Letter Match

JKMSMKJ
/
Letter Match
on 2 Nov 2026
2
15
10
0
9715
game.m
function g = game()
%LETTERMATCH One-button letter-matching game.
%
%   A word is shown at the top; its next letter glows gold. Letters
%   rise from the bottom of the screen. Tap when the gold letter is
%   inside the gold band. A miss costs -1, a wrong letter -2. Match
%   all 5 words and compare your score with the ideal.

g.init   = @initState;
g.update = @updateState;
g.render = @renderFrame;
end

function state = initState(ax)
    ax.YDir = 'reverse';
    ax.Color = [0.04 0.05 0.10];

    % ---- game constants ----
    state.WORDS = {'SHEAR' 'ROTATE' 'REFLECT' 'SYMMETRY' 'TRANSFORM'};
    state.bandTop = 150;    % gold band bounds (y dir is reversed)
    state.bandMid = 180;
    state.bandBottom = 210;
    state.nPool = 15; % letters to float up!

    % ---- state ----
    state.mode = 'title'; % title | play | clear | won
    state.t = 0;
    state.round = 1;
    state.score = 0;
    state.roundStartScore = 0;
    state.progress = 0;
    state.spawnT = 0;
    state.flashT = 0;
    state.flashKind = 0; % 1 = decoy, 2 = miss
    state.popT = 0;
    state.popIdx = 0;
    state.guardT = 0.5;

    % letter stream pool
    state.letActive = false(1, state.nPool);
    state.letX = zeros(1, state.nPool);
    state.letY = zeros(1, state.nPool);
    state.letV = zeros(1, state.nPool);
    state.letPh = zeros(1, state.nPool);
    state.letC = repmat({''}, 1, state.nPool);

    % ---- graphics (all created once; render only mutates) ----
    state.gh.band = rectangle(ax, Position=[0 state.bandTop 800 state.bandBottom - state.bandTop], LineWidth=1.5,...
        EdgeColor=[1 0.80 0.25], FaceColor=[0.30 0.22 0.02]);
    state.gh.word = gobjects(1, 9);
    for k = 1:9
        state.gh.word(k) = text(ax, 400, 90, '', FontName='Courier New', FontSize=30, FontWeight='bold',...
            HorizontalAlignment='center', Color=[0.62 0.72 0.90], Visible='off');
    end
    state.gh.let = gobjects(1, state.nPool);
    for k = 1:state.nPool
        state.gh.let(k) = text(ax, 0, 0, '', FontName='Courier New', FontSize=24, FontWeight='bold',...
            HorizontalAlignment='center', Color=[0.90 0.96 1], Visible='off');
    end
    state.gh.score = text(ax, 15, 22, '', FontSize=16, FontWeight='bold', Color=[0.90 0.92 1]);
    state.gh.round = text(ax, 785, 22, '', FontSize=16, FontWeight='bold', HorizontalAlignment='right',...
        Color=[0.90 0.92 1]);
    state.gh.msg = text(ax, 400, 285, '', FontWeight='bold', HorizontalAlignment='center', Color=[1 0.85 0.35]);
    state.gh.sub = text(ax, 400, 355, '', FontSize=20, HorizontalAlignment='center', Color=[0.70 0.80 1]);
    state.gh.prompt = text(ax, 400, 470, '', FontSize=20, FontWeight='bold', HorizontalAlignment='center',...
        Color=[0.35 1 0.60]);
    % clicks must reach the button handler, not the graphics
    set([state.gh.band, state.gh.word, state.gh.let, state.gh.score,...
        state.gh.round, state.gh.msg, state.gh.sub, state.gh.prompt], HitTest='off', PickableParts='none');
end

function state = updateState(state, dt, pressed)
    state.t = state.t + dt;
    if state.popT > 0
        state.popT = state.popT - dt;
    end
    if state.flashT > 0
        state.flashT = state.flashT - dt;
    end
    if state.guardT > 0
        state.guardT = state.guardT - dt;
    end

    switch state.mode
        case 'title'
            if pressed && state.guardT <= 0
                state = startRound(state, 1);
            end
        case 'play'
            if pressed
                state = handleTap(state);
            end
            if strcmp(state.mode, 'play')
                state = stepLetters(state, dt);
                state.spawnT = state.spawnT - dt;
                if state.spawnT <= 0
                    state = spawnLetter(state);
                end
            end
        otherwise % clear | won
            if pressed && state.guardT <= 0
                if strcmp(state.mode, 'clear')
                    state = startRound(state, state.round + 1);
                else
                    state.mode = 'title';
                    state.round = 1;
                    state.score = 0;
                    state.guardT = 0.5;
                end
            end
    end
end

function state = startRound(state, r)
    state.round = r;
    state.progress = 0;
    state.roundStartScore = state.score;
    state.letActive(:) = false;
    state.spawnT = 0.3;
    state.mode = 'play';
    state.guardT = 0.5;
end

function state = handleTap(state)
    mask = state.letActive & state.letY >= state.bandTop & state.letY <= state.bandBottom;
    idxs = find(mask);
    if isempty(idxs)
        state.score = state.score - 1; % missed
        state.flashT = 0.30;
        state.flashKind = 2;
        return
    end
    [~, b] = min(abs(state.letY(idxs) - state.bandMid));
    k = idxs(b);
    word = state.WORDS{state.round};
    needed = word(state.progress + 1);
    if strcmp(state.letC{k}, needed)
        state.score = state.score + 1; % matched
        state.progress = state.progress + 1;
        state.letActive(k) = false;
        state.popT = 0.25;
        state.popIdx = state.progress;
        if state.progress >= numel(word)
            state.letActive(:) = false;
            if state.round >= numel(state.WORDS)
                state.mode = 'won';
            else
                state.mode = 'clear';
            end
            state.guardT = 0.5;
        end
    else
        state.score = state.score - 2; % decoy penalty
        state.flashT = 0.35;
        state.flashKind = 1;
    end
end

function state = stepLetters(state, dt)
    for k = 1:state.nPool
        if state.letActive(k)
            state.letY(k) = state.letY(k) - state.letV(k) * dt;
            state.letPh(k) = state.letPh(k) + 2.5 * dt;
            if state.letY(k) < -30
                state.letActive(k) = false;
            end
        end
    end
end

function state = spawnLetter(state)
    word = state.WORDS{state.round};
    needed = word(state.progress + 1);
    if rand < 0.30
        c = needed;
    else
        c = char(64 + randi(26));
        if strcmp(c, needed) % decoy is never the needed letter
            c = char(65 + mod(c - 65 + randi(25), 26));
        end
    end
    k = find(~state.letActive, 1);
    if isempty(k)
        state.spawnT = 0.15; % pool full: retry soon
        return
    end
    state.letActive(k) = true;
    state.letX(k) = 70 + 660 * rand;
    state.letY(k) = 640;
    state.letV(k) = (135 + 12 * state.round) * (0.85 + 0.30 * rand);
    state.letC{k} = c;
    state.letPh(k) = 6.28 * rand;
    state.spawnT = max(0.3, 0.6 - 0.05 * state.round) * (0.75 + 0.5 * rand);
end

function renderFrame(~, state)
    % rising letters
    for k = 1:state.nPool
        if state.letActive(k)
            set(state.gh.let(k), String=state.letC{k}, Position=[state.letX(k) + 9*sin(state.letPh(k)),...
                state.letY(k), 0], Visible='on');
        else
            state.gh.let(k).Visible ='off';
        end
    end

    % gold band flash color
    if state.flashT > 0 && state.flashKind == 1
        state.gh.band.FaceColor = [0.45 0.08 0.08];
    elseif state.flashT > 0 && state.flashKind == 2
        state.gh.band.FaceColor = [0.25 0.25 0.30];
    else
        state.gh.band.FaceColor = [0.30 0.22 0.02];
    end

    % word at the top
    showWord = strcmp(state.mode, 'play') || strcmp(state.mode, 'clear');
    if showWord
        word = state.WORDS{state.round};
        n = numel(word);
    end
    for i = 1:9
        h = state.gh.word(i);
        if showWord && i <= n
            h.String = word(i);
            h.Position = [400 + (i - (n + 1) / 2) * 42, 90, 0];
            if i <= state.progress
                h.Color = [0.35 1 0.60]; % matched
            elseif i == state.progress + 1 && strcmp(state.mode, 'play')
                h.Color = [1 0.85 0.35]; % next needed
            else
                h.Color = [0.62 0.72 0.90]; % pending (bright for dark bg)
            end
            if state.popT > 0 && i == state.popIdx
                h.FontSize = 36;
            else
                h.FontSize = 30;
            end
            h.Visible = 'on';
        else
            h.Visible = 'off';
        end
    end

    % HUD
    state.gh.score.String = sprintf('SCORE: %d', state.score);
    state.gh.round.String = sprintf('ROUND: %d/5', state.round);

    % center messages
    msgSize = 32;
    switch state.mode
        case 'title'
            state.gh.msg.String = 'LETTER MATCH';
            state.gh.msg.Visible = 'on';
            state.gh.sub.String = sprintf(['A word will be displayed above. Letters will rise from below.\n',...
                'Tap when a letter matching the golden letter of the word is in the gold band.\n' ...
                'Right letter: 1   Missed letter: -1   Wrong letter: -2']);
            state.gh.sub.Visible = 'on';
            state.gh.prompt.String = 'TAP TO START';
            state.gh.prompt.Visible = mod(state.t, 1.2) < 0.75;
        case 'play'
            state.gh.msg.Visible = 'off';
            state.gh.sub.Visible = 'off';
            state.gh.prompt.Visible = 'off';
        case 'clear'
            msgSize = 22;
            rs = state.score - state.roundStartScore;
            cumIdeal = sum(cellfun(@numel, state.WORDS(1:state.round)));
            state.gh.msg.String = sprintf('Round %d Clear!', state.round);
            state.gh.msg.Visible = 'on';
            state.gh.sub.String = sprintf('Round: %d / %d\nTotal: %d / %d', rs, numel(state.WORDS{state.round}),...
                state.score, cumIdeal);
            state.gh.sub.Visible = 'on';
            state.gh.prompt.String = 'TAP FOR NEXT WORD';
            state.gh.prompt.Visible = mod(state.t, 1.2) < 0.75;
        otherwise  % won: verdict replaces the round-clear text
            msgSize = 26;
            rs = state.score - state.roundStartScore;
            cumIdeal = sum(cellfun(@numel, state.WORDS(1:state.round)));
            if state.score > 0
                vind = 'You WON!';
            elseif state.score < 0
                vind = 'You LOST!';
            else
                vind = 'You LEGEND!';
            end
            state.gh.msg.String = vind;
            state.gh.msg.Visible = 'on';
            state.gh.sub.String = sprintf('Round: %d / %d\nTotal: %d / %d', rs, numel(state.WORDS{state.round}),...
                state.score, cumIdeal);
            state.gh.sub.Visible = 'on';
            state.gh.prompt.String = 'TAP TO PLAY AGAIN';
            state.gh.prompt.Visible = mod(state.t, 1.2) < 0.75;
    end
    state.gh.msg.FontSize = msgSize;
end
Play Game
Preview

Play Game opens this in MATLAB Drive. Click Run this app there to play.