In QML canvas, I am trying to draw an image which is in svg format and contains lines with arrow heads like below.
svg in not supported by stackoverflow, so I put the png of svg image above just for diplay.
original svg is here : https://svgshare.com/i/9u8.svg
And when I tried to draw this image in QML canvas, resulted image doesn't contain the arrow heads. The result look similar to below. Even in Qt creator, arrow heads are not shown.
I want to know is it problem with SVG generation or problem with drawing on canvas?
The reason this happens is that Qts SVG implementation is based on TinySVG - it only supports a subset of SVG and can't handle all features of the specification. Looking at the code of the SVG-file, it is propably the <marker> elements that are not supported.
A possible solution would be to either edit the image (with e.g. Inkscape) to convert these markers to normal paths or to create a bunch of PNGs of variing sizes and load them conditionally.
Related
In a C++ Qt6 desktop application I would like to display a schematic drawing of an industrial process (which I have in SVG format), overlayed with some ui widgets, like radio buttons and combo-boxes, that represent configurable parameters.
It looks like this can be achieved with QSvgRenderer, but there is a problem:
the rendered svg will not be theme-aware.
Is there any way to modify the colors used by this renderer, without parsing and manipulating the SVG myself to edit the color values?
We can assume that all SVG elements are the same color.
Alternatively, can I do something else with my SVG schematic, that does not involve manually drawing it again e.g. in QPainter, but still accomplishes my original goal?
I need create clickable component with custom shape. Appearance is set by svg file. Clickable area must be constrained by svg shape. I find great example of what I need, but it use pixel mask or circle mask. Can you help me find solution?
Most probably you will need to create a pixel mask yourself from the SVG shape.
The question is how to approach this. Qt does not offer a simple way of doing it. However, in Qt you can render the SVG offscreen into an image that you initialize with transparent pixels or a color key. You can then use this image as a mask.
If the size of your viewpoint changes frequently, you might want to do the mask rendering in a higher resolution first and then scale it down accordingly for performance. Also note that if your SVG is animated, you would have to accomodate for that.
Or you might use a different library than Qt to obtain the mask. Also, if your SVG contains only a single polygon, you might go for a point-polygon test. But I doubt it, and such a test is also not trivial when the polygon is non-convex (you typically end up with a scanline algorithm anyways).
I'm designing a website which uses a SVG-document as background. I want this image to tile on the X-axis. Which works great, but I wanted to know if it is possible to show one group in the SVG only once, such that in subsequent tiles the group is hidden.
The above image visualizes what I want to achieve. The image having one group (in the image the red circle) that is invisible in the following tiles.
Now I am aware such things can be achieved using additional CSS backgrounds but I am really interested if such thing could be achieved using a single SVG background.
Thanks in advance!
The answer is no. If you are relying on CSS to tile the background - ie. with repeat-x, then no. there isn't any way to do what you want. When an SVG is used as a background like that, it becomes immutable - effectively the same as a PNG or a JPEG.
You will need to use a different method.
I have an SCNNode that has its geometry populated from a collada file (.dae) and displays correctly on screen. I can apply materials to the geometry easily enough, however I'd like to change the scale of the material.
I currently populate it with
nodeArray[0].geometry?.firstMaterial!.diffuse.contents="wood.png"
but the scale of the material is too small. While I can edit the png in GIMP or something similar and import it as wood2.png is there any way I can set the material scale programatically?
what do you mean by "too small" ?
Geometries are made of different sources such as the vertices' positions, but also their texture coordinates. These texture coordinates (they belong in [0,1]x[0,1]) are specified per vertex and indicate where to look in the texture.
In your 3D modeler please check that your texture coordinates match what you want (i.e. they cover the whole image i.e. they go from 0 to 1 in very direction), and make sure that your image has no extra transparent margin or other wasted space.
You can have a look at SCNMaterialProperty's contentsTransform property. But please check your model and texture before using it.
You need to open your UV snapshot in an image editing software like Photoshop, scale the wood texture in Photoshop over your UV's, then resave your PNG/JPG, move PNG/JPG back to Xcode
I recently purchased Drew Wilson's Pictos icon library. It is a library of flat, monochromatic icons for use on the web and elsewhere. The only issue is: they're vectors. I know my way around Illustrator a little bit, but ultimately I want to import these icons into Photoshop CS4 and resize to various dimensions.
When I import an icon and resize it to, say, 20x20 pixels, I notice that there is a fair bit of aliasing around the edges of the icon. I'm sure there is some magic number where the edges of these icons will remain crisp, but I can't find any option or setting that will allow me to size these icons properly.
How can I snap these icons to the closest size that removes or minimizes the aliasing?
The aliasing / pixelating is because vectors export out of illustator # whatever size they're copied #
Try opening the icons in illustrator... scaling them waaay up
And then just keep a copy of the huge ones in a separate layer
Copy that layer when you want to scale it down ..annnd that way you'll have a copy to work with..and u won't have to re
Open the file every time u need to make an edit
And a good rule of thumb for pixelation is
You can always size down.. but sizing up will create pixelating in bitmaps
Chances are, you have your logo in .eps format. If you do, open your .eps file in Photoshop. A dialog box will pop up asking the size you want to import. Be sure to select RGB color if this will display on the web. Select the Anti-aliasing checkbox. When your file opens up, zoom in, and you'll notice that Photoshop has neatly anti-aliased all of your edges for you.