/** Returns a 3-width zero-padded version of an int

 * ex: 3 -> "003"

 */

function zero_pad(number) {

	var temp = number.toString(10);

	while (temp.length < 3) {

		temp = '0' + temp;

	}

	return temp;

}

	return img_prefix+'/'+zero_pad(z)+'_'+zero_pad(x)+'_'+zero_pad(y)+'.jpg';

	    this.im.visible_width = this.tile.width*(this.ntiles.x-1)+this.last_tile.width;

	    this.is_updated = true;

	    this.im.width = this.im.visible_width;

	    this.im.height = this.tile.height*(this.ntiles.y-1)+this.last_tile.height;

	    if (this.last_tile.width > this.tile.width) {

		    this.max_tile.width = this.im.last_tile.width;

		    this.max_tile.width = this.tile.width;

	    if (this.last_tile.height > this.tile.height) {

		    this.max_tile.height = this.im.last_tile.height;

	    } else {

		    this.max_tile.height = this.tile.height;

	    var ord_pts = new Array();

	    for(var label in ref_points) {

		    ord_pts.push(ref_points[label]);

	    ord_pts = ord_pts.sort(tri_ref_points);

	    is_located = i > 1 || image_loop && i > 0;

	    var alpha_domain = {start:0, end:360};

	    this.pixel_y_ratio = this.im.width/360;

	    if (is_located) {

		    this.ref_pixels = new Array;

		    this.ref_pixels[0] = new Array();    // Attention il faut compter un intervalle de plus !

		    for (var i=0; i < ord_pts.length; i++) { // premier parcours pour les paramètres cap/x

			    this.ref_pixels[i+1] = new Array();

			    this.ref_pixels[i+1].x = Math.floor(ord_pts[i].x*this.im.width);

			    this.ref_pixels[i+1].cap = fmodulo(ord_pts[i].cap, 360);

			    if (i != ord_pts.length-1) {

				    this.ref_pixels[i+1].ratio_x = (ord_pts[i+1].x - ord_pts[i].x) /

					    fmodulo(ord_pts[i+1].cap - ord_pts[i].cap, 360)*this.im.width;

			    }

		    }

		    if (image_loop == true) {

			    var dpix = this.im.width;

			    var dangle = 360;

			    if (ord_pts.length > 1) {

				    dpix = this.im.width - this.ref_pixels[this.ref_pixels.length-1].x + this.ref_pixels[1].x;

				    dangle = fmodulo(this.ref_pixels[1].cap - this.ref_pixels[this.ref_pixels.length-1].cap, 360);

			    }

			    this.ref_pixels[0].ratio_x = dpix/dangle;

			    this.ref_pixels[ord_pts.length].ratio_x = this.ref_pixels[0].ratio_x;

			    dpix = this.im.width - this.ref_pixels[ord_pts.length].x;

			    this.ref_pixels[0].cap = fmodulo(this.ref_pixels[ord_pts.length].cap + dpix / this.ref_pixels[0].ratio_x, 360);

		    } else {

			    this.ref_pixels[0].ratio_x = this.ref_pixels[1].ratio_x;

			    this.ref_pixels[ord_pts.length].ratio_x = this.ref_pixels[ord_pts.length-1].ratio_x;

			    this.ref_pixels[0].cap = fmodulo(this.ref_pixels[1].cap - this.ref_pixels[1].x / this.ref_pixels[1].ratio_x, 360);

			    alpha_domain.start = this.ref_pixels[0].cap;

			    alpha_domain.end = fmodulo(this.ref_pixels[ord_pts.length].cap+(this.im.width-this.ref_pixels[ord_pts.length].x)/this.ref_pixels[ord_pts.length].ratio_x, 360);

			    this.pixel_y_ratio = this.im.width/fmodulo(alpha_domain.end-alpha_domain.start, 360);

		    }

		    this.ref_pixels[0].x = 0;

		    for (var i=0; i < ord_pts.length; i++) { // second parcours pour les paramètres elevation/y

			    this.ref_pixels[i+1].shift_y = Math.floor(this.pixel_y_ratio*ord_pts[i].ele - ord_pts[i].y*this.im.height);

			    if (i != ord_pts.length-1) {

				    var next_shift = Math.floor(this.pixel_y_ratio*ord_pts[i+1].ele - ord_pts[i+1].y*this.im.height);

				    this.ref_pixels[i+1].dshft_y = (next_shift - this.ref_pixels[i+1].shift_y)/(this.ref_pixels[i+2].x - this.ref_pixels[i+1].x);

			    }

		    if (image_loop == true) {

			    var dpix  = this.im.width;

			    var delt = 0;

			    if (ord_pts.length > 1) {

				    dpix  = this.im.width - this.ref_pixels[this.ref_pixels.length-1].x + this.ref_pixels[1].x;

				    delt = this.ref_pixels[this.ref_pixels.length-1].shift_y - this.ref_pixels[1].shift_y;

			    }

			    this.ref_pixels[0].dshft_y = -delt/dpix;

			    this.ref_pixels[ord_pts.length].dshft_y = this.ref_pixels[0].dshft_y;

			    dpix = this.im.width - this.ref_pixels[ord_pts.length].x;

			    this.ref_pixels[0].shift_y = this.ref_pixels[ord_pts.length].shift_y + dpix*this.ref_pixels[0].dshft_y;

			    this.ref_pixels[0].shift_y = this.ref_pixels[1].shift_y;

			    this.ref_pixels[0].dshft_y = 0;

			    this.ref_pixels[ord_pts.length].dshft_y = 0;

		    }

		    if (debug_mode) {

			    var res = document.getElementById('res');

			    res.innerHTML = 'liste des '+this.ref_pixels.length+' valeurs de correction (image = '+this.im.width+'x'+this.im.height+') zoom = '+this.value+':<br/>';

			    for (var i=0; i < this.ref_pixels.length; i++) { // pour le debug

				    res.innerHTML += '<p>point '+i+' :</p><ul>';

				    for (var key in this.ref_pixels[i]) { // pour le debug

					    res.innerHTML += '<li>'+key + '['+i+'] = '+this.ref_pixels[i][key]+'</li>';

				    }

				    if (i != this.ref_pixels.length-1) {

					    var tx0 = this.ref_pixels[i+1].x-1;

					    //var ty0 = this.ref_pixels[i+1].shift_y;

					    var ty0 = 0;

				    } else {

					    var tx0 = this.im.width-1;

					    var ty0 = 0;

				    }

				    res.innerHTML += '</ul><p>test sur : '+tx0+','+ty0+'</p>';

				    var tst = this.get_cap_ele(tx0, ty0);

				    res.innerHTML += '<p>cap:'+tst.cap+', ele:'+tst.ele+'</p>';

				    var tst2 = this.get_pos_xy(tst.cap, tst.ele);

				    res.innerHTML += '</ul><p>x:'+tst2.x+', y:'+tst2.y+'</p>';

			    }

	    this.pt_list = new Array();

	    for (var i=0; i<point_list.length; i++) {

		    var lbl = point_list[i][0];

		    var dst = point_list[i][1];

		    var cap = point_list[i][2];

		    var ele = point_list[i][3];

		    var lnk = point_list[i][4];

		    var typ = 'unlocated';

		    var rxy = this.get_pos_xy(cap, ele);

		    var is_visible = fmodulo(cap - alpha_domain.start, 360) <= fmodulo(alpha_domain.end - alpha_domain.start -0.0001, 360)+0.0001 && is_located;

		    this.pt_list[i] = new Array();

		    if (ref_points[lbl] != undefined) {

			    typ = 'ref_point';

			    if (!is_located) rxy = {x:ref_points[lbl].x*this.im.width, y:ref_points[lbl].y*this.im.height}

		    } else if(lnk == '' && is_visible && lbl != 'point temporaire') {

			    typ = 'loc_point';

		    }else if(is_visible && lbl =='point temporaire') {

			    typ = 'temporary';

		    } else if(is_visible) {

			    typ = 'pano_point';

			    lnk += '&to_zoom='+this.value;

		    }

		    this.pt_list[i]['type'] = typ;

		    this.pt_list[i]['cap'] = cap;

		    this.pt_list[i]['ele'] = ele;

		    this.pt_list[i]['dist'] = dst;

		    this.pt_list[i]['label'] = lbl;

		    this.pt_list[i]['lnk'] = lnk;

		    this.pt_list[i]['xc'] = rxy.x;

		    this.pt_list[i]['yc'] = Math.floor(this.im.height/2 - rxy.y);

    },