));
hb_buffer_guess_segment_properties(buf);
hb_buffer_get_segment_properties(buf, &segment_props);
shape_plan = hb_shape_plan_create_cached(hbFace, &segment_props, features, nFeatures, NULL);
int res = hb_shape_plan_execute(shape_plan, hb_ft_font, buf, features, nFeatures);
glyph_info = hb_buffer_get_glyph_infos(buf, &glyph_count);
glyph_pos = hb_buffer_get_glyph_positions(buf, &glyph_count);
lua_checkstack(L, glyph_count);
for (j = 0; j < glyph_count; ++j) {
char namebuf[255];
box glyph_extents = { 0.0, 0.0, 0.0 };
calculate_extents(&glyph_extents, glyph_info[j], glyph_pos[j], face, point_size, direction);
lua_newtable(L);
lua_pushstring(L, "name");
FT_Get_Glyph_Name( face, glyph_info[j].codepoint, namebuf, 255 );
lua_pushstring(L, namebuf);
lua_settable(L, -3);
if (direction != HB_DIRECTION_TTB) { /* XXX */
if (glyph_pos[j].x_offset) {
lua_pushstring(L, "x_offset");
lua_pushnumber(L, glyph_pos[j].x_offset / 64.0);
lua_settable(L, -3);
}
if (glyph_pos[j].y_offset) {
lua_pushstring(L, "y_offset");
lua_pushnumber(L, glyph_pos[j].y_offset / 64.0);
lua_settable(L, -3);
}
}
lua_pushstring(L, "codepoint");
lua_pushinteger(L, glyph_info[j].codepoint);
lua_settable(L, -3);
lua_pushstring(L, "width");
lua_pushnumber(L, glyph_extents.width);
lua_settable(L, -3);
lua_pushstring(L, "height");
lua_pushnumber(L, glyph_extents.height);
lua_settable(L, -3);
lua_pushstring(L, "depth");
lua_pushnumber(L, glyph_extents.depth);
lua_settable(L, -3);
}
/* Cleanup */
hb_buffer_destroy(buf);
hb_font_destroy(hb_ft_font);
hb_shape_plan_destroy(shape_plan);
free(features);
return glyph_count;
}
int shape (lua_State *L) {
size_t font_l;
const char * text = luaL_checkstring(L, 1);
const char * font_s = luaL_checklstring(L, 2, &font_l);
unsigned int font_index = luaL_checknumber(L, 3);
const char * script = luaL_checkstring(L, 4);
const char * direction_s = luaL_checkstring(L, 5);
const char * lang = luaL_checkstring(L, 6);
double point_size = luaL_checknumber(L, 7);
const char * featurestring = luaL_checkstring(L, 8);
hb_segment_properties_t segment_props;
hb_shape_plan_t *shape_plan;
hb_direction_t direction;
hb_feature_t* features;
int nFeatures = 0;
unsigned int glyph_count = 0;
hb_font_t *hbFont;
hb_buffer_t *buf;
hb_glyph_info_t *glyph_info;
hb_glyph_position_t *glyph_pos;
unsigned int j;
features = scan_feature_string(featurestring, &nFeatures);
if (!strcasecmp(direction_s,"RTL"))
direction = HB_DIRECTION_RTL;
else if (!strcasecmp(direction_s,"TTB"))
direction = HB_DIRECTION_TTB;
else
direction = HB_DIRECTION_LTR;
hb_blob_t* blob = hb_blob_create (font_s, font_l, HB_MEMORY_MODE_WRITABLE, (void*)font_s, NULL);
hb_face_t* hbFace = hb_face_create (blob, font_index);
hbFont = hb_font_create (hbFace);
unsigned int upem = hb_face_get_upem(hbFace);
hb_font_set_scale(hbFont, upem, upem);
/* Harfbuzz's support for OT fonts is great, but
there's currently no support for CFF fonts, so
downgrade to Freetype for those. */
if (strncmp(font_s, "OTTO", 4) == 0) {
hb_ft_font_set_funcs(hbFont);
} else {
hb_ot_font_set_funcs(hbFont);
}
buf = hb_buffer_create();
hb_buffer_add_utf8(buf, text, strlen(text), 0, strlen(text));
hb_buffer_set_script(buf, hb_tag_from_string(script, strlen(script)));
hb_buffer_set_direction(buf, direction);
hb_buffer_set_language(buf, hb_language_from_string(lang,strlen(lang)));
hb_buffer_guess_segment_properties(buf);
hb_buffer_get_segment_properties(buf, &segment_props);
shape_plan = hb_shape_plan_create_cached(hbFace, &segment_props, features, nFeatures, NULL);
int res = hb_shape_plan_execute(shape_plan, hbFont, buf, features, nFeatures);
if (direction == HB_DIRECTION_RTL) {
hb_buffer_reverse(buf); /* URGH */
}
glyph_info = hb_buffer_get_glyph_infos(buf, &glyph_count);
glyph_pos = hb_buffer_get_glyph_positions(buf, &glyph_count);
lua_checkstack(L, glyph_count);
for (j = 0; j < glyph_count; ++j) {
char namebuf[255];
hb_glyph_extents_t extents = {0,0,0,0};
hb_font_get_glyph_extents(hbFont, glyph_info[j].codepoint, &extents);
lua_newtable(L);
lua_pushstring(L, "name");
hb_font_get_glyph_name( hbFont, glyph_info[j].codepoint, namebuf, 255 );
lua_pushstring(L, namebuf);
lua_settable(L, -3);
/* We don't apply x-offset and y-offsets for TTB, which
is arguably a bug. We should. The reason we don't is that
Harfbuzz assumes that you want to shift the character from a
top-center baseline to a bottom-left baseline, and gives you
offsets which do that. We don't want to do that so we ignore the
offsets. I'm told there is a way of configuring HB's idea of the
baseline, and we should use that and take out this condition. */
if (direction != HB_DIRECTION_TTB) {
if (glyph_pos[j].x_offset) {
lua_pushstring(L, "x_offset");
lua_pushnumber(L, glyph_pos[j].x_offset * point_size / upem);
lua_settable(L, -3);
}
if (glyph_pos[j].y_offset) {
lua_pushstring(L, "y_offset");
lua_pushnumber(L, glyph_pos[j].y_offset * point_size / upem);
lua_settable(L, -3);
}
}
lua_pushstring(L, "codepoint");
lua_pushinteger(L, glyph_info[j].codepoint);
lua_settable(L, -3);
lua_pushstring(L, "index");
lua_pushinteger(L, glyph_info[j].cluster);
lua_settable(L, -3);
double height = extents.y_bearing * point_size / upem;
double tHeight = extents.height * point_size / upem;
double width = glyph_pos[j].x_advance * point_size / upem;
/* The PDF model expects us to make positioning adjustments
after a glyph is painted. For this we need to know the natural
glyph advance. libtexpdf will use this to compute the adjustment. */
double glyphAdvance = hb_font_get_glyph_h_advance(hbFont, glyph_info[j].codepoint) * point_size / upem;
if (direction == HB_DIRECTION_TTB) {
height = -glyph_pos[j].y_advance * point_size / upem;
tHeight = -height; /* Set depth to 0 - depth has no meaning for TTB */
width = glyphAdvance;
glyphAdvance = height;
}
lua_pushstring(L, "glyphAdvance");
lua_pushnumber(L, glyphAdvance);
lua_settable(L, -3);
lua_pushstring(L, "width");
lua_pushnumber(L, width);
lua_settable(L, -3);
lua_pushstring(L, "height");
lua_pushnumber(L, height);
lua_settable(L, -3);
lua_pushstring(L, "depth");
lua_pushnumber(L, -tHeight - height);
lua_settable(L, -3);
}
/* Cleanup */
hb_buffer_destroy(buf);
hb_font_destroy(hbFont);
hb_shape_plan_destroy(shape_plan);
free(features);
return glyph_count;
}
