2014/10/15 下午 10:11:19

iphone Programming Glossary: matrices

Use Quaternions to compute yaw, pitch and roll from iphone?

http://stackoverflow.com/questions/12322797/use-quaternions-to-compute-yaw-pitch-and-roll-from-iphone

to my question that most of the users will benefit from it Thanks in advance iphone xcode quaternion rotational matrices cmmotionmanager share improve this question You don't have to implement anything the API provides the quaternion for.. the API provides the quaternion for you CMAttitude Class Reference quaternion propery I personally like rotation matrices better because I find them easier to understand and to work with. As I am reading your question I still have the impression..

Where can I find an explanation of all transform matrix fields?

http://stackoverflow.com/questions/1260741/where-can-i-find-an-explanation-of-all-transform-matrix-fields

a matrix itself and the format of this matrix differs from the one described in the wikipedia article on transform matrices. This is because a point is usually represented by a single column 4 row matrix however Apple represents them as 4 column.. a point is usually represented by a single column 4 row matrix however Apple represents them as 4 column single row matrices. This means that any transform matrix you see in the wikipedia article needs to be transposed before using it on the iPhone.. Here is more info on transforms from Apple. A bunch of utility transforms are provided by Apple for generating these matrices see this link . They don't actually discuss the math behind CATransform3DMakeRotation but this link does. share improve..

CGAffineTransformInvert: singular matrix in UIImagePickerController with showsCameraControls = NO

http://stackoverflow.com/questions/13708496/cgaffinetransforminvert-singular-matrix-in-uiimagepickercontroller-with-showsca

believe it to be largely benign as Apple's own PhotoPicker sample code generates this warning. Rotation has to do with matrices and while I'm not sure which matrix in particular is getting rotated it is considered a mathematical violation to perform.. sure which matrix in particular is getting rotated it is considered a mathematical violation to perform operations on matrices with a determinant of zero similar to dividing by zero . Such a matrix is not invertible or 'singular' http en.wikipedia.org..

obtaining the rotation and size of a UIImageView based on its transformation matrices

http://stackoverflow.com/questions/1379811/obtaining-the-rotation-and-size-of-a-uiimageview-based-on-its-transformation-mat

the rotation and size of a UIImageView based on its transformation matrices If I have the original transform matrix of a rectangular UIImageView and this image is scaled and rotated and by the end..

UIView. How do I constrain scaling to one dimension only

http://stackoverflow.com/questions/1423119/uiview-how-do-i-constrain-scaling-to-one-dimension-only

and adjust it so that the scaling only takes effect in one direction. From the documentation on how CGAffineTransform matrices are constructed I believe the following implementation should constrain your scaling to be just along the horizontal direction..

Explain how OpenGL ES background images work

http://stackoverflow.com/questions/4820372/explain-how-opengl-es-background-images-work

in your 3d world so that it appears to be background I do this because my camera angle is fixed. or you can push some matrices to make use of glOrthof before drawing the images and pop the matrices off after. Here is some code to help you with the.. my camera angle is fixed. or you can push some matrices to make use of glOrthof before drawing the images and pop the matrices off after. Here is some code to help you with the image draw to opengl glPushMatrix glGenTextures 1 texture 0 glBindTexture..

Convert decimal to fraction in Objective-C?

http://stackoverflow.com/questions/5552537/convert-decimal-to-fraction-in-objective-c

1 0 1 0 1 0 Instead of keeping the sequence of continued fraction terms we just keep the last partial product of these matrices. Fraction fractionFromReal double realNumber long maxDenominator double atof int atoi void exit long m 2 2 double startx..

OpenGL ES, OpenFrameworks, Cinder and IOS creative development

http://stackoverflow.com/questions/5776839/opengl-es-openframeworks-cinder-and-ios-creative-development

that you're not re inventing the wheel. OpenGL doesn't come with a lot of classes you would normally need Vectors matrices cameras colour images etc and the methods that you will need to work with them normalise arithmetic cross product etc Of..

Transitioning from OpenGL ES 1.1 to OpenGL ES 2.0

http://stackoverflow.com/questions/5866256/transitioning-from-opengl-es-1-1-to-opengl-es-2-0

probably already have huge code bases in OpenGL ES 1.1 How does one transitionf rom ES 1.1 to ES 2.0 I suppose the matrices need to be taken care of as well as stuff like GL_FOG GL_CULL maybe Is it possible to write substitutes for these functions..

In OpenGL ES, how do I convert screen coordinates to world coordinates?

http://stackoverflow.com/questions/611468/in-opengl-es-how-do-i-convert-screen-coordinates-to-world-coordinates

opengl es share improve this question If you're doing a 2D game you can set up your projection and model view matrices so that you don't need to convert at all This goes in your init code somewhere Set up 480x320 orthographic projection glMatrixMode.. etc. Since the iPhone's screen is 480x320 you won't need to convert between world and screen coordinates with your matrices set up thusly. Of course if you want to be able to move the camera then you'll need to offset by the camera's location...

Store orientation to an array - and compare

http://stackoverflow.com/questions/6368618/store-orientation-to-an-array-and-compare

measured Obviously the second array is similar to the newly measured and the first is not. Let's compute the cost matrices according to this paper subsection 2.1 D i j Dist i j MIN D i 1 j D i j 1 D i 1 j 1 Here D i j is the i j element of the.. are comparing arrays A and B then Dist i j is the distance between A i and B j . I simply used ABS A i B j . The cost matrices for this example For Array 1 we have 13 as score for Array 2 we have 5. The lower score wins so the most similar array is.. North matter I guess not. It is far easier to compare the acceleration vectors than orientations Euler angles rotation matrices quaternions as tc pointed that out. If you are using acceleration data you have 3 dimensional vectors at each time point..