angle

what is in XNA in 2D the standard way vector angles work ? 0 degrees points right, 90 points up, 180 left, 270 down ? What are the 'standard' implementations of float VectortoAngle(Vector2 vec) and Vector2 AngleToVector(float angle) so that VectortoAngle(AngleToVector(PI)) == PI ? To answer your first question, 0 degrees points up, 90 degrees points right, 180 degrees points down, and 270 degrees points left. Here is a simple 2D XNA rotation tutorial to give you more information. As for converting vectors to angles and back, I found a couple good implementations here : Vector2 AngleToVector

The OpenGL designers were never afraid of mathematics, and knowledge of linear algebra is essential for all but the simplest OpenGL applications. I think it can safely be assumed that OpenGL programmers are familiar with angles in radians. Mathematically, radians are more elegant than degrees in every respect. They also have practical advantages: The C standard library uses radians. Pretty much any other library out there uses radians as well. Radians are more convenient in some computations, e.g. the length of a circular arc. Why, then, did the OpenGL designers decide to specify functions

Hi all, I have written an application where I have a speedometer with a needle vertically set at 90 degree and I am trying to rotate the needle around its center with the speed that changes for every one second(I am displaying the speed in a text view that changes randomly from 0 to 120) I am getting the speed from a remote service and displaying in a textview. so as the speed changes the speedometer needle gauge should change accordingly around its center. I mean If speed is 30 the needle should be at 30 and so on in speedometer. My code is not working exactly, How to get around this problem?

I am trying to get ANGLE working in C# using P/Invoke. Basically, I am creating a simple 2D surface, and then passing that off to skia (using SkiaSharp). Everything is working and all that, but I am having a problem marshalling PropertySet to the unmanaged code. This bit works fine: // the properties var props = new PropertySet(); props.Add("EGLNativeWindowTypeProperty", swapChainPanel); // the surface attributes int[] surfaceAttrs = { EGL_ANGLE_SURFACE_RENDER_TO_BACK_BUFFER, EGL_TRUE, EGL_NONE }; // create the surface surface = eglCreateWindowSurface(eglDisplay, eglConfig, props, surfaceAttrs

I know how to find out angle between 2 vectors, but it always gives me internal angle, but I want it to give me always the angle in anticlockwise direction, even if it is greater then 180. I'm using C++ but it is not really important because I need to get the theory. This is what I am using now You're looking for the atan2(y,x) function ( http://en.wikipedia.org/wiki/Atan2 ). If you give it the two components of a 2D vector, it will give you the angle of the vector from the x axis, in the counter-clockwise direction. To solve your specific problem try: atan2(v_y, v_x) - atan2(u_y, u_x) Then

I am converting angles-axis representation to Euler angles. I decided to check and make sure that the Euler angles I got from the conversion would lead back to the original axis-angle. I print out the values, but they do not match! I have read http://forum.onlineconversion.com/showthread.php?t=5408 and http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles as well as similar conversion questions on this website. In the code below I start with angle 'angle' and axis (rx,ry,rz), then I convert it to quaternions (q0,q1,q2,q3). I convert the quaternions to euler angles (roll,

I am designing an app that needs to check the device's orientation (Azimuth, Pitch and Roll). I use the following code to achieve this: @Override public void onSensorChanged(SensorEvent event) { if(event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) gravityMatrix = event.values.clone();// Fill gravityMatrix with accelerometer values else if(event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) geomagneticMatrix = event.values.clone();// Fill geomagneticMatrix with magnetic-field sensor values if(gravityMatrix != null && geomagneticMatrix != null){ RMatrix = new float[16]; IMatrix = new float

I'm having a big problem limiting the camera pitch angle (between -90º and 90º) with the code below. This is somewhat a follow up to this question . The problem, it seems, is that the camera rotates more than -90º or more than +90º and when that happens, I'll be looking down (or up) but but the view just rotated 180º around the Y axis. Example: I'm facing north looking at the horizon and I start to look down until I can't go down anymore (limited by the code below). Then I start to look up and I'll be facing south. void Camera::Rotate(Vector3D angle) { angle = angle * CAMERA_ROTATION_SPEED;

I'm trying to find a way to calculate the intersection between two arcs. I need to use this to determine how much of an Arc is visually on the right half of a circle, and how much on the left. I though about creating an arc of the right half, and intersect that with the actual arc. But it takes me wayyy to much time to solve this, so I thought about asking here - someone must have done it before. Edit: I'm sorry the previous illustration was provided when my head was too heavy after crunching angles. I'll try to explain again: In this link you can see that I cut the arc in the middle to two