CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

• Improved: grid auto-styles are now parameterized; d-grid5 / d-grid10 are gone (d-grid remains as-is) and new d-grid-N where N is any integer from 1 to 100 creates an appropriately dimensioned grid. The d-hatch, d-crosshatch and d-stipple classes are parameterized in the same way. New classes d-grid-v and d-grid-h (also parameterizable) provide vertical / horizontal grid lines.

• Editor: Fixed SVG download button to make a fresh request without metadata for a cleaner download file. Also removed the base64 data URI copy, replacing with simple copy of the generated SVG.

[0.16.0 - 2024-12-31]

• Added: auto styles for text-outlines. These use the SVG2 paint-order attribute to ensure the fill is painted after the stroke, and use stroke-width to create an appropriate text outline. This is available through the class d-text-ol, which applies a default text outline, as well as the more specific d-text-ol-[colour] and d-text-ol-[width], where colour is an SVG colour name and width is one of thinner, thin, medium (the default), thick or thicker.

  As part of supporting clean text outlines, stroke-linecap and stroke-linejoin styles are both set to round for everything; this generally results in tidier output where separate line objects join at the same point, compared to the SVG defaults of butt/miter, but has a noticeable effect on stroke-dasharray, so the d-dot / d-dash / d-flow (and a new stroke pattern d-dot-dash) have been updated to match. In particular, d-dot now renders as a series of circular dots rather than small squares.

• Added: new config option svg-style available as TransformConfig::svg_style or --svg-style command line argument, inserted as style attribute on the root SVG. Use-case is to provide inline style when embedded in a larger document.

• Added: <box> element. Analogous to the <point> element, but defining a 'phantom' rectangle which may be used for relative positioning.

• Internal: replaced regex with basic string parsing throughout, eliminating a dependency and reducing size of WASM build.

• Improved: refactor to consolidate element reference parsing; improves consistency, allowing e.g.:

  • edge spec to be used in connectors
  • allowing 'previous element' references (^) in contexts which previously only supported id-based references, including connector start / end attributes.
  • element id references may use the '-' character

• Fixed: text-style values now applied to <tspan> as well as <text> elements.

• Fixed: avoid use of CSS :not() pseudo selector, not supported in many SVG contexts (e.g. Inkscape)

• Fixed: substituting multiple auto-style classes into an element via variable expansion.

• Fixed: <path> element without d attr is no longer an error when computing bbox.

• Fixed: merging auto-style defs/style elements with any existing such elements was broken, and has been abandoned as not worth the hassle.

• Fixed: bbox calculation for <g> elements with transform attributes.

• svgdx-server: add basic CLI options to specify listening address & port, as well as an --open flag to open a web browser with the svgdx editor.

• Editor: limit zoom range

• Editor: add SVG2 help link

[0.15.1 - 2024-12-15]

• Changed: '%' operator now computes non-negative result, as in the Python '%' operator rather than the Rust '%' operator. This only affects negative operands, and is more useful when using '%' to compute indices into lists. Previous behaviour was -1 % 4 == -1; this change means -1 % 4 == 3.

• Fixed: precedence of the unary minus operator was incorrect. This fixes expressions such as -5 - 8 (now -13 rather than 3).

• Improved: inside attribute behaviour for inscribing circles / ellipses. Still room for further improvements here, but simple cases (e.g. ellipse inside rect) now work as expected.

• Fixed: Default text anchor for relative positioning of <text> elements to center of target element.

• Fixed: Arrow connector (class="d-arrow") did not display correctly on Firefox.

[0.15.0 - 2024-12-13]

• Internal: event processing logic has been significantly refactored.

  This significantly simplifies the internals of svgdx, which should improve consistency and streamline improvements. The previous ElementLike trait has been replaced with an EventGen trait which is simpler and implemented by SvgElement as well as other types wrapping this to provide element-specific behaviour.

  This is a long-overdue improvement, but it does make changes to whitespace in rendered documents, and other minor changes may be observed.

• Internal: changed the error handling from using anyhow to a new SvgdxError enum. The use of anyhow made it too easy to treat all errors alike, which is unhelpful for distinguishing between recoverable (e.g. reference) and non-recoverable errors.

  The set of error variants is not yet fixed.

• Added: <svg> elements with the xmlns attribute may be used anywhere in a document to suppress svgdx processing the content of that element, passing it through unaltered.

• Fixed: bounding box calculation for <reuse> elements targeting a compound element such as <g> where an offset transform (e.g. x, y attributes on the reuse element) is present. Similarly fixed <use> elements referencing <symbol> elements.

• Fixed: avoid infinite recursion on use/reuse circular references; a new depth-limit config value (default 100).

• Fixed: specifying relative sizes for circles and ellipses, e.g. r="#abc 25%"

• Editor & svgdx-server changes:

  • implemented rate-limiting on calls to /transform endpoint, and added defer attribute to various JavaScript file loading. These improve behaviour on high-latency connections to an svgdx-server instance.
  • source line highlighting now reflects the first line of an element, not the last.
  • the 'Text Output' view no longer includes the source-line metadata, which cluttered the generated SVG.

[0.14.0 - 2024-11-18]

• Improved text positioning, useful when needing multiple text labels inside or around another shape (though it's still only possible to provide a single label via the text attribute within a single element)

  • <text> elements positioned relative to another element using the xy attribute gain automatic text-loc anchoring depending on the relative position. For example if positioned above (e.g. xy="#id:V") an element, the anchor will be bottom-center of the text.
  • text-loc attributes can now use edgespec (e.g. "b:30%")
  • New d-text-inside and d-text-outside classes can override the default text placement of 'inside' basic shapes / 'outside' lines & points.

• Changed: renamed text-inset attribute to text-offset, since this is equally usable outside shapes as inside them. Any use of this attribute will need to be renamed in your svgdx documents.

• Added use-local-styles CLI and <config> element option. If active, this adds a random id attribute to the top-level <svg> output element, and uses that with CSS nesting to keep all styles tied to the immediate document. This is useful when embedding svgdx output documents in another e.g. HTML document (as done by mdbook-svgdx, for example), but may not function correctly in non-browser applications.

• svgdx-server / editor: Added a Content-Security-Policy for improved web-security.

[0.13.1 - 2024-11-01]

• Added font-size and font-family config options, available in the <config> element or via command line options; defaults remain 3.0 and sans-serif respectively, but now text classes such as d-text-smaller can scale together based on the base font size.

• svgdx-server: vendored the CodeMirror5 editor source used for the online editor. This allows totally local use of svgdx-server without relying on any internet connectivity.

[0.13.0 - 2024-10-03]

• Improved / changed: better positioning support for <use> and <reuse> elements. This includes use as relative positioning targets, as well as support for the SVG standard x and y attributes to translate where an instantiated element will be placed. NOTE: this implies that x and y (as well as translate) are acted on at the <reuse> element level, and do not become 'attribute variables' available in the context of the target.

• Fixed: <symbol> as a <reuse> target no longer generates invalid SVG output. (The <symbol> is translated to <g> element in the instantiated output, as the SVG spec states is the behaviour when a <use> of a <symbol> element occurs)

• Added: improved support for the transform attribute, for example generated <text> elements now inherit any transform from the source element, and basic transform changes in position / size (particular translate and scale) are honoured when constructing a bounding box. KNOWN ISSUES: interactions between transform, <reuse>, and <g> elements have various failing edge cases which will be addressed in a future release.

• Added: <point> element, used to define positions which may be referred to in refspec values, but (unlike a zero-radius circle) do not appear in the output. See the ninedots.xml example.

• Changed: variable substitution now occurs prior to evaluting numeric expressions. Previously an expression such as {{count($e, $e, $e)}} with e="" would evaluate to 0, as each variable lookup would be done as part of the expression evaluation, and empty values would be implicitly filtered out. Following this change, the variable lookup happens first, resulting in count(,,), which will fail to parse and be the output. The advantage to early substitution is being able to do {{$target.h / 4}} (see examples/skyline.xml) with (e.g.) target="#abc". Without early substitution, tokenisation will fail trying to parse $target.h.

• Changed: variables are now locally scoped to the nesting level they are defined in. Previously a <var n="2"/> inside a <g> element would set it permanently for the rest of the document (until later overridden, either by an attribute or another var element). Now variable definitions cease once their 'scope' finishes, aligning var definitions and attribute values.

• Change (minor): order of generated position attributes improved so width / height aren't separated by any rx on rectangles.

• Added: public VERSION constant for the library version.

• Changed / Added: if width or height are provided in the SVG root element, a viewBox will still be generated if missing. In addition, if only one of width or height are provided, the other will be generated automatically based on the aspect ratio of the calculated viewBox, including any units. For example on a 4:3 aspect ratio diagram (after adding the border), if <svg width="10cm"> is given, an additional height="7.5cm" attribute will be generated.

• Added: new fill pattern classes d-grid, d-grid5, d-grid10. These render an axis-aligned grid of fine lines in the themes default stroke colour at the appropriate scale (1, 5, or 10 user-coordinate units), and can be useful when building a diagram. See examples/grid.xml.

[0.12.0 - 2024-09-05]

• Added: if element, used to selectively include a fragment. Previously this could be emulated with a while loop, but now the simpler <if test="condition"> element is available.

• Added: scalarspec support in d and points attributes (for path/polyline/polygon elements). This is useful for <path> fragments such as h #abc.w to draw a horizontal line from the current position for a distance corresponding to the width of #abc.

• Added: initial support for themes. These are an extension of auto-styles, where some styles are parameterized by a theme. Current themes are fine, bold, glass, light, and dark, as well as the default theme which acts as previous. There are minor changes to the generated style rules even for the default theme, but these shouldn't change the visual display of rendered SVG images. One minor change is that the background setting now defaults to default rather than none; the new setting applies the theme default. This allows the value none to be explicitly provided to generate a transparent background when this is not the theme default.

• Added: new auto-styles d-hatch, d-crosshatch, and d-stipple for various patterned fill effects. NOTE: this overrides any specified colour fill (setting the theme default).

• Added: initial support for x / y / transform attributes on <reuse> elements aligning with the equivalent SVG attributes on <use> elements. This is only partial support; while they are carried through to a new transform attribute, bounding box evaluation doesn't (yet) take this into account.

• Added: in(x, a1, a2, ...) function, which returns if x is in the given list.

• Change (minor): Comments generated from _ / __ attributes are now surrounded by whitespace for readability.

• Change: The PRNG used for the random() and randint() functions is now Pcg32 rather than SmallRng. This change ensures repeatability between native and WASM builds; SmallRng has a (documented) limitation that it is not portable. Any document using these functions will be change, but will become consistent between the WASM-based svgdx editor and the command line svgdx binary.

[0.11.1 - 2024-08-16]

• Added: a touch of animation comes to svgdx with the new d-flow auto-styles. Typically used on lines to indicate directionality without relying on arrows, this animates the stroke-dashoffset parameter where the SVG viewer supports CSS3 animations. Suffixes -slower, -slow, -fast and -faster may be appended to d-flow to change the speed of 'flow', and the direction can be reversed with d-flow-rev. These styles automatically add a d-dash type appearance, but can also be combined with d-dot.

• Enhanced: d-arrow / d-biarrow styling is changed to show filled arrowheads, which butt-up against shapes at exactly the end of the line. This may change again in the future, as it's a compromise between simplicity and presentation.

• Enhanced: stroke-width auto-styles d-thin and d-thick are now joined by d-thinner and d-thicker. Each increment is by a factor of 2.

• Added: var-limit config variable (can be set by --var-limit N with CLI or the <config var-limit="N"/> element within a document). This defaults to 1024, and is the maximum length of a value assigned to a variable. This is intended to identify the an incorrect 'string expansion' rather than expression evaluation, e.g. when <var thing="$thing + 1"/> is used rather than <var thing="{{$thing + 1}}"/>.

• Changed: loop-limit (and the new var-limit) are 'maximum valid' values, rather than the point at which things break (as previously).

• svgdx-editor: limited zoom speed from wheel events to make scrolling with a trackpad more controllable (and less CPU intensive!)

[0.11.0 - 2024-08-07]

• svgdx-editor: now uses WASM for browser-local transforms, and server transforms when using svgdx-server. See svgdx.net hosted using GitHub Pages.

• More refactoring to support bounding boxes for <g> elements, with the following changes:

  • Added: <g> groups now have bounding boxes and can be used as the target of a relspec.
  • Removed: the repeat attribute is no more; use <loop> instead. While <loop> is more verbose, it more cleanly separates 'control' elements from 'graphic' elements.
  • Internal: use of traits to define element behaviour, allowing different classes of element to behave differently.

• Fixed: loop-limit can be set in <config> elements, as documented.

• Fixed: variable expansion now works in class attributes.

[0.10.0 - 2024-07-04]

• Substantial refactor of positioning / layout logic with following key changes:

  • Changed: 'relspec deltas' such as the '1 2' in 'xy="#abc@t 1 2"' indicate an offsets from the point given by the relspec as an (x, y) pair. Previously if only a single value was given, it would be the 'dx' value with 'dy' implicitly set to zero. From this release a single value is duplicated across both dx and dy, equivalent to a single entry in a dxy attribute.
  • Added: constraint-based positioning. The x1/x2/y1/y2/cx/cy/width/height attributes (and compound combinations, e.g. xy1, cxy) may be provided for any basic shape, providing the position is sufficiently tied down. For example, a circle may be specified by the combination y2, x1 and r, or the combination cx, y1, and x2.
  • Changed: attribute ordering is no longer preserved. Given the additional number of positional source attributes and transformations around these, a different approach of forcing selected generated attributes to appear in a specific order is used - for example in a rectangle the generated x / y / width / height attributes will always appear in that order, and any id attribute will always be the first attribute of an output element.

• Added: various functions making use of expression lists:

  • Rectangular / polar conversion functions r2p(x, y) and p2r(r, theta).
  • Vector-arithmetic functions addv(a0, a1, ...aN, b0, b1, ...bN), subv(a0, a1, ...aN, b0, b1, ...bN) and scalev(s, a0, a1, ...aN), where addv and subv return the element-wise sum / difference of each list, and scalev multiplies each element by the first s argument.
  • List processing functions: head() (return first entry), tail() (remainder after removing head), empty() (return 1 if the given list is empty, else 0), and count() (cardinality of list) - each taking a (possibly empty) list, and select(n, a0, a1, ...aN) to retrieve the nth item in the list.

• Added: support for loop-var, start and step attributes in while and until loop types (in addition to count).

• Added: the repeat element is now available within <reuse> targets and supports expressions rather than only hardcoded integer counts.

[0.9.3 - 2024-06-14]

• Change (minor): style attributes are no longer copied into any <text> elements generated by text attributes, as conflicts between 'outer' and 'text' element styles are common. A new text-style attribute is provided which becomes the style attribute of any generated text element.

• Added: Support for multiple (comma-separated) expressions in a single {{...}} block. This also provides the concept of an 'expression list', which is a natural fit for variadic functions. The min() and max() functions can now take any number of arguments, as can the new variadic sum(), product() and mean() functions. Note all these functions require at least one argument.

• Fixed: don't attempt to derive bounding box for elements (including root <svg>) where size / position attributes have units or %age values - e.g. x="5%" width="10cm" etc. Previously this prevented processing many SVG examples using units or percentages.

• svgdx-editor: Added 'Copy PNG' button(s) which copy a PNG image to clipboard in the selected resolution.

[0.9.2 - 2024-05-28]

• Fixed (regression in 0.9.0): overriding compound attribute derived positions caused position deltas (dx/dy/dw/dh) to stop working correctly in some cases.

• Change (minor): text-dx/text-dy/text-dxy are now applied after any text insetting, rather than instead of insetting. This means text-dxy="0" is now a no-op.

• Added: Support a text-inset attribute for varying the inset value (i.e. how much non-centered text is 'pulled in' from a corner or edge). Previously this was hard-coded to 1.

[0.9.1 - 2024-05-27]

• Added: support for vertical text; add the d-text-vertical class to an element to cause text to be rendered vertically. The same integration with basic shapes and use of the text-loc attribute if available for vertical text.

• Added: improve loop ergonomics with support for loop-var, start and step attributes on count loops. By default the variable assigned by loop-var will take the values 0..count-1, incrementing each iteration. start and step allow overriding the initial value and increment. Previously using a loop counter as a variable value required a combination of two <var> elements (for initialisation and increment) and a while loop.

• Fixed: attributes derived from compound attribute expansion are lower priority than equivalent target attributes, i.e. an xy attribute should not overwrite an existing y attribute.

• Fixed: various error handling improvements

[0.9.0 - 2024-05-13]

• Added: support for <loop> element, with count, while and until attributes defining multiple iterations of the contained elements. See the loop element docs for more information.

• Added: element id attributes are now evaluated as with other attributes, allowing id value to include variable values; useful to keep id unique inside loop bodies.

• Added: Check for circular references in expressions to avoid stack overflow.

• Fixed: positioning relative to a connector (<line> with start/end attributes).

• Fixed: dx / dy attributes were being incorrectly stripped from feOffset elements.

• svgdx-editor enhancements: Increased number of tabs from 5 to 10; added 'text output' view with toggle button; minor styling improvements.

[0.8.0 - 2024-04-27]

• Changed: various auto-styles relating to text, including the ability to specify text colour, size, style, and a change to prevent d-softshadow / d-hardshadow being applied to rendered text. A new d-thick style has been added as a complement to d-thin. See auto_styles.md for more information.

• Changed: attribute-based variable lookup now starts at the parent (rather than the current) element. Note that when reuse is in effect, the source reuse element itself is considered the immediate parent of target element.

• Added: <reuse> element now supports <g> targets allowing more complex shapes to be reused. Note that (currently) there are still limitations around positioning; <g> doesn't yet have it's own bounding box, and elements within a reused group element do not support the multiple passes required for forward references.

• minor svgdx-editor enhancements including timestamp in download filenames

[0.7.1 - 2024-04-07]

• svgdx-editor enhancements, including both horizontal and vertical editor layouts, copy as data URI, highlight source lines on element hover, and various bug fixes.

[0.7.0 - 2024-04-01]

• Changed: Split out features for cli and server (support for the new svgdx-server). Both these are default features, but if only the library is needed a no-default-features build will be smaller / faster to compile.

• Added: 'svgdx-server' - a simple web-based frontend for editing and viewing svgdx documents. Run with cargo run --bin svgdx-server. I'm not sure what direction this will go in - for me it's a workflow improvement over the --watch + Gapplin (or similar) I'd been using previously.

• Added: Support wh and xy attributes for <use>, <image>, <svg> and <foreignObject> elements.

• Changed / Added: text-pre attribute which if present (with any value) converts spaces in text to non-breaking spaces, to defeat the XML whitespace processing and allow space-preserving text to be displayed. Previously leading spaces were converted in this way, but not internal space.

[0.6.0 - 2024-03-10]

• Changed: relspec positioning modified to be more consistent: the referenced element must now be given explicitly as ^ or #id, rather than the previous implicit 'previous element' default. Direction-based relative positioning ('dirspec') now always requires a ':' separator. See layout.md for details of the new relspec definition.

• Changed: margin now takes up to 4 entries, analogous with CSS margin and padding values. Previously it took either one or two entries, and with two entries the first was an 'x' margin and the second a 'y' margin. Now the CSS approach is used with support for separate TRBL margins.

• Added: inside attribute, analogous to surround but as the intersection of bounding boxes rather than their union.

• Added: support for providing text content for graphical elements using XML text or CData in addition to the text attribute. This makes pre-formatted text much easier to include.

• Changed: leading whitespace in text content of elements is now replaced with non-breaking spaces, to allow arbitrary indenting.

• Added: Relational and logical functions. Function notation (e.g. lt(a,b) rather than a < b) is chosen to avoid the need to use XML entities ('<' etc). It also avoids the need for more levels of precedence, though that's not a good reason on its own. Note logical values adhere to C-language values; non-zero evaluates to true, and true/false will be indicated by the numeric values 1.0 & 0.0 respectively.

[0.5.0 - 2024-02-11]

• Changed: Removed the custom elements <tbox>, <person> and <pipeline>, since these are now better implemented with <specs> and <reuse>. The person and pipeline examples have been updated to use the new <reuse> templating approach.

• Added: Support for <specs> and <reuse> custom elements to allow templating of elements in the rendered document.

• Changed: Variable lookups now first reference attributes of the input element (provided this is not a <vars> element) before checking the global namespace. This is particularly useful in conjunction with the <reuse> element to provide 'custom element'-like behaviour.

• Added: a bunch of builtin functions for expressions, including basics such as min, max, and abs, trigonometric functions, and random number generation. See the function documentation for a full list.

• Added: a --seed command-line argument (and <config seed="..."> setting) to initialise the random number generation for the random() and randint() functions.

[0.4.2 - 2024-02-04]

• Added: initial support for <path> bounding boxes. Note this currently ignores any curves (cubic, quadratic, arcs) and considers only visited endpoints of these shapes.

• Changed approach to indentation so this now works consistently with elements processed out-of-order (e.g. geometry defined in terms of elements occurring later in the document)

• Added a <config> element which can define config options within an input document. See the element docs for more info. This allows the examples/refresh.sh script to be run cleanly over all the examples.

[0.4.1 - 2024-01-22]

• Improved error handling, with fewer panics caused by invalid input.

• Added a check that the output won't override the input file (after being bitten by exactly this...)

• Updated examples to use .xml / .svg for input and output filenames respectively, rather than -in.svg / -out.svg. While the auto-completion for input files which .svg might provide in some editors is useful, the extension lies about it being a valid SVG file which can be confusing, e.g. when viewing input source for examples in GitHub.

• Update shlex to address RUSTSEC-2024-0006 (no relevant parts of the affected API are used in svgdx.)

[0.4.0] - 2024-01-15

• Changed: auto-styles are no-longer suppressed when user-defined styles / defs are present. Note this may require changing user-styles to increase priority over auto-styles.

• Added: Additional values for scalar specs, including cx, cy, rx, ry. Existing scalar values can now be referenced by alternate names, e.g. width in addition to w or y in addition to t. The intent here is that SVG attribute names (e.g. y or height for a rectangle) are used as scalar names.

• Added: support for out-of-order references in surround and other contexts.

  Since surround is intended to support 'background' fills around shapes, it needs to be painted before the shapes in contains - and therefore reference elements occurring later in the document (which may in turn reference other elements later in the document to establish placement).

  A more general approach to these 'recursive' references is implemented, though it may be slow in the general case with large documents. The previous populate() stage followed by 'simple' / 'not-simple' calls to expand_attributes() have been replaced by repeated 'process remaining elements which couldn't be handled' stages until success (no further elements) or stall (couldn't reduce the number of remaining elements).

  NOTE: one (temporary) limitation of the approach here is the generated indentation/newline placement is less consistent, as output elements are no longer processed in document order.

• Internal: Made fields of TransformerContext private with appropriate access methods, e.g. elem_map.get() -> get_element(). Evaluation functions now take a &TransformerContext where previously they took &HashMaps etc corresponding to the internal types.

• Internal: pop_idx / insert_idx functions on SvgElement, to allow an attribute to be removed and replaced 'in sequence' with multiple other attributes without having to iterate through all existing attributes and rebuild a new AttrList. NOTE: This isn't a nice API and may change.

• Internal: switch to using lazy_regex for performance.

[0.3.1] - 2024-01-04

• Fixed: expressions including a variable as e.g. "20 24" would become "2024" with whitespace collapsed. When used in numeric contexts this would create problems. It now remains as the text value "20 24" as intended.
• Fixed: panic resolving element size with dwh (etc) when wh referred to a variable or other expression.

[0.3.0] - 2024-01-03

• Changed: more consistent public API; get_config() and run() are still top-level functions, but the various transform_* functions allow a range of input/output options for processing documents.
• Changed: split svgdx::TransformConfig out of svgdx::Config to handle per-transform settings, leaving top-level Config for 'front-end' options from the svgdx command-line program.
• Changed: default styles now use fill: white for shapes to improve appearance of overlapping shapes. Shapes using surround still have no fill via a d-surround class.
• Added: additional command-line options to tweak transformation:
  • --debug to include more debugging info in the generated document
  • --scale to allow scales other than 1 user-unit == 1mm
  • --border to specify width of border around entire image
  • --no-auto-style to prevent svgdx automatically adding style/defs entries
  • --background to specify background colour (default none)
• Fixed: Blank lines in multi-line text are now rendered correctly.
• Fixed: Move dwh handling to ensure it works with cxy.

[0.2.0] - 2024-01-01

• Added: Initial support for <path> elements, though currently very limited.
• Changed: single value refspec is now #abc.x to avoid #abc.h (height of #abc) conflicting with #abc:h (position horizontally on the right of #abc). Mnemonic: '.' has a single dot and returns a single numeric value...
• Add support for locspecs in points attribute for polyline and polygon.
• Add dx/dy/dxy support for points values, translating each point in turn.
• Added d-thin and d-biarrow auto-style classes.
• Add support for dirspec (h/H/v/V) relative positioning from a referenced element, e.g. xy="#abc:h"
• Add various auto-style classes: d-{colour} & d-fill-{colour} for various colours, d-dot / d-dash for stroke styling, d-arrow for arrowhead marker, etc.
• Added surround attribute for rect / circle / ellipse which takes a list of element references and creates a shape surrounding them; a margin attribute can provide x & y margins expanding the surrounding shape from the minimal bounding box enclosed.

[0.1.0] - 2023-12-25

• Initial public release. Happy Christmas!