XNA 4.0 Game Development by Example: Beginner's Guide

上QQ阅读APP看书，第一时间看更新

Time for action – handling mouse input

Add the HandleMouseInput() helper method to the Game1 class:

private void HandleMouseInput(MouseState mouseState)
{

    int x = ((mouseState.X -
        (int)gameBoardDisplayOrigin.X) / GamePiece.PieceWidth);

    int y = ((mouseState.Y -
        (int)gameBoardDisplayOrigin.Y) / GamePiece.PieceHeight);

    if ((x >= 0) && (x < GameBoard.GameBoardWidth) &&
      (y >= 0) && (y < GameBoard.GameBoardHeight))
    {
        if (mouseState.LeftButton == ButtonState.Pressed)
        {
            gameBoard.RotatePiece(x, y, false);
            timeSinceLastInput = 0.0f;
        }

        if (mouseState.RightButton == ButtonState.Pressed)
        {
            gameBoard.RotatePiece(x, y, true);
            timeSinceLastInput = 0.0f;
        }
    }
}

What just happened?

The MouseState class reports the X and Y position of the mouse relative to the upper left corner of the window. What we really need to know is what square on the game board the mouse was over.

We calculate this by taking the mouse position and subtracting the gameBoardDisplayOrigin from it and then dividing the remaining number by the size of a game board square.

If the resulting X and Y locations fall within the game board, the left and right mouse buttons are checked. If the left button is pressed, the piece is rotated counterclockwise. The right button rotates the piece clockwise. In either case, the input delay timer is reset to 0.0f since input was just processed.

Letting the player play!

Only one more section to go and you can begin playing Flood Control. We need to code the Update() method to tie together all of the game logic we have created so far.

本周热推：

Midjourney版AIGC绘画原理+提示词+关键词+商业创作电磁场数值计算及基于FreeFEM的编程实现 Photoshop摄影后期三板斧新手学Flash CS6动画制作 Elasticsearch实战与原理解析