ODF drawings beyond SVM: enhanced geometry, the missing shape elements, embedded chart objects, and transforms

[andiwand]

ODF drawings only render as far as a bounding box or an SVM replacement image. Everything the shape geometry itself carries — the enhanced-geometry path, draw:object chart XML, the less common shape elements, draw:transform — is dropped. This is the umbrella issue for closing that gap; the sub-topics already filed are listed at the bottom.

Where we are today

parse_element_tree (src/odr/internal/odf/odf_parser.cpp:302) knows exactly nine drawing elements:

draw:frame  draw:image  draw:rect  draw:line  draw:circle
draw:custom-shape  draw:text-box  draw:g  draw:a

draw:custom-shape maps to ElementType::custom_shape, and html::translate_custom_shape
(src/odr/internal/html/document_element.cpp:652) emits a positioned <div> with fill and
stroke — the box, never the shape. Anything not in that table falls through
parse_element_tree's final return {null_element_id, ...} and vanishes with its subtree.

What is dropped

Enhanced geometry. draw:enhanced-geometry (with draw:enhanced-path, draw:equation,
draw:handle, draw:modifiers, view box, mirror/text rotation) is what makes a custom shape an
arrow, a callout, a star. We parse none of it, so every one of them renders as a rectangle.
draw:enhanced-path is close enough to an SVG path that an SVG-based renderer is plausible.

Shape elements with no parser at all:
draw:path · draw:polygon · draw:polyline · draw:ellipse · draw:measure ·
draw:connector · draw:caption · draw:regular-polygon · dr3d:scene

Embedded objects (draw:object / draw:object-ole). A LibreOffice chart is
<draw:frame><draw:object xlink:href="./Object 1"/><draw:image xlink:href="./ObjectReplacements/Object 1"/></draw:frame>.
We ignore draw:object and render the sibling draw:image, which is the SVM raster-ish
replacement. So a chart is only ever as good as LibreOffice's replacement image, and where no
replacement was written the chart is simply absent. The real content — Object 1/content.xml,
a full <chart:chart> with series, axes, and a table:table of the plotted data — is right
there in the package and unused.

Transforms. draw:transform (rotate/translate/skew/scale) is not read at all, so
anything rotated or flipped is drawn in its unrotated position.

Why "beyond SVM" matters

SVM is a fallback with three problems: it is LibreOffice-specific and optional, it is a flattened
metafile so the output has no text to select and no structure to style, and its own coverage is
incomplete (bitmaps are unimplemented, #194). Drawing straight from the ODF markup gives real
vector output, selectable text, and something that survives a producer that never wrote a
replacement image.

Suggested order

1. draw:transform on the shapes we already parse — smallest change, visible on real files.
2. The missing shape elements above, rendered as SVG.
3. draw:enhanced-geometry → SVG path (support odf custom-shape #159).
4. draw:object chart XML → a rendered chart, with the SVM replacement kept as the fallback (ods chart missing #179).

Test files

• odg/sample.odg — 6 × custom-shape/enhanced-geometry, 51 × draw:equation, 6 × draw:handle
• odg/SpotfaceCoord40270-L.odg — 5 × enhanced-geometry, 1 × draw:path
• odg/Sealver Measurements.odg — 25 × enhanced-geometry, 27 × draw:measure, 3 × draw:path
• ods/Bloods.ods, ods/style+svm-chart-1.ods, ods/style+svm-chart-2.ods — draw:object charts

Related

• support odf custom-shape #159 support odf custom-shape (enhanced geometry)
• ods chart missing #179 ods chart missing (draw:object / chart XML)
• svm support bitmaps #194 svm support bitmaps (the fallback's own gap)
• alignment in ODG #214 alignment in ODG

References

• http://docs.oasis-open.org/office/v1.2/os/OpenDocument-v1.2-os-part1.html#a10_Graphic_Content
• https://wiki.openoffice.org/wiki/Create_a_New_Custom_Shape_in_Source_in_File#Features_in_Detail

[andiwand]

Closed by the five stages, in the order the corpus argued for:

• feat(odf): draw a shape where its draw:transform puts it #796 — draw:transform, its operation list composed to one matrix. The list applies left to right and rotate is counter-clockwise, both settled against libreoffice's own svg export rather than the spec text.
• feat(odf): draw the shape elements the parser used to drop #797 — the shape elements with no parser: draw:path, draw:polygon, draw:polyline, draw:regular-polygon, draw:connector, draw:ellipse, draw:measure, draw:caption, mapped onto the types that already exist and drawn as svg.
• feat(odf): read the enhanced geometry languages, formulas and path alike #798 — draw:formula (20.36) and draw:enhanced-path (19.145) as pure functions over strings, unit-tested from literals.
• feat(odf): draw a custom shape as the shape, not as its box #799 — that wired into CustomShape::path(), so a custom shape draws as the shape. Closes support odf custom-shape #159.
• feat(odf): draw the chart an embedded object holds, not its replacement image #800 — odf_chart.cpp renders the embedded part's <chart:chart>, and the draw:image replacement stays the fallback. Closes ods chart missing #179.

What remains of ODF drawings is tracked as the unticked boxes in odf/README.md: draw:text-areas, draw:handle, F/S, gradient and hatch fills with draw:opacity and stroke dashes, arrowheads (draw:marker), draw:mirror-* on a shape with no enhanced geometry, and the chart features — stacked and percentage plots, secondary axes, trend lines, data labels, and the number format an axis names.

dr3d:scene, draw:object-ole, preset draw:type shapes and connector re-routing are deliberately not decoded; the reasoning is in odf/AGENTS.md.