Added rotation support for viewport and WPF renderers

[scottdewald]

When the viewport is rotated, the IViewport.Extent is expanded to include the rotated rectangular view. Simply expanding the viewport's extent to be the circumscribed rectangle around the rotated viewport makes the logic easier and eliminated the need to change the fetcher or the BruTile library.

Along with Rotation, the IViewport has a new WindowExtent property which represents the visible bounds of the viewport. Since the IViewport.Extent box is rotated, some of it will be outside the visible region.

I still need to correct the pixel rounding or expand the tiles by 1 pixel when the viewport is rotated as sometimes you can see the tile borders. However, works well enough to see what you think.

[scottdewald]

... there is a slider in the sample WPF application you can use to test out the map rotation

[pauldendulk]

hi, im away right now. I hope to look at this the coming days.

Did you notice my comments at issue #10?

[scottdewald]

Didn't see it until just now....

I can see pros/cons to both approaches. I think the first approach of
rotating the entire context after the rendering would be easiest like you
mentioned. One con of this approach, however, is if the user wants to draw
HUD-like (heads up display) features over the screen, the context will be
rotated. This may be a small sacrifice.

I ended up taking the second approach in which I rotate the individual
elements. This makes text/labels stay oriented up as well. However, your
first approach may solve the slight rounding issue I'm seeing sometimes in
which the tile borders can be seen in some orientations.

Looks like the rest of your comments are in line with what I did.

Sent from my "smart" phone
On Sep 12, 2014 7:31 AM, "Paul den Dulk" notifications@github.com wrote:

hi, im away right now. I hope to look at this the coming days.

Did you notice my comments at issue #10
https://github.com/pauldendulk/Mapsui/issues/10?

—
Reply to this email directly or view it on GitHub
https://github.com/pauldendulk/Mapsui/pull/11#issuecomment-55396101.

[scottdewald]

Had a chance to look into this? About to start integrating this feature into my application and it would be good to know which rotation approach you're going to take as my other drawing items will depend on it.

Thanks

[pauldendulk]

I will try to look at this tomorrow.

[pauldendulk]

Thanks a lot! I did not have time to look at the changes in detail. I hope I can give more feedback later. I will try to add rotation to OpenTK as well, and will learn more about the rotation code in the process.

If I understand correctly you rotate the whole canvas and then counter rotate the labels. This way most of the code will stay intact. I saw you even made sure the stacklayels function sitll correct, awesome.

Using the Quad in the Viewport with the ToBoundingBox on top is a fairly simple solution. The name 'ToBoundingBox' suggest a conversion but that is not really what it does, better to use 'GetBoundingBox', which is in line with the IGeometry.GetBoundingBox.

[scottdewald]

Glad to help. Changing to GetBoundingBox makes sense.

Actually, I did not rotate the entire canvas that way the screen
coordinates returned by Viewport.WorldToScreen() would always be oriented
properly with the actual screen (i.e. - adding to the screen.X value moves
right, while adding to screen.Y moves down). To position and orient items
in the world I call GeometryRenderer.PositionRaster() which adjusts the
RenderTransform accordingly.

If you want the canvas rotated instead of the elements, that probably
wouldn't be too difficult to change. I may be able to look at it for the
WPF side in a couple days.

On Fri, Sep 19, 2014 at 8:07 AM, Paul den Dulk notifications@github.com
wrote:

Thanks a lot! I did not have time to look at the changes in detail. I hope
I can give more feedback later. I will try to add rotation to OpenTK as
well, and will learn more about the rotation code in the process.

If I understand correctly you rotate the whole canvas and the counter
rotate the labels. This way most of the code will stay intact. I saw you
even made sure the stacklayels function sitll correct, awesome.

Using the Quad in the Viewport with the ToBoundingBox on top is a fairly
simple solution. The name 'ToBoundingBox' suggest a conversion but that is
not really what it does, better to use 'GetBoundingBox', which is in line
with the IGeometry.GetBoundingBox.

—
Reply to this email directly or view it on GitHub
https://github.com/pauldendulk/Mapsui/pull/11#issuecomment-56174276.