Comment puis-je faire pivoter une image à l'aide de Java/Swing et ensuite définir son origine 0,0?

Utiliser le g2d.transform() pour déplacer l'image en arrière, là où c'est nécessaire. Je suis juste en imaginant ce que le calcul peut être, mais je pense que quelque chose comme:

int diff = ( image.getWidth() - image.getHeight() ) / 2;
g2.transform( -diff, diff );

BTW, vous pouvez avoir un problème avec l'étiquette de déclaration de sa taille préférée - vous pourriez avoir besoin pour remplacer getPreferredSize() et compte pour permuter les images de la largeur et de la hauteur en les faisant pivoter.

OriginalL'auteur staticman

La fonction suivante va tourner un tampon d'image qui vient à durée indéterminée si c'est un carré parfait ou pas.

public BufferedImage rotate(BufferedImage image)
{
/*
* Affline transform only works with perfect squares. The following
*   code is used to take any rectangle image and rotate it correctly.
*   To do this it chooses a center point that is half the greater
*   length and tricks the library to think the image is a perfect
*   square, then it does the rotation and tells the library where
*   to find the correct top left point. The special cases in each
*   orientation happen when the extra image that doesn't exist is
*   either on the left or on top of the image being rotated. In
*   both cases the point is adjusted by the difference in the
*   longer side and the shorter side to get the point at the 
*   correct top left corner of the image. NOTE: the x and y
*   axes also rotate with the image so where width > height
*   the adjustments always happen on the y axis and where
*   the height > width the adjustments happen on the x axis.
*   
*/
AffineTransform xform = new AffineTransform();
if (image.getWidth() > image.getHeight())
{
xform.setToTranslation(0.5 * image.getWidth(), 0.5 * image.getWidth());
xform.rotate(_theta);
int diff = image.getWidth() - image.getHeight();
switch (_thetaInDegrees)
{
case 90:
xform.translate(-0.5 * image.getWidth(), -0.5 * image.getWidth() + diff);
break;
case 180:
xform.translate(-0.5 * image.getWidth(), -0.5 * image.getWidth() + diff);
break;
default:
xform.translate(-0.5 * image.getWidth(), -0.5 * image.getWidth());
break;
}
}
else if (image.getHeight() > image.getWidth())
{
xform.setToTranslation(0.5 * image.getHeight(), 0.5 * image.getHeight());
xform.rotate(_theta);
int diff = image.getHeight() - image.getWidth();
switch (_thetaInDegrees)
{
case 180:
xform.translate(-0.5 * image.getHeight() + diff, -0.5 * image.getHeight());
break;
case 270:
xform.translate(-0.5 * image.getHeight() + diff, -0.5 * image.getHeight());
break;
default:
xform.translate(-0.5 * image.getHeight(), -0.5 * image.getHeight());
break;
}
}
else
{
xform.setToTranslation(0.5 * image.getWidth(), 0.5 * image.getHeight());
xform.rotate(_theta);
xform.translate(-0.5 * image.getHeight(), -0.5 * image.getWidth());
}
AffineTransformOp op = new AffineTransformOp(xform, AffineTransformOp.TYPE_BILINEAR);
BufferedImage newImage =new BufferedImage(image.getHeight(), image.getWidth(), image.getType());
return op.filter(image, newImage);
}

OriginalL'auteur Aleksandr Movsesyan