TextFacetDefinitionWriter.java
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* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* See the License for the specific language governing permissions and
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package org.apache.commons.geometry.io.euclidean.threed.txt;
import java.io.Writer;
import java.util.Iterator;
import java.util.List;
import java.util.stream.Stream;
import org.apache.commons.geometry.euclidean.internal.EuclideanUtils;
import org.apache.commons.geometry.euclidean.threed.BoundarySource3D;
import org.apache.commons.geometry.euclidean.threed.PlaneConvexSubset;
import org.apache.commons.geometry.euclidean.threed.Triangle3D;
import org.apache.commons.geometry.euclidean.threed.Vector3D;
import org.apache.commons.geometry.io.core.utils.AbstractTextFormatWriter;
import org.apache.commons.geometry.io.euclidean.threed.FacetDefinition;
/** Class for writing 3D facet geometry in a simple human-readable text format. The
* format simply consists of sequences of decimal numbers defining the vertices of each
* facet, with one facet defined per line. Facet vertices are defined by listing their
* {@code x}, {@code y}, and {@code z} components in that order. At least 3 vertices are
* required for each facet but more can be specified. The facet normal is defined implicitly
* from the facet vertices using the right-hand rule (i.e. vertices are arranged counter-clockwise).
*
* <p>Delimiters can be configured for both {@link #getVertexComponentSeparator() vertex components} and
* {@link #getVertexSeparator() vertices}. This allows a wide range of outputs to be configured, from standard
* {@link #csvFormat(Writer) CSV format} to formats designed for easy human readability.</p>
*
* <p><strong>Examples</strong></p>
* <p>The examples below demonstrate output from two square facets using different writer
* configurations.</p>
*
* <p><em>Default</em></p>
* <p>The default writer configuration uses distinct vertex and vertex component separators to make it
* easier to visually distinguish vertices. Comments are supported and facets are allowed to have
* any geometrically valid number of vertices. This format is designed for human readability and ease
* of editing.</p>
* <pre>
* # two square facets
* 0 0 0; 1 0 0; 1 1 0; 0 1 0
* 0 0 0; 0 1 0; 0 1 1; 0 0 1
* </pre>
*
* <p><em>CSV</em></p>
* <p>The example below uses a comma as both the vertex and vertex component separators to produce
* a standard CSV format. The facet vertex count is set to 3 to ensure that each row has the same number
* of columns and all numbers are written with at least a single fraction digit to ensure proper interpretation
* as floating point data. Comments are not supported. This configuration is produced by the
* {@link #csvFormat(Writer)} factory method.</p>
* <pre>
* 0.0,0.0,0.0,1.0,0.0,0.0,1.0,1.0,0.0
* 0.0,0.0,0.0,1.0,1.0,0.0,0.0,1.0,0.0
* 0.0,0.0,0.0,0.0,1.0,0.0,0.0,1.0,1.0
* 0.0,0.0,0.0,0.0,1.0,1.0,0.0,0.0,1.0
* </pre>
*
* @see TextFacetDefinitionReader
*/
public class TextFacetDefinitionWriter extends AbstractTextFormatWriter {
/** Vertex and vertex component separator used in the CSV format. */
static final String CSV_SEPARATOR = ",";
/** Number of vertices required per facet in the CSV format. */
static final int CSV_FACET_VERTEX_COUNT = 3;
/** Default vertex component separator. */
static final String DEFAULT_VERTEX_COMPONENT_SEPARATOR = " ";
/** Default vertex separator. */
static final String DEFAULT_VERTEX_SEPARATOR = "; ";
/** Default facet vertex count. */
static final int DEFAULT_FACET_VERTEX_COUNT = -1;
/** Default comment token. */
private static final String DEFAULT_COMMENT_TOKEN = "# ";
/** String used to separate vertex components, ie, x, y, z values. */
private String vertexComponentSeparator = DEFAULT_VERTEX_COMPONENT_SEPARATOR;
/** String used to separate vertices. */
private String vertexSeparator = DEFAULT_VERTEX_SEPARATOR;
/** Number of vertices required per facet; will be -1 if disabled. */
private int facetVertexCount = DEFAULT_FACET_VERTEX_COUNT;
/** Comment start token; may be null. */
private String commentToken = DEFAULT_COMMENT_TOKEN;
/** Construct a new instance that writes facet information to the given writer.
* @param writer writer to write output to
*/
public TextFacetDefinitionWriter(final Writer writer) {
super(writer);
}
/** Get the string used to separate vertex components (ie, individual x, y, z values).
* The default value is {@value #DEFAULT_VERTEX_COMPONENT_SEPARATOR}.
* @return string used to separate vertex components
*/
public String getVertexComponentSeparator() {
return vertexComponentSeparator;
}
/** Set the string used to separate vertex components (ie, individual x, y, z values).
* @param sep string used to separate vertex components
*/
public void setVertexComponentSeparator(final String sep) {
this.vertexComponentSeparator = sep;
}
/** Get the string used to separate facet vertices. The default value is {@value #DEFAULT_VERTEX_SEPARATOR}.
* @return string used to separate facet vertices
*/
public String getVertexSeparator() {
return vertexSeparator;
}
/** Set the string used to separate facet vertices.
* @param sep string used to separate facet vertices
*/
public void setVertexSeparator(final String sep) {
this.vertexSeparator = sep;
}
/** Get the number of vertices required per facet or {@code -1} if no specific
* number is required. The default value is {@value #DEFAULT_FACET_VERTEX_COUNT}.
* @return the number of vertices required per facet or {@code -1} if any geometricallly
* valid number is allowed (ie, any number greater than or equal to 3)
*/
public int getFacetVertexCount() {
return facetVertexCount;
}
/** Set the number of vertices required per facet. This can be used to enforce a consistent
* format in the output. Set to {@code -1} to allow any geometrically valid number of vertices
* (ie, any number greater than or equal to 3).
* @param vertexCount number of vertices required per facet or {@code -1} to allow any number
* @throws IllegalArgumentException if the argument would produce invalid geometries (ie, is
* greater than -1 and less than 3)
*/
public void setFacetVertexCount(final int vertexCount) {
if (vertexCount > -1 && vertexCount < 3) {
throw new IllegalArgumentException("Facet vertex count must be less than 0 or greater than 2; was " +
vertexCount);
}
this.facetVertexCount = Math.max(-1, vertexCount);
}
/** Get the string used to begin comment lines in the output.
* The default value is {@value #DEFAULT_COMMENT_TOKEN}
* @return the string used to begin comment lines in the output; may be null
*/
public String getCommentToken() {
return commentToken;
}
/** Set the string used to begin comment lines in the output. Set to null to disable the
* use of comments.
* @param commentToken comment token string
* @throws IllegalArgumentException if the argument is empty or begins with whitespace
*/
public void setCommentToken(final String commentToken) {
if (commentToken != null) {
if (commentToken.isEmpty()) {
throw new IllegalArgumentException("Comment token cannot be empty");
} else if (Character.isWhitespace(commentToken.charAt(0))) {
throw new IllegalArgumentException("Comment token cannot begin with whitespace");
}
}
this.commentToken = commentToken;
}
/** Write a comment to the output.
* @param comment comment string to write
* @throws IllegalStateException if the configured {@link #getCommentToken() comment token} is null
* @throws java.io.UncheckedIOException if an I/O error occurs
*/
public void writeComment(final String comment) {
if (commentToken == null) {
throw new IllegalStateException("Cannot write comment: no comment token configured");
}
if (comment != null) {
for (final String line : comment.split("\\R")) {
write(commentToken + line);
writeNewLine();
}
}
}
/** Write a blank line to the output.
* @throws java.io.UncheckedIOException if an I/O error occurs
*/
public void writeBlankLine() {
writeNewLine();
}
/** Write all boundaries in the argument to the output. If the
* {@link #getFacetVertexCount() facet vertex count} has been set to {@code 3}, then each
* boundary is converted to triangles before being written. Otherwise, the boundaries are
* written as-is.
* @param src object providing the boundaries to write
* @throws IllegalArgumentException if any boundary has infinite size or a
* {@link #getFacetVertexCount() facet vertex count} has been configured and a boundary
* cannot be represented using the required number of vertices
* @throws java.io.UncheckedIOException if an I/O error occurs
*/
public void write(final BoundarySource3D src) {
try (Stream<PlaneConvexSubset> stream = src.boundaryStream()) {
final Iterator<PlaneConvexSubset> it = stream.iterator();
while (it.hasNext()) {
write(it.next());
}
}
}
/** Write the vertices defining the argument to the output. If the
* {@link #getFacetVertexCount() facet vertex count} has been set to {@code 3}, then the convex subset
* is converted to triangles before being written to the output. Otherwise, the argument
* vertices are written as-is.
* @param convexSubset convex subset to write
* @throws IllegalArgumentException if the argument has infinite size or a
* {@link #getFacetVertexCount() facet vertex count} has been configured and the number of required
* vertices does not match the number present in the argument
* @throws java.io.UncheckedIOException if an I/O error occurs
*/
public void write(final PlaneConvexSubset convexSubset) {
if (convexSubset.isInfinite()) {
throw new IllegalArgumentException("Cannot write infinite convex subset");
}
if (facetVertexCount == EuclideanUtils.TRIANGLE_VERTEX_COUNT) {
// force conversion to triangles
for (final Triangle3D tri : convexSubset.toTriangles()) {
write(tri.getVertices());
}
} else {
// write as-is; callers are responsible for making sure that the number of
// vertices matches the required number for the writer
write(convexSubset.getVertices());
}
}
/** Write the vertices in the argument to the output.
* @param facet facet containing the vertices to write
* @throws IllegalArgumentException if a {@link #getFacetVertexCount() facet vertex count}
* has been configured and the number of required vertices does not match the number
* present in the argument
* @throws java.io.UncheckedIOException if an I/O error occurs
*/
public void write(final FacetDefinition facet) {
write(facet.getVertices());
}
/** Write a list of vertices defining a facet as a single line of text to the output. Vertex components
* (ie, individual x, y, z values) are separated with the configured
* {@link #getVertexComponentSeparator() vertex component separator} and vertices are separated with the
* configured {@link #getVertexSeparator() vertex separator}.
* @param vertices vertices to write
* @throws IllegalArgumentException if the vertex list contains less than 3 vertices or a
* {@link #getFacetVertexCount() facet vertex count} has been configured and the number of required
* vertices does not match the number given
* @throws java.io.UncheckedIOException if an I/O error occurs
* @see #getVertexComponentSeparator()
* @see #getVertexSeparator()
* @see #getFacetVertexCount()
*/
public void write(final List<Vector3D> vertices) {
final int size = vertices.size();
if (size < EuclideanUtils.TRIANGLE_VERTEX_COUNT) {
throw new IllegalArgumentException("At least " + EuclideanUtils.TRIANGLE_VERTEX_COUNT +
" vertices are required per facet; found " + size);
} else if (facetVertexCount > -1 && size != facetVertexCount) {
throw new IllegalArgumentException("Writer requires " + facetVertexCount +
" vertices per facet; found " + size);
}
final Iterator<Vector3D> it = vertices.iterator();
write(it.next());
while (it.hasNext()) {
write(vertexSeparator);
write(it.next());
}
writeNewLine();
}
/** Write a single vertex to the output.
* @param vertex vertex to write
* @throws java.io.UncheckedIOException if an I/O error occurs
*/
private void write(final Vector3D vertex) {
write(vertex.getX());
write(vertexComponentSeparator);
write(vertex.getY());
write(vertexComponentSeparator);
write(vertex.getZ());
}
/** Construct a new instance configured to write CSV output to the given writer.
* The returned instance has the following configuration:
* <ul>
* <li>Vertex separator and vertex components separator are set to the "," string.</li>
* <li>Comments are disabled (i.e., comment token is set to null).</li>
* <li>Facet vertex count is set to 3 to ensure a consistent number of columns.</li>
* </ul>
* This configuration produces output similar to the following:
* <pre>
* 0.0,0.0,0.0,1.0,0.0,0.0,1.0,1.0,0.0
* 0.0,0.0,0.0,1.0,1.0,0.0,0.0,1.0,0.0
* </pre>
*
* @param writer writer to write output to
* @return a new facet definition writer configured to produce CSV output
*/
public static TextFacetDefinitionWriter csvFormat(final Writer writer) {
final TextFacetDefinitionWriter fdWriter = new TextFacetDefinitionWriter(writer);
fdWriter.setVertexComponentSeparator(CSV_SEPARATOR);
fdWriter.setVertexSeparator(CSV_SEPARATOR);
fdWriter.setFacetVertexCount(CSV_FACET_VERTEX_COUNT);
fdWriter.setCommentToken(null);
return fdWriter;
}
}