coordinate-transformation

Projection is not working when cutting particular area from top and bottom of openGL control

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问题 With the help of this link i can apply projection on my texture. Now I want to cut/remove equal area from top and bottom of my glcontrol and then need to apply same projection on remain area. I have tried like below. But as shown in the image top and bottom curve is missing on projection. How can I bring it back in remain area? precision highp float; uniform sampler2D sTexture; varying vec2 vTexCoord; void main() { float img_h_px = 432.0; // height of the image in pixel float area_h_px = 39.0

C# rotation (transformation) issue

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问题 I'm trying to create program where will be List of fishes drawn on the canvas. (Next step will be changing the place of fishes based on some calculation) Each fish is represented by bitmap (png file 7x12 px with picture of fish). I created Form on which is PictureBox which is my drawing canvas. It has size 640x480 px. In code below is simplified code I use (I cutted off all not necesary stuff). My problem is with tranformation matrix, at the moment only with rotation. Problem is in class Fish

How can I rotate multiple quads separately? (Pygame, PyOpengl)

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问题 I'd like to rotate my quads roughly around they own axis. My first thought was to use glPushMatrix() and glPophMatrix(), but doesn't work. Regardless of that I believe this is the good way. Code: import time, pygame from pygame.locals import * from OpenGL.GL import * from OpenGL.GLU import * def makeQuad(): glBegin(GL_QUADS) glVertex2f(0, 0) glVertex2f(0, 50) glVertex2f(50, 50) glVertex2f(50, 0) glEnd() def main(): pygame.init() display = (800,800) pygame.display.set_mode(display, DOUBLEBUF

Convert CLRegion to MKMapRect or similar

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问题 I'd like to convert a CLRegion (center and radius) to two points (top left, bottom right) set of coordinates. I've seen this answer, but it is not appropriate: Convert MKCoordinateRegion to MKMapRect The reason I have CLRegion is because it is the output of Forward Geolocation. I need the two latitude/longitude points to query a database (therefore cannot use CLRegion containsCoordinate). 回答1: Here is a method to make the conversion between a CLCircularRegion (similar for CLRegion) to a

How to compute (alt, az) for given Galactic coordinate (GLON, GLAT) with PyEphem?

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问题 For a given observer (lon, lat, time) on Earth and a given Galactic coordinate (GLON, GLAT), how can I compute the corresponding (alt, az) point in the sky with PyEphem? 回答1: Given the way that PyEphem currently works, there are two steps to answering your question. First, you have to convert a pair of galactic coordinates into an equatorial RA/dec pair of coordinates instead. import ephem # Convert a Galactic coordinate to RA and dec galactic_center = ephem.Galactic(0, 0) eq = ephem

Converting Southing/Easting GPS coordinates to Latitude/Longitude

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问题 I am developing a web application using JQuery Framework and am using Geolocation to determine the locations of our hardware stations to display on Google Maps. In our database the locations of the sites are stored in Southing/Easting format. I need a way to convert Southing/Easting coordinates to Latitude/Longitude that Google Maps can understand. Can anyone please tell me the formula or the best way to approach this problem? I have done searches on Southing/Easting however nothing came up,

convert wgs 84 to lat/long

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问题 Hi I am having a little trouble figuring out how to convert between types of coordinates. I have a list of coordinate sets with the following description "Coordinates are always in the WGS84 system. All coordinates a represented as integer values x and y where the coordinate value is multiplied with 1,000,000." An example: 559262 6319512 Well, I need to convert these to long/lat (and back) so i can use these in google maps (android). But this is not as easy as it seams. I have been searching

Rotating a multipart object

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I've created an object that has about 7+ parts to it including its body and smaller parts that 'attach' to it in different places. My goal is to rotate the entire object. I tried to simply call glRotatef(angle, 0, 1, 0) before constructing the entire object, but I realize that this seems to rotate 'everything' around the origin, no matter the translation. The following code was an attempt to rotate the body itself and rotate the attached parts to it. // glRotatef(angle, 0, 1, 0); //old way of rotating the object // body glPushMatrix(); // movement glTranslatef(subx, suby + y, subz); //rotating

How to project a point on to a sphere

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问题 If i have a point (x,y,z) how to project it on to a sphere(x0,y0,z0,radius) (on its surface). My input will be the coordinates of point and sphere. The output should be the coordinates of the projected point on sphere. Just convert from cartesian to spherical coordinates? 回答1: For the simplest projection (along the line connecting the point to the center of the sphere): Write the point in a coordinate system centered at the center of the sphere (x0,y0,z0): P = (x',y',z') = (x - x0, y - y0, z

How can I determine if a GPS Coordinate is on or in an Ellipse?

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问题 Ok, so I am still new to asking questions on Stack Overflow, so please be nice :) I have an issue that I have been trying to solve for a month now with failed results time and time again. I have found various questions somewhat similar to this, but nothing that has struck me as the definitive answer. The closest that I have found so far is this: Convert GPS coordinates to coordinate plane. In short, what I need is to know is if a GPS Coordinate is either on or inside an ellipse. KNOWNS: Width