var displayClass = {
    new: func(node, role) {
        var m = { parents: [ displayClass ] };
        
        m.display = canvas.new({
                "name"      : role,
                "size"      : [1024, 768],
                "view"      : [1024, 768],
                "mipmapping": 1
        });
        m.display.addPlacement({
                "node": "Screen",
                "parent": role
        });
        m.display.setColorBackground(0,0,0);
        m.role = role;
        m.screenElements = {};

        return m;
    },

    loadsvg : func () {
        me.screen = me.display.createGroup();
        me.screen.hide();
        canvas.parsesvg(me.screen, "Aircraft/Instruments-3d/zkv1000/Systems/screen.svg");
    },

    _showInitProgress : func (p,t) {
        p.setText(t);
        if (zkv.getNode(me.role ~ 'init').getValue() != 0) {
            if (size(t) >= 10) t = '';
            settimer(func { me._showInitProgress(p, t ~ '.'); }, 0.1);
        }
        else {
            me.progress.hide();
            me.screen.show();
            me.loadGroup({
                show : [
                    'SoftKeysTexts', 
                    'COMM', 
                    'NAV', 
                    'XPDR-TIME', 
                    'FlightInstruments',
                    'Horizon',
                    'bankPointer',
                    'VSI',
                    'Rose',
                ],
                hide : [
                    'HDI',
                    'NAV1-pointer',
                    'NAV2-pointer',
                    'GPS-pointer',
                    'Bearing1',
                    'Bearing2',
                ],
                text: [
                    'VSIText',
                    'Speed110',
                    'Alt11100',
                    'HDG-text',
                ],
                clip: [
                    'SpeedLint1',
                    'SpeedTape',
                    'LintAlt',
                    'AltLint00011'
                ],
            });

            var AltBigAltSmall = [ 'AltBigC', 'AltSmallC' ];
            for (var place = 1; place <= 6; place +=1) {
                append(AltBigAltSmall,
                    'AltBigU' ~ place,
                    'AltSmallU' ~ place,
                    'AltBigD' ~ place,
                    'AltSmallD' ~ place
                );
            }
            me.loadGroup({text: AltBigAltSmall});

            me.updateAI(getprop('/orientation/roll-deg'),getprop('orientation/pitch-deg'));
            me.updateVSI(getprop('/instrumentation/vertical-speed-indicator/indicated-speed-fpm'));
            me.updateIAS(getprop('/velocities/airspeed-kt'));
            me.updateALT(getprop('instrumentation/altimeter/indicated-altitude-ft'));
            me.updateHSI(getprop('orientation/heading-deg'));
            me.progress.removeAllChildren();
            me.progress = nil;
            me.showInitProgress = nil;
            me._showInitProgress = nil;
            zkv.removeChild(me.role ~ 'init');
        }
    },

    showInitProgress : func (role) {
        me.progress = me.display.createGroup();
        me.progress.show();
        me.progress.createChild("text", role ~ " title")
            .setTranslation(512, 384)
            .setAlignment("center-center")
            .setFont("LiberationFonts/LiberationSans-Italic.ttf")
            .setFontSize(64, 1)
            .setColor(1,1,1)
            .setText("ZKV1000 " ~ role ~ " init");

        zkv.getNode(role ~ 'init',1).setIntValue(1);

        me._showInitProgress(me.progress.createChild("text", role ~ "progress")
            .setTranslation(512, 484)
            .setAlignment("center-center")
            .setFont("LiberationFonts/LiberationSans-Bold.ttf")
            .setFontSize(128, 1)
            .setColor(1,0,0), '.');
    },

    loadGroup : func (h) {
        if (typeof(h) != 'hash') {
            msg_dbg(sprintf("%s need a hash, but get a %s from %s",
                    caller(0)[0],
                    typeof(h),
                    caller(1)[0]));
            return;
        }
        var setMethod = func (e, t) {
            if (t == 'hide')
                me.screenElements[e].hide();
            elsif (t == 'show')
                me.screenElements[e].show();
            elsif (t == 'rot' or t == 'trans') {
                if (! contains(me.screenElements[e], t))
                    me.screenElements[e][t] = me.screenElements[e].createTransform();
            }
            elsif (t == 'clip') {
                if (contains(me.clips, e))
                    me.screenElements[e].set("clip", me.clips[e]);
                else
                    print('no defined clip for ' ~ e);
            }
            elsif (t == 'text') {
                if (contains(me.texts, e)) {
                    if (contains(me.texts[e], 'alignment'))
                        me.screenElements[e].setAlignment(me.texts[e].alignment);
                    if (contains(me.texts[e], 'default'))
                        me.screenElements[e].setText(me.texts[e].default);
                }
                else
                    print('no alignment for ' ~ e);
            }
            else
                print('unknown method ' ~ t);
        };
        foreach (var todo; keys(h)) {
            if (typeof(h[todo]) != 'vector') h[todo] = [ h[todo] ];
            foreach (var id; h[todo]) {
                if (! contains(me.screenElements, id)) {
                    me.screenElements[id] = me.screen.getElementById(id);
                    if (me.screenElements[id] != nil)
                        setMethod(id, todo);
                    else
                        print('SVG ID ' ~ id ~ ' not found');
                }
                else
                    setMethod(id, todo);
            }
        }
    },

    clips : {
        PitchScale : "rect(70,664,370,256)",
        SpeedLint1 : "rect(252,226,318,204)",
        SpeedTape : "rect(115,239,455,156)",
        LintAlt : "rect(115,808,455,704)",
        AltLint00011 : "rect(252,804,318,771)",
    },

    texts : {
        VSIText : {
            alignment: "right-bottom", default : num('0'),
        },
        Speed110 : {
            default: '', alignment : 'left-bottom'
        },
        Alt11100 : {
            default:'', alignment:'left-bottom'
        },
    },

    updateAI: func(roll,pitch){
        if (pitch > 80)
            pitch = 80;
        elsif(pitch < -80)
            pitch = -80;
        me.screenElements.Horizon
            .setRotation(-roll * D2R)
            .setTranslation(0, pitch * 6.8571428);
        me.screenElements.bankPointer
            .setRotation(-roll * D2R);
        settimer(func me.updateAI(getprop('/orientation/roll-deg'),getprop('orientation/pitch-deg')), 0.1);
    },

    updateVSI: func (vsi) {
        me.screenElements.VSIText
            .setText(num(math.round(vsi, 10)));
        if (vsi > 4500)
            vsi = 4500;
        elsif (vsi < -4500)
            vsi = -4500;
        me.screenElements.VSI
            .setTranslation(0, vsi * -0.03465);
        settimer(func me.updateVSI(getprop('/instrumentation/vertical-speed-indicator/indicated-speed-fpm')), 0.1);
    },

    updateIAS: func (ias) {
        if (ias >= 10)
            me.screenElements.Speed110
                .setText(sprintf("% 2u",num(math.floor(ias/10))));
        else
            me.screenElements.Speed110
                .setText('');
        me.screenElements.SpeedLint1
            .setTranslation(0,(math.mod(ias,10) + (ias >= 10)*10) * 36);
        me.screenElements.SpeedTape
            .setTranslation(0,ias * 5.711);
        settimer(func me.updateIAS(getprop('/velocities/airspeed-kt')), 0.1);
    },

    updateALT: func (alt) {
        if (alt < 0)
            me.screenElements.Alt11100
                .setText(sprintf("% 3i",math.ceil(alt/100)));
        elsif (alt < 100)
            me.screenElements.Alt11100
                .setText('');
        else
            me.screenElements.Alt11100
                .setText(sprintf("% 3i",math.floor(alt/100)));
        me.screenElements.AltLint00011
            .setTranslation(0,math.fmod(alt,100) * 1.24);

        # From Farmin/G1000 http://wiki.flightgear.org/Project_Farmin/FG1000
        if (alt> -1000 and alt< 1000000) {
            var Offset10 = 0;
            var Offset100 = 0;
            var Offset1000 = 0;
            if (alt< 0) {
                var Ne = 1;
                var alt= -alt;
            }
            else
                var Ne = 0;

            var Alt10       = math.mod(alt,100);
            var Alt100      = int(math.mod(alt/100,10));
            var Alt1000     = int(math.mod(alt/1000,10));
            var Alt10000    = int(math.mod(alt/10000,10));
            var Alt20       = math.mod(Alt10,20)/20;
            if (Alt10 >= 80)
                var Alt100 += Alt20;

            if (Alt10 >= 80 and Alt100 >= 9)
                var Alt1000 += Alt20;

            if (Alt10 >= 80 and Alt100 >= 9 and Alt1000 >= 9)
                var Alt10000 += Alt20;

            if (alt> 100)
                var Offset10 = 100;

            if (alt> 1000)
                var Offset100 = 10;

            if (alt> 10000)
                var Offset1000 = 10;

            if (!Ne) {
                me.screenElements.LintAlt.setTranslation(0,(math.mod(alt,100))*0.57375);
                var altCentral = (int(alt/100)*100);
            }
            elsif (Ne) {
                me.screenElements.LintAlt.setTranslation(0,(math.mod(alt,100))*-0.57375);
                var altCentral = -(int(alt/100)*100);
            }
            me.screenElements["AltBigC"].setText("");
            me.screenElements["AltSmallC"].setText("");
            for (var place = 1; place <= 6; place += 1) {
                var altUP = altCentral + (place*100);
                var offset = -30.078;
                if (altUP < 0) {
                    var altUP = -altUP;
                    var prefix = "-";
                    var offset += 15.039;
                }
                else
                    var prefix = "";

                if (altUP == 0) {
                    var AltBigUP    = "";
                    var AltSmallUP  = "0";

                }
                elsif (math.mod(altUP,500) == 0 and altUP != 0) {
                    var AltBigUP    = sprintf(prefix~"%1d", altUP);
                    var AltSmallUP  = "";
                }
                elsif (altUP < 1000 and (math.mod(altUP,500))) {
                    var AltBigUP    = "";
                    var AltSmallUP  = sprintf(prefix~"%1d", int(math.mod(altUP,1000)));
                    var offset = -30.078;
                }
                elsif ((altUP < 10000) and (altUP >= 1000) and (math.mod(altUP,500))) {
                    var AltBigUP    = sprintf(prefix~"%1d", int(altUP/1000));
                    var AltSmallUP  = sprintf("%1d", int(math.mod(altUP,1000)));
                    var offset += 15.039;
                }
                else {
                    var AltBigUP    = sprintf(prefix~"%1d", int(altUP/1000));
                    var mod = int(math.mod(altUP,1000));
                    var AltSmallUP  = sprintf("%1d", mod);
                    var offset += 30.078;
                }

                me.screenElements["AltBigU"~place].setText(AltBigUP);
                me.screenElements["AltSmallU"~place].setText(AltSmallUP);
                me.screenElements["AltSmallU"~place].setTranslation(offset,0);
                var altDOWN = altCentral - (place*100);
                var offset = -30.078;
                if (altDOWN < 0) {
                    var altDOWN = -altDOWN;
                    var prefix = "-";
                    var offset += 15.039;
                }
                else
                    var prefix = "";

                if (altDOWN == 0) {
                    var AltBigDOWN  = "";
                    var AltSmallDOWN    = "0";
                }
                elsif (math.mod(altDOWN,500) == 0 and altDOWN != 0) {
                    var AltBigDOWN  = sprintf(prefix~"%1d", altDOWN);
                    var AltSmallDOWN    = "";
                }
                elsif (altDOWN < 1000 and (math.mod(altDOWN,500))) {
                    var AltBigDOWN  = "";
                    var AltSmallDOWN    = sprintf(prefix~"%1d", int(math.mod(altDOWN,1000)));
                    var offset = -30.078;
                }
                elsif ((altDOWN < 10000) and (altDOWN >= 1000) and (math.mod(altDOWN,500))) {
                    var AltBigDOWN  = sprintf(prefix~"%1d", int(altDOWN/1000));
                    var AltSmallDOWN    = sprintf("%1d", int(math.mod(altDOWN,1000)));
                    var offset += 15.039;
                }
                else {
                    var AltBigDOWN  = sprintf(prefix~"%1d", int(altDOWN/1000));
                    var mod = int(math.mod(altDOWN,1000));
                    var AltSmallDOWN    = sprintf("%1d", mod);
                    var offset += 30.078;
                }
                me.screenElements["AltBigD"~place].setText(AltBigDOWN);
                me.screenElements["AltSmallD"~place].setText(AltSmallDOWN);
                me.screenElements["AltSmallD"~place].setTranslation(offset,0);
            }
        }
        settimer(func me.updateALT(getprop('instrumentation/altimeter/indicated-altitude-ft')), 0.2);
    },

    updateHSI : func (hdg) {
        me.screenElements.Rose
            .setRotation(-hdg * D2R);
        me.screenElements['HDG-text']
            .setText(sprintf("%03u°", hdg));
        settimer(func me.updateHSI(getprop('orientation/heading-deg')), 0.1);
    },
};