Function Graphing with MATLAB & Sparkfun Digital Sandbox

% This function displays the key points for the graph selected by the user. 
function Grapher(app, index)
    if strcmp(app.graphChoices(index),'Linear 1')
        hold(app.UIAxes, 'off');
        plot([0 .2 .4 .6 .8 1],[0 .2 .4 .6 .8 1],'ro','Parent',app.UIAxes);
        app.XPoints = [0 0.2 0.4 0.6 0.8 1];
        app.YPoints = [0 0.2 0.4 0.6 0.8 1];
        hold(app.UIAxes,'on');
        app.UIAxes.Title.String = 'Unknown Function';
        app.sliderIndicator = line(0,0,'Marker','o','MarkerFaceColor',[1 0 0],'Parent', app.UIAxes);
        drawnow limitrate;
    elseif strcmp(app.graphChoices(index),'Linear 2')
        hold(app.UIAxes, 'off');
        plot([0 .2 .4 .6 .8 1], [1 .8 .6 .4 .2 0], 'ro', 'Parent', app.UIAxes);
        app.XPoints = [0 0.2 0.4 0.6 0.8 1];
        app.YPoints = [1 0.8 0.6 0.4 0.2 0];
        hold(app.UIAxes,'on');
        app.UIAxes.Title.String = 'Unknown Function';
        app.sliderIndicator = line(0,0,'Marker','o','MarkerFaceColor',[1 0 0],'Parent', app.UIAxes);
        drawnow limitrate;
    elseif strcmp(app.graphChoices(index),'Sinusoid 1')
        hold(app.UIAxes,'off')
        plot(round(0:pi/2:2*pi,1), round(sin(0:pi/2:2*pi),1), 'ro','Parent', app.UIAxes)
        app.XPoints = 0:pi/2:2*pi;
        app.YPoints = round(sin(0:pi/2:2*pi));
        hold(app.UIAxes,'on');
        app.UIAxes.Title.String = 'Unknown Function';
        app.sliderIndicator = line(0,0,'Marker','o','MarkerFaceColor',[1 0 0],'Parent', app.UIAxes);
        drawnow limitrate;
    elseif strcmp(app.graphChoices(index),'Sinusoid 2')
        hold(app.UIAxes,'off')
        plot(round(0:pi/2:2*pi,1), round(cos(0:pi/2:2*pi),1), 'ro','Parent', app.UIAxes)
        app.XPoints = 0:pi/2:2*pi;
        app.YPoints = round(cos(0:pi/2:2*pi),1);
        hold(app.UIAxes,'on');
        app.UIAxes.Title.String = 'Unknown Function';
        app.sliderIndicator = line(0,0,'Marker','o','MarkerFaceColor',[1 0 0],'Parent', app.UIAxes);
        drawnow limitrate;
    end
end

% This function determines whether the user selects a correct point or not and contains function calls to a majority of the game's main operations.
function CheckPts(app, index)
    app.ButtonIsPressed = readDigitalPin(app.a, app.buttonPin);
    if app.ButtonIsPressed && strcmp(app.graphChoices(index), 'Linear 1')
        if find(app.XPoints == app.sliderIndicator.XData) == (find(app.YPoints == app.sliderIndicator.YData))
            correctAnswer(app);
            progressGraph(app, index);
        else
            wrongAnswer(app);
        end
    elseif app.ButtonIsPressed && strcmp(app.graphChoices(index), 'Linear 2')
        if find(app.XPoints == app.sliderIndicator.XData) == (find(app.YPoints == app.sliderIndicator.YData))
            correctAnswer(app);
            progressGraph(app, index);
        else
            wrongAnswer(app);
        end
    elseif app.ButtonIsPressed && strcmp(app.graphChoices(index), 'Sinusoid 1')
        if any(find(app.XPoints == app.sliderIndicator.XData) == (find(app.YPoints == app.sliderIndicator.YData)))
            correctAnswer(app);
            progressGraph(app, index);
        else
            wrongAnswer(app);
        end
    elseif app.ButtonIsPressed && strcmp(app.graphChoices(index), 'Sinusoid 2')
        if any(find(app.XPoints == app.sliderIndicator.XData) == (find(app.YPoints == app.sliderIndicator.YData)))
            correctAnswer(app);
            progressGraph(app, index);
        else
            wrongAnswer(app);
        end
    end
end

% This function handles the case where the user selects a correct point. It keeps a log of all of the correct points that they selected on the current graph. Additionally, it handles the case where they already pressed a point.
function correctAnswer(app)
    if ~isempty(app.pointsPressed) && ismember([app.sliderIndicator.XData, app.sliderIndicator.YData], app.pointsPressed,'rows')
        app.Lamp.Color = 'yellow';
        app.TextArea.Value = 'You already pressed that! Try something else.';
    else
        writeDigitalPin(app.a, app.correctPin, 1);
        pause(.5)
        writeDigitalPin(app.a, app.correctPin, 0);
        app.Lamp.Color = 'green';
        app.numCorrect = app.numCorrect + 1;
        app.pointsPressed(app.numCorrect,1) = app.sliderIndicator.XData;
        app.pointsPressed(app.numCorrect,2) = app.sliderIndicator.YData;
        plot(round(app.sliderIndicator.XData,1), app.sliderIndicator.YData, 'go', 'Parent', app.UIAxes);
        hold(app.UIAxes,'on')
        app.TextArea.Value = 'Good job! Keep it up!';
    end
end

% This function handles the case where the user selects an incorrect point. 
function wrongAnswer(app)
    writeDigitalPin(app.a, app.wrongPin, 1);
    pause(.5)
    writeDigitalPin(app.a, app.wrongPin, 0);
    app.Lamp.Color = 'red';
    app.TextArea.Value = 'Oh no! That is not correct.  You should try one of the highlighted points';
end

% This function creates a graph of the function that the user is learning up to the maximum X point that they correctly selected. 
function progressGraph(app,index)
    if strcmp(app.graphChoices(index), 'Linear 1')
        plot(0:0.2:app.sliderIndicator.XData, 0:0.2:app.sliderIndicator.YData, 'Color', [0 1 0], 'Parent', app.UIAxes)
        hold(app.UIAxes,'on')
    elseif strcmp(app.graphChoices(index), 'Linear 2')
        plot(0:0.2:app.sliderIndicator.XData, 1:-0.2:app.sliderIndicator.YData, 'Color', [0 1 0], 'Parent', app.UIAxes)
        hold(app.UIAxes,'on')
    elseif strcmp(app.graphChoices(index), 'Sinusoid 1')
        plot(0:pi/20:app.sliderIndicator.XData, sin(0:pi/20:app.sliderIndicator.XData), 'Color', [0 1 0], 'Parent', app.UIAxes)
        hold(app.UIAxes,'on')
    elseif strcmp(app.graphChoices(index), 'Sinusoid 2')
        plot(0:pi/20:app.sliderIndicator.XData, cos(0:pi/20:app.sliderIndicator.XData), 'Color', [0 1 0], 'Parent', app.UIAxes)
        hold(app.UIAxes,'on')
    end
    if length(app.pointsPressed) == length(app.XPoints)
        GraphComplete(app,index);
        app.pointsPressed = [];
    end
end

function ButtonButtonPushed(app)
% Determine what graphs the user wants to learn
  determineMode(app);
  
% Don't start the game until the on/off switch (slide switch) is in the 'ON' position
  while 1
      app.SwitchIsOn = readDigitalPin(app.a, app.switchPin);
      if app.SwitchIsOn
          break
      end
  end
  
% For each option that they selected, graph the key points of the function  
  for k = 1:length(app.graphChoices)
      Grapher(app, k);
      while true
% If they ever change the position of the on/off switch, end the game
          app.SwitchIsOn = readDigitalPin(app.a, app.switchPin);
          if ~app.SwitchIsOn
              break;
          else
% Determine the x and y coordinates for the user's cursor and make sure the 
% y-coordinate is within the range of the Y-Axis
              app.x = round(readVoltage(app.a, app.slidePin) / app.slideMax,1);
              app.y = round(readVoltage(app.a, app.photoPin) / app.photoMax, 1);
              if app.y >= 1
                  app.y = 1;
              end
              
% If they are currently learning a Sinusoid, digitize their raw inputs
              if strcmp(app.graphChoices(k), 'Sinusoid 1') || strcmp(app.graphChoices(k), 'Sinusoid 2')
                  SinusoidScaler(app);
              end
              
% Update the position of the user's cursor in the game and check if they have pressed a correct point
              app.sliderIndicator.XData = app.x;
              app.sliderIndicator.YData = app.y;
              drawnow limitrate;
              CheckPts(app, k);
              
% If they pressed all of the necessary points, reset the graphing axes and move on the next function that they want to learn
              if isempty(app.pointsPressed) && app.numCorrect ~= 0
                  app.numCorrect = 0;
                  app.TextArea.Value = '';
                  app.UIAxes.Title.String = ''; 
                  app.Lamp.Color = [1 1 1];
                  break;
              end
          end                
      end
  end
% If they learned all of the functions, show them the dancing function man
  if length(app.graphChoices) == 4
      app.UIAxes.Title.String = 'The Function Dance!';
      app.TextArea.Value = 'Check out this dance of the functions that you learned!';
      pause(1);
    
% Create the dancing man's body 
      app.faceX = app.radiusOfFace*cosd(0:360);
      app.faceY = app.radiusOfFace*sind(0:360) +3;
      app.bodyX = 0*ones(1,5);
      app.bodyY = app.radiusOfFace+1:-1:app.radiusOfFace-3;
      app.leftLegX = app.radiusOfFace-1:-1:app.radiusOfFace-4;
      app.leftLegY = app.radiusOfFace-3:-1:app.radiusOfFace-6; 
      app.rightLegX = app.radiusOfFace-1:1:app.radiusOfFace+2;
      app.rightLegY = app.radiusOfFace-3:-1:app.radiusOfFace-6;   
      app.handX = -pi:pi/30:pi;
      hold(app.UIAxes,'off')
% Show them the dance for Y = X and Y = -X
      for i = 1:2
          app.UIAxes.Title.String = 'Y = -X and Y = X';
          app.TextArea.Value = 'Check out what Y = X and Y = -X look like!';
          plot(app.faceX, app.faceY,'b', 'Parent', app.UIAxes)
          hold(app.UIAxes, 'on');
          plot(app.bodyX,app.bodyY,'b', 'Parent', app.UIAxes)
          plot(app.leftLegX,app.leftLegY,'b', 'Parent', app.UIAxes)
          plot(app.rightLegX,app.rightLegY,'b', 'Parent', app.UIAxes)
          
          hold(app.UIAxes, 'on');
          app.handY = abs(app.handX);
          plot(app.handX, app.handY,'b', 'Parent', app.UIAxes)
          hold(app.UIAxes,'off')
          pause(1)
          
          plot(app.faceX, app.faceY,'b','Parent', app.UIAxes )
          hold(app.UIAxes, 'on');
          plot(app.bodyX,app.bodyY,'b', 'Parent', app.UIAxes)
          plot(app.leftLegX,app.leftLegY,'b', 'Parent', app.UIAxes)
          plot(app.rightLegX,app.rightLegY,'b', 'Parent', app.UIAxes)
          
          app.handY = -abs(app.handX);
          plot(app.handX, app.handY,'b', 'Parent', app.UIAxes)
          
          pause(1)
          hold(app.UIAxes,'off')  
      end
% Show them the dance for Y = sin(x) and Y = cos(x)
      for i = 1:2
          app.UIAxes.Title.String = 'Y = sin(x) and Y= cos(x)';
          app.TextArea.Value = 'Check out what Y = sin(x) and Y = cos(x) look like!';
          plot(app.faceX, app.faceY,'b', 'Parent', app.UIAxes)
          hold(app.UIAxes, 'on');
          plot(app.bodyX,app.bodyY,'b', 'Parent', app.UIAxes)
          plot(app.leftLegX,app.leftLegY,'b', 'Parent', app.UIAxes)
          plot(app.rightLegX,app.rightLegY,'b', 'Parent', app.UIAxes)
          
          app.handY = sin(app.handX);
          plot(app.handX, app.handY,'b', 'Parent', app.UIAxes)
          hold(app.UIAxes,'off')
          pause(1)

          plot(app.faceX, app.faceY,'b', 'Parent', app.UIAxes)
          hold(app.UIAxes, 'on');
          plot(app.bodyX,app.bodyY,'b', 'Parent', app.UIAxes)
          plot(app.leftLegX,app.leftLegY,'b', 'Parent', app.UIAxes)
          plot(app.rightLegX,app.rightLegY,'b', 'Parent', app.UIAxes)
          
          app.handY = -sin(app.handX);
          plot(app.handX, app.handY,'b', 'Parent', app.UIAxes)
          
          pause(1);
          hold(app.UIAxes,'off');
      end
% Once the man finishes dancing, the game is over until they select another mode
      app.TextArea.Value = 'Thanks for playing!';
  end