XAML: rotation around its axis 3d - wpf

Is it possible to create animations for two controls like they are on two sides of rectangle. And rectangle is rotating around its axe (3d)?
Something like this:
Blue side - first control, and the green one - second.
I.e. I want both controls to be shown one by one eternally.

Related

Drawing in draw call-back and drawing outside draw call-back

Custom drawing in Gtk3 with Cairo is explained in https://developer.gnome.org/gtk3/stable/ch01s05.html
Here draw_brush in the handler for motion-notify-event draws small rectangles as the mouse is dragged. In the original code there is no other drawing. Suppose I draw a filled blue rectangle in draw_cb by adding the following code:
cairo_set_source_rgb(cr,0.1,0.1,0.8);
cairo_rectangle(cr,80,80,50,50);
cairo_fill(cr);
and similarly another filled red rectangle in clear_surface which is called from configure_event_cb, I get a strange behavior where the blue rectangle is not over-written by draw-brush, but the red rectangle gets over-written, as seen in the picture below:
Can anyone explain this behavior so that I can correctly make custom drawings in the application I am developing.
So, in clear_surface / configure_event_cb, you draw to surface, which is also the surface where the brush draws to. Since the brush is drawn later, it ends up ontop of the red rectangle that you draw here.
In draw_cb, this temporary surface that is used for the drawing is copied to the screen. If you draw a blue rectangle afterwards to the screen, this blue rectangle ends up ontop of what you drew before.
So basically: The reason is the two different targets for drawing that are used here. One is the "actual stuff" on screen, which can disappear at any time. The other is an internal surface created in configure_event_cb that does not go away unexpectedly.

Shapes Clipping

I'm having a problem that's driving me crazy for a couple hours...
Situation:
I am drawing a shape - ellipse,
then im creating a new brush - from an image,
I apply the brush to my shape,
and then I rotate the shape..
The problem is: Everthying is displaying correctly - but...
As soon as I drag the shape to the edge of the window - thats where the formular ends,
it's starting to cut of some parts of the shape.
It's simply not drawing the part that should be not visible, because overflowing the form.
But in my case, I've rotated the shape, so it's cutting the wrong part of it.
This is what it look's like. Is there a way to kinda "reset" the cliping.. Or another solution...
Solved It.
Set the parent element's width and height larger then the window is (its was HorizontalAlignment.Stretch) before.
Now you'll never reach the cliping edge of the parent

How to display a background control in transparent overlapping control?

I'm building a form with two layers of controls. The bottom layer is a set of Panels with defined properties, one of which is a color different from the form background. The top layer is a set of picture boxes I'm using to display a circle. I've set the PictureBox Background to Color.Transparent, and I've offset it from the underlying Panel by one pixel to get the form to draw the underlying Panel. However, the area around the circle in the PictureBox is displaying the Form Background color, not the panel color. I don't want to draw the circle in the Panel, because I want the circles to move between Panels, and actually look like just a circle that's floating across the form independent of the Panel board underneath. Think of the effect as moving a piece on a board game (you see the peg move across the board, possibly on a diagonal not following the normal game path, then stop in a place on the game).
How can I get the PictureBox to have the underlying Form and panels show through, not just the form background color? I'm using C# Visual Studio 2010, and I'm not a terribly experienced programmer, so a code example would be helpful. An image of the form is at:
http://www.imageurlhost.com/images/salgmpcxvcz830c3flt.jpg
Found a way around the problem. I got rid of the Panels for the spaces in the game, and instead drew them as rectangles on the form's background image.

WPF 3D transparent textures - clipping?

http://www.youtube.com/watch?v=gZNdfVwkttM - you can see all of the problem described on this video if you can't see pictures.
All of walls in all images below have a semitransparent PNG texture. Each square wall, floor and ceiling tile is a separate GeometryModel3D (I know that is no good for performance but...). The floor and the ceiling of the central cube have no any geometry and textures - so they have a color the same as Window.Background (black). But the effect considered appears in any way of transparency obtaining: texture for ImageBrush with transparency, Material.Color (for example DiffuseMAterial.Color) where Color has alpha channel, ImageBrush as material where ImageBrush has Opacity - all the way I have the same problem.
All of walls consists of two triangles. Where are no explicit normals , because I define triangle indices so normals culculated automatically by WPF.
http://imagepost.ru/images/i/ma/image00001.png
It also haven't any back material or extra triangles from the back side.
As you can see there is no problem if you look only from +Z to -Z (standing on the blue square and looking to the red square - that is the second picture).
But if you look backward (from red to blue - the first picture) there is no transparency!
Well, I desided to look from the yellow square (third picture).
And then I walked nearer - you can see what was happening (pictures from 4 to 6).
There are no geometry construction error or texture mapping error or lighting error! It is some kind of clipping, I guessed! In addition there are some interested pictures 7 and 8 to prove my guess.
The last picture shows the white background of the window that hosted Viewport3D (previous was black), and my guess about clipping confirmed - WPF just not painted this part of the scene and we can see the window background!
BUT! If this happens from various looks, why the look from +Z to -Z (second picture) seems well?!
You need to sort the triangles based on their distances from the viewpoint. Only then, wpf will be able to blend the transparent textures.
DirectX is able to blend triangles on top of each other but only when drawing them back to front
http://www.ericsink.com/wpf3d/2_Transparency.html

WPF Canvas: centered origin, scaled axes (and y inverted), responding to mouse events

In a simple code-only WPF application I'm writing, I would like to have a custom Canvas.
I've found questions similar to this one here in StackOverflow, but couldn't find exactly this one, nor a simple way to adapt another answer to my specific problem (please note that I have not much experience in WPF).
In my canvas, I'd like it to have the following properties:
the point (0, 0) is on the center of the Canvas;
the x-axis points to the right;
the y-axis points to the top;
the point (1, 0) is about 1 inch to the right of the origin; and
in every event, the position of the mouse is given in the coordinate system defined above.
In this answer, Ray Burns propose a very simple solution to my first 3 points. It is trivial to modify that code so that it deals with my point number 4 as well (change 1 and -1 in the RenderTransform to other constants).
However, that very simple and excellent solution for many problems is based on setting width and height to 0, and centering the canvas on its container. Therefore, there's no canvas to capture events like a click, so this solution won't handle my fifth property.
What's the easiest way to achieve this? Inherit from Panel and do everything by hand? Inherit from Canvas, intercept every event and modify the coordinates?
Put Canvas inside a Border. Border has mouse events. Another case is to place Border on the top of the Canvas.

Resources