From aae448a093b1df473f2fb6a210d22f3490a0aa60 Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Mon, 22 Sep 2025 15:37:48 -0700
Subject: [PATCH 01/18] WIP on color bars

---
 .../polyscope/{histogram.h => color_bar.h}    | 37 +++++-----
 .../polyscope/curve_network_scalar_quantity.h |  1 -
 .../polyscope/point_cloud_color_quantity.h    |  1 -
 .../polyscope/point_cloud_scalar_quantity.h   |  1 -
 include/polyscope/scalar_quantity.h           |  4 +-
 .../polyscope/scalar_render_image_quantity.h  |  1 -
 .../surface_parameterization_quantity.h       |  1 -
 include/polyscope/surface_scalar_quantity.h   |  1 -
 .../polyscope/volume_grid_scalar_quantity.h   |  1 -
 .../polyscope/volume_mesh_scalar_quantity.h   |  1 -
 src/CMakeLists.txt                            |  4 +-
 src/{histogram.cpp => color_bar.cpp}          | 73 ++++++++++---------
 12 files changed, 61 insertions(+), 65 deletions(-)
 rename include/polyscope/{histogram.h => color_bar.h} (55%)
 rename src/{histogram.cpp => color_bar.cpp} (76%)

diff --git a/include/polyscope/histogram.h b/include/polyscope/color_bar.h
similarity index 55%
rename from include/polyscope/histogram.h
rename to include/polyscope/color_bar.h
index bf1575603..0619de611 100644
--- a/include/polyscope/histogram.h
+++ b/include/polyscope/color_bar.h
@@ -13,12 +13,12 @@ namespace polyscope {
 // A histogram that shows up in ImGUI window
 // ONEDAY: we could definitely make a better histogram widget for categorical data...
 
-class Histogram {
+class ColorBar {
 public:
-  Histogram();                                              // must call buildHistogram() with data after
-  Histogram(std::vector<float>& values, DataType datatype); // internally calls buildHistogram()
+  ColorBar();                                              // must call buildHistogram() with data after
+  ColorBar(std::vector<float>& values, DataType datatype); // internally calls buildHistogram()
 
-  ~Histogram();
+  ~ColorBar();
 
   void buildHistogram(const std::vector<float>& values, DataType datatype);
   void updateColormap(const std::string& newColormap);
@@ -29,30 +29,33 @@ class Histogram {
   std::pair<double, double> colormapRange; // in DATA values, not [0,1]
 
 private:
-  // = Helpers
+  //
+  DataType dataType = DataType::STANDARD;
+  std::pair<double, double> dataRange;
 
-  // Manage the actual histogram
-  void fillBuffers();
-  size_t rawHistBinCount = 51;
+  // == The inline horizontal histogram visualization in the structures bar
 
-  DataType dataType = DataType::STANDARD;
+  // Manage histogram counts for 
+  void fillHistogramBuffers();
+  size_t rawHistBinCount = 51;
   std::vector<float> rawHistCurveY;
   std::vector<std::array<float, 2>> rawHistCurveX;
-  std::pair<double, double> dataRange;
-
-  // Render to texture
-  void renderToTexture();
-  void prepare();
 
+  // Render to a texture for the inline histogram visualization in the structures bar
+  void renderInlineHistogramToTexture();
+  void prepareInlineHistogram();
   unsigned int texDim = 600;
-  std::shared_ptr<render::TextureBuffer> texture = nullptr;
-  std::shared_ptr<render::FrameBuffer> framebuffer = nullptr;
-  std::shared_ptr<render::ShaderProgram> program = nullptr;
+  std::shared_ptr<render::TextureBuffer> inlineHistogramTexture = nullptr;
+  std::shared_ptr<render::FrameBuffer> inlineHistogramFramebuffer = nullptr;
+  std::shared_ptr<render::ShaderProgram> inlineHistogramProgram = nullptr;
   std::string colormap = "viridis";
 
   // A few parameters which control appearance
   float bottomBarHeight = 0.35;
   float bottomBarGap = 0.1;
+  
+  // == The optional vertical colorbar which floats ont he main display
+  
 };
 
 
diff --git a/include/polyscope/curve_network_scalar_quantity.h b/include/polyscope/curve_network_scalar_quantity.h
index 27c79bedf..8885a9cc4 100644
--- a/include/polyscope/curve_network_scalar_quantity.h
+++ b/include/polyscope/curve_network_scalar_quantity.h
@@ -4,7 +4,6 @@
 
 #include "polyscope/affine_remapper.h"
 #include "polyscope/curve_network.h"
-#include "polyscope/histogram.h"
 #include "polyscope/render/color_maps.h"
 #include "polyscope/scalar_quantity.h"
 
diff --git a/include/polyscope/point_cloud_color_quantity.h b/include/polyscope/point_cloud_color_quantity.h
index 8ebc346cb..8c924b5ab 100644
--- a/include/polyscope/point_cloud_color_quantity.h
+++ b/include/polyscope/point_cloud_color_quantity.h
@@ -4,7 +4,6 @@
 
 #include "polyscope/affine_remapper.h"
 #include "polyscope/color_quantity.h"
-#include "polyscope/histogram.h"
 #include "polyscope/point_cloud.h"
 #include "polyscope/point_cloud_quantity.h"
 
diff --git a/include/polyscope/point_cloud_scalar_quantity.h b/include/polyscope/point_cloud_scalar_quantity.h
index 903b9ed7a..644d60209 100644
--- a/include/polyscope/point_cloud_scalar_quantity.h
+++ b/include/polyscope/point_cloud_scalar_quantity.h
@@ -3,7 +3,6 @@
 #pragma once
 
 #include "polyscope/affine_remapper.h"
-#include "polyscope/histogram.h"
 #include "polyscope/point_cloud.h"
 #include "polyscope/render/color_maps.h"
 #include "polyscope/scalar_quantity.h"
diff --git a/include/polyscope/scalar_quantity.h b/include/polyscope/scalar_quantity.h
index 9d55dbb6b..aeb8d146a 100644
--- a/include/polyscope/scalar_quantity.h
+++ b/include/polyscope/scalar_quantity.h
@@ -3,7 +3,7 @@
 #pragma once
 
 #include "polyscope/affine_remapper.h"
-#include "polyscope/histogram.h"
+#include "polyscope/color_bar.h"
 #include "polyscope/persistent_value.h"
 #include "polyscope/polyscope.h"
 #include "polyscope/render/engine.h"
@@ -79,7 +79,7 @@ class ScalarQuantity {
   std::pair<double, double> dataRange;
   PersistentValue<float> vizRangeMin;
   PersistentValue<float> vizRangeMax;
-  Histogram hist;
+  ColorBar hist;
 
   // Parameters
   PersistentValue<std::string> cMap;
diff --git a/include/polyscope/scalar_render_image_quantity.h b/include/polyscope/scalar_render_image_quantity.h
index 9614a0c00..50851e7e6 100644
--- a/include/polyscope/scalar_render_image_quantity.h
+++ b/include/polyscope/scalar_render_image_quantity.h
@@ -3,7 +3,6 @@
 #pragma once
 
 #include "polyscope/affine_remapper.h"
-#include "polyscope/histogram.h"
 #include "polyscope/render/color_maps.h"
 #include "polyscope/render_image_quantity_base.h"
 #include "polyscope/scalar_quantity.h"
diff --git a/include/polyscope/surface_parameterization_quantity.h b/include/polyscope/surface_parameterization_quantity.h
index 957bac4a6..656c5a9d9 100644
--- a/include/polyscope/surface_parameterization_quantity.h
+++ b/include/polyscope/surface_parameterization_quantity.h
@@ -3,7 +3,6 @@
 #pragma once
 
 #include "polyscope/affine_remapper.h"
-#include "polyscope/histogram.h"
 #include "polyscope/parameterization_quantity.h"
 #include "polyscope/render/color_maps.h"
 #include "polyscope/render/engine.h"
diff --git a/include/polyscope/surface_scalar_quantity.h b/include/polyscope/surface_scalar_quantity.h
index 80260f114..1b2eab618 100644
--- a/include/polyscope/surface_scalar_quantity.h
+++ b/include/polyscope/surface_scalar_quantity.h
@@ -5,7 +5,6 @@
 #include "polyscope/polyscope.h"
 
 #include "polyscope/affine_remapper.h"
-#include "polyscope/histogram.h"
 #include "polyscope/render/color_maps.h"
 #include "polyscope/render/engine.h"
 #include "polyscope/scalar_quantity.h"
diff --git a/include/polyscope/volume_grid_scalar_quantity.h b/include/polyscope/volume_grid_scalar_quantity.h
index 503c046a6..5bc200e98 100644
--- a/include/polyscope/volume_grid_scalar_quantity.h
+++ b/include/polyscope/volume_grid_scalar_quantity.h
@@ -5,7 +5,6 @@
 #include "polyscope/polyscope.h"
 
 #include "polyscope/affine_remapper.h"
-#include "polyscope/histogram.h"
 #include "polyscope/render/color_maps.h"
 #include "polyscope/scalar_quantity.h"
 #include "polyscope/surface_mesh.h"
diff --git a/include/polyscope/volume_mesh_scalar_quantity.h b/include/polyscope/volume_mesh_scalar_quantity.h
index a31be7a02..795537add 100644
--- a/include/polyscope/volume_mesh_scalar_quantity.h
+++ b/include/polyscope/volume_mesh_scalar_quantity.h
@@ -5,7 +5,6 @@
 #include "polyscope/polyscope.h"
 
 #include "polyscope/affine_remapper.h"
-#include "polyscope/histogram.h"
 #include "polyscope/render/color_maps.h"
 #include "polyscope/render/engine.h"
 #include "polyscope/scalar_quantity.h"
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index e5a0679b4..4fab560c5 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -183,7 +183,7 @@ SET(SRCS
   disjoint_sets.cpp
   file_helpers.cpp
   camera_parameters.cpp
-  histogram.cpp
+  color_bar.cpp
   persistent_value.cpp
   color_management.cpp
   transformation_gizmo.cpp
@@ -271,6 +271,7 @@ SET(HEADERS
   ${INCLUDE_ROOT}/camera_view.h
   ${INCLUDE_ROOT}/camera_view.ipp
   ${INCLUDE_ROOT}/check_invalid_values.h
+  ${INCLUDE_ROOT}/color_bar.h
   ${INCLUDE_ROOT}/color_management.h
   ${INCLUDE_ROOT}/color_image_quantity.h
   ${INCLUDE_ROOT}/color_render_image_quantity.h
@@ -293,7 +294,6 @@ SET(HEADERS
   ${INCLUDE_ROOT}/floating_quantity.h
   ${INCLUDE_ROOT}/floating_quantities.h
   ${INCLUDE_ROOT}/group.h
-  ${INCLUDE_ROOT}/histogram.h
   ${INCLUDE_ROOT}/image_quantity.h
   ${INCLUDE_ROOT}/imgui_config.h
   ${INCLUDE_ROOT}/implicit_helpers.h
diff --git a/src/histogram.cpp b/src/color_bar.cpp
similarity index 76%
rename from src/histogram.cpp
rename to src/color_bar.cpp
index 12394e62b..5556f9dda 100644
--- a/src/histogram.cpp
+++ b/src/color_bar.cpp
@@ -1,6 +1,6 @@
 // Copyright 2017-2023, Nicholas Sharp and the Polyscope contributors. https://polyscope.run
 
-#include "polyscope/histogram.h"
+#include "polyscope/color_bar.h"
 
 #include "polyscope/affine_remapper.h"
 #include "polyscope/polyscope.h"
@@ -13,13 +13,13 @@
 
 namespace polyscope {
 
-Histogram::Histogram() {}
+ColorBar::ColorBar() {}
 
-Histogram::Histogram(std::vector<float>& values, DataType dataType) { buildHistogram(values, dataType); }
+ColorBar::ColorBar(std::vector<float>& values, DataType dataType) { buildHistogram(values, dataType); }
 
-Histogram::~Histogram() {}
+ColorBar::~ColorBar() {}
 
-void Histogram::buildHistogram(const std::vector<float>& values, DataType dataType_) {
+void ColorBar::buildHistogram(const std::vector<float>& values, DataType dataType_) {
   dataType = dataType_;
 
   // Build arrays of values
@@ -80,14 +80,14 @@ void Histogram::buildHistogram(const std::vector<float>& values, DataType dataTy
 }
 
 
-void Histogram::updateColormap(const std::string& newColormap) {
+void ColorBar::updateColormap(const std::string& newColormap) {
   colormap = newColormap;
-  if (program) {
-    program.reset();
+  if (inlineHistogramProgram) {
+    inlineHistogramProgram.reset();
   }
 }
 
-void Histogram::fillBuffers() {
+void ColorBar::fillHistogramBuffers() {
 
   if (rawHistCurveY.size() == 0) {
     exception("histogram fillBuffers() called before buildHistogram");
@@ -129,65 +129,65 @@ void Histogram::fillBuffers() {
   coords.push_back(glm::vec2{0., bottomBarHeight});
 
 
-  program->setAttribute("a_coord", coords);
+  inlineHistogramProgram->setAttribute("a_coord", coords);
 }
 
-void Histogram::prepare() {
+void ColorBar::prepareInlineHistogram() {
 
-  framebuffer = render::engine->generateFrameBuffer(texDim, texDim);
-  texture = render::engine->generateTextureBuffer(TextureFormat::RGBA8, texDim, texDim);
-  framebuffer->addColorBuffer(texture);
+  inlineHistogramFramebuffer = render::engine->generateFrameBuffer(texDim, texDim);
+  inlineHistogramTexture = render::engine->generateTextureBuffer(TextureFormat::RGBA8, texDim, texDim);
+  inlineHistogramFramebuffer->addColorBuffer(inlineHistogramTexture);
 
-  // Create the program
+  // Create the inlineHistogramProgram
   if (dataType == DataType::CATEGORICAL) {
     // for categorical data only
-    program = render::engine->requestShader("HISTOGRAM_CATEGORICAL", {"SHADE_CATEGORICAL_COLORMAP"},
-                                            render::ShaderReplacementDefaults::Process);
+    inlineHistogramProgram = render::engine->requestShader("HISTOGRAM_CATEGORICAL", {"SHADE_CATEGORICAL_COLORMAP"},
+                                                           render::ShaderReplacementDefaults::Process);
   } else {
     // common case
-    program = render::engine->requestShader("HISTOGRAM", {"SHADE_COLORMAP_VALUE"},
-                                            render::ShaderReplacementDefaults::Process);
+    inlineHistogramProgram = render::engine->requestShader("HISTOGRAM", {"SHADE_COLORMAP_VALUE"},
+                                                           render::ShaderReplacementDefaults::Process);
   }
 
-  program->setTextureFromColormap("t_colormap", colormap, true);
+  inlineHistogramProgram->setTextureFromColormap("t_colormap", colormap, true);
 
   fillBuffers();
 }
 
 
-void Histogram::renderToTexture() {
+void ColorBar::renderInlineHistogramToTexture() {
 
-  if (!program) {
-    prepare();
+  if (!inlineHistogramProgram) {
+    prepareInlineHistogram();
   }
 
-  framebuffer->clearColor = {0.0, 0.0, 0.0};
-  framebuffer->clearAlpha = 0.2;
-  framebuffer->setViewport(0, 0, texDim, texDim);
-  framebuffer->bindForRendering();
-  framebuffer->clear();
+  inlineHistogramFramebuffer->clearColor = {0.0, 0.0, 0.0};
+  inlineHistogramFramebuffer->clearAlpha = 0.2;
+  inlineHistogramFramebuffer->setViewport(0, 0, texDim, texDim);
+  inlineHistogramFramebuffer->bindForRendering();
+  inlineHistogramFramebuffer->clear();
 
   // = Set uniforms
 
   if (dataType == DataType::CATEGORICAL) {
     // Used to restore [0,1] tvals to the orininal data range for the categorical int remapping
-    program->setUniform("u_dataRangeLow", dataRange.first);
-    program->setUniform("u_dataRangeHigh", dataRange.second);
+    inlineHistogramProgram->setUniform("u_dataRangeLow", dataRange.first);
+    inlineHistogramProgram->setUniform("u_dataRangeHigh", dataRange.second);
   } else {
     // Colormap range (remapped to the 0-1 coords we use)
     float rangeLow = (colormapRange.first - dataRange.first) / (dataRange.second - dataRange.first);
     float rangeHigh = (colormapRange.second - dataRange.first) / (dataRange.second - dataRange.first);
-    program->setUniform("u_rangeLow", rangeLow);
-    program->setUniform("u_rangeHigh", rangeHigh);
+    inlineHistogramProgram->setUniform("u_rangeLow", rangeLow);
+    inlineHistogramProgram->setUniform("u_rangeHigh", rangeHigh);
   }
 
 
   // Draw
-  program->draw();
+  inlineHistogramProgram->draw();
 }
 
 
-void Histogram::buildUI(float width) {
+void ColorBar::buildUI(float width) {
 
   // NOTE: I'm surprised this works, since we're drawing in the middle of imgui's processing. Possible source of bugs?
   renderToTexture();
@@ -201,8 +201,9 @@ void Histogram::buildUI(float width) {
   float h = w / aspect;
 
   // Render image
-  ImGui::Image((ImTextureID)(intptr_t)texture->getNativeHandle(), ImVec2(w, h), ImVec2(0, 1), ImVec2(1, 0));
-  render::engine->preserveResourceUntilImguiFrameCompletes(texture);
+  ImGui::Image((ImTextureID)(intptr_t)inlineHistogramTexture->getNativeHandle(), ImVec2(w, h), ImVec2(0, 1),
+               ImVec2(1, 0));
+  render::engine->preserveResourceUntilImguiFrameCompletes(inlineHistogramTexture);
 
   // Helpful info for drawing annotations below
   ImU32 annoColor = ImGui::ColorConvertFloat4ToU32(ImVec4(254 / 255., 221 / 255., 66 / 255., 1.0));

From 63bc26fcd0ee6c2d6b2263d230e915e9f565e206 Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Fri, 5 Dec 2025 23:39:36 -0800
Subject: [PATCH 02/18] fix missed rename

---
 src/color_bar.cpp | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/color_bar.cpp b/src/color_bar.cpp
index 5556f9dda..7ab3bcca3 100644
--- a/src/color_bar.cpp
+++ b/src/color_bar.cpp
@@ -151,7 +151,7 @@ void ColorBar::prepareInlineHistogram() {
 
   inlineHistogramProgram->setTextureFromColormap("t_colormap", colormap, true);
 
-  fillBuffers();
+  fillHistogramBuffers();
 }
 
 
@@ -189,8 +189,7 @@ void ColorBar::renderInlineHistogramToTexture() {
 
 void ColorBar::buildUI(float width) {
 
-  // NOTE: I'm surprised this works, since we're drawing in the middle of imgui's processing. Possible source of bugs?
-  renderToTexture();
+  renderInlineHistogramToTexture();
 
   // Compute size for image
   float aspect = 4.0;

From 47c82835d4416c4a6ee826b6bc4504d4b35b2780 Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Fri, 5 Dec 2025 23:46:29 -0800
Subject: [PATCH 03/18] WIP more structure

---
 include/polyscope/color_bar.h         | 35 ++++++++++++++++++------
 include/polyscope/scalar_quantity.h   |  3 ++-
 include/polyscope/scalar_quantity.ipp | 17 +++++++-----
 src/color_bar.cpp                     | 38 ++++++++++++++++++++++++---
 src/surface_scalar_quantity.cpp       | 12 ++++-----
 src/volume_mesh_scalar_quantity.cpp   |  4 +--
 6 files changed, 81 insertions(+), 28 deletions(-)

diff --git a/include/polyscope/color_bar.h b/include/polyscope/color_bar.h
index 0619de611..b34fd1995 100644
--- a/include/polyscope/color_bar.h
+++ b/include/polyscope/color_bar.h
@@ -2,8 +2,10 @@
 
 #pragma once
 
+#include "polyscope/quantity.h"
 #include "polyscope/render/color_maps.h"
 #include "polyscope/render/engine.h"
+#include "polyscope/widget.h"
 
 #include <vector>
 
@@ -15,9 +17,8 @@ namespace polyscope {
 
 class ColorBar {
 public:
-  ColorBar();                                              // must call buildHistogram() with data after
-  ColorBar(std::vector<float>& values, DataType datatype); // internally calls buildHistogram()
-
+  ColorBar(Quantity& parent_); // must call buildHistogram() with data after
+  ColorBar(Quantity& parent_, std::vector<float>& values, DataType datatype); // internally calls buildHistogram()
   ~ColorBar();
 
   void buildHistogram(const std::vector<float>& values, DataType datatype);
@@ -26,16 +27,23 @@ class ColorBar {
   // Width = -1 means set automatically
   void buildUI(float width = -1.0);
 
+  Quantity& parent;
   std::pair<double, double> colormapRange; // in DATA values, not [0,1]
 
+
+  // Getters and setters
+
+  void setOnscreenColorbarEnabled(bool newEnabled);
+  bool getOnscreenColorbarEnabled();
+
 private:
-  //
+  // Basic data defining the color map
   DataType dataType = DataType::STANDARD;
   std::pair<double, double> dataRange;
 
   // == The inline horizontal histogram visualization in the structures bar
 
-  // Manage histogram counts for 
+  // Manage histogram counts
   void fillHistogramBuffers();
   size_t rawHistBinCount = 51;
   std::vector<float> rawHistCurveY;
@@ -53,10 +61,21 @@ class ColorBar {
   // A few parameters which control appearance
   float bottomBarHeight = 0.35;
   float bottomBarGap = 0.1;
-  
+
   // == The optional vertical colorbar which floats ont he main display
-  
+  PersistentValue<bool> onscreenColorbarEnabled;
+  void prepareOnscreenColorBar();
+  std::unique_ptr<Widget> onscreenColorBarWidget = nullptr;
+};
+
+class OnscreenColorBarWidget : public Widget {
+public:
+  OnscreenColorBarWidget(ColorBar& parent_);
+  virtual void draw() override;
+
+private:
+  ColorBar& parent;
 };
 
 
-}; // namespace polyscope
+} // namespace polyscope
diff --git a/include/polyscope/scalar_quantity.h b/include/polyscope/scalar_quantity.h
index aeb8d146a..42f13dd6a 100644
--- a/include/polyscope/scalar_quantity.h
+++ b/include/polyscope/scalar_quantity.h
@@ -79,7 +79,8 @@ class ScalarQuantity {
   std::pair<double, double> dataRange;
   PersistentValue<float> vizRangeMin;
   PersistentValue<float> vizRangeMax;
-  ColorBar hist;
+  
+  ColorBar colorBar;
 
   // Parameters
   PersistentValue<std::string> cMap;
diff --git a/include/polyscope/scalar_quantity.ipp b/include/polyscope/scalar_quantity.ipp
index bff31d155..dde0a446c 100644
--- a/include/polyscope/scalar_quantity.ipp
+++ b/include/polyscope/scalar_quantity.ipp
@@ -12,7 +12,7 @@ ScalarQuantity<QuantityT>::ScalarQuantity(QuantityT& quantity_, const std::vecto
       dataType(dataType_), dataRange(robustMinMax(values.data, 1e-5)),
       vizRangeMin(quantity.uniquePrefix() + "vizRangeMin", -777.), // set later,
       vizRangeMax(quantity.uniquePrefix() + "vizRangeMax", -777.), // including clearing cache
-      cMap(quantity.uniquePrefix() + "cmap", defaultColorMap(dataType)),
+      colorBar(quantity), cMap(quantity.uniquePrefix() + "cmap", defaultColorMap(dataType)),
       isolinesEnabled(quantity.uniquePrefix() + "isolinesEnabled", false),
       isolineStyle(quantity.uniquePrefix() + "isolinesStyle", IsolineStyle::Stripe),
       isolinePeriod(quantity.uniquePrefix() + "isolinePeriod",
@@ -22,8 +22,8 @@ ScalarQuantity<QuantityT>::ScalarQuantity(QuantityT& quantity_, const std::vecto
 
 {
   values.checkInvalidValues();
-  hist.updateColormap(cMap.get());
-  hist.buildHistogram(values.data, dataType);
+  colorBar.updateColormap(cMap.get());
+  colorBar.buildHistogram(values.data, dataType);
   // TODO: I think we might be building the histogram ^^^ twice for many quantities
 
   if (vizRangeMin.holdsDefaultValue()) { // min and max should always have same cache state
@@ -38,7 +38,7 @@ void ScalarQuantity<QuantityT>::buildScalarUI() {
 
   if (render::buildColormapSelector(cMap.get())) {
     quantity.refresh();
-    hist.updateColormap(cMap.get());
+    colorBar.updateColormap(cMap.get());
     setColorMap(getColorMap());
   }
 
@@ -82,10 +82,10 @@ void ScalarQuantity<QuantityT>::buildScalarUI() {
 
 
   // Draw the histogram of values
-  hist.colormapRange = std::pair<float, float>(vizRangeMin.get(), vizRangeMax.get());
+  colorBar.colormapRange = std::pair<float, float>(vizRangeMin.get(), vizRangeMax.get());
   float windowWidth = ImGui::GetWindowWidth();
   float histWidth = 0.75 * windowWidth;
-  hist.buildUI(histWidth);
+  colorBar.buildUI(histWidth);
 
   // Data range
   // Note: %g specifiers are generally nicer than %e, but here we don't acutally have a choice. ImGui (for somewhat
@@ -220,6 +220,9 @@ void ScalarQuantity<QuantityT>::buildScalarOptionsUI() {
   if (dataType != DataType::CATEGORICAL) {
     if (ImGui::MenuItem("Enable isolines", NULL, isolinesEnabled.get())) setIsolinesEnabled(!isolinesEnabled.get());
   }
+  if (ImGui::MenuItem("Onscreen Colormap", NULL, colorBar.getOnscreenColorbarEnabled())) {
+    colorBar.setOnscreenColorbarEnabled(!colorBar.getOnscreenColorbarEnabled());
+  }
 }
 
 template <typename QuantityT>
@@ -306,7 +309,7 @@ void ScalarQuantity<QuantityT>::updateData(const V& newValues) {
 template <typename QuantityT>
 QuantityT* ScalarQuantity<QuantityT>::setColorMap(std::string val) {
   cMap = val;
-  hist.updateColormap(cMap.get());
+  colorBar.updateColormap(cMap.get());
   quantity.refresh();
   requestRedraw();
   return &quantity;
diff --git a/src/color_bar.cpp b/src/color_bar.cpp
index 7ab3bcca3..355ac6935 100644
--- a/src/color_bar.cpp
+++ b/src/color_bar.cpp
@@ -13,9 +13,14 @@
 
 namespace polyscope {
 
-ColorBar::ColorBar() {}
+ColorBar::ColorBar(Quantity& parent_)
+    : parent(parent_), onscreenColorbarEnabled(parent.uniquePrefix() + "onscreenColorbarEnabled", false) {
+  prepareOnscreenColorBar();
+}
 
-ColorBar::ColorBar(std::vector<float>& values, DataType dataType) { buildHistogram(values, dataType); }
+ColorBar::ColorBar(Quantity& parent_, std::vector<float>& values, DataType dataType) : ColorBar(parent_) {
+  buildHistogram(values, dataType);
+}
 
 ColorBar::~ColorBar() {}
 
@@ -180,10 +185,30 @@ void ColorBar::renderInlineHistogramToTexture() {
     inlineHistogramProgram->setUniform("u_rangeLow", rangeLow);
     inlineHistogramProgram->setUniform("u_rangeHigh", rangeHigh);
   }
+}
+
+void ColorBar::setOnscreenColorbarEnabled(bool newEnabled) {
+  onscreenColorbarEnabled.set(newEnabled);
+  if (newEnabled) {
+    prepareOnscreenColorBar();
+  }
+}
+bool ColorBar::getOnscreenColorbarEnabled() { return onscreenColorbarEnabled.get(); }
+
+void ColorBar::prepareOnscreenColorBar() {
+  if (onscreenColorBarWidget) {
+    // Already created, nothing to do
+    return;
+  }
+  onscreenColorBarWidget = std::unique_ptr<OnscreenColorBarWidget>(new OnscreenColorBarWidget(*this));
+}
 
+OnscreenColorBarWidget::OnscreenColorBarWidget(ColorBar& parent_) : parent(parent_) {}
 
-  // Draw
-  inlineHistogramProgram->draw();
+void OnscreenColorBarWidget::draw() {
+  if (parent.getOnscreenColorbarEnabled()) {
+    std::cout << "drawing color bar" << std::endl;
+  }
 }
 
 
@@ -274,6 +299,11 @@ void ColorBar::buildUI(float width) {
   }
 
   */
+
+
+  // NOTE: the onscreen colorbar gets drawn in the draw() command, rather than with
+  // the rest of the UI stuff here, because we need it to happen even if this UI
+  // panel is collapsed.
 }
 
 
diff --git a/src/surface_scalar_quantity.cpp b/src/surface_scalar_quantity.cpp
index 35948f140..812bcae9b 100644
--- a/src/surface_scalar_quantity.cpp
+++ b/src/surface_scalar_quantity.cpp
@@ -66,7 +66,7 @@ SurfaceVertexScalarQuantity::SurfaceVertexScalarQuantity(std::string name, const
 
 {
   values.ensureHostBufferPopulated();
-  hist.buildHistogram(values.data, dataType);
+  colorBar.buildHistogram(values.data, dataType);
 }
 
 void SurfaceVertexScalarQuantity::createProgram() {
@@ -135,7 +135,7 @@ SurfaceFaceScalarQuantity::SurfaceFaceScalarQuantity(std::string name, const std
 {
   values.ensureHostBufferPopulated();
   parent.faceAreas.ensureHostBufferPopulated();
-  hist.buildHistogram(values.data, dataType);
+  colorBar.buildHistogram(values.data, dataType);
 }
 
 void SurfaceFaceScalarQuantity::createProgram() {
@@ -184,7 +184,7 @@ SurfaceEdgeScalarQuantity::SurfaceEdgeScalarQuantity(std::string name, const std
 
 {
   values.ensureHostBufferPopulated();
-  hist.buildHistogram(values.data, dataType);
+  colorBar.buildHistogram(values.data, dataType);
 }
 
 void SurfaceEdgeScalarQuantity::createProgram() {
@@ -229,7 +229,7 @@ SurfaceHalfedgeScalarQuantity::SurfaceHalfedgeScalarQuantity(std::string name, c
 
 {
   values.ensureHostBufferPopulated();
-  hist.buildHistogram(values.data, dataType);
+  colorBar.buildHistogram(values.data, dataType);
 }
 
 void SurfaceHalfedgeScalarQuantity::createProgram() {
@@ -274,7 +274,7 @@ SurfaceCornerScalarQuantity::SurfaceCornerScalarQuantity(std::string name, const
 
 {
   values.ensureHostBufferPopulated();
-  hist.buildHistogram(values.data, dataType);
+  colorBar.buildHistogram(values.data, dataType);
 }
 
 void SurfaceCornerScalarQuantity::createProgram() {
@@ -343,7 +343,7 @@ SurfaceTextureScalarQuantity::SurfaceTextureScalarQuantity(std::string name, Sur
       TextureMapQuantity(*this, dimX_, dimY_, origin_), param(param_) {
   values.setTextureSize(dimX, dimY);
   values.ensureHostBufferPopulated();
-  hist.buildHistogram(values.data, dataType);
+  colorBar.buildHistogram(values.data, dataType);
 
   if (dataType == DataType::CATEGORICAL) {
     // default to nearest filtering for categorical data, it's probably what the user wants
diff --git a/src/volume_mesh_scalar_quantity.cpp b/src/volume_mesh_scalar_quantity.cpp
index 3170b2f28..127d89015 100644
--- a/src/volume_mesh_scalar_quantity.cpp
+++ b/src/volume_mesh_scalar_quantity.cpp
@@ -217,8 +217,8 @@ void VolumeMeshVertexScalarQuantity::buildCustomUI() {
   VolumeMeshScalarQuantity::buildCustomUI();
 
   if (isDrawingLevelSet) {
-    ImGui::DragFloat("##value", &levelSetValue, 0.01f, (float)hist.colormapRange.first,
-                     (float)hist.colormapRange.second);
+    ImGui::DragFloat("##value", &levelSetValue, 0.01f, (float)colorBar.colormapRange.first,
+                     (float)colorBar.colormapRange.second);
     if (ImGui::BeginMenu("Show Quantity")) {
       std::map<std::string, std::unique_ptr<polyscope::VolumeMeshQuantity>>::iterator it;
       for (it = parent.quantities.begin(); it != parent.quantities.end(); it++) {

From f0f660831bfca88d1dc706c6b2b4a36d29967221 Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Fri, 5 Dec 2025 23:59:23 -0800
Subject: [PATCH 04/18] remove unused code, fix bug

---
 include/polyscope/color_bar.h   |  1 -
 src/color_bar.cpp               | 10 +++-------
 src/surface_scalar_quantity.cpp | 28 +++++-----------------------
 3 files changed, 8 insertions(+), 31 deletions(-)

diff --git a/include/polyscope/color_bar.h b/include/polyscope/color_bar.h
index b34fd1995..a212a71ad 100644
--- a/include/polyscope/color_bar.h
+++ b/include/polyscope/color_bar.h
@@ -18,7 +18,6 @@ namespace polyscope {
 class ColorBar {
 public:
   ColorBar(Quantity& parent_); // must call buildHistogram() with data after
-  ColorBar(Quantity& parent_, std::vector<float>& values, DataType datatype); // internally calls buildHistogram()
   ~ColorBar();
 
   void buildHistogram(const std::vector<float>& values, DataType datatype);
diff --git a/src/color_bar.cpp b/src/color_bar.cpp
index 355ac6935..b0945323f 100644
--- a/src/color_bar.cpp
+++ b/src/color_bar.cpp
@@ -14,13 +14,7 @@
 namespace polyscope {
 
 ColorBar::ColorBar(Quantity& parent_)
-    : parent(parent_), onscreenColorbarEnabled(parent.uniquePrefix() + "onscreenColorbarEnabled", false) {
-  prepareOnscreenColorBar();
-}
-
-ColorBar::ColorBar(Quantity& parent_, std::vector<float>& values, DataType dataType) : ColorBar(parent_) {
-  buildHistogram(values, dataType);
-}
+    : parent(parent_), onscreenColorbarEnabled(parent.uniquePrefix() + "onscreenColorbarEnabled", false) {}
 
 ColorBar::~ColorBar() {}
 
@@ -185,6 +179,8 @@ void ColorBar::renderInlineHistogramToTexture() {
     inlineHistogramProgram->setUniform("u_rangeLow", rangeLow);
     inlineHistogramProgram->setUniform("u_rangeHigh", rangeHigh);
   }
+
+  inlineHistogramProgram->draw();
 }
 
 void ColorBar::setOnscreenColorbarEnabled(bool newEnabled) {
diff --git a/src/surface_scalar_quantity.cpp b/src/surface_scalar_quantity.cpp
index 812bcae9b..894c5f57c 100644
--- a/src/surface_scalar_quantity.cpp
+++ b/src/surface_scalar_quantity.cpp
@@ -64,10 +64,7 @@ SurfaceVertexScalarQuantity::SurfaceVertexScalarQuantity(std::string name, const
                                                          SurfaceMesh& mesh_, DataType dataType_)
     : SurfaceScalarQuantity(name, mesh_, "vertex", values_, dataType_)
 
-{
-  values.ensureHostBufferPopulated();
-  colorBar.buildHistogram(values.data, dataType);
-}
+{}
 
 void SurfaceVertexScalarQuantity::createProgram() {
   // Create the program to draw this quantity
@@ -132,11 +129,7 @@ SurfaceFaceScalarQuantity::SurfaceFaceScalarQuantity(std::string name, const std
                                                      SurfaceMesh& mesh_, DataType dataType_)
     : SurfaceScalarQuantity(name, mesh_, "face", values_, dataType_)
 
-{
-  values.ensureHostBufferPopulated();
-  parent.faceAreas.ensureHostBufferPopulated();
-  colorBar.buildHistogram(values.data, dataType);
-}
+{}
 
 void SurfaceFaceScalarQuantity::createProgram() {
   // Create the program to draw this quantity
@@ -182,10 +175,7 @@ SurfaceEdgeScalarQuantity::SurfaceEdgeScalarQuantity(std::string name, const std
                                                      SurfaceMesh& mesh_, DataType dataType_)
     : SurfaceScalarQuantity(name, mesh_, "edge", values_, dataType_)
 
-{
-  values.ensureHostBufferPopulated();
-  colorBar.buildHistogram(values.data, dataType);
-}
+{}
 
 void SurfaceEdgeScalarQuantity::createProgram() {
   // Create the program to draw this quantity
@@ -227,10 +217,7 @@ SurfaceHalfedgeScalarQuantity::SurfaceHalfedgeScalarQuantity(std::string name, c
                                                              SurfaceMesh& mesh_, DataType dataType_)
     : SurfaceScalarQuantity(name, mesh_, "halfedge", values_, dataType_)
 
-{
-  values.ensureHostBufferPopulated();
-  colorBar.buildHistogram(values.data, dataType);
-}
+{}
 
 void SurfaceHalfedgeScalarQuantity::createProgram() {
   // Create the program to draw this quantity
@@ -272,10 +259,7 @@ SurfaceCornerScalarQuantity::SurfaceCornerScalarQuantity(std::string name, const
                                                          SurfaceMesh& mesh_, DataType dataType_)
     : SurfaceScalarQuantity(name, mesh_, "corner", values_, dataType_)
 
-{
-  values.ensureHostBufferPopulated();
-  colorBar.buildHistogram(values.data, dataType);
-}
+{}
 
 void SurfaceCornerScalarQuantity::createProgram() {
   // Create the program to draw this quantity
@@ -342,8 +326,6 @@ SurfaceTextureScalarQuantity::SurfaceTextureScalarQuantity(std::string name, Sur
     : SurfaceScalarQuantity(name, mesh_, "vertex", values_, dataType_),
       TextureMapQuantity(*this, dimX_, dimY_, origin_), param(param_) {
   values.setTextureSize(dimX, dimY);
-  values.ensureHostBufferPopulated();
-  colorBar.buildHistogram(values.data, dataType);
 
   if (dataType == DataType::CATEGORICAL) {
     // default to nearest filtering for categorical data, it's probably what the user wants

From 711cb60e22e60a66ca96b7e536ccd05d8db29a52 Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 00:35:44 -0800
Subject: [PATCH 05/18] add colormap texture getter

---
 include/polyscope/render/engine.h |  1 +
 src/render/engine.cpp             | 21 ++++++++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/include/polyscope/render/engine.h b/include/polyscope/render/engine.h
index 48a7493cc..5272b4f4d 100644
--- a/include/polyscope/render/engine.h
+++ b/include/polyscope/render/engine.h
@@ -614,6 +614,7 @@ class Engine {
   std::vector<std::unique_ptr<ValueColorMap>> colorMaps;
   const ValueColorMap& getColorMap(const std::string& name);
   void loadColorMap(std::string cmapName, std::string filename);
+  std::shared_ptr<TextureBuffer> getColorMapTexture2d(const std::string& cmapName);
 
   // Helpers
   std::vector<glm::vec3> screenTrianglesCoords(); // two triangles which cover the screen
diff --git a/src/render/engine.cpp b/src/render/engine.cpp
index c959a2628..1c82db01e 100644
--- a/src/render/engine.cpp
+++ b/src/render/engine.cpp
@@ -356,7 +356,7 @@ void Engine::buildEngineGui() {
         options::ssaaFactor = ssaaFactor;
         requestRedraw();
       }
-      
+
       if (ImGui::InputFloat("UI Scale", &options::uiScale, 0.25f)) {
         options::uiScale = std::min(options::uiScale, 4.f);
         options::uiScale = std::max(options::uiScale, 0.25f);
@@ -1160,6 +1160,25 @@ void Engine::loadDefaultColorMaps() {
   loadDefaultColorMap("hsv");
 }
 
+std::shared_ptr<TextureBuffer> Engine::getColorMapTexture2d(const std::string& cmapName) {
+  const ValueColorMap& colormap = render::engine->getColorMap(cmapName);
+
+  // Fill a buffer with the data
+  unsigned int dataLength = colormap.values.size() * 3;
+  std::vector<float> colorBuffer(dataLength);
+  for (unsigned int i = 0; i < colormap.values.size(); i++) {
+    colorBuffer[3 * i + 0] = static_cast<float>(colormap.values[i][0]);
+    colorBuffer[3 * i + 1] = static_cast<float>(colormap.values[i][1]);
+    colorBuffer[3 * i + 2] = static_cast<float>(colormap.values[i][2]);
+  }
+
+  std::shared_ptr<TextureBuffer> textureBuffer =
+      engine->generateTextureBuffer(TextureFormat::RGB32F, 1, colormap.values.size(), &(colorBuffer[0]));
+
+  textureBuffer->setFilterMode(FilterMode::Linear);
+
+  return textureBuffer;
+}
 
 void Engine::showTextureInImGuiWindow(std::string windowName, TextureBuffer* buffer) {
   ImGui::Begin(windowName.c_str());

From 52e1ec38076d233885bc12b45c66199bb81f77ff Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 00:36:12 -0800
Subject: [PATCH 06/18] more window pane placement logic

---
 src/internal.cpp  |  8 ++++++
 src/polyscope.cpp | 68 ++++++++++++++++++++++++++---------------------
 2 files changed, 46 insertions(+), 30 deletions(-)

diff --git a/src/internal.cpp b/src/internal.cpp
index fb874d626..29e9c9f84 100644
--- a/src/internal.cpp
+++ b/src/internal.cpp
@@ -14,5 +14,13 @@ uint64_t getNextUniqueID() { return uniqueID++; }
 bool& pointCloudEfficiencyWarningReported = state::globalContext.pointCloudEfficiencyWarningReported;
 FloatingQuantityStructure*& globalFloatingQuantityStructure = state::globalContext.globalFloatingQuantityStructure;
 
+float imguiStackMargin = 10;
+float lastWindowHeightPolyscope = 200;
+float lastWindowHeightUser = 200;
+float lastRightSideFreeX = 10;
+float lastRightSideFreeY = 10;
+float leftWindowsWidth = -1.;
+float rightWindowsWidth = -1.;
+
 } // namespace internal
 } // namespace polyscope
diff --git a/src/polyscope.cpp b/src/polyscope.cpp
index 9d9b360e6..209dbfb24 100644
--- a/src/polyscope.cpp
+++ b/src/polyscope.cpp
@@ -45,13 +45,8 @@ bool redrawNextFrame = true;
 bool unshowRequested = false;
 
 // Some state about imgui windows to stack them
-float imguiStackMargin = 10;
-float lastWindowHeightPolyscope = 200;
-float lastWindowHeightUser = 200;
 constexpr float INITIAL_LEFT_WINDOWS_WIDTH = 305;
 constexpr float INITIAL_RIGHT_WINDOWS_WIDTH = 500;
-float leftWindowsWidth = -1.;
-float rightWindowsWidth = -1.;
 
 auto prevMainLoopTime = std::chrono::steady_clock::now();
 float rollingMainLoopDurationMicrosec = 0.;
@@ -137,12 +132,12 @@ void writePrefsFile() {
 }
 
 void setInitialWindowWidths() {
-  leftWindowsWidth = INITIAL_LEFT_WINDOWS_WIDTH * options::uiScale;
-  rightWindowsWidth = INITIAL_RIGHT_WINDOWS_WIDTH * options::uiScale;
+  internal::leftWindowsWidth = INITIAL_LEFT_WINDOWS_WIDTH * options::uiScale;
+  internal::rightWindowsWidth = INITIAL_RIGHT_WINDOWS_WIDTH * options::uiScale;
 }
 
 void ensureWindowWidthsSet() {
-  if (leftWindowsWidth <= 0. || rightWindowsWidth <= 0.) {
+  if (internal::leftWindowsWidth <= 0. || internal::rightWindowsWidth <= 0.) {
     setInitialWindowWidths();
   }
 }
@@ -662,14 +657,15 @@ void userGuiBegin() {
   ImVec2 userGuiLoc;
   if (options::userGuiIsOnRightSide) {
     // right side
-    userGuiLoc = ImVec2(view::windowWidth - (rightWindowsWidth + imguiStackMargin), imguiStackMargin);
-    ImGui::SetNextWindowSize(ImVec2(rightWindowsWidth, 0.));
+    userGuiLoc = ImVec2(view::windowWidth - (internal::rightWindowsWidth + internal::imguiStackMargin),
+                        internal::imguiStackMargin);
+    ImGui::SetNextWindowSize(ImVec2(internal::rightWindowsWidth, 0.));
   } else {
     // left side
     if (options::buildDefaultGuiPanels) {
-      userGuiLoc = ImVec2(leftWindowsWidth + 3 * imguiStackMargin, imguiStackMargin);
+      userGuiLoc = ImVec2(internal::leftWindowsWidth + 3 * internal::imguiStackMargin, internal::imguiStackMargin);
     } else {
-      userGuiLoc = ImVec2(imguiStackMargin, imguiStackMargin);
+      userGuiLoc = ImVec2(internal::imguiStackMargin, internal::imguiStackMargin);
     }
   }
 
@@ -682,10 +678,15 @@ void userGuiBegin() {
 void userGuiEnd() {
 
   if (options::userGuiIsOnRightSide) {
-    rightWindowsWidth = INITIAL_RIGHT_WINDOWS_WIDTH * options::uiScale;
-    lastWindowHeightUser = imguiStackMargin + ImGui::GetWindowHeight();
+    internal::rightWindowsWidth = INITIAL_RIGHT_WINDOWS_WIDTH * options::uiScale;
+    internal::lastWindowHeightUser =
+        internal::imguiStackMargin + ImGui::GetWindowHeight(); // TODO using deprecated function
+    internal::lastRightSideFreeX = view::windowWidth - internal::imguiStackMargin;
+    internal::lastRightSideFreeY = internal::lastWindowHeightUser + internal::imguiStackMargin;
   } else {
-    lastWindowHeightUser = 0;
+    internal::lastWindowHeightUser = 0;
+    internal::lastRightSideFreeX = view::windowWidth - internal::imguiStackMargin;
+    internal::lastRightSideFreeY = internal::imguiStackMargin;
   }
   ImGui::End();
   ImGui::PopID();
@@ -698,8 +699,8 @@ void buildPolyscopeGui() {
 
   // Create window
   static bool showPolyscopeWindow = true;
-  ImGui::SetNextWindowPos(ImVec2(imguiStackMargin, imguiStackMargin));
-  ImGui::SetNextWindowSize(ImVec2(leftWindowsWidth, 0.));
+  ImGui::SetNextWindowPos(ImVec2(internal::imguiStackMargin, internal::imguiStackMargin));
+  ImGui::SetNextWindowSize(ImVec2(internal::leftWindowsWidth, 0.));
 
   ImGui::Begin("Polyscope", &showPolyscopeWindow);
 
@@ -740,7 +741,8 @@ void buildPolyscopeGui() {
   }
   if (ImGui::IsItemHovered()) {
 
-    ImGui::SetNextWindowPos(ImVec2(2 * imguiStackMargin + leftWindowsWidth, imguiStackMargin));
+    ImGui::SetNextWindowPos(
+        ImVec2(2 * internal::imguiStackMargin + internal::leftWindowsWidth, internal::imguiStackMargin));
     ImGui::SetNextWindowSize(ImVec2(0., 0.));
 
     // clang-format off
@@ -848,8 +850,8 @@ void buildPolyscopeGui() {
   }
 
 
-  lastWindowHeightPolyscope = imguiStackMargin + ImGui::GetWindowHeight();
-  leftWindowsWidth = ImGui::GetWindowWidth();
+  internal::lastWindowHeightPolyscope = internal::imguiStackMargin + ImGui::GetWindowHeight();
+  internal::leftWindowsWidth = ImGui::GetWindowWidth();
 
   ImGui::End();
 }
@@ -860,9 +862,10 @@ void buildStructureGui() {
   // Create window
   static bool showStructureWindow = true;
 
-  ImGui::SetNextWindowPos(ImVec2(imguiStackMargin, lastWindowHeightPolyscope + 2 * imguiStackMargin));
-  ImGui::SetNextWindowSize(
-      ImVec2(leftWindowsWidth, view::windowHeight - lastWindowHeightPolyscope - 3 * imguiStackMargin));
+  ImGui::SetNextWindowPos(
+      ImVec2(internal::imguiStackMargin, internal::lastWindowHeightPolyscope + 2 * internal::imguiStackMargin));
+  ImGui::SetNextWindowSize(ImVec2(internal::leftWindowsWidth, view::windowHeight - internal::lastWindowHeightPolyscope -
+                                                                  3 * internal::imguiStackMargin));
   ImGui::Begin("Structures", &showStructureWindow);
 
   // only show groups if there are any
@@ -920,7 +923,7 @@ void buildStructureGui() {
     ImGui::PopID();
   }
 
-  leftWindowsWidth = ImGui::GetWindowWidth();
+  internal::leftWindowsWidth = ImGui::GetWindowWidth();
 
   ImGui::End();
 }
@@ -930,9 +933,9 @@ void buildPickGui() {
 
   if (haveSelection()) {
 
-    ImGui::SetNextWindowPos(ImVec2(view::windowWidth - (rightWindowsWidth + imguiStackMargin),
-                                   2 * imguiStackMargin + lastWindowHeightUser));
-    ImGui::SetNextWindowSize(ImVec2(rightWindowsWidth, 0.));
+    ImGui::SetNextWindowPos(ImVec2(view::windowWidth - (internal::rightWindowsWidth + internal::imguiStackMargin),
+                                   internal::lastRightSideFreeY + internal::imguiStackMargin));
+    ImGui::SetNextWindowSize(ImVec2(internal::rightWindowsWidth, 0.));
 
     ImGui::Begin("Selection", nullptr);
     PickResult selection = getSelection();
@@ -957,7 +960,8 @@ void buildPickGui() {
       ImGui::TextUnformatted("ERROR: INVALID STRUCTURE");
     }
 
-    rightWindowsWidth = ImGui::GetWindowWidth();
+    internal::rightWindowsWidth = ImGui::GetWindowWidth();
+    internal::lastRightSideFreeY += 2 * internal::imguiStackMargin + ImGui::GetWindowHeight();
     ImGui::End();
   }
 }
@@ -981,11 +985,15 @@ void buildUserGuiAndInvokeCallback() {
     if (beganUserGUI) {
       userGuiEnd();
     } else {
-      lastWindowHeightUser = imguiStackMargin;
+      internal::lastWindowHeightUser = internal::imguiStackMargin;
+      internal::lastRightSideFreeX = view::windowWidth - internal::imguiStackMargin;
+      internal::lastRightSideFreeY = internal::imguiStackMargin;
     }
 
   } else {
-    lastWindowHeightUser = imguiStackMargin;
+    internal::lastWindowHeightUser = internal::imguiStackMargin;
+    internal::lastRightSideFreeX = view::windowWidth - internal::imguiStackMargin;
+    internal::lastRightSideFreeY = internal::imguiStackMargin;
   }
 }
 

From 0161d29e4d0cbb9304565278727786b057046d41 Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 00:36:29 -0800
Subject: [PATCH 07/18] missed header from pane placement

---
 include/polyscope/internal.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/polyscope/internal.h b/include/polyscope/internal.h
index 962183388..e57ffa821 100644
--- a/include/polyscope/internal.h
+++ b/include/polyscope/internal.h
@@ -26,5 +26,15 @@ extern bool& pointCloudEfficiencyWarningReported;
 // global members
 extern FloatingQuantityStructure*& globalFloatingQuantityStructure;
 
+
+// == UI and layout related
+extern float imguiStackMargin;
+extern float lastWindowHeightPolyscope;
+extern float lastWindowHeightUser;
+extern float lastRightSideFreeX;
+extern float lastRightSideFreeY;
+extern float leftWindowsWidth;
+extern float rightWindowsWidth;
+
 } // namespace internal
 } // namespace polyscope

From 47b21381f4ad622168a63161117ba1990d7e2c2e Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 00:36:49 -0800
Subject: [PATCH 08/18] working version of onscreen colorbar

---
 include/polyscope/color_bar.h |  4 +++
 src/color_bar.cpp             | 60 ++++++++++++++++++++++++++++++++---
 2 files changed, 59 insertions(+), 5 deletions(-)

diff --git a/include/polyscope/color_bar.h b/include/polyscope/color_bar.h
index a212a71ad..c66d3d4c6 100644
--- a/include/polyscope/color_bar.h
+++ b/include/polyscope/color_bar.h
@@ -15,8 +15,11 @@ namespace polyscope {
 // A histogram that shows up in ImGUI window
 // ONEDAY: we could definitely make a better histogram widget for categorical data...
 
+class OncreenColorBarWidget;
+
 class ColorBar {
 public:
+  friend class OnscreenColorBarWidget;
   ColorBar(Quantity& parent_); // must call buildHistogram() with data after
   ~ColorBar();
 
@@ -63,6 +66,7 @@ class ColorBar {
 
   // == The optional vertical colorbar which floats ont he main display
   PersistentValue<bool> onscreenColorbarEnabled;
+  std::shared_ptr<render::TextureBuffer> cmapTexture; // this is just the plain colormap rgb
   void prepareOnscreenColorBar();
   std::unique_ptr<Widget> onscreenColorBarWidget = nullptr;
 };
diff --git a/src/color_bar.cpp b/src/color_bar.cpp
index b0945323f..ff1157476 100644
--- a/src/color_bar.cpp
+++ b/src/color_bar.cpp
@@ -81,9 +81,8 @@ void ColorBar::buildHistogram(const std::vector<float>& values, DataType dataTyp
 
 void ColorBar::updateColormap(const std::string& newColormap) {
   colormap = newColormap;
-  if (inlineHistogramProgram) {
-    inlineHistogramProgram.reset();
-  }
+  inlineHistogramProgram.reset();
+  cmapTexture.reset();
 }
 
 void ColorBar::fillHistogramBuffers() {
@@ -202,9 +201,60 @@ void ColorBar::prepareOnscreenColorBar() {
 OnscreenColorBarWidget::OnscreenColorBarWidget(ColorBar& parent_) : parent(parent_) {}
 
 void OnscreenColorBarWidget::draw() {
-  if (parent.getOnscreenColorbarEnabled()) {
-    std::cout << "drawing color bar" << std::endl;
+  if (!parent.parent.isEnabled()) return;
+  if (!parent.getOnscreenColorbarEnabled()) return;
+
+  if (!parent.cmapTexture) {
+    parent.cmapTexture = render::engine->getColorMapTexture2d(parent.colormap);
   }
+
+  // Draw the color bar
+
+  // NOTE: right nwo the size of the colorbar is scaled by uiScale, but the positioning/margins are not. This is
+  // consistent with the other positioning/marching logic in the main gui panels. (Maybe they should all be scaled?)
+  float barRegionWidth = 30.0f * options::uiScale;
+  float tickRegionWidth = 80.0f * options::uiScale;
+  float marginWidth = 10.0f * options::uiScale;
+  float barRegionHeight = 300.0f * options::uiScale;
+  float borderWidth = 2.0f * options::uiScale;
+  ImVec2 barTopLeft(internal::lastRightSideFreeX - barRegionWidth - tickRegionWidth - marginWidth,
+                    internal::lastRightSideFreeY + marginWidth);
+
+  ImDrawList* dl = ImGui::GetBackgroundDrawList();
+
+  // Add a semi-transparent background
+  dl->AddRectFilled(ImVec2(barTopLeft.x - marginWidth, barTopLeft.y - marginWidth),
+                    ImVec2(barTopLeft.x + barRegionWidth + tickRegionWidth + marginWidth,
+                           barTopLeft.y + barRegionHeight + marginWidth),
+                    IM_COL32(255, 255, 255, 200));
+
+  render::engine->preserveResourceUntilImguiFrameCompletes(parent.cmapTexture);
+  dl->AddImage((ImTextureID)(intptr_t)parent.cmapTexture->getNativeHandle(), ImVec2(barTopLeft.x, barTopLeft.y),
+               ImVec2(barTopLeft.x + barRegionWidth, barTopLeft.y + barRegionHeight), ImVec2(0, 1), ImVec2(1, 0));
+
+  dl->AddRect(barTopLeft, ImVec2(barTopLeft.x + barRegionWidth, barTopLeft.y + barRegionHeight), IM_COL32(0, 0, 0, 255),
+              0.f, ImDrawFlags_None, borderWidth);
+
+  // draw text ticks
+  int nTicks = 5;
+  for (int i = 0; i < nTicks; i++) {
+    float t = (float)i / (float)(nTicks - 1);
+    float yPos = barTopLeft.y + t * (barRegionHeight - 0.5 * borderWidth);
+    double val = parent.colormapRange.second - t * (parent.colormapRange.second - parent.colormapRange.first);
+    char buffer[64];
+    snprintf(buffer, sizeof(buffer), "%.3g", val);
+
+    // Make a little tick mark
+    dl->AddLine(ImVec2(barTopLeft.x + barRegionWidth - borderWidth, yPos),
+                ImVec2(barTopLeft.x + barRegionWidth + 5.0f, yPos), IM_COL32(0, 0, 0, 255), borderWidth);
+
+    // Draw the actual text
+    ImVec2 textSize = ImGui::CalcTextSize(buffer);
+    dl->AddText(ImVec2(barTopLeft.x + barRegionWidth + 10.0f, yPos - textSize.y / 2), IM_COL32(0, 0, 0, 255), buffer);
+  }
+
+  internal::lastRightSideFreeX -=
+      (barRegionWidth + tickRegionWidth + 2 * marginWidth + 10.0f) + 0.5 * barRegionWidth; // last bit is some padding
 }
 
 

From 428c406a82a3049ab3e3c6c49b2bda0008579885 Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 00:37:03 -0800
Subject: [PATCH 09/18] expose setters for onscreen colorbar

---
 include/polyscope/scalar_quantity.h   |  2 ++
 include/polyscope/scalar_quantity.ipp | 12 ++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/include/polyscope/scalar_quantity.h b/include/polyscope/scalar_quantity.h
index 42f13dd6a..5da8c2ddb 100644
--- a/include/polyscope/scalar_quantity.h
+++ b/include/polyscope/scalar_quantity.h
@@ -45,6 +45,8 @@ class ScalarQuantity {
   // The color map
   QuantityT* setColorMap(std::string val);
   std::string getColorMap();
+  QuantityT* setOnscreenColorbarEnabled(bool newEnabled);
+  bool getOnscreenColorbarEnabled();
 
   // Data limits mapped in to colormap
   QuantityT* setMapRange(std::pair<double, double> val);
diff --git a/include/polyscope/scalar_quantity.ipp b/include/polyscope/scalar_quantity.ipp
index dde0a446c..cdf64334f 100644
--- a/include/polyscope/scalar_quantity.ipp
+++ b/include/polyscope/scalar_quantity.ipp
@@ -319,6 +319,18 @@ std::string ScalarQuantity<QuantityT>::getColorMap() {
   return cMap.get();
 }
 
+
+template <typename QuantityT>
+QuantityT* ScalarQuantity<QuantityT>::setOnscreenColorbarEnabled(bool newEnabled) {
+  colorBar.setOnscreenColorbarEnabled(newEnabled);
+  requestRedraw();
+  return &quantity;
+}
+template <typename QuantityT>
+bool ScalarQuantity<QuantityT>::getOnscreenColorbarEnabled() {
+  return colorBar.getOnscreenColorbarEnabled();
+}
+
 template <typename QuantityT>
 QuantityT* ScalarQuantity<QuantityT>::setMapRange(std::pair<double, double> val) {
   vizRangeMin = val.first;

From 27567682f9ba4dc2475a0bb0d905da33ae0d67cd Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 00:46:53 -0800
Subject: [PATCH 10/18] style tweaks

---
 src/color_bar.cpp | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/color_bar.cpp b/src/color_bar.cpp
index ff1157476..ad1cf41ee 100644
--- a/src/color_bar.cpp
+++ b/src/color_bar.cpp
@@ -213,7 +213,7 @@ void OnscreenColorBarWidget::draw() {
   // NOTE: right nwo the size of the colorbar is scaled by uiScale, but the positioning/margins are not. This is
   // consistent with the other positioning/marching logic in the main gui panels. (Maybe they should all be scaled?)
   float barRegionWidth = 30.0f * options::uiScale;
-  float tickRegionWidth = 80.0f * options::uiScale;
+  float tickRegionWidth = 90.0f * options::uiScale;
   float marginWidth = 10.0f * options::uiScale;
   float barRegionHeight = 300.0f * options::uiScale;
   float borderWidth = 2.0f * options::uiScale;
@@ -221,17 +221,20 @@ void OnscreenColorBarWidget::draw() {
                     internal::lastRightSideFreeY + marginWidth);
 
   ImDrawList* dl = ImGui::GetBackgroundDrawList();
+  ImU32 backgroundColor = IM_COL32(255, 255, 255, 180);
 
-  // Add a semi-transparent background
+  // dd a semi-transparent background
   dl->AddRectFilled(ImVec2(barTopLeft.x - marginWidth, barTopLeft.y - marginWidth),
                     ImVec2(barTopLeft.x + barRegionWidth + tickRegionWidth + marginWidth,
                            barTopLeft.y + barRegionHeight + marginWidth),
-                    IM_COL32(255, 255, 255, 200));
+                    backgroundColor);
 
+  // draw the actual colormap gradient rectangle
   render::engine->preserveResourceUntilImguiFrameCompletes(parent.cmapTexture);
   dl->AddImage((ImTextureID)(intptr_t)parent.cmapTexture->getNativeHandle(), ImVec2(barTopLeft.x, barTopLeft.y),
                ImVec2(barTopLeft.x + barRegionWidth, barTopLeft.y + barRegionHeight), ImVec2(0, 1), ImVec2(1, 0));
 
+  // draw the border around the map
   dl->AddRect(barTopLeft, ImVec2(barTopLeft.x + barRegionWidth, barTopLeft.y + barRegionHeight), IM_COL32(0, 0, 0, 255),
               0.f, ImDrawFlags_None, borderWidth);
 
@@ -242,15 +245,15 @@ void OnscreenColorBarWidget::draw() {
     float yPos = barTopLeft.y + t * (barRegionHeight - 0.5 * borderWidth);
     double val = parent.colormapRange.second - t * (parent.colormapRange.second - parent.colormapRange.first);
     char buffer[64];
-    snprintf(buffer, sizeof(buffer), "%.3g", val);
+    snprintf(buffer, sizeof(buffer), "%.4g", val);
 
     // Make a little tick mark
     dl->AddLine(ImVec2(barTopLeft.x + barRegionWidth - borderWidth, yPos),
-                ImVec2(barTopLeft.x + barRegionWidth + 5.0f, yPos), IM_COL32(0, 0, 0, 255), borderWidth);
+                ImVec2(barTopLeft.x + barRegionWidth + 5.0f, yPos), IM_COL32_BLACK, borderWidth);
 
     // Draw the actual text
     ImVec2 textSize = ImGui::CalcTextSize(buffer);
-    dl->AddText(ImVec2(barTopLeft.x + barRegionWidth + 10.0f, yPos - textSize.y / 2), IM_COL32(0, 0, 0, 255), buffer);
+    dl->AddText(ImVec2(barTopLeft.x + barRegionWidth + 10.0f, yPos - textSize.y / 2), IM_COL32_BLACK, buffer);
   }
 
   internal::lastRightSideFreeX -=

From 03b306e9a88c5434262b88af50c0403c1ad576ae Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 00:55:51 -0800
Subject: [PATCH 11/18] unrelated spacing fixes

---
 src/polyscope.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/polyscope.cpp b/src/polyscope.cpp
index 209dbfb24..171f8ee3a 100644
--- a/src/polyscope.cpp
+++ b/src/polyscope.cpp
@@ -682,11 +682,11 @@ void userGuiEnd() {
     internal::lastWindowHeightUser =
         internal::imguiStackMargin + ImGui::GetWindowHeight(); // TODO using deprecated function
     internal::lastRightSideFreeX = view::windowWidth - internal::imguiStackMargin;
-    internal::lastRightSideFreeY = internal::lastWindowHeightUser + internal::imguiStackMargin;
+    internal::lastRightSideFreeY = internal::lastWindowHeightUser;
   } else {
     internal::lastWindowHeightUser = 0;
     internal::lastRightSideFreeX = view::windowWidth - internal::imguiStackMargin;
-    internal::lastRightSideFreeY = internal::imguiStackMargin;
+    internal::lastRightSideFreeY = 0;
   }
   ImGui::End();
   ImGui::PopID();
@@ -850,7 +850,7 @@ void buildPolyscopeGui() {
   }
 
 
-  internal::lastWindowHeightPolyscope = internal::imguiStackMargin + ImGui::GetWindowHeight();
+  internal::lastWindowHeightPolyscope = ImGui::GetWindowHeight();
   internal::leftWindowsWidth = ImGui::GetWindowWidth();
 
   ImGui::End();
@@ -961,7 +961,7 @@ void buildPickGui() {
     }
 
     internal::rightWindowsWidth = ImGui::GetWindowWidth();
-    internal::lastRightSideFreeY += 2 * internal::imguiStackMargin + ImGui::GetWindowHeight();
+    internal::lastRightSideFreeY += internal::imguiStackMargin + ImGui::GetWindowHeight();
     ImGui::End();
   }
 }

From 38c7ab385c419e46386de9416c78718ca2e00788 Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 00:55:58 -0800
Subject: [PATCH 12/18] more style tuning

---
 src/color_bar.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/color_bar.cpp b/src/color_bar.cpp
index ad1cf41ee..179182869 100644
--- a/src/color_bar.cpp
+++ b/src/color_bar.cpp
@@ -217,8 +217,9 @@ void OnscreenColorBarWidget::draw() {
   float marginWidth = 10.0f * options::uiScale;
   float barRegionHeight = 300.0f * options::uiScale;
   float borderWidth = 2.0f * options::uiScale;
+  float tickWidth = 5.0f * options::uiScale;
   ImVec2 barTopLeft(internal::lastRightSideFreeX - barRegionWidth - tickRegionWidth - marginWidth,
-                    internal::lastRightSideFreeY + marginWidth);
+                    internal::lastRightSideFreeY + marginWidth + internal::imguiStackMargin);
 
   ImDrawList* dl = ImGui::GetBackgroundDrawList();
   ImU32 backgroundColor = IM_COL32(255, 255, 255, 180);
@@ -249,15 +250,15 @@ void OnscreenColorBarWidget::draw() {
 
     // Make a little tick mark
     dl->AddLine(ImVec2(barTopLeft.x + barRegionWidth - borderWidth, yPos),
-                ImVec2(barTopLeft.x + barRegionWidth + 5.0f, yPos), IM_COL32_BLACK, borderWidth);
+                ImVec2(barTopLeft.x + barRegionWidth + tickWidth, yPos), IM_COL32_BLACK, borderWidth);
 
     // Draw the actual text
     ImVec2 textSize = ImGui::CalcTextSize(buffer);
-    dl->AddText(ImVec2(barTopLeft.x + barRegionWidth + 10.0f, yPos - textSize.y / 2), IM_COL32_BLACK, buffer);
+    dl->AddText(ImVec2(barTopLeft.x + barRegionWidth + 2.f * tickWidth, yPos - textSize.y / 2), IM_COL32_BLACK, buffer);
   }
 
   internal::lastRightSideFreeX -=
-      (barRegionWidth + tickRegionWidth + 2 * marginWidth + 10.0f) + 0.5 * barRegionWidth; // last bit is some padding
+      (barRegionWidth + tickRegionWidth + marginWidth + 2.f * tickWidth) + internal::imguiStackMargin;
 }
 
 

From 7589e6c4f79c348e2937dd7c7c565ce9a6da9adc Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 01:27:18 -0800
Subject: [PATCH 13/18] add export function

---
 include/polyscope/color_bar.h         |  1 +
 include/polyscope/render/color_maps.h |  7 ++-
 include/polyscope/scalar_quantity.h   |  3 ++
 include/polyscope/scalar_quantity.ipp | 11 +++++
 src/color_bar.cpp                     | 66 +++++++++++++++++++++++++++
 5 files changed, 86 insertions(+), 2 deletions(-)

diff --git a/include/polyscope/color_bar.h b/include/polyscope/color_bar.h
index c66d3d4c6..d350190cd 100644
--- a/include/polyscope/color_bar.h
+++ b/include/polyscope/color_bar.h
@@ -32,6 +32,7 @@ class ColorBar {
   Quantity& parent;
   std::pair<double, double> colormapRange; // in DATA values, not [0,1]
 
+  void exportColorbarToSVG(const std::string& filename); 
 
   // Getters and setters
 
diff --git a/include/polyscope/render/color_maps.h b/include/polyscope/render/color_maps.h
index ebd59f279..660089e36 100644
--- a/include/polyscope/render/color_maps.h
+++ b/include/polyscope/render/color_maps.h
@@ -81,8 +81,11 @@ struct ValueColorMap {
     double scaledVal = val * (values.size() - 1);
     double lowerVal = std::floor(scaledVal);
     double upperBlendVal = scaledVal - lowerVal;
-    unsigned int lowerInd = static_cast<unsigned int>(lowerVal);
-    unsigned int upperInd = lowerInd + 1;
+    int lowerInd = static_cast<unsigned int>(lowerVal);
+    int upperInd = lowerInd + 1;
+
+    lowerInd = std::min(std::max(0, lowerInd), (int)values.size() - 1);
+    upperInd = std::min(std::max(0, upperInd), (int)values.size() - 1);
 
     return (float)(1.0 - upperBlendVal) * values[lowerInd] + (float)upperBlendVal * values[upperInd];
   }
diff --git a/include/polyscope/scalar_quantity.h b/include/polyscope/scalar_quantity.h
index 5da8c2ddb..aa2cda386 100644
--- a/include/polyscope/scalar_quantity.h
+++ b/include/polyscope/scalar_quantity.h
@@ -33,6 +33,9 @@ class ScalarQuantity {
   template <class V>
   void updateData(const V& newValues);
 
+  // Export the current colorbar as an SVG file
+  void exportColorbarToSVG(const std::string& filename); 
+
   // === Members
   QuantityT& quantity;
 
diff --git a/include/polyscope/scalar_quantity.ipp b/include/polyscope/scalar_quantity.ipp
index cdf64334f..a2f2e91c5 100644
--- a/include/polyscope/scalar_quantity.ipp
+++ b/include/polyscope/scalar_quantity.ipp
@@ -223,6 +223,11 @@ void ScalarQuantity<QuantityT>::buildScalarOptionsUI() {
   if (ImGui::MenuItem("Onscreen Colormap", NULL, colorBar.getOnscreenColorbarEnabled())) {
     colorBar.setOnscreenColorbarEnabled(!colorBar.getOnscreenColorbarEnabled());
   }
+  if (ImGui::MenuItem("Export Colormap", NULL, colorBar.getOnscreenColorbarEnabled())) {
+    std::string filename = quantity.parent.name + "_" + quantity.name + "_colorbar.svg";
+    colorBar.exportColorbarToSVG(filename);
+    polyscope::info("Exported colormap to " + filename);
+  }
 }
 
 template <typename QuantityT>
@@ -297,6 +302,12 @@ QuantityT* ScalarQuantity<QuantityT>::resetMapRange() {
   return &quantity;
 }
 
+
+template <typename QuantityT>
+void ScalarQuantity<QuantityT>::exportColorbarToSVG(const std::string& filename) {
+  colorBar.exportColorbarToSVG(filename);
+}
+
 template <typename QuantityT>
 template <class V>
 void ScalarQuantity<QuantityT>::updateData(const V& newValues) {
diff --git a/src/color_bar.cpp b/src/color_bar.cpp
index 179182869..7a4303d65 100644
--- a/src/color_bar.cpp
+++ b/src/color_bar.cpp
@@ -8,6 +8,7 @@
 #include "imgui.h"
 
 #include <algorithm>
+#include <fstream>
 #include <limits>
 #include <stdexcept>
 
@@ -261,6 +262,71 @@ void OnscreenColorBarWidget::draw() {
       (barRegionWidth + tickRegionWidth + marginWidth + 2.f * tickWidth) + internal::imguiStackMargin;
 }
 
+void ColorBar::exportColorbarToSVG(const std::string& filename) {
+  std::ofstream svgFile(filename);
+  if (!svgFile.is_open()) {
+    polyscope::warning("Failed to open file for SVG export: " + filename);
+    return;
+  }
+
+  const render::ValueColorMap& valueColormap = render::engine->getColorMap(colormap);
+
+  // SVG dimensions
+  float svgWidth = 100.0f;
+  float svgHeight = 400.0f;
+  float barWidth = 30.0f;
+  float tickLength = 10.0f;
+  float textOffset = 15.0f;
+  int nTicks = 5;
+
+  // SVG header
+  svgFile << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
+  svgFile << "<svg width=\"" << (svgWidth + 80) << "\" height=\"" << svgHeight
+          << "\" xmlns=\"http://www.w3.org/2000/svg\">\n";
+
+  // Gradient definition
+  svgFile << "  <defs>\n";
+  svgFile << "    <linearGradient id=\"colorbarGradient\" x1=\"0%\" y1=\"100%\" x2=\"0%\" y2=\"0%\">\n";
+
+  // Sample colormap at multiple points
+  int nSamples = 50;
+  for (int i = 0; i <= nSamples; i++) {
+    float t = (float)i / (float)nSamples;
+    glm::vec3 color = valueColormap.getValue(t);
+    int r = static_cast<int>(color.x * 255);
+    int g = static_cast<int>(color.y * 255);
+    int b = static_cast<int>(color.z * 255);
+    svgFile << "      <stop offset=\"" << (t * 100) << "%\" style=\"stop-color:rgb(" << r << "," << g << "," << b
+            << ");stop-opacity:1\" />\n";
+  }
+
+  svgFile << "    </linearGradient>\n";
+  svgFile << "  </defs>\n";
+
+  // Draw the colorbar rectangle
+  svgFile << "  <rect x=\"10\" y=\"10\" width=\"" << barWidth << "\" height=\"" << (svgHeight - 20)
+          << "\" fill=\"url(#colorbarGradient)\" stroke=\"black\" stroke-width=\"2\"/>\n";
+
+  // Ticks and labels
+  for (int i = 0; i < nTicks; i++) {
+    float t = (float)i / (float)(nTicks - 1);
+    float yPos = 10 + t * (svgHeight - 20);
+    double val = colormapRange.second - t * (colormapRange.second - colormapRange.first);
+
+    // tick mark
+    svgFile << "  <line x1=\"" << (10 + barWidth) << "\" y1=\"" << yPos << "\" x2=\"" << (10 + barWidth + tickLength)
+            << "\" y2=\"" << yPos << "\" stroke=\"black\" stroke-width=\"2\"/>\n";
+
+    // text label
+    char buffer[64];
+    snprintf(buffer, sizeof(buffer), "%.4g", val);
+    svgFile << "  <text x=\"" << (10 + barWidth + textOffset) << "\" y=\"" << (yPos + 5)
+            << "\" font-family=\"Arial\" font-size=\"14\" fill=\"black\">" << buffer << "</text>\n";
+  }
+
+  svgFile << "</svg>\n";
+  svgFile.close();
+}
 
 void ColorBar::buildUI(float width) {
 

From 19a58de3ede4d2e4be446cfbdc3270589dd08ade Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 16:07:26 -0800
Subject: [PATCH 14/18] minor fix to colorbar options menu

---
 include/polyscope/scalar_quantity.ipp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/polyscope/scalar_quantity.ipp b/include/polyscope/scalar_quantity.ipp
index a2f2e91c5..3a873927b 100644
--- a/include/polyscope/scalar_quantity.ipp
+++ b/include/polyscope/scalar_quantity.ipp
@@ -220,13 +220,13 @@ void ScalarQuantity<QuantityT>::buildScalarOptionsUI() {
   if (dataType != DataType::CATEGORICAL) {
     if (ImGui::MenuItem("Enable isolines", NULL, isolinesEnabled.get())) setIsolinesEnabled(!isolinesEnabled.get());
   }
-  if (ImGui::MenuItem("Onscreen Colormap", NULL, colorBar.getOnscreenColorbarEnabled())) {
+  if (ImGui::MenuItem("Onscreen Colorbar", NULL, colorBar.getOnscreenColorbarEnabled())) {
     colorBar.setOnscreenColorbarEnabled(!colorBar.getOnscreenColorbarEnabled());
   }
-  if (ImGui::MenuItem("Export Colormap", NULL, colorBar.getOnscreenColorbarEnabled())) {
+  if (ImGui::MenuItem("Export Colorbar")) {
     std::string filename = quantity.parent.name + "_" + quantity.name + "_colorbar.svg";
     colorBar.exportColorbarToSVG(filename);
-    polyscope::info("Exported colormap to " + filename);
+    polyscope::info("Exported colorbar to " + filename);
   }
 }
 

From 70979a7a9d7711d5cb79a2b67f7051798380a12f Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 23:23:38 -0800
Subject: [PATCH 15/18] add vec2 persistent value

---
 include/polyscope/persistent_value.h | 2 ++
 src/persistent_value.cpp             | 1 +
 2 files changed, 3 insertions(+)

diff --git a/include/polyscope/persistent_value.h b/include/polyscope/persistent_value.h
index 517a88b33..efc69ae47 100644
--- a/include/polyscope/persistent_value.h
+++ b/include/polyscope/persistent_value.h
@@ -134,6 +134,7 @@ extern PersistentCache<double> persistentCache_double;
 extern PersistentCache<float> persistentCache_float;
 extern PersistentCache<bool> persistentCache_bool;
 extern PersistentCache<std::string> persistentCache_string;
+extern PersistentCache<glm::vec2> persistentCache_glmvec2;
 extern PersistentCache<glm::vec3> persistentCache_glmvec3;
 extern PersistentCache<glm::mat4> persistentCache_glmmat4;
 extern PersistentCache<ScaledValue<double>> persistentCache_scaleddouble;
@@ -150,6 +151,7 @@ template<> inline PersistentCache<double>&                   getPersistentCacheR
 template<> inline PersistentCache<float>&                    getPersistentCacheRef<float>()                    { return persistentCache_float; }
 template<> inline PersistentCache<bool>&                     getPersistentCacheRef<bool>()                     { return persistentCache_bool; }
 template<> inline PersistentCache<std::string>&              getPersistentCacheRef<std::string>()              { return persistentCache_string; }
+template<> inline PersistentCache<glm::vec2>&                getPersistentCacheRef<glm::vec2>()                { return persistentCache_glmvec2; }
 template<> inline PersistentCache<glm::vec3>&                getPersistentCacheRef<glm::vec3>()                { return persistentCache_glmvec3; }
 template<> inline PersistentCache<glm::mat4>&                getPersistentCacheRef<glm::mat4>()                { return persistentCache_glmmat4; }
 template<> inline PersistentCache<ScaledValue<double>>&      getPersistentCacheRef<ScaledValue<double>>()      { return persistentCache_scaleddouble; }
diff --git a/src/persistent_value.cpp b/src/persistent_value.cpp
index 6476bb360..85e62f768 100644
--- a/src/persistent_value.cpp
+++ b/src/persistent_value.cpp
@@ -12,6 +12,7 @@ PersistentCache<double> persistentCache_double;
 PersistentCache<float> persistentCache_float;
 PersistentCache<bool> persistentCache_bool;
 PersistentCache<std::string> persistentCache_string;
+PersistentCache<glm::vec2> persistentCache_glmvec2;
 PersistentCache<glm::vec3> persistentCache_glmvec3;
 PersistentCache<glm::mat4> persistentCache_glmmat4;
 PersistentCache<ScaledValue<double>> persistentCache_scaleddouble;

From bbc06a9d99c20f7512550c0f12a6ed7d698d0005 Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 23:23:53 -0800
Subject: [PATCH 16/18] add set location option

---
 include/polyscope/color_bar.h         |  5 +++++
 include/polyscope/scalar_quantity.h   | 11 +++++++++--
 include/polyscope/scalar_quantity.ipp | 11 +++++++++++
 src/color_bar.cpp                     | 26 +++++++++++++++++++++-----
 4 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/include/polyscope/color_bar.h b/include/polyscope/color_bar.h
index d350190cd..afca0996b 100644
--- a/include/polyscope/color_bar.h
+++ b/include/polyscope/color_bar.h
@@ -38,6 +38,10 @@ class ColorBar {
 
   void setOnscreenColorbarEnabled(bool newEnabled);
   bool getOnscreenColorbarEnabled();
+ 
+  // Location in screen coords. (-1,-1), means "place automatically" (default)
+  void setOnscreenColorbarLocation(glm::vec2 newScreenCoords);
+  glm::vec2 getOnscreenColorbarLocation();
 
 private:
   // Basic data defining the color map
@@ -67,6 +71,7 @@ class ColorBar {
 
   // == The optional vertical colorbar which floats ont he main display
   PersistentValue<bool> onscreenColorbarEnabled;
+  PersistentValue<glm::vec2> onscreenColorbarLocation;
   std::shared_ptr<render::TextureBuffer> cmapTexture; // this is just the plain colormap rgb
   void prepareOnscreenColorBar();
   std::unique_ptr<Widget> onscreenColorBarWidget = nullptr;
diff --git a/include/polyscope/scalar_quantity.h b/include/polyscope/scalar_quantity.h
index aa2cda386..9644b7121 100644
--- a/include/polyscope/scalar_quantity.h
+++ b/include/polyscope/scalar_quantity.h
@@ -48,14 +48,21 @@ class ScalarQuantity {
   // The color map
   QuantityT* setColorMap(std::string val);
   std::string getColorMap();
-  QuantityT* setOnscreenColorbarEnabled(bool newEnabled);
-  bool getOnscreenColorbarEnabled();
 
   // Data limits mapped in to colormap
   QuantityT* setMapRange(std::pair<double, double> val);
   std::pair<double, double> getMapRange();
   QuantityT* resetMapRange(); // reset to full range
   std::pair<double, double> getDataRange();
+  
+  // Color bar options (it is always displayed inline in the structures panel)
+  QuantityT* setOnscreenColorbarEnabled(bool newEnabled);
+  bool getOnscreenColorbarEnabled();
+
+  // Location in screen coords. (-1,-1), means "place automatically" (default)
+  QuantityT* setOnscreenColorbarLocation(glm::vec2 newScreenCoords);
+  glm::vec2 getOnscreenColorbarLocation();
+
 
   // Isolines
   // NOTE there's a name typo, errant `s` in isolinesEnabled (leaving to avoid breaking change)
diff --git a/include/polyscope/scalar_quantity.ipp b/include/polyscope/scalar_quantity.ipp
index 3a873927b..31cb0f216 100644
--- a/include/polyscope/scalar_quantity.ipp
+++ b/include/polyscope/scalar_quantity.ipp
@@ -342,6 +342,17 @@ bool ScalarQuantity<QuantityT>::getOnscreenColorbarEnabled() {
   return colorBar.getOnscreenColorbarEnabled();
 }
 
+template <typename QuantityT>
+QuantityT* ScalarQuantity<QuantityT>::setOnscreenColorbarLocation(glm::vec2 newScreenCoords) {
+  colorBar.setOnscreenColorbarLocation(newScreenCoords);
+  requestRedraw();
+  return &quantity;
+}
+template <typename QuantityT>
+glm::vec2 ScalarQuantity<QuantityT>::getOnscreenColorbarLocation() {
+  return colorBar.getOnscreenColorbarLocation();
+}
+
 template <typename QuantityT>
 QuantityT* ScalarQuantity<QuantityT>::setMapRange(std::pair<double, double> val) {
   vizRangeMin = val.first;
diff --git a/src/color_bar.cpp b/src/color_bar.cpp
index 7a4303d65..20e68ab27 100644
--- a/src/color_bar.cpp
+++ b/src/color_bar.cpp
@@ -15,7 +15,8 @@
 namespace polyscope {
 
 ColorBar::ColorBar(Quantity& parent_)
-    : parent(parent_), onscreenColorbarEnabled(parent.uniquePrefix() + "onscreenColorbarEnabled", false) {}
+    : parent(parent_), onscreenColorbarEnabled(parent.uniquePrefix() + "onscreenColorbarEnabled", false),
+      onscreenColorbarLocation(parent.uniquePrefix() + "onscreenColorbarLocation", glm::vec2(-1., -1.)) {}
 
 ColorBar::~ColorBar() {}
 
@@ -191,6 +192,9 @@ void ColorBar::setOnscreenColorbarEnabled(bool newEnabled) {
 }
 bool ColorBar::getOnscreenColorbarEnabled() { return onscreenColorbarEnabled.get(); }
 
+void ColorBar::setOnscreenColorbarLocation(glm::vec2 newScreenCoords) { onscreenColorbarLocation.set(newScreenCoords); }
+glm::vec2 ColorBar::getOnscreenColorbarLocation() { return onscreenColorbarLocation.get(); }
+
 void ColorBar::prepareOnscreenColorBar() {
   if (onscreenColorBarWidget) {
     // Already created, nothing to do
@@ -209,6 +213,9 @@ void OnscreenColorBarWidget::draw() {
     parent.cmapTexture = render::engine->getColorMapTexture2d(parent.colormap);
   }
 
+  bool placeAutomatically =
+      (parent.onscreenColorbarLocation.get().x == -1.f && parent.onscreenColorbarLocation.get().y == -1.f);
+
   // Draw the color bar
 
   // NOTE: right nwo the size of the colorbar is scaled by uiScale, but the positioning/margins are not. This is
@@ -219,8 +226,15 @@ void OnscreenColorBarWidget::draw() {
   float barRegionHeight = 300.0f * options::uiScale;
   float borderWidth = 2.0f * options::uiScale;
   float tickWidth = 5.0f * options::uiScale;
-  ImVec2 barTopLeft(internal::lastRightSideFreeX - barRegionWidth - tickRegionWidth - marginWidth,
-                    internal::lastRightSideFreeY + marginWidth + internal::imguiStackMargin);
+
+
+  ImVec2 barTopLeft;
+  if (placeAutomatically) {
+    barTopLeft = ImVec2(internal::lastRightSideFreeX - barRegionWidth - tickRegionWidth - marginWidth,
+                        internal::lastRightSideFreeY + marginWidth + internal::imguiStackMargin);
+  } else {
+    barTopLeft = ImVec2(parent.onscreenColorbarLocation.get().x, parent.onscreenColorbarLocation.get().y);
+  }
 
   ImDrawList* dl = ImGui::GetBackgroundDrawList();
   ImU32 backgroundColor = IM_COL32(255, 255, 255, 180);
@@ -258,8 +272,10 @@ void OnscreenColorBarWidget::draw() {
     dl->AddText(ImVec2(barTopLeft.x + barRegionWidth + 2.f * tickWidth, yPos - textSize.y / 2), IM_COL32_BLACK, buffer);
   }
 
-  internal::lastRightSideFreeX -=
-      (barRegionWidth + tickRegionWidth + marginWidth + 2.f * tickWidth) + internal::imguiStackMargin;
+  if (placeAutomatically) {
+    internal::lastRightSideFreeX -=
+        (barRegionWidth + tickRegionWidth + marginWidth + 2.f * tickWidth) + internal::imguiStackMargin;
+  }
 }
 
 void ColorBar::exportColorbarToSVG(const std::string& filename) {

From 1c43c34f2596e2edcc10be12df1b79407d021839 Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 23:27:46 -0800
Subject: [PATCH 17/18] add tests

---
 test/src/misc_test.cpp | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/test/src/misc_test.cpp b/test/src/misc_test.cpp
index 6862cd3cc..e796ddcc9 100644
--- a/test/src/misc_test.cpp
+++ b/test/src/misc_test.cpp
@@ -21,7 +21,32 @@ TEST_F(PolyscopeTest, TestScalarQuantity) {
   q1->setMapRange(newRange);
   EXPECT_EQ(newRange, q1->getMapRange());
 
+  polyscope::show(3);
+
+  polyscope::removeAllStructures();
+}
+
+TEST_F(PolyscopeTest, TestScalarColormapQuantity) {
+  auto psPoints = registerPointCloud();
+
+  std::vector<double> vScalar(psPoints->nPoints(), 7.);
+  auto q1 = psPoints->addScalarQuantity("vScalar", vScalar);
+  q1->setEnabled(true);
+  polyscope::show(3);
 
+  // set colormap by name
+  q1->setColorMap("plasma");
+  EXPECT_EQ("plasma", q1->getColorMap());
+  polyscope::show(3);
+
+  // enable the onscreen colormap
+  q1->setOnscreenColorbarEnabled(true);
+  EXPECT_TRUE(q1->getOnscreenColorbarEnabled());
+  polyscope::show(3);
+  
+  // set its location manually
+  q1->setOnscreenColorbarLocation(glm::vec2(500.f, 500.f));
+  EXPECT_EQ(glm::vec2(500.f, 500.f), q1->getOnscreenColorbarLocation());
   polyscope::show(3);
 
   polyscope::removeAllStructures();

From 77efcc563d5f75a7dc785f1bab7fece8ff12d23d Mon Sep 17 00:00:00 2001
From: Nicholas Sharp <nmwsharp@gmail.com>
Date: Sun, 7 Dec 2025 23:28:24 -0800
Subject: [PATCH 18/18] add onscreen to demo

---
 examples/demo-app/demo_app.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/examples/demo-app/demo_app.cpp b/examples/demo-app/demo_app.cpp
index f1eaee4b3..c358f0f43 100644
--- a/examples/demo-app/demo_app.cpp
+++ b/examples/demo-app/demo_app.cpp
@@ -143,7 +143,8 @@ void processFileOBJ(std::string filename) {
     randColor[iV] = {{polyscope::randomUnit(), polyscope::randomUnit(), polyscope::randomUnit()}};
   }
   polyscope::getSurfaceMesh(niceName)->addVertexScalarQuantity("cX_really_really_stupid_long_name_how_dumb", valX);
-  polyscope::getSurfaceMesh(niceName)->addVertexScalarQuantity("cY", valY);
+  auto q = polyscope::getSurfaceMesh(niceName)->addVertexScalarQuantity("cY", valY);
+  q->setOnscreenColorbarEnabled(true); // set the onscreen colormap for this one
   polyscope::getSurfaceMesh(niceName)->addVertexScalarQuantity("cZ", valZ);
   polyscope::getSurfaceMesh(niceName)->addVertexColorQuantity("vColor", randColor);
   polyscope::getSurfaceMesh(niceName)->addVertexScalarQuantity("cY_sym", valY, polyscope::DataType::SYMMETRIC);