I got a Windows Forms app making use of Google Earth where users can draw a polygon on the map which is used as a geofence.
What I'd like to do is to be able to zoom to the polygon so that it fits nicely on screen with a click of a button. A sort of zoom to fit function.
Finding the centre of the polygon and setting the Google Earth camera to that lat/long is easy.
What I need is an algorithm that takes a bounding box of lats \ longs, screen height \ width and then determines the altitude to set the camera.
Does anyone have this algorithm or know where one can be found?
Thanks!!
To "zoom to the polygon" or any other KmlObject it is probably easiest to use the earth-api-utility-library.
See the methods createBoundsView, setToBoundsView and especially flyToObject
For example, where ge is the GEPlugin object and polygon is a KmlPolygon.
var gex = new GEarthExtensions(ge);
gex.util.flyToObject(polygon, { boundsFallback: true, aspectRatio: 1 } );
Related
Is it possible to have the vtkAxesActor small in a corner of the window?
Here is a image of what I currently got and what I would like to have. The colorful axes are the standard axesActor. But I would like the axes in a corner of the window and only there (bottom left in black). They shouldn't move around the window when the view is rotated. Only around their origin.
Is this possible? And if yes, how?
A possible solution is to put the vtkAxesActor into an orientation widget:
widget = vtk.vtkOrientationMarkerWidget()
widget.SetOrientationMarker(axisActor)
widget.SetInteractor(interactor)
widget.SetViewport(0, 0, size, size)
widget.InteractiveOff()
widget.EnabledOn()
The vtkAxesActor location is functional and it's location has a purpose. The anchor point of the AxesActor is the anchor point of the model. This provides context of where any transformations or translations would be calculated from.
Unfortunately the example of the axisActor in the corner you have proposed would only provide context of the orientation of the model and so not part of the standard options.
Following Quote from this source:
http://www.cambridgeincolour.com/tutorials/image-projections.htm
Equirectangular image projections map the latitude and longitude
coordinates of a spherical globe directly onto horizontal and vertical
coordinates of a grid, where this grid is roughly twice as wide as it
is tall.
I have a 13312 px width and 6656 pixel height Panorama picture. It's a equirectangular projection of a room and have a 2:1 ratio.
I use following formular to calculate the xPosition:
var xPosition = ( panorama.width / 360 ) * azimuth
Azimuth = Phi = Heading = Angle to the left or right
How do I project this now on a 1366x768px browser screen?
I think my results are wrong, because it's not on the point where it should be.. it could be because the sphere has a distortion on the left and right:
Is there any formular to calculate the position with attention to the distortion and scale it to fit on the browser screen? I looked many (MANY) sources to find a solution for this, but they always just say that equirectangular are just lat and long.. they don't consider the distortion.
Last question: To find a special solution, I tryed to put a plane on the circle and expanded the line which shows the alpha angle. I though with Phytagoras I could find the position.. but this didn't worked either.. maybe I did something wrong? Is this the way even possible or am I doing it wrong?
edit
THIS is what I'm actually looking for: http://othree.github.io/360-panorama/three-2d/
The black grid in the background. What is the name of this? For what do I have to google or look for? When you start the 2D Panorama, if you want to get the coordinations of the top right corner of the window, what do you have to do?
The whole calculation problem was about to create a Google Streetview similiar view from a 2:1 equirectangular image. We already found a solution for this with a great help from Martin Matysiak (https://github.com/marmat | Google).
It's been a while so I can't give a direct answer to what the main solution is, but I can provide a URL to an AddOn Martin wrote for adding the custom Markers that we actually were trying to make.
You can follow https://github.com/marmat/google-maps-api-addons and look for yourself. In the end it helped a lot to solve the main problem and let us continue with our main Framework for Google Business Tours.
If you follow the link in the threejs demo you included, it would take you to the source code.
particularly look at:
https://github.com/mrdoob/three.js/blob/dev/examples/webgl_panorama_equirectangular.html
and
https://github.com/mrdoob/three.js/blob/dev/src/geometries/SphereBufferGeometry.js
not sure if there is distortion though. The distortion comes from the fact that the texture is mapped to the sphere, and the sphere is rendered in 3D (openGL).
I'm using Raphael to draw rectangles. Whoo-hoo!
Is there a way to right align contents of an SVG file?
Not just text, but shapes as well?
I can do the math and get the computed x value, but I'm looking for the lazy-simple solution.
Thank you.
There isn't. Unlike normal web pages where the window is resized and the content flows into it, when a Raphael paper is resized, there is no sort of flow, so aligning is irrelevant. Instead of setting align=right, you just set the right edge to be the same position you set the width of the paper to be. If you enlarge the paper, you can scale the contents with a single operation. Once you've set the position of the right edge, you've essentially set the align position. You don't need to re-set all edge values when the paper changes size, you just scale everything with one command. Hope that helps
Have to implement a Directx9 project that involves zoom towards the cursor like Google maps with the mouse scroll wheel
(similar to this implementation by Phrogz).
Need the math and the variables required for the same.
Solved this problem using below steps
Decide per scroll movement, call it Z-SHIFT, in Z-direction towards the target point
such that the camera should travel to target in fixed scrolls(SCROLL_COUNT)
Calculate the distance to travel in X and Y directions, say DIST_X and DIST_Y
Movement per scroll in X-direction and Y-direction will be calculated as
X-SHIFT = DIST_X/SCROLL_COUNT
Y-SHIFT = DIST_Y/SCROLL_COUNT
Z-SHIFT = Pre decided suitable value
We have mathematical equation to guide the coordinates of the camera per scroll which when placed in the code provides the required zoom to cursor effect.
I'm trying to display text on a Windows control, rotated by 90 degrees, so that it reads from 'bottom to top' so to speak; basically it's the label on the Y axis of a graph.
I got my text to display vertically by changing my coordinate system for the DC by using SetGraphicsMode(GM_ADVANCED) and then using
XFORM transform;
const double angle = 90 * (boost::math::constants::pi<double>() / 180);
transform.eM11 = (FLOAT)cos(angle);
transform.eM12 = (FLOAT)(-sin(angle));
transform.eM21 = (FLOAT)sin(angle);
transform.eM22 = (FLOAT)cos(angle);
transform.eDx = 0.0;
transform.eDy = 0.0;
dc.SetWorldTransform(&transform);
Now when I run my program, the rotated text looks different from the same text when it's shown 'normally' (horizontally). I've tried with a fixed-width (system) font and the default WinXP font. The system font comes out look anti-aliased and the other one looks almost as if it's being drawn in a 1-pixel smaller font than the horizontal version, although they are drawn using the same DC and with no font changes in between. It looks as if Windows detects that I'm drawing a font not along the normal (0 degrees) axis and that it's trying to 'optimize' by anti-aliasing.
Now I don't want any of that. I just want to same text that I draw horizontally to be drawn exactly the same, except 90 degrees rotated, which is possible since it's a rotation of exactly 90 degrees. Does anyone know what's going on and whether I can change this easily to work as I want? I'd hate to have gone through all this trouble and finding up that I will have to resort to rendering to an off-screen bitmap, rotating it using a simple pixel-by-pixel rotation and having to bitblt that into my control :(
Have you tried setting the nEscapement and nOrientation parameters when you create the font instead of using SetWorldTransform? See CreateFont for details.