JavaFX Canvas GraphicsContext扩展错误？

Question

我正试图让画布上的图像正确缩放。

它正确缩小但不能正确缩放，那么如果“缩放”因子设置为1.0以外的任何值，只要我移动鼠标它就会一直放大。

示例：https://i.gyazo.com/98fcfd74a1094142b460781f937952c1.mp4 在这个例子中，我滚动到大约1.25的缩放，然后我移动我的鼠标，它只是放大，缩放从1.0开始。

Scaling在context.scale（scale，scale）的paint（）中完成

代码：

public class MapRenderer {

private final Canvas canvas;
private final GameMap gameMap;

public MapRenderer(final Canvas canvas, final GameMap gameMap) {
    this.canvas = canvas;
    this.gameMap = gameMap;
}

private double mapX = 0;
private double mapY = 0;
private double scale = 1.0;

private boolean isMoving = false;
private double startMouseX = 0;
private double startMouseY = 0;
private double pressMouseX = 0;
private double pressMouseY = 0;

private double curX = 0;
private double curY = 0;


public double screenXToMap(final double x) {
    return (this.mapX + (x / this.scale));
}

public double screenYToMap(final double y) {
    return (this.mapY + (y / this.scale));
}

public double screenXToTile(final double x) {
    return (this.screenXToMap(x) / this.gameMap.getTileSize()) + this.gameMap.getOffsetX();
}

public double screenYToTile(final double y) {
    return (this.gameMap.getHeightTiles() - ((this.screenYToMap(y) + 1) / this.gameMap.getTileSize()) + this.gameMap.getOffsetY());
}

public double tileXToScreen(final double x) {
    return (((x - this.gameMap.getOffsetX()) * this.gameMap.getTileSize()) - this.mapX) * this.scale;
}

public double tileYToScreen(final double y) {
    return (((this.gameMap.getHeightTiles() - (y - this.gameMap.getOffsetY())) * this.gameMap.getTileSize()) - this.mapY - 1) * this.scale;
}

public void update() {
    if (this.mapX < 0) {
        this.mapX = 0;
    } else if (this.mapX + this.canvas.getWidth() > this.gameMap.getWidth()) {
        this.mapX = this.gameMap.getWidth() -  this.canvas.getWidth(); // Calculate view port
    }

    if (this.mapY < 0) {
        this.mapY = 0;
    } else if (this.mapY + this.canvas.getHeight() > this.gameMap.getHeight()) {
        this.mapY = this.gameMap.getHeight() -  this.canvas.getHeight(); // Calculate view port
    }
    this.repaint();
}

public void init() {
    this.canvas.setOnMousePressed(e -> {
        System.out.println("PRESSED");
        if (e.getButton().equals(MouseButton.MIDDLE)) {
            this.isMoving = true;
            this.startMouseX = this.mapX;
            this.startMouseY = this.mapY;
            this.pressMouseX = e.getX();
            this.pressMouseY = e.getY();
        }
    });

    this.canvas.setOnMouseReleased(event -> {
        System.out.println("RELEASED");
        this.isMoving = false;
    });

    this.canvas.setOnScroll(e -> {
        System.out.println("SCROLL 1 " + this.scale);
        final double oldWidth = this.mapX + (this.canvas.getWidth() / this.scale);
        final double oldHeight = this.mapY + (this.canvas.getHeight() / this.scale);
        this.scale += (e.getDeltaY() > 0 ? 1 : -1) * 0.25 * -1.0;
        this.scale = Math.max(1.0, Math.min(8.0, this.scale));
        final double newWidth = this.mapX + (this.canvas.getWidth() / this.scale);
        final double newHeight = this.mapY + (this.canvas.getHeight() / this.scale);
        this.mapX += Math.floor((oldWidth - newWidth) / 2.0);
        this.mapY += Math.floor((oldHeight - newHeight) / 2.0);
        this.update();
        System.out.println("SCROLL 2 " + this.scale);
    });

    this.canvas.setOnMouseDragged(e -> {
        System.out.println("DRAGGED");
        this.curX = e.getX();
        this.curY = e.getY();
        if (this.isMoving) {
            this.mapX = (this.startMouseX - (e.getX() - this.pressMouseX) / this.scale);
            this.mapY = (this.startMouseY - (e.getY() - this.pressMouseY) / this.scale);
            this.update();
        }
        this.update();
    });

    this.canvas.setOnMouseMoved(e -> {
        System.out.println("MOVED " + this.mapX + ", " + this.mapY + "{ " + this.scale + " }");
        System.out.println("CANVAS " + this.canvas.getWidth() + ", " + this.canvas.getHeight());
        this.curX = e.getX();
        this.curY = e.getY();
        this.update();
    });
}

public void paint() {
    final GraphicsContext context = this.canvas.getGraphicsContext2D();

    context.scale(scale, scale);
    context.drawImage(this.gameMap.getMapImage(), -mapX, -mapY);

    context.setFill(Color.GREEN);
    context.fillRect(this.tileXToScreen(this.screenXToTile(this.curX)), this.tileYToScreen(this.screenYToTile(this.curY)),
            (this.gameMap.getTileSize() * this.scale), (this.gameMap.getTileSize() * this.scale));
}

public void repaint() {
    this.canvas.getGraphicsContext2D().clearRect(0, 0, this.canvas.getWidth(), this.canvas.getHeight());
    this.paint();
}

public GameMap getGameMap() {
    return gameMap;
}