rotation

问题 I am trying to rotate a vector around a certain point on the vector(in C++): 1 2 3 4 5 6 7 8 9 rotated around the point (1,1) (which is the "5") 90 degrees would result in: 7 4 1 8 5 2 9 6 3 Right now I am using: x = (x * cos(90)) - (y * sin(90)) y = (y * cos(90)) + (x * sin(90)) But I don't want it rotated around (0,0) 回答1: As Mehrdad Afshari commented on Pesto's post, including the translation back into the original coordinate system would be: x_rotated = ((x - x_origin) * cos(angle)) - ((y

问题 is it possible to easily 'rotate' an array in PHP ? Like this: 1, 2, 3, 4 -> 2, 3 ,4 ,1 Is there some kind of built-in PHP function for this? 回答1: Most of the current answers are correct, but only if you don't care about your indices: $arr = array('foo' => 'bar', 'baz' => 'qux', 'wibble' => 'wobble'); array_push($arr, array_shift($arr)); print_r($arr); Output: Array ( [baz] => qux [wibble] => wobble [0] => bar ) To preserve your indices you can do something like: $arr = array('foo' => 'bar',

问题 Yes, i do know you can use AffineTransformation, however i want my sword image to rotate around a character that i have made (black block drawn in graphics) 360 degrees visibly instead of just one rotation. Basically i want a rotation system like that of Terraria. I know how to get the x and y of the character so the question is: How do i make it rotate around a point that i define? my code is set up like this f.addMouseListener(new MouseAdapter(){ public void mouseClicked(MouseEvent e){

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 3 years ago . Have fragment on activity, and when rotation content disappears. Any idea what is wrong? public class MenuActivity extends AppCompatActivity { static MenuActivity menuActivity; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); menuActivity = this;

问题 I am writing a webapp which loads the image and display on canvas (more exact, I am writing a Tizen app which uses HTML5/JavaScript). I can load the image properly: function loadImage(file) { var img = new Image(); img.src = file; return img; } Everything works fine until I started to get images which display in wrong orientation. I figure out how to get the EXIF and orientation, and I was wondering how do I change the above function to return a proper image? function loadImage(file) { var

问题 I have below code which rotates an image. But the rotated image has different dimensions. How could we ensure that the rotated images has same dimensions? i.e. if the original image has 50 rows and 30 columns then the rotated image should have 30 rows and 50 columns. library(raster) r1 <- brick("watch1.JPG")#please use any jpg image plotRGB(r1) png("SaveThisPlot.png") plotRGB(t(flip(r1, 2))) dev.off() 回答1: png("SaveThisPlot.png",width=nrow(r1),height=ncol(r1)) 来源： https://stackoverflow.com

问题 I have below code which rotates an image. But the rotated image has different dimensions. How could we ensure that the rotated images has same dimensions? i.e. if the original image has 50 rows and 30 columns then the rotated image should have 30 rows and 50 columns. library(raster) r1 <- brick("watch1.JPG")#please use any jpg image plotRGB(r1) png("SaveThisPlot.png") plotRGB(t(flip(r1, 2))) dev.off() 回答1: png("SaveThisPlot.png",width=nrow(r1),height=ncol(r1)) 来源： https://stackoverflow.com

问题 I am currently working with Unity and transform.rotation. The problem is that I have 2 rotating objects as parent-child. This makes the child scale weirdly and going from a box to a paralelogram. Gooing I found transform.lossyScale that should fix my problem but I don´t know how to implement it. TL:DR how to implement transform.lossyscale to prevent parent-child scaling issues. current code float currentR = transform.eulerAngles.x; if(currentR < 30){ transform.Rotate (rotation * Time

问题 I have a circular shape object, which I want to rotate like a fan along it's own axis. I can change the rotation in any direction i.e. dx, dy, dz using my transformation matrix. The following it's the code: Matrix4f matrix = new Matrix4f(); matrix.setIdentity(); Matrix4f.translate(translation, matrix, matrix); Matrix4f.rotate((float) Math.toRadians(rx), new Vector3f(1,0,0), matrix, matrix); Matrix4f.rotate((float) Math.toRadians(ry), new Vector3f(0,1,0), matrix, matrix); Matrix4f.rotate(

问题 I have a matrix for transforming an image. Old matrix is a function of a scale and translation. Now how to apply rotation from center in old Matrix without affecting the other transformation like scale and translation. i already try this //get old matrix Matrix matrix = getImageMatrix(); float tx = getMatrixValue(matrix, Matrix.MTRANS_X); float ty = getMatrixValue(matrix, Matrix.MTRANS_Y); float scaleX = getMatrixValue(matrix, Matrix.MSCALE_X); float scaleY = getMatrixValue(matrix, Matrix