If I render to a bitmap then the bitmap has a specific number of pixels and a DPI. That combination makes it easy to draw a square that is 1" x 1" - I render lines for each side that are DPI pixels long.
When I create a SVG, I think it should still be able to be set this way. Where I set the units per inch and also the size in those units of the object as a whole. Yes you can zoom on a SVG file as it's all vectors, but it should still have a 100% zoom size to render to.
In my case I am using EMUs for my units. So 914400 units/inch. So question #1 is, how do I set the scaling using Batik. For a bitmap it's:
AffineTransform scaleToEmus = AffineTransform.getScaleInstance(dpi / (float) DrawingSurface.EPI, dpi / (float) DrawingSurface.EPI);
graphics.transform(scaleToEmus);
But there is no dpi equivalent for SVG.
And then for a given width & height that is in EMUs, do I set the size (or maximum extent) of the image using:
svgGraphics.setSVGCanvasSize(new Dimension(width, height));
I think I'm not fully understanding SVG, or at least Batik as I don't see how to set the units to render at for a 100% zoom.
Related
I Have a viewport and a scaled image inside like this:
both the images are scaled to 0.1 but the one inside the viewport is of less resolution
Is there anyway to fix this?
The Viewport has a size, that size sets the resolution at which the contents of the Viewport will be rendered. And it does not have to match the size at which it is displayed (it could be stretched/scaled).
With the ViewportContainer you can decide if it will automatically set the size of the Viewport or if it will stretch it (scaling the ViewportContainer will also result in stretchering). If you prefer to not use the ViewportContainer※, set the size of the Viewport in the Inspector or form code.
※: For example, you can display a ViewportTexture with a TextureRect, which will give you more control on how it is displayed. But it is less convinnient to setup.
I want to generate PDF to Jpeg image with a width of 900px and 150 dpi with the help of Ghostscript rasterizer.
You can set the size of the image in 2 ways; firstly if you know the size of the PDF media (the MediaBox), which is in the PDF file, and is in PostScript units (1/72 of an inch) then a simple calculation will give you the required rendering resolution:
target X resolution = output width in pixels / (Media width / 72)
target Y resolution = output height in pixels / (Media height / 72)
You can then set the resolution using the -r switch as described in the documentation here
Alternatively you can set the output media size in pixels using the -g switch, and then use the -dPDFFitPage switch to have Ghostscript scale the PDF content so that it fits into the output. Note that this method scales isomorphically. That is the same scale factor is applied to both the x and y directions.
The -g switch is described in the documentation here and the -dPDFFitPage switch is described here.
I'm using several libraries to generate SVG images in-browser, which can be bounced off the server through svgexport to generate PNGs or JPEGs at user-specified resolutions. (This works as expected.)
I'd like to offer the user the option of downloading the SVG that gets fed into the conversion, with the resolution used to set the width and height attributes. When I do that, the viewbox is not scaled to the specified width and height, but is padded so that the image occupies the original size area in the upper left.
While looking for solutions, I found images in the W3C documentation that illustrate the problem. If you open these images in Chrome and use the inspector to change the width and height properties,
ViewBox.svg will expand to fill the width and height (linked from here)
PreserveAspectRatio.svg will be padded to stay in the upper left (linked from here)
This does not appear related the presence or value of thepreserveAspectRatio property, or the nesting of svg tags. My files are rendered as padded rather than scaled in Chrome/Chromium, Firefox, Safari/WebKit, Opera, Inkscape, and Gapplin.
How do I ensure that my SVG is scaled rather than padded to fill the width and height?
The viewbox is not scaled when it's entered as viewbox rather than viewBox; svg attribute names are case sensitive.
The second link does not have a viewBox attribute, and adding a viewbox (lowercase) attribute has no effect.
I want to convert a svg to a png with the inkscape command line tool. Despite of what is specified in the svg i want to set both the width of the resulting png and the dpi to be used. From the inkscape docu it seems this is not possible:
-w WIDTH, --export-width=WIDTH
The width of generated bitmap in pixels. This value overrides the --export-dpi setting (or the DPI hint if used with --export-use-hints).
I can't really understand how this could be as the width and the dpi used should not be directly related. How can I achieve to set both values.
Thanks, Martin
Ok got it I think, here as it goes in my concrete example:
In the svg the width is 2480 pixel (what you need for DinA4 300 dpi print). Now my mistake was to add "-d 300" to the inkscape call which doesn't make sense if the svg does not give the width in some unit. When doing so the resultant image has a width of 2480 * 300 / 90 = 8267 pixel . So if working with pixel in the svg you need to be aware of the fact the inkscape interprets this as 90 dpi ...
Well i guess only my confusion here yet happy to share ;-)
I'm trying to display text on a Windows control, rotated by 90 degrees, so that it reads from 'bottom to top' so to speak; basically it's the label on the Y axis of a graph.
I got my text to display vertically by changing my coordinate system for the DC by using SetGraphicsMode(GM_ADVANCED) and then using
XFORM transform;
const double angle = 90 * (boost::math::constants::pi<double>() / 180);
transform.eM11 = (FLOAT)cos(angle);
transform.eM12 = (FLOAT)(-sin(angle));
transform.eM21 = (FLOAT)sin(angle);
transform.eM22 = (FLOAT)cos(angle);
transform.eDx = 0.0;
transform.eDy = 0.0;
dc.SetWorldTransform(&transform);
Now when I run my program, the rotated text looks different from the same text when it's shown 'normally' (horizontally). I've tried with a fixed-width (system) font and the default WinXP font. The system font comes out look anti-aliased and the other one looks almost as if it's being drawn in a 1-pixel smaller font than the horizontal version, although they are drawn using the same DC and with no font changes in between. It looks as if Windows detects that I'm drawing a font not along the normal (0 degrees) axis and that it's trying to 'optimize' by anti-aliasing.
Now I don't want any of that. I just want to same text that I draw horizontally to be drawn exactly the same, except 90 degrees rotated, which is possible since it's a rotation of exactly 90 degrees. Does anyone know what's going on and whether I can change this easily to work as I want? I'd hate to have gone through all this trouble and finding up that I will have to resort to rendering to an off-screen bitmap, rotating it using a simple pixel-by-pixel rotation and having to bitblt that into my control :(
Have you tried setting the nEscapement and nOrientation parameters when you create the font instead of using SetWorldTransform? See CreateFont for details.