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使用仿射变换将形状缩放/转换为给定矩形

affinetransform shapes drawing graphics java

3

Pierre · 技术社区 · 15 年前

我正在尝试缩放/转换java.awt文件. 形状具有以便在定义的边界矩形中绘制它。

缩放 '参数。

double zoom=(...);/* current zoom */
Rectangle2D viewRect=(...)/** the rectangle where we want to paint the shape */
Shape shape=(...)/* the original shape that should fit in the rectangle viewRect */
Rectangle2D bounds=shape.getBounds2D();

double ratioW=(viewRect.getWidth()/bounds.getWidth());
double ratioH=(viewRect.getHeight()/bounds.getHeight());


AffineTransform transforms[]=
    {
    AffineTransform.getScaleInstance(zoom, zoom),
    AffineTransform.getTranslateInstance(-bounds.getX(),-bounds.getY()),
    AffineTransform.getTranslateInstance(viewRect.getX(),viewRect.getY()),
    AffineTransform.getScaleInstance(ratioW, ratioH)
    };


AffineTransform tr=new AffineTransform();
for(int i=0;i< transforms.length;++i)
    {
    tr.concatenate(transforms[i]);
    }

Shape shape2=tr.createTransformedShape(shape);
graphics2D.draw(shape2);

非常感谢

皮埃尔

2 回复 | 直到 15 年前

1

8

trashgod 15 年前

请注意 AffineTransform 转换被“以最常用的方式”连接起来,这可以被视为 最后一个 先出命令。效果可见于此 example Shape 首先旋转,然后缩放,最后平移。

at.translate(SIZE/2, SIZE/2);
at.scale(60, 60);
at.rotate(Math.PI/4);
return at.createTransformedShape(...);

2

1

Pierre 15 年前

受垃圾神的回答启发,正确的顺序是:

AffineTransform transforms[]=
{
AffineTransform.getScaleInstance(zoom, zoom),
AffineTransform.getTranslateInstance(viewRect.getX(),viewRect.getY()),
AffineTransform.getScaleInstance(ratioW, ratioH),
AffineTransform.getTranslateInstance(-bounds.getX(),-bounds.getY())
};



AffineTransform tr=new AffineTransform();
for(int i=0;i< transforms.length;++i)
 {
 tr.concatenate(transforms[i]);
 }