svg2-changelog.md

SVG 2 changelog

An attempt to list all changes between SVG 1.1 and SVG 2.

Somewhat similar to Changes from SVG 1.1 from the SVG 2 spec, but actually lists all changes and not just changes to the spec itself. For example, that page doesn't list filter related changes and most of the text related changes are either omitted or scattered around the spec.

This document contains changes only to the static SVG subset. No animations, events and scripting.

A checkbox indicates that the related feature is implemented in resvg.

NOTE: This list is not final. This just things I was able to find so far. Patches are welcome.

Data Types

Added

• A turn unit to <angle>.
• Following units: ch, rem, vw, vh, vmin, vmax and Q to <length>.
• rgba(), hsl() and hsla() notations to <color>.
• A transparent keyword to <color>.
• A #RRGGBBAA and #RGBA notation for colors. Part of CSS Color 4.
• A opacity property allows <percentage> now.

Changed

• <length> no longer includes the % unit. This variant was moved into a separate type: <length-percentage>.
• <FuncIRI> was replaced with an <url>. The main change here is that <url> allows quoted strings.

Deprecated

• CSS2 system colors.

Quirks

• <color> includes an alpha value now, which should be accounted by fill, stroke, flood-color and stop-color properties. But not by lighting-color property. At least Chrome 92 and Firefox 91 doesn't do this.

Document Structure

Added

• refX and refY properties to the symbol element.
• An auto variant to image element's width and height properties.
• A lang attribute. The same as xml:lang, but without the namespace.

Changed

• width and height properties of the svg element are set to auto by default.

Removed

• A baseProfile attribute from the svg element.
• A version attribute from the svg element.
• A externalResourcesRequired attribute.
• A requiredFeatures attribute.
• A xml:base attribute.

Styling

Deprecated

• A clip property.

Coordinate Systems, Transformations and Units

Added

• A transform-box property.
• A transform-origin property.
• A vector-effect property.

Changed

• transform, patternTransform and gradientTransform are presentation attributes now. Which means that they can be resolved from CSS now.

Removed

• A defer keyword from the preserveAspectRatio attribute.

Quirks

• CSS transform and SVG transform have different syntax.

Basic Shapes

Added

• A pathLength attribute to all basic shapes.

Changed

• rx/ry attributes on ellipse should be resolved using the same logic as rect uses.

Text

Added

Basically everything from CSS Text Module Level 3.

• WOFF font support is required now.
• A path property to textPath.
• A side property to textPath.
• A font-feature-settings property.
• A font-kerning property.
• A font-synthesis property.
• A font-variant-caps property.
• A font-variant-east-asian property.
• A font-variant-ligatures property.
• A font-variant-numeric property.
• A font-variant-position property.
• A line-height property.
• A text-align-last property.
• A text-align property.
• A text-indent property.
• A text-orientation property.
• A text-overflow property.
• A text-transform property.
• A unicode-range property.
• A white-space property.
• A text-decoration-line property.
• A text-decoration-style property.
• A text-decoration-color property.
• A text-underline-position property.
• A text-decoration-fill property.
• A text-decoration-stroke property.
• A inline-size property.
• A shape-inside property.
• A shape-subtract property.
• A shape-image-threshold property.
• A shape-margin property.
• A shape-padding property.
• New variants to font-variant property. Previously it allowed only small-caps.
• A font-variant-css21 value to font property.

Changed

• textPath can reference basic shapes now.
• Since CSS Fonts Module Level 4, the font-weight property allows any value in a 1..1000 range.
• A writing-mode property introduces the horizontal-tb and vertical-lr values from CSS Writing Modes Level 3.
• dominant-baseline is inherited now.
• baseline-shift is 0 by default, instead of baseline.
• Percentage values in a word-spacing relate to a percentage of the affected character's width and not to viewport size now.
• filter, clip-path, mask and opacity properties can be set on tspan and textPath elements.
• A text-decoration property has a new, but backward compatible syntax.

Removed

• A tref element.
• A kerning property. Use font-kerning instead.
• A glyph-orientation-horizontal property.
• A altGlyph element.
• A altGlyphDef element.
• A altGlyphItem element.
• A glyphRef element.
• reset-size, use-script and no-change variants from dominant-baseline.
• auto, before-edge, and after-edge variants from alignment-baseline.
• baseline variant from baseline-shift.
• Percentage values from letter-spacing.

Deprecated

• A xml:space property.
• A glyph-orientation-vertical property.
• A baseline-shift property. Use vertical-align instead.

Quirks

• As of 2021, only Inkscape has Text layout – Content Area support, but still a very minimal one.
• text-transform is technically a CSS 2.1 property, but was not allowed in SVG 1.1

Painting

Added

• An arcs variant to the stroke-linejoin property.
• A miter-clip variant to the stroke-linejoin property.
• (partial support) A paint-order property.
• context-fill and context-stroke variants to the <paint> type.
• A mix-blend-mode property.
• An isolation property.
• left, center and right variants to refX and refY properties of the marker element.
• An auto-start-reverse variant to orient property of the marker element
• The image-rendering can appear as a presentation attribute with additional possible values. Currently, there is only best-effort support for "pixelated".

Changed

• Markers can be set on all shapes and not only on path.

Quirks

• As of 2021, no one supports stroke-linejoin:arcs.

Gradients and Patterns

Added

• A fr attribute to the radialGradient element

Clipping, Masking and Compositing

Added

• <basic-shape> and <geometry-box> variants to the clip-path property.
• A mask-image property.
• A mask-mode property.
• A mask-position property.
• A mask-clip property.
• A mask-origin property.
• A mask-size property.
• A mask-composite property.
• A mask-type property.
• A mask-border-source property.
• A mask-border-mode property.
• A mask-border-slice property.
• A mask-border-width property.
• A mask-border-outset property.
• A mask-border-repeat property.
• A mask-border property.

Changed

• A mask property has a new grammar, backward compatible with SVG 1.1 one.
• An element can have multiple masks now.

Filter Effects

Added

• A feDropShadow element.
• An edgeMode attribute to feGaussianBlur element.
• Filter functions.
• New blend modes to feBlend element.
• A no-composite property to feBlend element.

Changed

• A filter property type changed from <FuncIRI> to <filter-value-list>.
• The saturate type in feColorMatrix can be larger than 1 now.

Deprecated

• An enable-background property.

Quirks

• Filter functions doesn't have a filter region. Which means blur() and drop-shadow() cannot be losslessly converted to filter element. We have to manually calculate a new region (somehow).
• Filter functions are always in sRGB color space, unlike a filter element, which is in linearRGB by default.

Linking

Deprecated

• xlink:href in favor of href.

Fonts

Removed

• A font element.
• A glyph element.
• A missing-glyph element.
• A hkern element.
• A vkern element.
• A font-face element.
• A font-face-src element.
• A font-face-uri element.
• A font-face-format element.
• A font-face-name element.