feat: add a new webgl polar chart operator (#4221)

### What changes were proposed in this PR?
<img width="1502" height="855" alt="Screenshot 2026-02-16 at 1 51 11 PM"
src="https://github.com/user-attachments/assets/0833347c-b6f0-4f7c-8468-f7a773bffab3"
/>

This change introduces a WebGL Polar Chart operator, which visualizes
data using polar coordinates rendered with GPU-accelerated WebGL. The
WebGL Polar Chart operator enables high-performance and interactive
visualization of datasets that are naturally expressed in angular and
radial dimensions.
In a WebGL polar chart:
- The angular axis represents categories or continuous angular values.
- The radial axis represents magnitude or distance from the center.
- Data points are rendered using WebGL for efficient GPU-based
visualization.
- The visualization supports smooth rendering of larger datasets
compared to traditional DOM/SVG approaches.

This visualization is useful for:
- Displaying cyclic or directional data.
- Comparing magnitudes across angular segments.
- Identifying patterns in periodic datasets.
- Enabling efficient, interactive visual analytics workflows.

The operator has been integrated into the Texera workflow system and
appears under the visualization category.

### Any related issues, documentation, discussions?
Needs python library scikit-image
Can be installed using: pip install scikit-image

### How was this PR tested?
Tested with existing test cases

### Was this PR authored or co-authored using generative AI tooling?
No

---------

Signed-off-by: Xinyuan Lin <xinyual3@uci.edu>
Co-authored-by: Anish Shivamurthy <anish@dhcp-10-8-033-008.mobile.reshsg.uci.edu>
Co-authored-by: Anish Shivamurthy <anish@dhcp-172-31-198-097.mobile.uci.edu>
Co-authored-by: Xinyuan Lin <xinyual3@uci.edu>

Author: 4 people

common/workflow-operator/src/main/scala/org/apache/texera/amber/operator/LogicalOp.scala

@@ -132,6 +132,7 @@ import org.apache.texera.amber.operator.visualization.scatter3DChart.Scatter3dCh
 import org.apache.texera.amber.operator.visualization.scatterplot.ScatterplotOpDesc
 import org.apache.texera.amber.operator.visualization.tablesChart.TablesPlotOpDesc
 import org.apache.texera.amber.operator.visualization.ternaryPlot.TernaryPlotOpDesc
+import org.apache.texera.amber.operator.visualization.polarChart.PolarChartOpDesc
 import org.apache.texera.amber.operator.visualization.timeSeriesplot.TimeSeriesOpDesc
 import org.apache.texera.amber.operator.visualization.treeplot.TreePlotOpDesc
 import org.apache.texera.amber.operator.visualization.urlviz.UrlVizOpDesc
@@ -194,6 +195,7 @@ trait StateTransferFunc
     new Type(value = classOf[WaterfallChartOpDesc], name = "WaterfallChart"),
     new Type(value = classOf[WindRoseChartOpDesc], name = "WindRoseChart"),
     new Type(value = classOf[BarChartOpDesc], name = "BarChart"),
+    new Type(value = classOf[PolarChartOpDesc], name = "PolarChart"),
     new Type(value = classOf[RangeSliderOpDesc], name = "RangeSlider"),
     new Type(value = classOf[PieChartOpDesc], name = "PieChart"),
     new Type(value = classOf[QuiverPlotOpDesc], name = "QuiverPlot"),

common/workflow-operator/src/main/scala/org/apache/texera/amber/operator/visualization/polarChart/PolarChartOpDesc.scala

@@ -0,0 +1,113 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more 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, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.texera.amber.operator.visualization.polarChart
+
+import com.fasterxml.jackson.annotation.{JsonProperty, JsonPropertyDescription}
+import com.kjetland.jackson.jsonSchema.annotations.JsonSchemaTitle
+import org.apache.texera.amber.core.tuple.{AttributeType, Schema}
+import org.apache.texera.amber.core.workflow.OutputPort.OutputMode
+import org.apache.texera.amber.core.workflow.{InputPort, OutputPort, PortIdentity}
+import org.apache.texera.amber.operator.PythonOperatorDescriptor
+import org.apache.texera.amber.operator.metadata.annotations.AutofillAttributeName
+import org.apache.texera.amber.operator.metadata.{OperatorGroupConstants, OperatorInfo}
+import org.apache.texera.amber.pybuilder.PyStringTypes.EncodableString
+import org.apache.texera.amber.pybuilder.PythonTemplateBuilder.PythonTemplateBuilderStringContext
+
+class PolarChartOpDesc extends PythonOperatorDescriptor {
+
+  @JsonProperty(value = "r", required = true)
+  @JsonSchemaTitle("r")
+  @JsonPropertyDescription("The column name for radial values (must be numeric)")
+  @AutofillAttributeName
+  var r: EncodableString = ""
+
+  @JsonProperty(value = "theta", required = true)
+  @JsonSchemaTitle("theta")
+  @JsonPropertyDescription("The column name for angular values (must be numeric)")
+  @AutofillAttributeName
+  var theta: EncodableString = ""
+
+  override def getOutputSchemas(
+      inputSchemas: Map[PortIdentity, Schema]
+  ): Map[PortIdentity, Schema] = {
+    val outputSchema = Schema()
+      .add("html-content", AttributeType.STRING)
+
+    Map(operatorInfo.outputPorts.head.id -> outputSchema)
+  }
+
+  override def operatorInfo: OperatorInfo =
+    OperatorInfo(
+      "Polar Chart",
+      "Displays data points in a polar scatter plot",
+      OperatorGroupConstants.VISUALIZATION_SCIENTIFIC_GROUP,
+      inputPorts = List(InputPort()),
+      outputPorts = List(OutputPort(mode = OutputMode.SINGLE_SNAPSHOT))
+    )
+
+  override def generatePythonCode(): String = {
+    val finalCode =
+      pyb"""from pytexera import *
+       |import plotly.graph_objects as go
+       |import plotly.io as pio
+       |import numpy as np
+       |
+       |class ProcessTableOperator(UDFTableOperator):
+       |
+       |    @overrides
+       |    def process_table(self, table: Table, port: int) -> Iterator[Optional[TableLike]]:
+       |
+       |        if table is None or table.empty:
+       |            yield {'html-content': '<h3>No data available for Polar Chart</h3>'}
+       |            return
+       |
+       |        if $r not in table.columns or $theta not in table.columns:
+       |            yield {'html-content': '<h3>Selected columns not found in input table</h3>'}
+       |            return
+       |
+       |        if not np.issubdtype(table[$r].dtype, np.number) or not np.issubdtype(table[$theta].dtype, np.number):
+       |            yield {'html-content': '<h3>Selected columns must be numeric</h3>'}
+       |            return
+       |
+       |        r_vals = table[$r].values
+       |        theta_vals = table[$theta].values
+       |
+       |        fig = go.Figure(data=go.Scatterpolargl(
+       |            r=r_vals,
+       |            theta=theta_vals,
+       |            mode='markers',
+       |            marker=dict(
+       |                size=10,
+       |                opacity=0.7,
+       |                line=dict(color='white')
+       |            )
+       |        ))
+       |
+       |        fig.update_layout(
+       |            title='Polar Chart',
+       |            showlegend=False
+       |        )
+       |
+       |        html = pio.to_html(fig, include_plotlyjs='cdn', full_html=False)
+       |        yield {'html-content': html}
+       |"""
+    finalCode.encode
+  }
+}