Is there a possibility to make a part of svg rect transparent? f.x. it has width 100px, and between 40 and 70 px it is transparent. Problem is - the central part should be really transparent and show elements below, it should be not filled with background color like mask.
Thank you in advance.
Use a clipPath to define which parts of your SVG should be transparent.
Complete example here.
Related
I'm trying to use d3's brush control. All works good except the rect.background of the brush is not expanding to fill the whole SVG, thus not allowing me to use the brush on the most right and bottom areas of SVG (which are not covered with background).
This jsFiddle illustrates the problem (scroll to the right and try using brush there) I've outlined the .background rect with the border.
What is the reason of this? And how to make the brush control to work all over the SVG?
Here are the facts:
I have a div with rounded corners containing an SVG element with rounded corners that creates a circle.
Inside the circle (SVG) I am drawing four polygons that make out different circle quadrants.
The polygons respond to hover by changing color - so that when a user mouse is over a specific quadrant in the circle - it lights up.
The SVG and the div containing the SVG both have overflow:hidden CSS directive.
When I mouse over an area outside the circle (but inside the clipped rectangle of the polygon) - the corresponding quadrant lights up...
Why is the element responding to mouse over even though I am hovering over a clipped area?
How can I make sure this will not happen? (without creating occluding transparent elements - I want to be able to touch something in the layer below...).
EDIT:
added fiddle as requested:
http://jsfiddle.net/JVQD8/
In the fiddle - note that the surrounding div is bordered with a red line.
the polygons (in blue) are clipped by the red border (div), and when you hover over a polygon it becomes a lighter shade of blue.
The polygon highlights outside the area of the red circle border if on the polygon.
Edit:
As commented by Robert Longson, there is no problem at all in Firefox.
However, in chrome the problem is as described, and in IE the SVG polygon is not even responding to hover.
So the question about chrome remains as is - only in chrome. How do i know if this is a bug that i should report, or if this is a designed behavioral difference?
Try experimenting with the pointer-events attribute.
https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/pointer-events
I am trying to mimic the behavior of markers on white boards and was wondering if it I can do it with svg polylines. I know the stroke width can be set but can be it changed to vary depending on the velocity of the mouse which I can figure out or is it just a constant value for the stroke?
Or if you wanted to use SVG, instead of using a <polyline>, use a series of connected <line>s
You can't have multiple stroke widths in a single polyline element. I think canvas is probably a better fit for this task.
Suppose that I have an existing SVG scene. I would now like to paint a rectangle on top of this scene, and for all background pixels that are covered by this rectangle, I would like to apply some filter, e.g. desaturation. Note that I can do darkening/lightening using opacity, but in this case, I'd like a more complicated effect. Is this possible to do?
Sure, use an feColorMatrix filter type="saturate" See here
When rendering textures that have an alpha-channel, a white border appears around the non-transparent part (the border seems to be the pixels that have an alpha > 0 and < 1):
The original texture is created in illustrator and exported as a png. here it is:
(well, seems stackoverflow altered the image, adjusting pixels that are not completely opaque/transparent, so here is a link)
it is probably the blending, though i dont know what is wrong with the setup:
gl.enable(gl.BLEND);
gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
[Update]
Here is a rendered version, where i added a alpha-gradient to the left part of the texture (so it is getting from 0 opacity to 1 until the half)
this texture is the only texture rendered at this position. it seems to be whitest around a=0.5. really weird. the background is just a cleared color:
gl.clearColor(0.603, 0.76, 0.804, 1.0);
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
// render objects here
the depth-function looks like:
gl.enable(gl.DEPTH_TEST);
gl.depthFunc(gl.LEQUAL);
any ideas? thanks a lot.
[Update 2]
Answering my own question: the effect occurs when the background-color of the canvas or the body of the html-page is white. I don't have an explanation, though.
Use premultiplied alpha and this problem will go away.
See: http://home.comcast.net/~tom_forsyth/blog.wiki.html#%5B%5BPremultiplied%20alpha%5D%5D
This is problem related to texturing linear interpolation. On borders, some interpolated pixels will take half white half green, and 0.5 alpha. You should modify your texture to extend your borders with one more green pixel, even if it is totally transparent.
What's your draw order? This looks like a depth buffering issue to me — you start with a white background, draw the thing with the border so that it's composited on the white, then draw the thing behind the thing with the border. Those areas where the border was blended with the original white background will have stored a value in the depth buffer equal to the depth of their plane, so when the object behind is subsequently drawn, its pixels are discarded in that area.
The general rule is to draw transparent objects after opaque objects, usually from back to front. If you're using additive blending then it's often good enough to disable the depth buffer after the opaque draw and draw them in any order.
When setting the FragColor in the shader, try multiplying the image RGB with the image alpha.