#include "config.h"

#ifdef ENABLE_SVG_FONTS

#include <2geom/pathvector.h>

#include <2geom/transforms.h>

#include "../style.h"

#include <cairo.h>

#include <vector>

#include "svg/svg.h"

#include "inkscape-cairo.h"

#include "nr-svgfonts.h"

static cairo_user_data_key_t key;

static cairo_status_t font_init_cb (cairo_scaled_font_t *scaled_font,

cairo_t */*cairo*/, cairo_font_extents_t *metrics){

cairo_font_face_t* face;

face = cairo_scaled_font_get_font_face(scaled_font);

SvgFont* instance = (SvgFont*) cairo_font_face_get_user_data(face, &key);

return instance->scaled_font_init(scaled_font, metrics);

}

static cairo_status_t font_text_to_glyphs_cb ( cairo_scaled_font_t *scaled_font,

const char *utf8,

int utf8_len,

cairo_glyph_t **glyphs,

int *num_glyphs,

cairo_text_cluster_t **clusters,

int *num_clusters,

cairo_text_cluster_flags_t *flags){

cairo_font_face_t* face;

face = cairo_scaled_font_get_font_face(scaled_font);

SvgFont* instance = (SvgFont*) cairo_font_face_get_user_data(face, &key);

return instance->scaled_font_text_to_glyphs(scaled_font, utf8, utf8_len, glyphs, num_glyphs, clusters, num_clusters, flags);

}

static cairo_status_t font_render_glyph_cb (cairo_scaled_font_t *scaled_font,

unsigned long glyph,

cairo_t *cr,

cairo_text_extents_t *metrics){

cairo_font_face_t* face;

face = cairo_scaled_font_get_font_face(scaled_font);

SvgFont* instance = (SvgFont*) cairo_font_face_get_user_data(face, &key);

return instance->scaled_font_render_glyph(scaled_font, glyph, cr, metrics);

}

UserFont::UserFont(SvgFont* instance){

this->face = cairo_user_font_face_create ();

cairo_user_font_face_set_init_func (this->face, font_init_cb);

cairo_user_font_face_set_render_glyph_func (this->face, font_render_glyph_cb);

cairo_user_font_face_set_text_to_glyphs_func(this->face, font_text_to_glyphs_cb);

cairo_font_face_set_user_data (this->face, &key, (void*)instance, (cairo_destroy_func_t) NULL);

}

SvgFont::SvgFont(SPFont* spfont){

this->font = spfont;

this->missingglyph = NULL;

this->userfont = NULL;

}

SvgFont::scaled_font_init (cairo_scaled_font_t */*scaled_font*/,

cairo_font_extents_t */*metrics*/)

{

return CAIRO_STATUS_SUCCESS;

}

unsigned int size_of_substring(const char* substring, gchar* str){

const gchar* original_substring = substring;

while((g_utf8_get_char(substring)==g_utf8_get_char(str)) && g_utf8_get_char(substring) != 0 && g_utf8_get_char(str) != 0){

substring = g_utf8_next_char(substring);

str = g_utf8_next_char(str);

}

if (g_utf8_get_char(substring)==0)

return substring - original_substring;

else

return 0;

}

#define Match_VKerning_Rule (((SPVkern*)node)->u1->contains(previous_unicode[0])\

|| ((SPVkern*)node)->g1->contains(previous_glyph_name)) &&\

(((SPVkern*)node)->u2->contains(this->glyphs[i]->unicode[0])\

|| ((SPVkern*)node)->g2->contains(this->glyphs[i]->glyph_name.c_str()))

#define Match_HKerning_Rule (((SPHkern*)node)->u1->contains(previous_unicode[0])\

|| ((SPHkern*)node)->g1->contains(previous_glyph_name)) &&\

(((SPHkern*)node)->u2->contains(this->glyphs[i]->unicode[0])\

|| ((SPHkern*)node)->g2->contains(this->glyphs[i]->glyph_name.c_str()))

SvgFont::scaled_font_text_to_glyphs (cairo_scaled_font_t */*scaled_font*/,

const char *utf8,

int /*utf8_len*/,

cairo_glyph_t **glyphs,

int *num_glyphs,

cairo_text_cluster_t **/*clusters*/,

int */*num_clusters*/,

cairo_text_cluster_flags_t */*flags*/)

{

//This function receives a text string to be rendered. It then defines what is the sequence of glyphs that

// is used to properly render this string. It also defines the respective coordinates of each glyph. Thus, it

// has to read the attributes of the SVGFont hkern and vkern nodes in order to adjust the glyph kerning.

//It also determines the usage of the missing-glyph in portions of the string that does not match any of the declared glyphs.

unsigned long i;

int count = 0;

gchar* _utf8 = (gchar*) utf8;

unsigned int len;

bool missing;

//First we findout whats the number of glyphs needed.

while(g_utf8_get_char(_utf8)){

missing = true;

for (i=0; i < (unsigned long) this->glyphs.size(); i++){

if ( (len = size_of_substring(this->glyphs[i]->unicode.c_str(), _utf8)) ){

//TODO: store this cluster

_utf8+=len;

count++;

missing=false;

break;

}

}

if (missing){

//TODO: store this cluster

_utf8++;

count++;

}

}

//We use that info to allocate memory for the glyphs

*glyphs = (cairo_glyph_t*) malloc(count*sizeof(cairo_glyph_t));

char* previous_unicode = NULL; //This is used for kerning

gchar* previous_glyph_name = NULL; //This is used for kerning

count=0;

double x=0, y=0;//These vars store the position of the glyph within the rendered string

bool is_horizontal_text = true; //TODO

_utf8 = (char*) utf8;

while(g_utf8_get_char(_utf8)){

len = 0;

for (i=0; i < (unsigned long) this->glyphs.size(); i++){

//check whether is there a glyph declared on the SVG document

// that matches with the text string in its current position

if ( (len = size_of_substring(this->glyphs[i]->unicode.c_str(), _utf8)) ){

for(SPObject* node = this->font->children;previous_unicode && node;node=node->next){

//apply glyph kerning if appropriate

if (SP_IS_HKERN(node) && is_horizontal_text && Match_HKerning_Rule ){

x -= (((SPHkern*)node)->k / 1000.0);//TODO: use here the height of the font

}

if (SP_IS_VKERN(node) && !is_horizontal_text && Match_VKerning_Rule ){

y -= (((SPVkern*)node)->k / 1000.0);//TODO: use here the "height" of the font

}

}

previous_unicode = (char*) this->glyphs[i]->unicode.c_str();//used for kerning checking

previous_glyph_name = (char*) this->glyphs[i]->glyph_name.c_str();//used for kerning checking

(*glyphs)[count].index = i;

(*glyphs)[count].x = x;

(*glyphs)[count++].y = y;

//advance glyph coordinates:

if (is_horizontal_text) x+=(this->font->horiz_adv_x/1000.0);//TODO: use here the height of the font

else y+=(this->font->vert_adv_y/1000.0);//TODO: use here the "height" of the font

_utf8+=len; //advance 'len' bytes in our string pointer

//continue;

goto raptorz;

}

}

raptorz:

if (len==0){

(*glyphs)[count].index = i;

(*glyphs)[count].x = x;

(*glyphs)[count++].y = y;

//advance glyph coordinates:

if (is_horizontal_text) x+=(this->font->horiz_adv_x/1000.0);//TODO: use here the height of the font

else y+=(this->font->vert_adv_y/1000.0);//TODO: use here the "height" of the font

_utf8 = g_utf8_next_char(_utf8); //advance 1 char in our string pointer

}

}

*num_glyphs = count;

return CAIRO_STATUS_SUCCESS;

}

SvgFont::scaled_font_render_glyph (cairo_scaled_font_t */*scaled_font*/,

unsigned long glyph,

cairo_t *cr,

cairo_text_extents_t */*metrics*/)

{

// This method does the actual rendering of glyphs.

// We have glyphs.size() glyphs and possibly one missing-glyph declared on this SVG document

// The id of the missing-glyph is always equal to glyphs.size()

// All the other glyphs have ids ranging from 0 to glyphs.size()-1

if (glyph > this->glyphs.size()) return CAIRO_STATUS_SUCCESS;//TODO: this is an error!

SPObject* node;

if (glyph == this->glyphs.size()){

if (!this->missingglyph) return CAIRO_STATUS_SUCCESS;

node = (SPObject*) this->missingglyph;

} else {

node = (SPObject*) this->glyphs[glyph];

}

//glyphs can be described by arbitrary SVG declared in the childnodes of a glyph node

// or using the d attribute of a glyph node.

// pathv stores the path description from the d attribute:

Geom::PathVector pathv;

if (SP_IS_GLYPH(node) && ((SPGlyph*)node)->d) {

pathv = sp_svg_read_pathv(((SPGlyph*)node)->d);

} else if (SP_IS_MISSING_GLYPH(node) && ((SPMissingGlyph*)node)->d) {

pathv = sp_svg_read_pathv(((SPMissingGlyph*)node)->d);

} else {

return CAIRO_STATUS_SUCCESS; // FIXME: is this the right code to return?

}

if (!pathv.empty()){

//This glyph has a path description on its d attribute, so we render it:

cairo_new_path(cr);

//adjust scale of the glyph

Geom::Scale s(1.0/1000);//TODO: use here the units-per-em attribute?

//This matrix flips the glyph vertically

Geom::Matrix m(Geom::Coord(1),Geom::Coord(0),Geom::Coord(0),Geom::Coord(-1),Geom::Coord(0),Geom::Coord(0));

//then we offset it

pathv += Geom::Point(Geom::Coord(0),Geom::Coord(-1000));//TODO: use here the units-per-em attribute?

Geom::Rect area( Geom::Point(0,0), Geom::Point(1,1) ); //I need help here! (reaction: note that the 'area' parameter is an *optional* rect, so you can pass an empty Geom::OptRect() )

feed_pathvector_to_cairo (cr, pathv, s*m, area, false, 0);

cairo_fill(cr);

}

//TODO: render the SVG described on this glyph's child nodes.

return CAIRO_STATUS_SUCCESS;

}

cairo_font_face_t*

SvgFont::get_font_face(){

if (!this->userfont) {

for(SPObject* node = this->font->children;node;node=node->next){

if (SP_IS_GLYPH(node)){

this->glyphs.push_back((SPGlyph*)node);

}

if (SP_IS_MISSING_GLYPH(node)){

this->missingglyph=(SPMissingGlyph*)node;

}

}

this->userfont = new UserFont(this);

}

return this->userfont->face;

}

void SvgFont::refresh(){

this->glyphs.clear();

delete this->userfont;

this->userfont = NULL;

}

#endif //#ifdef ENABLE_SVG_FONTS