tetrixboard.cpp Example File

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  #include <QtWidgets>

  #include "tetrixboard.h"

  TetrixBoard::TetrixBoard(QWidget *parent)
      : QFrame(parent)
  {
      setFrameStyle(QFrame::Panel | QFrame::Sunken);
      setFocusPolicy(Qt::StrongFocus);
      isStarted = false;
      isPaused = false;
      clearBoard();

      nextPiece.setRandomShape();
  }

  void TetrixBoard::setNextPieceLabel(QLabel *label)
  {
      nextPieceLabel = label;
  }

  QSize TetrixBoard::sizeHint() const
  {
      return QSize(BoardWidth * 15 + frameWidth() * 2,
                   BoardHeight * 15 + frameWidth() * 2);
  }

  QSize TetrixBoard::minimumSizeHint() const
  {
      return QSize(BoardWidth * 5 + frameWidth() * 2,
                   BoardHeight * 5 + frameWidth() * 2);
  }

  void TetrixBoard::start()
  {
      if (isPaused)
          return;

      isStarted = true;
      isWaitingAfterLine = false;
      numLinesRemoved = 0;
      numPiecesDropped = 0;
      score = 0;
      level = 1;
      clearBoard();

      emit linesRemovedChanged(numLinesRemoved);
      emit scoreChanged(score);
      emit levelChanged(level);

      newPiece();
      timer.start(timeoutTime(), this);
  }

  void TetrixBoard::pause()
  {
      if (!isStarted)
          return;

      isPaused = !isPaused;
      if (isPaused) {
          timer.stop();
      } else {
          timer.start(timeoutTime(), this);
      }
      update();
  }

  void TetrixBoard::paintEvent(QPaintEvent *event)
  {
      QFrame::paintEvent(event);

      QPainter painter(this);
      QRect rect = contentsRect();

      if (isPaused) {
          painter.drawText(rect, Qt::AlignCenter, tr("Pause"));
          return;
      }

      int boardTop = rect.bottom() - BoardHeight*squareHeight();

      for (int i = 0; i < BoardHeight; ++i) {
          for (int j = 0; j < BoardWidth; ++j) {
              TetrixShape shape = shapeAt(j, BoardHeight - i - 1);
              if (shape != NoShape)
                  drawSquare(painter, rect.left() + j * squareWidth(),
                             boardTop + i * squareHeight(), shape);
          }
      }

      if (curPiece.shape() != NoShape) {
          for (int i = 0; i < 4; ++i) {
              int x = curX + curPiece.x(i);
              int y = curY - curPiece.y(i);
              drawSquare(painter, rect.left() + x * squareWidth(),
                         boardTop + (BoardHeight - y - 1) * squareHeight(),
                         curPiece.shape());
          }
      }
  }

  void TetrixBoard::keyPressEvent(QKeyEvent *event)
  {
      if (!isStarted || isPaused || curPiece.shape() == NoShape) {
          QFrame::keyPressEvent(event);
          return;
      }

      switch (event->key()) {
      case Qt::Key_Left:
          tryMove(curPiece, curX - 1, curY);
          break;
      case Qt::Key_Right:
          tryMove(curPiece, curX + 1, curY);
          break;
      case Qt::Key_Down:
          tryMove(curPiece.rotatedRight(), curX, curY);
          break;
      case Qt::Key_Up:
          tryMove(curPiece.rotatedLeft(), curX, curY);
          break;
      case Qt::Key_Space:
          dropDown();
          break;
      case Qt::Key_D:
          oneLineDown();
          break;
      default:
          QFrame::keyPressEvent(event);
      }
  }

  void TetrixBoard::timerEvent(QTimerEvent *event)
  {
      if (event->timerId() == timer.timerId()) {
          if (isWaitingAfterLine) {
              isWaitingAfterLine = false;
              newPiece();
              timer.start(timeoutTime(), this);
          } else {
              oneLineDown();
          }
      } else {
          QFrame::timerEvent(event);
      }
  }

  void TetrixBoard::clearBoard()
  {
      for (int i = 0; i < BoardHeight * BoardWidth; ++i)
          board[i] = NoShape;
  }

  void TetrixBoard::dropDown()
  {
      int dropHeight = 0;
      int newY = curY;
      while (newY > 0) {
          if (!tryMove(curPiece, curX, newY - 1))
              break;
          --newY;
          ++dropHeight;
      }
      pieceDropped(dropHeight);
  }

  void TetrixBoard::oneLineDown()
  {
      if (!tryMove(curPiece, curX, curY - 1))
          pieceDropped(0);
  }

  void TetrixBoard::pieceDropped(int dropHeight)
  {
      for (int i = 0; i < 4; ++i) {
          int x = curX + curPiece.x(i);
          int y = curY - curPiece.y(i);
          shapeAt(x, y) = curPiece.shape();
      }

      ++numPiecesDropped;
      if (numPiecesDropped % 25 == 0) {
          ++level;
          timer.start(timeoutTime(), this);
          emit levelChanged(level);
      }

      score += dropHeight + 7;
      emit scoreChanged(score);
      removeFullLines();

      if (!isWaitingAfterLine)
          newPiece();
  }

  void TetrixBoard::removeFullLines()
  {
      int numFullLines = 0;

      for (int i = BoardHeight - 1; i >= 0; --i) {
          bool lineIsFull = true;

          for (int j = 0; j < BoardWidth; ++j) {
              if (shapeAt(j, i) == NoShape) {
                  lineIsFull = false;
                  break;
              }
          }

          if (lineIsFull) {
              ++numFullLines;
              for (int k = i; k < BoardHeight - 1; ++k) {
                  for (int j = 0; j < BoardWidth; ++j)
                      shapeAt(j, k) = shapeAt(j, k + 1);
              }
              for (int j = 0; j < BoardWidth; ++j)
                  shapeAt(j, BoardHeight - 1) = NoShape;
          }
      }

      if (numFullLines > 0) {
          numLinesRemoved += numFullLines;
          score += 10 * numFullLines;
          emit linesRemovedChanged(numLinesRemoved);
          emit scoreChanged(score);

          timer.start(500, this);
          isWaitingAfterLine = true;
          curPiece.setShape(NoShape);
          update();
      }
  }

  void TetrixBoard::newPiece()
  {
      curPiece = nextPiece;
      nextPiece.setRandomShape();
      showNextPiece();
      curX = BoardWidth / 2 + 1;
      curY = BoardHeight - 1 + curPiece.minY();

      if (!tryMove(curPiece, curX, curY)) {
          curPiece.setShape(NoShape);
          timer.stop();
          isStarted = false;
      }
  }

  void TetrixBoard::showNextPiece()
  {
      if (!nextPieceLabel)
          return;

      int dx = nextPiece.maxX() - nextPiece.minX() + 1;
      int dy = nextPiece.maxY() - nextPiece.minY() + 1;

      QPixmap pixmap(dx * squareWidth(), dy * squareHeight());
      QPainter painter(&pixmap);
      painter.fillRect(pixmap.rect(), nextPieceLabel->palette().background());

      for (int i = 0; i < 4; ++i) {
          int x = nextPiece.x(i) - nextPiece.minX();
          int y = nextPiece.y(i) - nextPiece.minY();
          drawSquare(painter, x * squareWidth(), y * squareHeight(),
                     nextPiece.shape());
      }
      nextPieceLabel->setPixmap(pixmap);
  }

  bool TetrixBoard::tryMove(const TetrixPiece &newPiece, int newX, int newY)
  {
      for (int i = 0; i < 4; ++i) {
          int x = newX + newPiece.x(i);
          int y = newY - newPiece.y(i);
          if (x < 0 || x >= BoardWidth || y < 0 || y >= BoardHeight)
              return false;
          if (shapeAt(x, y) != NoShape)
              return false;
      }

      curPiece = newPiece;
      curX = newX;
      curY = newY;
      update();
      return true;
  }

  void TetrixBoard::drawSquare(QPainter &painter, int x, int y, TetrixShape shape)
  {
      static const QRgb colorTable[8] = {
          0x000000, 0xCC6666, 0x66CC66, 0x6666CC,
          0xCCCC66, 0xCC66CC, 0x66CCCC, 0xDAAA00
      };

      QColor color = colorTable[int(shape)];
      painter.fillRect(x + 1, y + 1, squareWidth() - 2, squareHeight() - 2,
                       color);

      painter.setPen(color.light());
      painter.drawLine(x, y + squareHeight() - 1, x, y);
      painter.drawLine(x, y, x + squareWidth() - 1, y);

      painter.setPen(color.dark());
      painter.drawLine(x + 1, y + squareHeight() - 1,
                       x + squareWidth() - 1, y + squareHeight() - 1);
      painter.drawLine(x + squareWidth() - 1, y + squareHeight() - 1,
                       x + squareWidth() - 1, y + 1);
  }