Technical Q&A QA1332
Shearing a Coordinate Space with NSAffineTransform

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ÉäÉXÉg 1.NSAffineTransform_Shearing.h

#import <Cocoa/Cocoa.h>

@interface NSAffineTransform (Shearing)

- (void) shearXBy:(float) xShear yBy:(float) yShear;
- (void) shearXBy:(float) xShear;
- (void) shearYBy:(float) yShear;

@end




ÉäÉXÉg 2.NSAffineTransform_Shearing.m


@implementation NSAffineTransform (Shearing)
  
- (void) shearXBy: (float) xShear yBy: (float) yShear;
  {
  NSAffineTransform 
    *shearTransform = [[NSAffineTransform alloc] init];
    
  NSAffineTransformStruct 
    transformStruct = [shearTransform transformStruct];
    
  transformStruct.m21 = xShear;
  transformStruct.m12 = yShear;
  
  [shearTransform setTransformStruct:transformStruct];
  [self appendTransform:shearTransform];
  [shearTransform release];
  }

  // ìØéûÇ… 1 ǬÇÃé≤ÇæÇØÇÉVÉAÅ[ïœå`ǵÇΩÇ¢èÍçá...
- (void) shearXBy:(float) xShear { [self shearXBy:xShear yBy:0.0];  }
- (void) shearYBy:(float) yShear  {  [self shearXBy:0.0 yBy:yShear]; }

@end


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[2004 îN 1 åé 29 ì˙]