I am struggling to understand exactly how min-x and min-y on viewBox works, from a technical standpoint (without metaphors).
Two helpful resources I have spent quite a lot of time on:
SVG 1.1 (official specification) - 7.7 The ‘viewBox’ attribute
Understanding SVG Coordinate Systems and Transformations (Part 1) - by Sara Soueidan
According to the SVG 1.1 specification:
The value of the ‘viewBox’ attribute is a list of four numbers
, , and , separated by whitespace and/or
a comma, which specify a rectangle in user space which should be
mapped to the bounds of the viewport established by the given element,
taking into account attribute ‘preserveAspectRatio’.
And:
The effect of the ‘viewBox’ attribute is that the user agent
automatically supplies the appropriate transformation matrix to map
the specified rectangle in user space to the bounds of a designated
region (often, the viewport).
And:
(Note: in some cases the user agent will need to supply a translate
transformation in addition to a scale transformation. For example, on
an outermost svg element, a translate transformation will be needed if
the ‘viewBox’ attributes specifies values other than zero for
or .)
So, my expectation was that defining a viewBox is the same as:
First scaling the viewbox, so it fills the viewport (assuming same aspect ratio on viewport and viewBox)
Then translating the viewBox, so it is placed in the viewport according to min-x and min-y viewBox attributes.
If we look at Sara's two examples, starting here, that is not what seems to be happening.
In her first example (<svg width="800" height="600" viewbox="100 100 200 150">...</svg>), it looks like:
viewBox is placed according to min-x / min-y in viewport
viewBox is scaled to same size as viewport
viewBox origin is translated (moved) to coincide with viewport origin
In her second example however (<svg width="800" height="600" viewbox="-100 -100 400 300">...</svg>), it looks like a completely different order:
viewBox is scaled to same size as viewport
viewBox origin is translated (moved) somehow in the opposite direction of what viewBox min-x min-y indicates. It does not coincide with viewport origin - This is different from the first example
Thus, I recognize that I do not fully understand it, because technically it should work the same way in both cases.
Finally, in Sara's examples, I do not understand why the blue coordinate system (user coordinate system) does not itself move, to (100, 100) or (-100, -100) in viewport coordinate system. I thought viewBox was supposed to translate and scale the user coordinate system?
EDIT:
According to this SO answer, min-x and min-y does indeed follow my first set of steps. The viewBox origin is placed in the viewport according to min-x and min-y, and then translated so its origin is on top of viewport origin. It is then (before or after) scaled to fill viewport.
If that is correct, I have a hard time understanding why the blue user coordinate system in Sara's examples do not always end up with its origin on top of viewport origin. After all, viewBox should modify the user coordinate system.
The offset of the origin of the coordinates viewBox on the x-axis (min-x=70px)
<svg width="400" height="400" viewBox="70px, 0, 400px, 400px">
In the figure, the origin of user coordinates shifts to the right by 70px, thereby shifting the entire rectangular viewing areaviewBox (400 x 400px)to the right along the horizontal axis.
When this happens, the image of the SVG document fragment that is under the viewBox is captured and then the viewBox viewing area with the captured fragment is back aligned with the fixed user viewport area with the origin (0,0) in the upper left corner.
The coordinates of the figures are recalculated with the last shift of 70px to the left. Formally it turns out that in the fixed viewing area of the viewport when applying the viewBox the fragment of the SVG document has shifted to the left.
Live Demo
The offset of the origin of the viewBox along two axes
min-x=70px, min-y="70px"
<svg width="400" height="400" viewBox="70px, 70px, 400px, 400px">
For clarity, add another red rectangle at the bottom of the picture - 6
After transferring the origin to the viewBox, a rectangular 400 × 400 px SVG document fragment with a width and height count from the origin (70.70) gets into the viewBox.
Image capture occurs. Next, the origin of the viewBox (70,70) is combined with the origin of the viewport (0,0). The coordinates of the figures are recalculated.
Therefore, red rectangles 5 and 6 become fully visible. Everything that does not fall into this area is cut off. For example, part of the areas of colored circles 1,2 and 4.
Live Demo
Zoom using viewBox
The scale of the SVG document fragment depends on the aspect ratio: viewport andviewBox
If viewport /viewBox = 1, then the scale will be 1
If viewport /viewBox different from one, the scale will change in the direction of increase or decrease.
How does the increase in scale explains the figure below
One pixel viewBox stretches to two pixelsviewport
Live Demo
Zoom out svg image 1: 2
<svg width="400" height="400" version="1.1"
viewBox="0 0 800 800">
viewport / viewBox = 1/2
The viewBox captures a rectangular fragment 800 x 800 px, that is, the entire scope of the SVG viewport 400 x 400 px and an additional 400px each on the right and bottom of the viewport.
That is two pixels of the viewBox are compressed into one pixel of the viewport. Therefore the SVG image is reduced by half.
Live Demo
In the picture, a gray rectangle is an infinite SVG canvas.
The green rectangle is the viewport that the user sees on its display.
The yellow rectangle is the virtual viewBox area through which the user looks at the viewport.
viewBox can move along the coordinate axes of the infinitesvg canvas as in the positive direction x-min> 0; y-min> 0 and in the negative direction-x-min; -y-min
Image processing svg
Next comes the capture of a fragment of the SVG canvas, located under
the viewBox.
In the next step, the coordinate system of the viewBox is aligned
with the origin of the coordinate system of the viewport. And the
fragment captured by the viewBox image is passed back to the
viewport.
There is a process of negotiation and options are possible here:
If min-x = 0 andmin-y = 0, the width and height of the viewports are equal, respectively, to the width and height ofviewBoxs, then the fragment image does not move or scale.
If the viewBox is shifted to the right - min-x> 0, the image is shifted to the left. It is clear that by capturing an image to the right of the viewport and then combining it with the origin, we thereby shift the image to the left.
If the viewBox is shifted below the viewports - min-y> 0, the image will go up.
Based on this, there are thoughts that you can implement horizontal and vertical parallax without using CSS,JavaScript. To do this, simply move the viewBox along the SVG canvas, as shown in the figure below. Click the Start button.
<svg version="1.1" xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink"
width="600" height="360" viewBox="0 0 600 360" >
<title> Explanation horizontal of parallax viewBox </title>
<desc> animate the horizontal parallax by modifying a coordinate of the viewBox </desc>
<defs>
<g id="canvas-svg" stroke-width="2px">
<g id="canvas-frame1">
<rect id="v-port1" x="25" y="200" width="110" height="110" stroke="skyblue" fill="yellowgreen" />
<text id="t-port1" x="75" y="255" style="font-size: 16pt;">1 </text>
<text x="26" y="303" > 0 </text>
</g>
<g id="canvas-frame2">
<rect id="v-port2" x="135" y="200" width="110" height="110" stroke="skyblue" fill="dodgerblue" />
<text id="t-port2" x="185" y="255" style="font-size: 16pt;">2 </text>
<text x="136" y="303" > 1168 </text>
</g>
<g id="canvas-frame3">
<rect id="v-port3" x="245" y="200" width="110" height="110" stroke="skyblue" fill="crimson" />
<text id="t-port3" x="295" y="255" style="font-size: 16pt;">3 </text>
<text x="246" y="303" > 2336 </text>
</g>
<g id="canvas-frame4">
<rect id="v-port4" x="355" y="200" width="110" height="110" stroke="skyblue" fill="orange" />
<text id="t-port4" x="405" y="255" style="font-size: 16pt;">4 </text>
<text x="356" y="303" > 3504 </text>
</g>
<g id="canvas-frame5">
<rect id="v-port5" x="465" y="200" width="110" height="110" stroke="skyblue" stroke-width="1px" fill="yellow" />
<text id="t-port5" x="515" y="255" style="font-size: 16pt;">5 </text>
<text x="466" y="303" > 4672 </text>
</g>
</g>
</defs>
<g id="first-rect">
<rect x="25" y="25" width="110" height="110" stroke="skyblue" stroke-width="1px" fill="yellowgreen" />
<text x="75" y="85" style="font-size: 16pt;">1 </text>
<text x="26" y="135" > 0 </text>
</g>
<desc>The SVG canvas is infinite in size. In our example, user a viewport of SVG is in the leftmost position.</desc>
<use xlink:href ="#canvas-svg" x="0" y="0"> </use>
<desc> viewBox is moved along canvas SVG</desc>
<g id="viewBox1">
<rect id="v-box" x="25" y="200" width="110" height="110" stroke="skyblue" stroke-width="5px" fill="none" />
<text id="t-port1" x="45" y="225" style="font-size: 16pt; fill:blue;">viewBox </text>
<animateTransform attributeName="transform" type="translate" begin="startButton.click+0.5s" end="stopButton.click" dur="20s" from="0 0" to="440 0" repeatCount="indefinite" restart="whenNotActive" fill="freeze"/>
</g>
<desc> The image moves to the left viewport</desc>
<use xlink:href ="#canvas-svg" x="0" y="0">
<animateTransform attributeName="transform" type="translate" begin="startButton.click+0.5s" end="stopButton.click" dur="20s" from="0 -170" to="-440 -170" repeatCount="indefinite" restart="whenNotActive" fill="freeze" />
</use>
<desc> Grey background image of the canvas SVG</desc>
<g fill="#E5E5E5" stroke="#E5E5E5">
<rect x="135" y="0" width="465" height="195" />
<rect x="0" y="0" width="25" height="195" />
<rect x="0" y="0" width="135" height="30" />
<rect x="25" y="135" width="135" height="60" />
<rect x="0" y="315" width="600" height="85" />
<rect x="0" y="195" width="25" height="120" />
<rect x="575" y="195" width="25" height="120" />
</g>
<g stroke-width="1px" stroke-dasharray = "5 5">
<line x1="25" y1="140" x2="25" y2="195" stroke="blue" />
<line x1="135" y1="140" x2="135" y2="195" stroke="blue" stroke-width="1px" />
</g>
<g style="font-size: 16pt; fill:blue;">
<text x="45" y="170" > viewport </text>
<text x="15" y="20" style="font-size: 14pt;"> display the user's </text>
<text x="230" y="90" style="font-size: 40pt; fill:#1E90FF"> canvas SVG </text>
</g>
<g id="startButton">
<rect x="520" y="325" rx="8" ry="8" width="60" height="20" fill="#58AE2A" />
<text x="550" y="340" font-size="16" font-weight="bold" font-family="Arial" text-anchor="middle"
fill="white" >Start</text>
</g>
<g id="stopButton">
<rect x="450" y="325" rx="8" ry="8" width="60" height="20" fill="#1E90FF" />
<text x="480" y="340" font-size="16" font-weight="bold" font-family="Arial" text-anchor="middle"
fill="white" >Stop</text>
</g>
</svg>
I always mix up viewBox and viewport. So I'll try to avoid it where possible. And I don't fully understand if you want to setup the transformation matrix for the browser or for SVG. So I'll try to avoid it as well.
The viewBox attribute provides information to your browser about the size and the coordinate origin of your SVG graphics. It defines the window into the SVG. Only parts within the window will be visible.
So let's look at an example:
<svg width="800" height="600" viewbox="100 100 200 150">
This tells the browser that it should draw an SVG graphics that will have the dimension 800px by 600px – in the browser's coordinate system. So within the browser DOM, the SVG component will have that size.
The viewbox attribute then tells the browser that the relevant/visible part of the SVG graphics is 200pt by 150pt in size (in the SVG coordinate system). So the browser knows that it will need to apply a scaling of 400% to convert SVG coordinates to browser coordinates.
Furthermore, the viewbox attribute tells the browser that the point (100, 100) in the SVG coordinate system will be the top left corner of the visible SVG graphics window. So the browser will translate it accordingly.
Everything with smaller x and y values in the SVG coordinate system will be clipped, i.e. not visible, as it's outside the windows and outside the space the browser has created for the SVG. Similarly, everything to the right of the SVG coordinate 300 (100 + 200) and below the coordinate 250 (100 + 150) will be outside the window and not visible.
I have an SVG like this :
<svg
xmlns="http://www.w3.org/2000/svg"
id="demo"
style="bottom:0px;left:0px;right:0px;top:0px;margin:auto;position:absolute;"
viewBox="0 0 40 28">
<rect x="0" y="0" width="40" height="14" fill="blue"/>
<rect x="0" y="14" width="40" height="14" fill="green"/>
</svg>
I would expect whatever its size, it will contains only pure blue or pure green.
However, that's not the case :
The same with zoom on it :
As you can see, there this half-transparent white border between blue and green rectangle.
Where does it come from ? Can I avoid it ?
Thank you.
You can turn off antialiasing if you want via shapeRendering:crispEdges. You might not like the result if you apply it to things that do not consist solely of vertical or horizontal lines though.
The viewBox also forces the shape to maintain an aspect ratio which can cause the edges to be blank to maintain that aspect ratio. Again you can turn that off via preserveAspectRatio="none" but your shape will then distort to match the container aspect ratio.
<svg
xmlns="http://www.w3.org/2000/svg"
id="demo"
style="bottom:0px;left:0px;right:0px;top:0px;margin:auto;position:absolute;shape-rendering:crispEdges"
viewBox="0 0 40 28" preserveAspectRatio="none">
<rect x="0" y="0" width="40" height="14" fill="blue"/>
<rect x="0" y="14" width="40" height="14" fill="green"/>
</svg>
The issue is anti-aliasing. It's a characteristic of the renderer, not your SVG representation. There's no real answer, and there's not meant to be - a pixel is an image sample, not a little square.
I need to make text automatically stretch in both dimensions, to fill a container. It will distort.
This shows the the container space in red
This shows what a long name would normally resize to put in that space and maintaining aspect ratio
.
This shows what my client wants to happen
.
I would prefer to use SVG but I will work with what works.
I have searched for a solution to the best of my abilities but all seem to either refer to maintaining aspect ratio or stretching text when the page or viewbox changes dimensions.
That's quite a broad question, but yes you can do it with svg, I'll let you implement it though since you didn't provided anything to chew on.
The key point is to set your svg's preserveAspectRatio to "none":
svg{
height: 100vh;
width: 50vw;
}
body{
margin:0;
}
<div>
<svg xmlns="http://www.w3.org/2000/svg"
viewBox="0 0 300 40" preserveAspectRatio="none">
<text x="0" y="35" font-family="Verdana" font-size="35">
Hello, out there
</text>
</svg>
</div>
If your text is already part of an SVG (as it appears in your example), you will probably need to use a nested <svg> element.
<svg width="400" height="400">
<rect width="400" height="400" fill="rebeccapurple"/>
<!-- rect representing area that our text has to squeeze into -->
<rect x="20" y="50" width="200" height="50" fill="white"/>
<!-- x y width height match above rect -->
<!-- viewBox values need to match text bounds -->
<svg x="20" y="50" width="200" height="50"
viewBox="0 8 244 28" preserveAspectRatio="none">
<text x="0" y="35" font-family="Verdana" font-size="35">
HELLO THERE
</text>
</svg>
</svg>
The hardest part is workoing out the correct values for viewBox. It needs to match the bounds of the (normal unsqueezed) text.
I'm looking to have an svg fill a particular space in my layout, so preserveAspectRatio="none" seems like a good first approach.
However, within the svg, there is a mask that I do not want to stretch / warp. Rather, it should occupy 100% the width, with the height scaling according to its ratio. The two images illustrate the mask's behaviour when the parent svg is in either landscape or portrait. (Note: the grey in the image is the rest of the <svg>, which should stretch to fit)
Can the mask have its own aspectRatio settings? Is there a better way to achieve this? Or, is it even possible?
```
<!-- this should scale according to its bounding parent -->
<svg class="fix" viewbox="0 0 2880 1620" preserveAspectRatio="none..?">
<!-- this should scale according to some intrinsic ratio -->
<mask id="mask"
maskUnits="userSpaceOnUse"
maskContentUnits="userSpaceOnUse">
<rect fill="white" x="0" y="0" width="2880" height="1620" />
<path fill="black" d="M57.59,60h409c344.17,.... ...."/>
</mask>
<rect mask="url(#mask)" x="0" y="0" width="100%" height="100%" />
</svg>
```
edit: using mask-image instead of just mask seems possible (as it has additional positioning options), but this does not seem to work with svg elements.
You don't need to use preserveAspectRatio="none" to have the rectangle and mask fill the page. Just extend the <rect> and <mask> past the boundaries of the SVG in all directions. Root <svg> elements have overflow: visible by default, so the extended rect will fill SVGs parent container - as long as you extend far enough of course.
<rect mask="url(#mask)" x="-1000%" y="-1000%" width="3000%" height="3000%" />
I've used 1000% here, but you can adjust that if you need more or less (than 10x).
And note that we are just using the standard default SVG preserveAspectRatio. So we still get the automatic centerinng and scaling of the SVG.
body {
margin: 0;
padding: 0;
}
svg {
width: 100vw;
height: 100vh;
}
<svg viewbox="0 0 2880 1620">
<!-- this should scale according to some intrinsic ratio -->
<mask id="mask"
maskUnits="userSpaceOnUse"
maskContentUnits="userSpaceOnUse"
x="-1000%" y="-1000%" width="3000%" height="3000%">
<rect fill="white" x="-1000%" y="-1000%" width="3000%" height="3000%" />
<circle cx="1440" cy="810" r="400" fill="black"/>
</mask>
<rect mask="url(#mask)" x="-1000%" y="-1000%" width="3000%" height="3000%" />
</svg>
Demo in fiddle format
i have SVG the property(fill/stroke/stroke-width) should be in style="..." or else out side
example :
<rect x="10" y="10" fill="red" stroke="green" stroke-width="1" width="80px" height="50"/>
-----------------------OR--------------------
<rect x="10" y="10" style="fill:red; stroke:green; stroke-width:1;" width="80px" height="50"/>
Which one is correct? Both are working and reason....
As a matter of fact, both are correct. SVG was created in the late 90s. There all kinds of ideas how to auto-generate stuff were floating around. One was, for example, XSL-FO, which uses most of CSS's properties, but as attributes on elements:
<fo:block font-size="16px" color="red>Hello</fo:block>
In that time it seemed a good idea to double the possibilities to style SVG.
You need to take care, however, how the different properties cascade:
If an element has a style attribute, this is used first
If the SVG file has central CSS declarations, e.g., in a <style> element, those are used second.
The attribute is only used then, as fallback.
For illustration:
<svg xmlns="http://www.w3.org/2000/svg">
<style>rect { fill: yellow; }</style>
<rect fill="red" style="fill: green" width="100" height="100"/>
</svg>
The resulting color of the <rect> is... green.