[Gdal-dev] plotting data
rogper at bredband.net
Sun Sep 19 05:49:08 EDT 2004
Thanks for the hint. But what projection are am suppose to use? If I
project the (lat, long, height)-coordinate onto a "Oblique
Stereographic" (x, y, z)-surface, then I must project a second time
onto a graphics device coordinate system (or OpenGL coordinate system)
before rendering. Is it up to me to calculate the latter (affine)
transformation, or is there an utility to do that ?
2004-09-19 kl. 00.00 skrev Chapman, Martin:
> There are several ways to draw your points in a window. All the ones
> I know, at a minimum, use the "graphics device context". The DC
> (device context) or objects that derive from it, have methods to draw
> to a window that take x, y as parameters. It also lets you control
> things like line width, fill color, etc. In addition to that, the
> device context can also be used to pass control of the rendering to a
> third party graphics library like OpenGL. There is a lot of good code
> on the internet that shows how to do this for your specific platform.
> With that said, I would search google for how to draw points in a
> window using the device context or opengl on Mac OSX. Once you get
> that plumbing hooked up it will be obvious how to feed the points to
> your screen from OGR.
> I would strongly recommend using OpenGL for vector, not for raster
> though...always use the device context for rasters unless you want to
> project the image into a vector map. Go to http://nehe.gamedev.net/
> and try some of the cross-platform examples for OpenGL as well.
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