X3D CAD/TransposeNurbsAxes
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Revision as of 13:29, 22 March 2012 by Vmarchetti (Talk | contribs)
The web page [[1]] demonstrates a disagreement among current X3D browsers that implement the NURBS Component as to how they interpret the standard to place the parametric axes (generally labelled the u-v axes) on the created and rendered 2D surface.
This discrepancy amounts to interchanging the labelling of the parametic axes on the surface. It is possible to similarly interchange the parametric axes in an X3D model by
- interchanging the parameters uOrder with vOrder, uClosed with vClosed, etc.
- Transposing (rows with columns) the array of control points and weights before flattening to a list to encode in the Coordinate.point field.
<?xml version="1.0" encoding="ISO-8859-1"?>
<!--
Transposes the u-v parametric coordinate axes on a NurbsPatchSurface or NurbsTrimmedSurface
For NurbsPatchSurface nodes and TrimmedNurbsSurface node the parameters which
come in u-v pairs (ex uKnot, vKnot) have their values swapped
The attributes NurbsPatchSurface/@weight and NurbsPatchSurface/Coordinate/@point
are, in the input x3d data, lists of numbers which are the weight,control_points arrays listed in column-major order.
In the transformed data these lists are the same arrays flattened in row-major order.
For the nodes ContourPolyline2D/@controlPoint and NurbsCurve2D//@controlPoint: these attributes are
lists of u-v coordinates of points in parametric coordinates. In the transformed attributes, each
element of this list is transformed u,v ==> v,u
The ordering of the list is unchanged.
Copyright 2012 Vincent Marchetti
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
-->
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:exsl="http://exslt.org/common"
xmlns:str="http://exslt.org/strings"
extension-element-prefixes="exsl"
xmlns:ksh="http://kshell.com/ns/x3d">
<xsl:output method="xml" encoding="utf-8"/>
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@uKnot|NurbsTrimmedSurface/@uKnot">
<xsl:if test="../@vKnot">
<xsl:attribute name="{name()}">
<xsl:value-of select="../@vKnot"/>
</xsl:attribute>
</xsl:if>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@vKnot|NurbsTrimmedSurface/@vKnot">
<xsl:if test="../@uKnot">
<xsl:attribute name="{name()}">
<xsl:value-of select="../@uKnot"/>
</xsl:attribute>
</xsl:if>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@uDimension|NurbsTrimmedSurface/@uDimension">
<xsl:if test="../@vDimension">
<xsl:attribute name="{name()}">
<xsl:value-of select="../@vDimension"/>
</xsl:attribute>
</xsl:if>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@vDimension|NurbsTrimmedSurface/@vDimension">
<xsl:if test="../@uDimension">
<xsl:attribute name="{name()}">
<xsl:value-of select="../@uDimension"/>
</xsl:attribute>
</xsl:if>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@uTessellation|NurbsTrimmedSurface/@uTessellation">
<xsl:if test="../@vTessellation">
<xsl:attribute name="{name()}">
<xsl:value-of select="../@vTessellation"/>
</xsl:attribute>
</xsl:if>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@vTessellation|NurbsTrimmedSurface/@vTessellation">
<xsl:if test="../@uTessellation">
<xsl:attribute name="{name()}">
<xsl:value-of select="../@uTessellation"/>
</xsl:attribute>
</xsl:if>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@uClosed|NurbsTrimmedSurface/@uClosed">
<xsl:if test="../@vClosed">
<xsl:attribute name="{name()}">
<xsl:value-of select="../@vClosed"/>
</xsl:attribute>
</xsl:if>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@vClosed|NurbsTrimmedSurface/@vClosed">
<xsl:if test="../@uClosed">
<xsl:attribute name="{name()}">
<xsl:value-of select="../@uClosed"/>
</xsl:attribute>
</xsl:if>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@uOrder|NurbsTrimmedSurface/@uOrder">
<xsl:if test="../@vOrder">
<xsl:attribute name="{name()}">
<xsl:value-of select="../@vOrder"/>
</xsl:attribute>
</xsl:if>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@vOrder|NurbsTrimmedSurface/@vOrder">
<xsl:if test="../@uOrder">
<xsl:attribute name="{name()}">
<xsl:value-of select="../@uOrder"/>
</xsl:attribute>
</xsl:if>
</xsl:template>
<xsl:template match="NurbsPatchSurface/@weight|NurbsTrimmedSurface/@weight">
<xsl:attribute name="{name()}">
<xsl:variable name="transposed_weights">
<xsl:call-template name="ksh:transpose">
<xsl:with-param name="NC" select="number(../@vDimension)"/>
<xsl:with-param name="NR" select="number(../@uDimension)"/>
<xsl:with-param name="elements" select="str:split(normalize-space(.))"/>
</xsl:call-template>
</xsl:variable>
<xsl:for-each select="exsl:node-set($transposed_weights)/token">
<xsl:value-of select="."/>
<xsl:if test="last()>position()"><xsl:text> </xsl:text></xsl:if>
</xsl:for-each>
</xsl:attribute>
</xsl:template>
<xsl:template match="NurbsPatchSurface/Coordinate/@point|NurbsTrimmedSurface/Coordinate/@point">
<xsl:attribute name="{name()}">
<xsl:variable name="transposed_point">
<xsl:call-template name="ksh:transpose">
<xsl:with-param name="NC" select="number(../../@vDimension)"/>
<xsl:with-param name="NR" select="number(../../@uDimension)"/>
<xsl:with-param name="elements" select="str:split(.,',')"/>
</xsl:call-template>
</xsl:variable>
<xsl:for-each select="exsl:node-set($transposed_point)/token">
<xsl:value-of select="."/>
<xsl:if test="last() > position()"><xsl:text>, </xsl:text></xsl:if>
</xsl:for-each>
</xsl:attribute>
</xsl:template>
<!--
Templates for taking an array of nodes , NR rows and NC columns, output in
column-major order, and preparing a node set of those nodes listed in
row-major order
-->
<xsl:template name="ksh:transpose">
<xsl:param name="IR" select="1"/>
<xsl:param name="NR"/>
<xsl:param name="NC"/>
<xsl:param name="elements"/>
<!-- call the template which will list (in row major order
the IR'th row -->
<xsl:call-template name="ksh:transpose-row-out">
<xsl:with-param name="IR" select="$IR"/>
<xsl:with-param name="NC" select="$NC"/>
<xsl:with-param name="NR" select="$NR"/>
<xsl:with-param name="elements" select="$elements"/>
</xsl:call-template>
<!-- the recursion: call this template starting at the next row -->
<xsl:if test="$NR > $IR">
<xsl:call-template name="ksh:transpose">
<xsl:with-param name="IR" select="$IR + 1"/>
<xsl:with-param name="NC" select="$NC"/>
<xsl:with-param name="NR" select="$NR"/>
<xsl:with-param name="elements" select="$elements"/>
</xsl:call-template>
</xsl:if>
</xsl:template>
<xsl:template name="ksh:transpose-row-out">
<xsl:param name="IC" select="1"/>
<xsl:param name="IR"/>
<xsl:param name="NR"/>
<xsl:param name="NC"/>
<xsl:param name="elements"/>
<!-- send out the IC'th column of the IR'th row, using the
indexing appropriate for column major indexing of the underlying list -->
<xsl:param name="index" select="($IC -1)*$NR + $IR"/>
<xsl:copy-of select="$elements[$index]"/>
<!-- and the recursion, send out the rest of the columns of this row,
starting at IC+1 -->
<xsl:if test="$NC > $IC">
<xsl:call-template name="ksh:transpose-row-out">
<xsl:with-param name="IC" select="$IC + 1"/>
<xsl:with-param name="IR" select="$IR"/>
<xsl:with-param name="NC" select="$NC"/>
<xsl:with-param name="NR" select="$NR"/>
<xsl:with-param name="elements" select="$elements"/>
</xsl:call-template>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
