#include "config.h"

#ifdef ENABLE_SVG_FONTS

#include <libnr/n-art-bpath.h>

#include "../style.h"

#include <cairo.h>

#include <vector>

#include "svg/svg.h"

#include "inkscape-cairo.h"

#include "nr-svgfonts.h"

class SvgFontDrawingArea : Gtk::DrawingArea{

public:

SvgFontDrawingArea(SvgFont* svgfont){

this->svgfont = svgfont;

}

private:

SvgFont* svgfont;

bool on_expose_event (GdkEventExpose *event){

Glib::RefPtr<Gdk::Window> window = get_window();

Cairo::RefPtr<Cairo::Context> cr = window->create_cairo_context();

cr->set_font_face( Cairo::RefPtr<Cairo::FontFace>(new Cairo::FontFace(this->svgfont->get_font_face(), false /* does not have reference */)) );

cr->set_font_size (100);

cr->move_to (100, 100);

cr->show_text ("A@!A!@A");

return TRUE;

}

};//class SvgFontDrawingArea

static cairo_user_data_key_t key;

static cairo_status_t font_init_cb (cairo_scaled_font_t *scaled_font,

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,

cairo_glyph_t **glyphs,

int *num_glyphs){

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, glyphs, num_glyphs);

}

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;

//This is an auxiliary gtkWindow used only while we do not have proper Pango integration with cairo-user-fonts.

Gtk::Window* window;

SvgFontDrawingArea* font_da;

window = new Gtk::Window();

window->set_default_size (1200, 850);

font_da = new SvgFontDrawingArea(this);

window->add((Gtk::Widget&) *font_da);

window->show_all();

}

SvgFont::scaled_font_init (cairo_scaled_font_t *scaled_font,

cairo_font_extents_t *metrics)

{

return CAIRO_STATUS_SUCCESS;

}

unsigned int compare_them(char* s1, char* s2){

unsigned int p=0;

while((s1[p] == s2[p]) && s1[p] != '\0' && s2[p] != '\0') p++;

if (s1[p]=='\0') return p;

else return 0;

}

SvgFont::scaled_font_text_to_glyphs (cairo_scaled_font_t *scaled_font,

const char *utf8,

cairo_glyph_t **glyphs,

int *num_glyphs)

{

//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 alse defines the respective coordinates of each glyph. Thus, it

// has to read the attributes od 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;

char* _utf8 = (char*) utf8;

unsigned int len;

//First we findout whats the worst case number of glyphs.

while(_utf8[0] != '\0'){

_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

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(_utf8[0] != '\0'){

len = 0;

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

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

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

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

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){

if ( (((SPHkern*)node)->u1[0] == previous_unicode[0]) && (((SPHkern*)node)->u2[0] == this->glyphs[i]->unicode[0]))//TODO: strings

x -= (((SPHkern*)node)->k / this->font->horiz_adv_x);

}

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

if ( (((SPVkern*)node)->u1[0] == previous_unicode[0]) && (((SPVkern*)node)->u2[0] == this->glyphs[i]->unicode[0]))//TODO: strings

y -= (((SPVkern*)node)->k / this->font->vert_adv_y);

}

}

previous_unicode = this->glyphs[i]->unicode;//used for kerning checking

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

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

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

//advance glyph coordinates:

if (is_horizontal_text) x++;

else y++;

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

continue;

}

}

if (!len){

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

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

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

//advance glyph coordinates:

if (is_horizontal_text) x++;

else y++;

_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;

g_warning("RENDER MISSING-GLYPH");

} else {

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

g_warning("RENDER %s", this->glyphs[glyph]->unicode);

}

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

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

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

NArtBpath *bpath = NULL;

if (SP_IS_GLYPH(node) && ((SPGlyph*)node)->d) bpath = sp_svg_read_path(((SPGlyph*)node)->d);

if (SP_IS_MISSING_GLYPH(node) && ((SPMissingGlyph*)node)->d) bpath = sp_svg_read_path(((SPMissingGlyph*)node)->d);

if (bpath){

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

cairo_new_path(cr);

NR::scale s(1.0/((SPFont*) node->parent)->horiz_adv_x);

NR::Matrix t(s);

NRRect area(0,0,1,1); //I need help here!

feed_curve_to_cairo (cr, bpath, t, area.upgrade(), 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)){

g_warning("glyphs.push_back((SPGlyph*)node); (node->unicode='%s')", ((SPGlyph*)node)->unicode);

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

}

if (SP_IS_MISSING_GLYPH(node)){

g_warning("missingglyph=(SPMissingGlyph*)node;");

this->missingglyph=(SPMissingGlyph*)node;

}

}

this->userfont = new UserFont(this);

}

return this->userfont->face;

}

#endif //#ifdef ENABLE_SVG_FONTS