NSAffineTransformクラスを中心にNSImageを回転させて動作させます。 コードはここにある:トランスフォーム後にNSImageがぼやける
- (NSImage*)rotateImage: (NSImage*)myImage angle:(float)rotateAngle {
NSRect imageBounds = {NSZeroPoint, [myImage size]};
NSRect transformedImageBounds = imageBounds;
NSBezierPath* boundsPath = [NSBezierPath bezierPathWithRect:imageBounds];
NSAffineTransform* transform = [NSAffineTransform transform];
// calculate the bounds for the rotated image
if (rotateAngle != 0) {
NSAffineTransform* temptransform = [NSAffineTransform transform];
[temptransform rotateByDegrees:rotateAngle];
[boundsPath transformUsingAffineTransform:temptransform];
NSRect rotatedBounds = {NSZeroPoint, [boundsPath bounds].size};
// center the image within the rotated bounds
imageBounds.origin.x += (NSWidth(rotatedBounds) - NSWidth (imageBounds))/2;
imageBounds.origin.y += (NSHeight(rotatedBounds) - NSHeight (imageBounds))/2;
// set up the rotation transform
[transform translateXBy:+(NSWidth(rotatedBounds)/2) yBy:+ (NSHeight(rotatedBounds)/2)];
[transform rotateByDegrees:rotateAngle];
[transform translateXBy:-(NSWidth(rotatedBounds)/2) yBy:- (NSHeight(rotatedBounds)/2)];
transformedImageBounds = rotatedBounds;
}
// draw the original image into the new image
NSImage* transformedImage = [[NSImage alloc] initWithSize:transformedImageBounds.size];;
[transformedImage lockFocus];
[transform concat];
[myImage drawInRect:imageBounds fromRect:NSZeroRect operation:NSCompositeCopy fraction:1.0] ;
[transformedImage unlockFocus];
return transformedImage;
}
しかし、結果画像の品質が非常に悪いです。 誰もそれを解決する方法を知っていますか?
"lockFocus"メソッドがこれを引き起こしたと言う人もいますが、このメソッドを使用せずにこれを行う方法はありません。