Always Centered Text

A small turtle to simply write centered text in the middle of the canvas

#text #font #utility

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// Forked from "Hello, world" by reinder
// https://turtletoy.net/turtle/1713ddbe99

const turtle = new Turtle(-25,-5);
const text = new Text();
const lineSpacing = 35
text.printMid(turtle, "Hello World\n~~", .8);

function Text() {
    class Text {
        print (t, str, scale = 1, italic = 0, kerning = 1) {
            t.radians();
            let pos = [t.x(), t.y()], h = t.h(), o = pos;
            str.split('').map(c => {
                const i = c.charCodeAt(0) - 32;
                if (i < 0 ) {
                    pos = o = this.rotAdd([0, 48*scale], o, h);
                } else if (i > 96 ) {
                    pos = this.rotAdd([16*scale, 0], o, h);
                } else {
                    const d = dat[i], lt = d[0]*scale, rt = d[1]*scale, paths = d[2];
                    paths.map( p => {
                        t.up();
                    	p.map( s=> {
                        	t.goto(this.rotAdd([(s[0]-s[1]*italic)*scale - lt, s[1]*scale], pos, h));
                        	t.down();
                        });
                    });
                    pos = this.rotAdd([(rt - lt)*kerning, 0], pos, h);
                }
            });
        }
        rotAdd (a, b, h) {
            return [Math.cos(h)*a[0] - Math.sin(h)*a[1] + b[0], 
                    Math.cos(h)*a[1] + Math.sin(h)*a[0] + b[1]];
        }
        getWidth(str, scale, italic, kerning) {
            let xMin=0, xMax=0
            let pos = [0, 0], h=0, o=pos;
            str.split('').map(c => {
                const i = c.charCodeAt(0) - 32;
                if (i < 0 ) {
                    pos = o = this.rotAdd([0, 48*scale], o, h);
                } else if (i > 96 ) {
                    pos = this.rotAdd([16*scale, 0], o, h);
                } else {
                    const d = dat[i], lt = d[0]*scale, rt = d[1]*scale, paths = d[2];
                    paths.map( p => {
                    	p.map( s=> {
                        	const x = this.rotAdd([(s[0]-s[1]*italic)*scale - lt, s[1]*scale], pos, h)[0];
                        	xMin = Math.min(x, xMin), xMax = Math.max(x, xMax);
                        });
                    });
                    pos = this.rotAdd([(rt - lt)*kerning, 0], pos, h);
                }
            });
            return xMax-xMin
            
        }
        printMid(t, str, scale = 1, italic = 0, kerning = 1) {
            const lines = str.split('\n')
            lines.map((line, index) => {
                const width = this.getWidth(line, scale, italic, kerning)
                t.up()
                t.goto([-width/2, (index-((lines.length-1)/2))*(lineSpacing)*scale])
                this.print(t, line, scale, italic, kerning)
            })
            
        }
    }

    
const dat = ('br>eoj^jl<jqirjskrjq>brf^fe<n^ne>`ukZdz<qZjz<dgrg<cmqm>`thZhw<lZlw<qao_l^h^e_caccdeefg'+
'gmiojpkqmqporlshsercp>^vs^as<f^h`hbgdeeceacaab_d^f^h_k`n`q_s^<olmmlolqnspsrrspsnqlol>]wtgtfsereqfph'+
'nmlpjrhsdsbraq`o`makbjifjekckaj_h^f_eaecffhimporqssstrtq>eoj`i_j^k_kajcid>cqnZl\\j_hcghglhqjulxnz>c'+
'qfZh\\j_lcmhmllqjuhxfz>brjdjp<egom<ogem>]wjajs<ajsj>fnkrjsirjqkrktiv>]wajsj>fnjqirjskrjq>_usZaz>`ti'+
'^f_dbcgcjdofrisksnrpoqjqgpbn_k^i^>`tfbhak^ks>`tdcdbe`f_h^l^n_o`pbpdofmicsqs>`te^p^jfmfogphqkqmppnrk'+
'shserdqco>`tm^clrl<m^ms>`to^e^dgefhekenfphqkqmppnrkshserdqco>`tpao_l^j^g_ebdgdlepgrjsksnrppqmqlping'+
'kfjfggeidl>`tq^gs<c^q^>`th^e_dadceegfkgnhpjqlqopqorlshserdqcocldjfhigmfoepcpao_l^h^>`tpeohmjjkikfjd'+
'hcecddaf_i^j^m_oapepjoomrjshserdp>fnjjikjlkkjj<jqirjskrjq>fnjjikjlkkjj<krjsirjqkrktiv>^vrabjrs>]wag'+
'sg<amsm>^vbarjbs>asdcdbe`f_h^l^n_o`pbpdofngjijl<jqirjskrjq>]xofndlcicgdfeehekfmhnknmmnk<icgefhfkgmh'+
'n<ocnknmpnrntluiugtdsbq`o_l^i^f_d`bbad`g`jambodqfrislsorqqrp<pcokompn>asj^bs<j^rs<elol>_tc^cs<c^l^o'+
'_p`qbqdpfoglh<chlhoipjqlqopqorlscs>`urcqao_m^i^g_eadccfckdnepgrismsorqprn>_tc^cs<c^j^m_oapcqfqkpnop'+
'mrjscs>`sd^ds<d^q^<dhlh<dsqs>`rd^ds<d^q^<dhlh>`urcqao_m^i^g_eadccfckdnepgrismsorqprnrk<mkrk>_uc^cs<'+
'q^qs<chqh>fnj^js>brn^nnmqlrjshsfreqdndl>_tc^cs<q^cl<hgqs>`qd^ds<dsps>^vb^bs<b^js<r^js<r^rs>_uc^cs<c'+
'^qs<q^qs>_uh^f_daccbfbkcndpfrhslsnrppqnrkrfqcpan_l^h^>_tc^cs<c^l^o_p`qbqepgohlici>_uh^f_daccbfbkcnd'+
'pfrhslsnrppqnrkrfqcpan_l^h^<koqu>_tc^cs<c^l^o_p`qbqdpfoglhch<jhqs>`tqao_l^h^e_caccdeefggmiojpkqmqpo'+
'rlshsercp>brj^js<c^q^>_uc^cmdpfrisksnrppqmq^>asb^js<r^js>^v`^es<j^es<j^os<t^os>`tc^qs<q^cs>asb^jhjs'+
'<r^jh>`tq^cs<c^q^<csqs>cqgZgz<hZhz<gZnZ<gznz>cqc^qv>cqlZlz<mZmz<fZmZ<fzmz>brj\\bj<j\\rj>asazsz>fnkc'+
'ieigjhkgjfig>atpeps<phnfleiegfehdkdmepgrislsnrpp>`sd^ds<dhffhekemfohpkpmopmrkshsfrdp>asphnfleiegfeh'+
'dkdmepgrislsnrpp>atp^ps<phnfleiegfehdkdmepgrislsnrpp>asdkpkpiognfleiegfehdkdmepgrislsnrpp>eqo^m^k_j'+
'bjs<gene>atpepuoxnylzizgy<phnfleiegfehdkdmepgrislsnrpp>ate^es<eihfjemeofpips>fni^j_k^j]i^<jejs>eoj^'+
'k_l^k]j^<kekvjyhzfz>are^es<oeeo<ikps>fnj^js>[y_e_s<_ibfdegeifjijs<jimfoeretfuius>ateees<eihfjemeofp'+
'ips>atiegfehdkdmepgrislsnrppqmqkphnfleie>`sdedz<dhffhekemfohpkpmopmrkshsfrdp>atpepz<phnfleiegfehdkd'+
'mepgrislsnrpp>cpgegs<gkhhjfleoe>bsphofleieffehfjhkmlompopporlsisfrep>eqj^jokrmsos<gene>ateeeofrhsks'+
'mrpo<peps>brdejs<pejs>_ubefs<jefs<jens<rens>bseeps<pees>brdejs<pejshwfydzcz>bspees<eepe<esps>cqlZj['+
'i\\h^h`ibjckekgii<j[i]i_jakbldlfkhgjkllnlpkrjsiuiwjy<ikkmkojqirhthvixjylz>fnjZjz>cqhZj[k\\l^l`kbjci'+
'eigki<j[k]k_jaibhdhfihmjilhnhpirjskukwjy<kkimiojqkrltlvkxjyhz>^vamakbhdgfghhlknlplrksi<akbidhfhhill'+
'nmpmrlsisg>brb^bscsc^d^dsese^f^fsgsg^h^hsisi^j^jsksk^l^lsmsm^n^nsoso^p^psqsq^r^rs').split('>').map(
    r=> { return [r.charCodeAt(0)-106,r.charCodeAt(1)-106, r.substr(2).split('<').map(a => {const ret 
    = []; for (let i=0; i<a.length; i+=2) {ret.push(a.substr(i, 2).split('').map(b => b.charCodeAt(0)
    -106));} return ret; })]; });

    return new Text();
}