Limpiando codigo. Todavia no entiendo todo

frog.cpp

 #include "mainwindow.h"
 #include "ui_mainwindow.h"
 
-frog::frog(QWidget *parent) :
-    QWidget(parent)
-{
-    myTimer= new QTimer(this);
-    flag = xFlag = false;
+
+// Constructor for the frog class
+
+frog::frog(QWidget *parent) : QWidget(parent) {
+
     Ysapo = 190;
     A = B = C = 0;
+
+    myTimer= new QTimer(this);
+    flag = xFlag = false;
+
+    // These are the x positions of the background?
     temp = 580;
     temp2 = 0;
+
     backFlag = false;
     moved = false;
-    textBool = false;
-    buttonCounter = 0;
-    xnenu = -(rand() %30);
-    Xsapo = xnenu;
-    initialX = Xsapo;
-    xnenu2 = (rand() % 100) + 100;
-    xnenu3 = xnenu2 + (rand() % 100) + 200;
+    showText = false;
+
+    computeNenuPositions();
 }
 
-void frog::updatenenu(){
+
+void frog::computeNenuPositions() {
     xnenu = -(rand() % 30);
     Xsapo = xnenu;
     initialX = Xsapo;
     temp2 = 0;
     backFlag = false;
     moved = false;
-    buttonCounter = 0;
-    textBool = false;
+    showText = false;
     repaint();
 
     myTimer->stop();
     delete myTimer;
     myTimer = new QTimer;
     connect(myTimer, SIGNAL(timeout()), this, SLOT(mySlot()));
-    xnenu = -(rand() %30);
-    Xsapo = xnenu;
-    initialX = Xsapo;
-    xnenu2 = (rand() % 100) + 100;
-    xnenu3 = xnenu2 + (rand() % 100) + 200;
 
+    computeNenuPositions();
 }
 
-void frog::paintEvent(QPaintEvent *event){
+void frog::paintEvent(QPaintEvent *){
     QPainter p(this);
-    QString frogger = ":/images/Frogger1.png";
+    QString frogger  = ":/images/Frogger1.png";
     QString frogger2 = ":/images/Frogger2.png";
     QString frogger3 = ":/images/Frogger3.png";
-    QString leaf = ":/images/Nenufar1.png";
-    QString back = ":/images/background.jpg";
+    QString leaf     = ":/images/Nenufar1.png";
+    QString back     = ":/images/background.jpg";
 
-//    Condiciones que permitian un rango de error (no caer en la x exacta de los nenufares)
+    //    Condiciones que permitian un rango de error (no caer en la x exacta de los nenufares)
 
     if(backFlag == true || (Xsapo <= (xnenu3 + 55) && Xsapo >= (xnenu3 - 55) && Ysapo == 190)
             || (Xsapo > xnenu && Ysapo == 190 && Xsapo < (xnenu2-55))
             || (Xsapo > xnenu2 && Ysapo == 190 && Xsapo < (xnenu3-55))
             || (Xsapo > xnenu3 && Ysapo == 190)){
 
-//    if(backFlag == true || (Ysapo == 190 && (Xsapo != xnenu && Xsapo != xnenu2))){
-        if (inter1Label == NULL){
-            delete inter1Label;
-        }
-        if (inter2Label == NULL){
-            delete inter2Label;
-        }
+        if (inter1Label == NULL)    delete inter1Label;
+        if (inter2Label == NULL)    delete inter2Label;
+
         backFlag = true;
         myTimer->stop();
         delete myTimer;
         QThread::msleep(5);
         connect(myTimer, SIGNAL(timeout()), this, SLOT(mySlot()));
 
-
-
         p.drawPixmap(temp2,-5,600,400,QPixmap(back));
         p.drawPixmap(temp,-5,600,400,QPixmap(back));
 
         p.drawPixmap(xnenu3,250,125,60,QPixmap(leaf));
         p.drawText(xnenu3+45,290,"x2 = " + QString::number(xnenu3));
 
-
-
         Xsapo=Xsapo-1;
         xnenu=xnenu-1;
         xnenu2=xnenu2-1;
         xnenu3=xnenu3-1;
+
+
+        // para que???
         temp= temp - 1;
         temp2 = temp2 -1;
 
-
         repaint();
 
-
-
         if(temp == 0 || xnenu3 == -10 || Xsapo == 0){
             backFlag = false;
             temp = 580;
             temp2 = 0;
             moved = true;
-            textBool = false;
-            updatenenu();
+            showText = false;
+            computeNenuPositions();
         }
 
     }
     else{
-          QFont font = p.font();
-          font.setBold(true);
-          p.setFont(font);
-
-          p.drawPixmap(temp2,-5,600,400,QPixmap(back));
-          p.drawPixmap(temp,-5,600,400,QPixmap(back));
-          p.drawPixmap(xnenu,250,125,60,QPixmap(leaf));
-          p.drawPixmap(xnenu2,250,125,60,QPixmap(leaf));
-          p.drawPixmap(xnenu3,250,125,60,QPixmap(leaf));
-
-//          Cambiada la condicion para que sea exacta la caida en el nenufar
-//          if(Xsapo < (xnenu2 + 55) && Ysapo == 190 && Xsapo > (xnenu2-55)){
-//               textBool = true;
-//          }
-
-          if(Ysapo == 190 && Xsapo == xnenu2){
-            textBool = true;
-          }
-
-          if(textBool){
-              p.drawText(xnenu2+35,290,"x1 = " + QString::number(xnenu2));
-              p.drawText(xnenu3+35,290,"x2 = " + QString::number(xnenu3));
-              p.drawPixmap(xnenu,250,125,60,QPixmap(leaf));
-          }
-          else{
-              p.drawText(xnenu2+35,290,"x2 = " + QString::number(xnenu2));
-          }
+        QFont font = p.font();
+        font.setBold(true);
+        p.setFont(font);
+
+        p.drawPixmap(temp2,-5,600,400,QPixmap(back));
+        p.drawPixmap(temp,-5,600,400,QPixmap(back));
+        p.drawPixmap(xnenu,250,125,60,QPixmap(leaf));
+        p.drawPixmap(xnenu2,250,125,60,QPixmap(leaf));
+        p.drawPixmap(xnenu3,250,125,60,QPixmap(leaf));
+
+        showText = (Ysapo == 190 && Xsapo == xnenu2);
+
+        if(showText){
+            p.drawText(xnenu2+35,290,"x1 = " + QString::number(xnenu2));
+            p.drawText(xnenu3+35,290,"x2 = " + QString::number(xnenu3));
+            p.drawPixmap(xnenu,250,125,60,QPixmap(leaf));
+        }
+        else
+            p.drawText(xnenu2+35,290,"x2 = " + QString::number(xnenu2));
 
     }
 
-//    Cambiada la condicion para que sea exacta la caida en el nenufar
+    //    Cambiada la condicion para que sea exacta la caida en el nenufar
     if(Xsapo > (xnenu + 55) && Ysapo == 190 && Xsapo < (xnenu2-55)
-        || (Xsapo > (xnenu2 + 55) && Ysapo == 190 && Xsapo < (xnenu3-55))
-        || (Xsapo > (xnenu3 + 55) && Ysapo == 190)){
+            || (Xsapo > (xnenu2 + 55) && Ysapo == 190 && Xsapo < (xnenu3-55))
+            || (Xsapo > (xnenu3 + 55) && Ysapo == 190)){
 
-//    if(Ysapo == 190 && (Xsapo != xnenu && Xsapo != xnenu2 && Xsapo != xnenu3)){
+        //    if(Ysapo == 190 && (Xsapo != xnenu && Xsapo != xnenu2 && Xsapo != xnenu3)){
         p.drawPixmap(Xsapo, Ysapo + 30, 100, 80, QPixmap(frogger3));
     }
     else if(Ysapo < 190){
     }else if(Ysapo == 190){
         qDebug() << "xsapo: " << Xsapo << "xnenu2: " << xnenu2;
         p.drawPixmap(Xsapo,Ysapo,100,100,QPixmap(frogger));
-        if(!textBool){
+        if(!showText){
             p.drawText(xnenu+45,290,"x1 = " + QString::number(xnenu+10));
         }
     }
 }
 
 
-void frog::mySlot(){
+void frog::animate(){
     float interX1 = 0;
     float interX2 = 0;
-    float temp = 0;
     float y = 0;
     float xtemp = 0;
     float xEnd = 0;
 
 
+    // use the functions implemented by the programmer to
+    // compute the x-intercept.
 
     interX1 = QuadraticMinus(A,B,C);
     interX2 = QuadraticPlus(A,B,C);
 
-    if(interX1 > interX2){
-        temp = interX1;
-        interX1 = interX2;
-        interX2 = temp;
-    }
-    if(moved){
+    if (interX1 > interX2) std::swap(interX1, interX2);
+
+
+    if (moved) {
         moved = false;
-        buttonCounter = 1;
         initialX = Xsapo;
     }
 
     xEnd = interX2 + initialX;
-        y = 1;
-        xtemp = 1;
-        if(!xFlag){
-            Ysapo = Ysapo - y;
-            Xsapo = Xsapo + xtemp;
-        }
-        else if(xFlag){
-            Ysapo = Ysapo + y;
-            Xsapo = Xsapo + xtemp;
-        }
+    y = 1;
+    xtemp = 1;
 
-        if(int(Xsapo) == int(xEnd/2)){
-            xFlag = true;
-        }
+    if(!xFlag){
+        Ysapo = Ysapo - y;
+        Xsapo = Xsapo + xtemp;
+    }
+    else if(xFlag){
+        Ysapo = Ysapo + y;
+        Xsapo = Xsapo + xtemp;
+    }
+
+    if(int(Xsapo) == int(xEnd/2)){
+        xFlag = true;
+    }
 
     repaint();
     if((int(Xsapo) == int(xEnd) && xFlag == true) || Ysapo == 190){
         myTimer->stop();
         delete myTimer;
         myTimer = new QTimer;
-        connect(myTimer, SIGNAL(timeout()), this, SLOT(mySlot()));
+        connect(myTimer, SIGNAL(timeout()), this, SLOT(animate()));
 
         initialX = Xsapo;
         xFlag = false;
     A = aa;
     B = bb;
     C = cc;
-    buttonCounter++;
+//    buttonCounter++;
 
     connect(myTimer, SIGNAL(timeout()), this, SLOT(mySlot()));
     myTimer->start(25);

frog.h

 public:
     explicit frog(QWidget *parent = 0);
     float Ysapo, Xsapo, initialX;
-    bool flag, xFlag, backFlag, moved, textBool;
-    int A, B, C, buttonCounter,temp,temp2,xnenu,xnenu2,xnenu3;
+    bool flag, xFlag, backFlag, moved, showText;
+
+    // coefficients from the quadratic formula
+    int A, B, C;
+
+    int temp,temp2,xnenu,xnenu2,xnenu3;
 
     double QuadraticPlus(int a, int b, int c);
     double QuadraticMinus(int a, int b, int c);
+    void computeNenuPositions();
     ~frog();
 
 private:
 signals:
 
 public slots:
-    void mySlot();
+    void animate();
     void run(int, int, int);
     void reset();
-    void updatenenu();
+
 
 protected:
     void paintEvent(QPaintEvent *event);

mainwindow.cpp

 {
     quadraticFormulaCheck();
 
-
     ui->setupUi(this);
     scene= new QGraphicsScene(this);
     scene->setSceneRect(QRectF(QPointF(0,0), QPointF(0,0)));
     ui->RunPushButton->move(10,385);
     ui->retryButton->move(180,385);
 
-
-
     frogger = new frog;
 
     globalTimer = new QTimer;
     scene->addWidget(frogger);
 
     ui->RunPushButton->setEnabled(false);
-
 }
 
 
     delete scene;
 }
 
+// This function validates if the results from the QuadraticPlus and QuadraticMinus
+// functions are correct. If they are not, then the program exits.
 
 void MainWindow::quadraticFormulaCheck()
 {
-    // float firstX;
     double resultFromFunction;
     bool pass = true;
+
+
+    // The values and valuesForMinus arrays contain precomputed a, b, c, and y values
+    // for the quadratic equations. They are used for testing if the functions written by
+    // the student are correct.
+    // For example: if a = 357, b = -1000, c = 698, then y = 1.4804781099
+
     double values[] = {357 , -1000 , 698 , 1.4804781099 , 748 , -392 , 51 , 0.28391805554 ,
-        689 , -689 , 172 , 0.519048482944 , 90 , 521 , 751 , -2.71178575308 , 5 , 107 ,
-        465 , -6.0642692054 , 1609 , -983 , 150 , 0.314734649792 , 273 , 496 , 224 ,
-        -0.839700867988 , 2 , 91 , 920 , -15.1630045473 , 48 , 300 , 463 , -2.77889067238 ,
-        852 , 907 , 241 , -0.510947439149};
+                       689 , -689 , 172 , 0.519048482944 , 90 , 521 , 751 , -2.71178575308 , 5 , 107 ,
+                       465 , -6.0642692054 , 1609 , -983 , 150 , 0.314734649792 , 273 , 496 , 224 ,
+                       -0.839700867988 , 2 , 91 , 920 , -15.1630045473 , 48 , 300 , 463 , -2.77889067238 ,
+                       852 , 907 , 241 , -0.510947439149};
 
     double valuesForMinus[] = {129 , -486 , 456 , 1.76744186047 , 384 , 980 , 625 , -1.30208333333 ,
-        270 , -904 , 755 , 1.59515823795 , 67 , -450 , 752 , 3.12650485528 , 98 , 506 , 651 ,
-        -2.72985550047 , 38 , -373 , 901 , 4.29396930804 , 273 , -282 , 72 , 0.461538461538 ,
-        225 , -889 , 874 , 1.84 , 8 , 136 , 522 , -11.1457513111 , 5 , 77 , 214 , -11.760788100};
+                               270 , -904 , 755 , 1.59515823795 , 67 , -450 , 752 , 3.12650485528 , 98 , 506 , 651 ,
+                               -2.72985550047 , 38 , -373 , 901 , 4.29396930804 , 273 , -282 , 72 , 0.461538461538 ,
+                               225 , -889 , 874 , 1.84 , 8 , 136 , 522 , -11.1457513111 , 5 , 77 , 214 , -11.760788100};
 
     double a, b, c, expected;
 
-    //Verifying if the equation written by the student is correct
+    // Validate the QuadraticPlus function....
+
     for (int i = 0; i < 40 && pass; i+=4){
         a        = values[i];
         b        = values[i+1];
         expected = values[i+3];
 
         resultFromFunction = frogger->QuadraticPlus(a,b,c);
-
-        if( fabs(resultFromFunction - expected) > 0.00001) {
-            pass = false;
-        }
+        pass = ( fabs(resultFromFunction - expected) < 0.00001) ;
     }
+
     if(!pass){
         QMessageBox::information(this, "Error", "La funcion cuadratica esta mal escrita!");
         exit(1);
     }
 
-    //Verifying if the equation written by the student is correct
+    // Validate the QuadraticMinus function....
+
     for (int i = 0; i < 40 && pass; i+=4){
         a        = valuesForMinus[i];
         b        = valuesForMinus[i+1];
         expected = valuesForMinus[i+3];
 
         resultFromFunction = frogger->QuadraticMinus(a,b,c);
-
-        if( fabs(resultFromFunction - expected) > 0.00001) {
-            pass = false;
-        }
+        pass =  ( fabs(resultFromFunction - expected) < 0.00001 );
     }
+
     if(!pass){
         QMessageBox::information(this, "Error", "La funcion cuadratica esta mal escrita!");
         exit(1);
     }
 }
 
-void MainWindow::on_RunPushButton_clicked()
-{
-    int a = 0;
-    int b = 0;
-    int c = 0;
-    int det = 0;
+void MainWindow::clearTheTextBoxes() {
+    ui->alineEdit->clear();
+    ui->blineEdit->clear();
+    ui->clineEdit->clear();
+}
+
+bool MainWindow::aTextBoxIsEmpty() {
+    return (ui->alineEdit->text().length() == 0 ||
+            ui->blineEdit->text().length() == 0 ||
+            ui->clineEdit->text().length() == 0);
+}
+
+
+void MainWindow::on_RunPushButton_clicked() {
+    int a = 0, b = 0, c = 0;
+    int det;
+
     a = (ui->alineEdit->text().toInt());
     b = (ui->blineEdit->text().toInt());
     c = (ui->clineEdit->text().toInt());
 
     det = (pow(b,2) - (4*a*c));
 
-    if(a > 0){
+    if(a > 0)
         QMessageBox::information(this, "Error", "La parabola abre hacia arriba y por lo tanto el sapo no brincara");
-        ui->alineEdit->clear();
-        ui->blineEdit->clear();
-        ui->clineEdit->clear();
-    }
-    else if(a == 0){
+    else if(a == 0)
         QMessageBox::information(this, "Error", "No hay parabola y por lo tanto el sapo no brincara");
-        ui->alineEdit->clear();
-        ui->blineEdit->clear();
-        ui->clineEdit->clear();
-    }
-    else{
-        if(det < 0){
+    else {
+        if(det < 0)
             QMessageBox::information(this, "Error", "No tiene intercepto y por lo tanto el sapo no brincara");
-            ui->alineEdit->clear();
-            ui->blineEdit->clear();
-            ui->clineEdit->clear();
-        }
-        else if(det == 0){
+        else if(det == 0)
             QMessageBox::information(this, "Error", "El vertice esta en el intercepto y por lo tanto el sapo no brincara");
-            ui->alineEdit->clear();
-            ui->blineEdit->clear();
-            ui->clineEdit->clear();
-        }
         else{
             frogger->run(a, b, c);
             ui->RunPushButton->setEnabled(false);
-            ui->alineEdit->clear();
-            ui->blineEdit->clear();
-            ui->clineEdit->clear();
         }
     }
-
-
+    clearTheTextBoxes();
 }
 
-void MainWindow::on_retryButton_clicked()
-{
+void MainWindow::on_retryButton_clicked() {
     frogger->reset();
 }
 
-void MainWindow::on_alineEdit_textChanged(const QString &)
-{
-    if(ui->alineEdit->text() != "" && ui->blineEdit->text() != "" && ui->clineEdit->text() != "" ){
-        ui->RunPushButton->setEnabled(true);
-    }
-    else{
-        ui->RunPushButton->setEnabled(false);
-    }
+void MainWindow::on_alineEdit_textChanged(const QString &) {
+    ui->RunPushButton->setEnabled(!aTextBoxIsEmpty());
 }
 
-void MainWindow::on_blineEdit_textChanged(const QString &)
-{
-    if(ui->alineEdit->text() != "" && ui->blineEdit->text() != "" && ui->clineEdit->text() != "" ){
-        ui->RunPushButton->setEnabled(true);
-    }
-    else{
-        ui->RunPushButton->setEnabled(false);
-    }
+void MainWindow::on_blineEdit_textChanged(const QString &) {
+    ui->RunPushButton->setEnabled(!aTextBoxIsEmpty());
 }
 
-void MainWindow::on_clineEdit_textChanged(const QString &)
-{
-    if(ui->alineEdit->text() != "" && ui->blineEdit->text() != "" && ui->clineEdit->text() != "" ){
-        ui->RunPushButton->setEnabled(true);
-    }
-    else{
-        ui->RunPushButton->setEnabled(false);
-    }
+void MainWindow::on_clineEdit_textChanged(const QString &) {
+    ui->RunPushButton->setEnabled(!aTextBoxIsEmpty());
 }

mainwindow.h

 
     void on_clineEdit_textChanged(const QString &arg1);
 
+    void clearTheTextBoxes();
+
+    bool aTextBoxIsEmpty();
+
 private:
     Ui::MainWindow *ui;
     QGraphicsScene*scene;