2014/10/15 下午 10:15:44

iphone Programming Glossary: vector

http://stackoverflow.com/questions/2351586/iphone-image-stretching-skew

such a transform is not linear. Therefore CATransform3D cannot perform this as a 2D transform either. However the vector x y z w 1 will be converted to the actual 3D vector x w y w z w before projection if CA follows usual 3D compute graphics.. cannot perform this as a 2D transform either. However the vector x y z w 1 will be converted to the actual 3D vector x w y w z w before projection if CA follows usual 3D compute graphics rules so you could cheat by using the transform P.. on the CATransform3DMake functions. You may need to perform a transpose due to convention of using row or column vectors. To obtain the transform to convert a rectangle X Y W H to any quadrilateral x1a y1a x2a y2a x3a y3a x4a y4a use this function..

How to detect iPhone movement in space using accelerometer?

http://stackoverflow.com/questions/2674717/how-to-detect-iphone-movement-in-space-using-accelerometer

is how I proceed admiting the device is hold verticaly 1 I have my default x y and z values. 2 I extract the gravity vector from this data using a low pass filter. 3 I substract the normalized gravity vector from each x y and z and get the movement.. z values. 2 I extract the gravity vector from this data using a low pass filter. 3 I substract the normalized gravity vector from each x y and z and get the movement acceleration. 4 Then I integrate this acceleration value with respect to time so.. now NSDate date if previousDate nil interval now timeIntervalSinceDate previousDate previousDate now Isolating gravity vector gravity.x currentAcceleration.x kFileringFactor gravity.x 1.0 kFileringFactor gravity.y currentAcceleration.y kFileringFactor..

Detecting Acceleration in a car (iPhone Accelerometer)

http://stackoverflow.com/questions/2733249/detecting-acceleration-in-a-car-iphone-accelerometer

implement for longer than I would like to admit. It's steps are as follows 1 During calibration measure gravity as a vector instead of a size. Store that vector. 2 When the car initially moves forward take the vector of motion and subtract gravity... to admit. It's steps are as follows 1 During calibration measure gravity as a vector instead of a size. Store that vector. 2 When the car initially moves forward take the vector of motion and subtract gravity. Use this as the forward momentum... measure gravity as a vector instead of a size. Store that vector. 2 When the car initially moves forward take the vector of motion and subtract gravity. Use this as the forward momentum. Ignore for now the user cases where this will be difficult..

Drawing a route in mapkit in iphone sdk

http://stackoverflow.com/questions/2834523/drawing-a-route-in-mapkit-in-iphone-sdk

information. I'd say you need to call an external API to get your data. I've been playing with cloudmade.com API. The vector stream server should return what you need and then you can draw that over your map. However discrepancies between the google..

Drawing formulas with Quartz 2d

http://stackoverflow.com/questions/2907045/drawing-formulas-with-quartz-2d

CALayer rendering architecture for the generation of PDFs from these equations because CALayers don't render as vector elements by default. For an example of how this rendering works in my application see the open source Core Plot project..

drawing on iphone

http://stackoverflow.com/questions/3352822/drawing-on-iphone

character of the alphabet. How will i compare the two shapes drawing and existing Any idea some code iphone drawing vector gestures share improve this question Using GLGestureRecognizer you can create a catalogue and it will compute a metric..

Getting displacement from accelerometer data with Core Motion

http://stackoverflow.com/questions/4449565/getting-displacement-from-accelerometer-data-with-core-motion

during an acceleration. The Apple Teapot example with Core Motion just adds the x y and z values of the acceleration vector to the position vector. This apart from having not much sense has the result of returning the object to the original position.. The Apple Teapot example with Core Motion just adds the x y and z values of the acceleration vector to the position vector. This apart from having not much sense has the result of returning the object to the original position after an acceleration...

What's the best way to put a c-struct in an NSArray?

http://stackoverflow.com/questions/4516991/whats-the-best-way-to-put-a-c-struct-in-an-nsarray

future readers... For some lateral thinking and looking more at performance Evgen has raised the issue of using STL vector in C . That raises an interesting issue is there a fast c library not unlike STL vector but much much lighter that allows.. raised the issue of using STL vector in C . That raises an interesting issue is there a fast c library not unlike STL vector but much much lighter that allows for the minimal tidy handling of arrays ... So the original question... For example typedef..

Drawing bezier curves with my finger in iOS?

http://stackoverflow.com/questions/4672646/drawing-bezier-curves-with-my-finger-in-ios

me a general summary of what would be required I just need help getting started on the right foot. iphone ipad ios vector bezier share improve this question If you want to stay in objective c you can use UIBezierPath's addCurveToPoint controlPoint1..

AES interoperability between .Net and iPhone?

http://stackoverflow.com/questions/538435/aes-interoperability-between-net-and-iphone

. .net iphone encryption aes share improve this question At the very least you are using differing initialization vectors IV . The .Net code uses the key for IV. private static AesCryptoServiceProvider GetProvider byte key Set up the encryption.. the wrapper code that you pointed at which has a serious bug in it... . The iPhone code uses 0 for IV. Initialization vector dummy in this case 0's. uint8_t iv kChosenCipherBlockSize memset void iv 0x0 size_t sizeof iv openssl by default prepends.. which is why the output is longer . The openssl output is more secure since it is prepending a random initialization vector. It looks like the first few bytes of the base64 decoded string is Salted__ . You can also ask openssl to not use a salt..

Simple gun in cocos2d+box2d game

http://stackoverflow.com/questions/9164146/simple-gun-in-cocos2dbox2d-game