# [TIMOB-4837] iOS: 2dmatrix rotation is transforming object the same way regardless of +/- value

GitHub Issue | n/a |

Type | Bug |

Priority | Medium |

Status | Closed |

Resolution | Invalid |

Resolution Date | 2013-07-29T23:37:52.000+0000 |

Affected Version/s | Release 1.8.0 |

Fix Version/s | n/a |

Components | iOS |

Labels | core |

Reporter | Natalie Huynh |

Assignee | Ingo Muschenetz |

Created | 2011-07-29T13:30:57.000+0000 |

Updated | 2017-03-13T17:49:25.000+0000 |

### Description

Steps to Reproduce:
1. Run the attached .js file
2. Click on the red square
Actual Result
both rotates counter clockwise
Expected Result:
Blue should rotate counter clockwise
Red should rotate clockwise

### Attachments

File | Date | Size |

app.js | 2011-07-29T13:31:09.000+0000 | 1143 |

### Comments

JSON Source

This is due to how rotations are implemented: iOS uses a pure mathematical 2D matrix, Android does not, and stores a rotation as a value as opposed to sin and cos values. A 2D matrix is a 2*3 matrix that can be used on (x,y) points to shear, scale, translate, and rotate an image. The values are stateless, and do not indicate a direction or path, only the final effect. To represent rotation of θ, sin(θ) and cos(θ) values are used. Note that because sin(360° + θ) is the same as sin(θ), and cos(360° + θ) also has no difference, there is no way to mathematically express a full rotation. Marking as invalid due to math.

2D matrices use sin and cos, and thus won't represent the direction of rotations.

Closing ticket as invalid.