Units In Inkscape: Document Unit Change - Revision history

Tavmjong at 08:15, 18 November 2014

2014-11-18T08:15:02Z

← Older revision		Revision as of 08:15, 18 November 2014
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	See also: [[Units In Inkscape]]		See also: [[Units In Inkscape]]

	The ''Document Unit'' can be changed from the ''Document Properties'' '''Page''' tab under "General: ~~Deafult~~ Units". Changing the Document Unit changes the relationship between the ''width''/''height'' and ''viewBox'' such that the initial ''user unit'' (aka 'px') is equal to the Document Unit.		The ''Document Unit'' can be changed from the ''Document Properties'' '''Page''' tab under "General: Default Units". Changing the Document Unit changes the relationship between the ''width''/''height'' and ''viewBox'' such that the initial ''user unit'' (aka 'px') is equal to the Document Unit.

	In order to make this change, Inkscape walks through the document changing all length units it finds (or attempt to). This has led to many bugs.		In order to make this change, Inkscape walks through the document changing all length units it finds (or attempt to). This has led to many bugs.
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	Question: Can we better describe what is happening when a user changes the ''Document Unit''. It is not clear that there is an invasive change happening inside the file (unlike changing the units for the 'Page Size' which alters just the outer 'width' and 'height').		Question: Can we better describe what is happening when a user changes the ''Document Unit''. It is not clear that there is an invasive change happening inside the file (unlike changing the units for the 'Page Size' which alters just the outer 'width' and 'height').

			Question: How is an externally generated SVG without an inkscape:document unit handled?


			Notes:

			# This is not the same as changing the GUI units which only effects what is displayed (you set a width to 1 inch but if the document unit is 'px' the value in the SVG file is 90px or 96px).
			# This is independent of the change from 90 pixels to one inch to the SVG/CSS value of 96 pixels per inch.


	=Implementation=		=Implementation=

~suv: /* Failings */

2014-09-25T14:49:26Z

Failings

← Older revision		Revision as of 14:49, 25 September 2014
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	* [https://bugs.launchpad.net/inkscape/+bug/1365451 Bug 1365451: Symbols scales wrong when document unit is not px (rev >= 12554)]		* [https://bugs.launchpad.net/inkscape/+bug/1365451 Bug 1365451: Symbols scales wrong when document unit is not px (rev >= 12554)]
	* [https://bugs.launchpad.net/inkscape/+bug/1369197 Bug 1369197: translations of groups are not converted to new units when changing document units]		* [https://bugs.launchpad.net/inkscape/+bug/1369197 Bug 1369197: translations of groups are not converted to new units when changing document units]
			* [https://bugs.launchpad.net/inkscape/+bug/1373311 Bug 1373311: Guides positions not stored in user unit]
	* ADD MORE BUGS		* ADD MORE BUGS

~suv: fix internal link

2014-09-21T14:30:40Z

fix internal link

← Older revision		Revision as of 14:30, 21 September 2014
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	See also: [[Units in Inkscape]]		See also: [[Units In Inkscape]]

	The ''Document Unit'' can be changed from the ''Document Properties'' '''Page''' tab under "General: Deafult Units". Changing the Document Unit changes the relationship between the ''width''/''height'' and ''viewBox'' such that the initial ''user unit'' (aka 'px') is equal to the Document Unit.		The ''Document Unit'' can be changed from the ''Document Properties'' '''Page''' tab under "General: Deafult Units". Changing the Document Unit changes the relationship between the ''width''/''height'' and ''viewBox'' such that the initial ''user unit'' (aka 'px') is equal to the Document Unit.

~suv: /* Failings */ add more bug links

2014-09-21T14:26:47Z

Failings: add more bug links

@@ Line 27: / Line 27: @@
 Bugs:
 * [https://bugs.launchpad.net/inkscape/+bug/1279534 Bug 1279534: text-on-path size changes if you change default document units]
 * ADD MORE BUGS

~suv: /* Failings */ fix bug link

2014-09-21T14:20:46Z

Failings: fix bug link

← Older revision		Revision as of 14:20, 21 September 2014
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	Bugs:		Bugs:
	* [~~[text-on-path size changes if you change default document units~~ https://bugs.launchpad.net/inkscape/+bug/1279534]]		* [https://bugs.launchpad.net/inkscape/+bug/1279534 Bug 1279534: text-on-path size changes if you change default document units]
	* ADD MORE BUGS		* ADD MORE BUGS

Tavmjong: Created page with " See also: Units in Inkscape The ''Document Unit'' can be changed from the ''Document Properties'' '''Page''' tab under "General: Deafult Units". Changing the Document Un..."

2014-09-21T07:46:21Z

Created page with " See also: Units in Inkscape The ''Document Unit'' can be changed from the ''Document Properties'' '''Page''' tab under "General: Deafult Units". Changing the Document Un..."

New page

See also: [[Units in Inkscape]]

The ''Document Unit'' can be changed from the ''Document Properties'' '''Page''' tab under "General: Deafult Units". Changing the Document Unit changes the relationship between the ''width''/''height'' and ''viewBox'' such that the initial ''user unit'' (aka 'px') is equal to the Document Unit.

In order to make this change, Inkscape walks through the document changing all length units it finds (or attempt to). This has led to many bugs.

Question: Do we want to disable changing ''Document Unit'' in 0.91 (until all the bugs are worked out)?

Question: Can we better describe what is happening when a user changes the ''Document Unit''. It is not clear that there is an invasive change happening inside the file (unlike changing the units for the 'Page Size' which alters just the outer 'width' and 'height').

=Implementation=

Changing "General: Default Units" calls:
:document_properties.cpp: DocumentProperties::onDocUnitChange()

This function sets transforms of stroke, rect corners, pattern, gradient to true. (Should filters also be transformed?) And then calls
:sp-item-group: SPGroup::scaleChildItemsRec()
on the root element. Which recursively goes through all ''groups'' in the document, making the required scale change.

Note that SPGroup::scaleChildItemsRec() is also used in metafile-inout.cpp

Question: Should scaleChildItemsRec really be a member function of SPGroup?

==Failings==

Bugs:
* [[text-on-path size changes if you change default document units https://bugs.launchpad.net/inkscape/+bug/1279534]]
* ADD MORE BUGS

Problems:

* Scaling should but does not occur in SPDefs, SPClipPath, SPMask, SPImage, SPGlyph? as these are not derived from SPGroup.
* Scaling applies a transform to child elements.
** This naive scaling does not always work, as the case of SPNamedView (grids and guidelines are not updated) or SPUse (where the 'x' and 'y' values are not scaled).
** For text on a path, the scaling is applied twice, once on the path and once on the text.
** It also introduces unwanted structural changes, introducing or removing the 'transform' property depending on the value of the "Store Transform" preference value ('Optimized' or 'Preserved').
* For elements with a 'viewBox' it is not clear what should happen:
** Should markers be scaled? How does this interact with 'stroke-width'? What about the 'refX' and 'refY' values?
** Should symbols be scaled? Probably not, as the same symbol added from an external library will be different depending on when it was added (before or after a unit change). (Same might be true for markers.)
* How are style properties handled? 'transform', 'x', and 'y' are being turned into properties from attributes.
* How are elements that define their coordinate space via 'userSpaceOnUse' or 'boundingBox' handled?

==Current Object Hierarchy==

This hierarchy is useful to trace what is effected by SPGroup::scaleChildItemsRec(), etc.

* Object
** SPDefs#
** SPDesc
**SPFilterPrimitive
**SPFilter
**SPFlowline
**SPFlowregionbreak
**SPFontFace
**SPFont
**SPGlyphKerning
**SPGlyph
**SPGuide
**SPItem
***SPFlowdiv
***SPFlowtpsan
***SPFlowpara
***SPFlowregion
***SPFlowregionexclude
***SPFlowtext
*** SPImage*#
*** SPLPEItem
**** SPGroup
***** SPBox3D
***** SPMarker*
***** SPAnchor
*****SPRoot*
*****SPSwitch
***** SPSymbol*#
**** SPShape
***** SPGenericEllipse
***** SPLine
***** SPOffset
***** SPPath
***** SPPolygon
***** SPPolyline
***** SPRect
***** SPSpiral
*** SPText
*** SPTextPath
*** SPTRef
*** SPTSpan
*** SPUse
** SPMeshPatch
** SPMeshRow
** SPMetadata
** SPMissingGlyph
** SPObjectGroup
*** SPClipPath#
*** SPMask#
*** SPNamedView (Does this really belong under SPObjectGroup?)
** SPPaintServer
*** SPGradient
**** SPLinearGradient
**** SPMeshGradient
**** SPRadialGradient
*** SPPattern*#
*** SPSolidColor
** SPScript
** SPStop
** SPString
** SPStyleElem
** SPTagUse
** SPTag
** SPTitle

* Has 'viewBox'.
# Is container.