refactor to support deeper ImGui customization (#145)

* refactor for custom GUIs

* move gui helpers to public namespace

* missing includes

Co-authored-by: xarthur <[email protected]>

Author: nmwsharp

include/polyscope/imgui_config.h

@@ -0,0 +1,15 @@
+// Copyright 2017-2019, Nicholas Sharp and the Polyscope contributors. http://polyscope.run.
+#pragma once
+
+#include <tuple>
+
+#include "imgui.h"
+
+
+namespace polyscope {
+
+// Default implementations of callbacks to set ImGui style / fonts
+void configureImGuiStyle();
+std::tuple<ImFontAtlas*, ImFont*, ImFont*> prepareImGuiFonts();
+
+} // namespace polyscope

include/polyscope/options.h

@@ -1,15 +1,18 @@
 // Copyright 2017-2019, Nicholas Sharp and the Polyscope contributors. http://polyscope.run.
 #pragma once
 
+#include <string>
+#include <functional>
+#include <tuple>
+
+#include "imgui.h"
+
 #include "polyscope/scaled_value.h"
 #include "polyscope/types.h"
 
-#include <string>
 
 namespace polyscope {
-namespace options {
-
-// A general name to use when referring to the program in window headings.
+namespace options { // A general name to use when referring to the program in window headings.
 extern std::string programName;
 
 // How much should polyscope print to std::out?
@@ -43,14 +46,6 @@ extern bool autoscaleStructures;
 // bounding box and length scale manually. (default: true)
 extern bool automaticallyComputeSceneExtents;
 
-// If false, Polyscope will not create any ImGui UIs at all, but will still set up ImGui and invoke its render steps
-// each frame. The allows advanced users to create their own UIs totally from scratch and circumvent the standard
-// Polyscope UIs. (default: true)
-extern bool buildGui;
-
-// Should the user call back start out with an imgui window context open (default: true)
-extern bool openImGuiWindowForUserCallback;
-
 // If true, the user callback will be invoked for nested calls to polyscope::show(), otherwise not (default: false)
 extern bool invokeUserCallbackForNestedShow;
 
@@ -80,6 +75,28 @@ extern int ssaaFactor;
 extern TransparencyMode transparencyMode;
 extern int transparencyRenderPasses;
 
+// === Advanced ImGui configuration
+
+// If false, Polyscope will not create any ImGui UIs at all, but will still set up ImGui and invoke its render steps
+// each frame. The allows advanced users to create their own UIs totally from scratch and circumvent the standard
+// Polyscope UIs. (default: true)
+extern bool buildGui;
+
+// Should the user call back start out with an imgui window context open (default: true)
+extern bool openImGuiWindowForUserCallback;
+
+// A callback function which will be invoked when an ImGui context is created (which may happen several times as
+// Polyscope runs). By default, this is set to invoke `configureImGuiStyle()` from Polyscope's imgui_config.cpp, but you
+// may assign your own function to create custom styles. If this callback is null, the default ImGui style will be used.
+extern std::function<void()> configureImGuiStyleCallback;
+
+// A callback function which will be invoked exactly once during initialization to construct a font atlas for ImGui to
+// use. The callback should return a tuple of three pointers: a newly created global shared font atlas, a regular font,
+// and a mono font. By default, this is set to invoke prepareImGuiFonts() from Polyscope's imgui_config.cpp, but you may
+// assign your own function to create custom styles. If this callback is null, default fonts will be used.
+extern std::function<std::tuple<ImFontAtlas*, ImFont*, ImFont*>()> prepareImGuiFontsCallback;
+
+
 // === Debug options
 
 // Enables optional error checks in the rendering system

include/polyscope/polyscope.h

@@ -113,6 +113,15 @@ bool redrawRequested();
 void pushContext(std::function<void()> callbackFunction, bool drawDefaultUI = true);
 void popContext();
 
+// These helpers are called internally by Polyscope to render and build the UI.
+// Normally, applications should not need to call them, but in advanced settings when making custom UIs, they may be
+// useful to manually build pieces of the interface.
+void buildPolyscopeGui();
+void buildStructureGui();
+void buildPickGui();
+void buildUserGuiAndInvokeCallback();
+
+
 // === Utility
 
 // Execute one iteration of the main loop

src/CMakeLists.txt

@@ -178,6 +178,7 @@ SET(SRCS
   volume_mesh_vector_quantity.cpp
 
   # Rendering utilities
+  imgui_config.cpp
   vector_artist.cpp
   trace_vector_field.cpp
   ribbon_artist.cpp
@@ -216,6 +217,7 @@ SET(HEADERS
   ${INCLUDE_ROOT}/file_helpers.h
   ${INCLUDE_ROOT}/histogram.h
   ${INCLUDE_ROOT}/image_scalar_artist.h
+  ${INCLUDE_ROOT}/imgui_config.h
   ${INCLUDE_ROOT}/messages.h
   ${INCLUDE_ROOT}/options.h
   ${INCLUDE_ROOT}/persistent_value.h

src/imgui_config.cpp

@@ -0,0 +1,103 @@
+// Copyright 2017-2019, Nicholas Sharp and the Polyscope contributors. http://polyscope.run.
+#include "polyscope/imgui_config.h"
+
+namespace polyscope {
+
+
+// Forward declare compressed binary font functions
+namespace render {
+unsigned int getCousineRegularCompressedSize();
+const unsigned int* getCousineRegularCompressedData();
+unsigned int getLatoRegularCompressedSize();
+const unsigned int* getLatoRegularCompressedData();
+} // namespace render
+
+void configureImGuiStyle() {
+
+  // Style
+  ImGuiStyle* style = &ImGui::GetStyle();
+  style->WindowRounding = 1;
+  style->FrameRounding = 1;
+  style->FramePadding.y = 4;
+  style->ScrollbarRounding = 1;
+  style->ScrollbarSize = 20;
+
+
+  // Colors
+  ImVec4* colors = style->Colors;
+  colors[ImGuiCol_Text] = ImVec4(0.90f, 0.90f, 0.90f, 1.00f);
+  colors[ImGuiCol_TextDisabled] = ImVec4(0.60f, 0.60f, 0.60f, 1.00f);
+  colors[ImGuiCol_WindowBg] = ImVec4(0.00f, 0.00f, 0.00f, 0.70f);
+  colors[ImGuiCol_ChildBg] = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
+  colors[ImGuiCol_PopupBg] = ImVec4(0.11f, 0.11f, 0.14f, 0.92f);
+  colors[ImGuiCol_Border] = ImVec4(0.50f, 0.50f, 0.50f, 0.50f);
+  colors[ImGuiCol_BorderShadow] = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
+  colors[ImGuiCol_FrameBg] = ImVec4(0.63f, 0.63f, 0.63f, 0.39f);
+  colors[ImGuiCol_FrameBgHovered] = ImVec4(0.47f, 0.69f, 0.59f, 0.40f);
+  colors[ImGuiCol_FrameBgActive] = ImVec4(0.41f, 0.64f, 0.53f, 0.69f);
+  colors[ImGuiCol_TitleBg] = ImVec4(0.27f, 0.54f, 0.42f, 0.83f);
+  colors[ImGuiCol_TitleBgActive] = ImVec4(0.32f, 0.63f, 0.49f, 0.87f);
+  colors[ImGuiCol_TitleBgCollapsed] = ImVec4(0.27f, 0.54f, 0.42f, 0.83f);
+  colors[ImGuiCol_MenuBarBg] = ImVec4(0.40f, 0.55f, 0.48f, 0.80f);
+  colors[ImGuiCol_ScrollbarBg] = ImVec4(0.63f, 0.63f, 0.63f, 0.39f);
+  colors[ImGuiCol_ScrollbarGrab] = ImVec4(0.00f, 0.00f, 0.00f, 0.30f);
+  colors[ImGuiCol_ScrollbarGrabHovered] = ImVec4(0.40f, 0.80f, 0.62f, 0.40f);
+  colors[ImGuiCol_ScrollbarGrabActive] = ImVec4(0.39f, 0.80f, 0.61f, 0.60f);
+  colors[ImGuiCol_CheckMark] = ImVec4(0.90f, 0.90f, 0.90f, 0.50f);
+  colors[ImGuiCol_SliderGrab] = ImVec4(1.00f, 1.00f, 1.00f, 0.30f);
+  colors[ImGuiCol_SliderGrabActive] = ImVec4(0.39f, 0.80f, 0.61f, 0.60f);
+  colors[ImGuiCol_Button] = ImVec4(0.35f, 0.61f, 0.49f, 0.62f);
+  colors[ImGuiCol_ButtonHovered] = ImVec4(0.40f, 0.71f, 0.57f, 0.79f);
+  colors[ImGuiCol_ButtonActive] = ImVec4(0.46f, 0.80f, 0.64f, 1.00f);
+  colors[ImGuiCol_Header] = ImVec4(0.40f, 0.90f, 0.67f, 0.45f);
+  colors[ImGuiCol_HeaderHovered] = ImVec4(0.45f, 0.90f, 0.69f, 0.80f);
+  colors[ImGuiCol_HeaderActive] = ImVec4(0.53f, 0.87f, 0.71f, 0.80f);
+  colors[ImGuiCol_Separator] = ImVec4(0.50f, 0.50f, 0.50f, 1.00f);
+  colors[ImGuiCol_SeparatorHovered] = ImVec4(0.60f, 0.70f, 0.66f, 1.00f);
+  colors[ImGuiCol_SeparatorActive] = ImVec4(0.70f, 0.90f, 0.81f, 1.00f);
+  colors[ImGuiCol_ResizeGrip] = ImVec4(1.00f, 1.00f, 1.00f, 0.16f);
+  colors[ImGuiCol_ResizeGripHovered] = ImVec4(0.78f, 1.00f, 0.90f, 0.60f);
+  colors[ImGuiCol_ResizeGripActive] = ImVec4(0.78f, 1.00f, 0.90f, 0.90f);
+  colors[ImGuiCol_PlotLines] = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
+  colors[ImGuiCol_PlotLinesHovered] = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
+  colors[ImGuiCol_PlotHistogram] = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
+  colors[ImGuiCol_PlotHistogramHovered] = ImVec4(1.00f, 0.60f, 0.00f, 1.00f);
+  colors[ImGuiCol_TextSelectedBg] = ImVec4(0.00f, 0.00f, 1.00f, 0.35f);
+  colors[ImGuiCol_ModalWindowDarkening] = ImVec4(0.20f, 0.20f, 0.20f, 0.35f);
+  colors[ImGuiCol_DragDropTarget] = ImVec4(1.00f, 1.00f, 0.00f, 0.90f);
+  colors[ImGuiCol_Tab] = ImVec4(0.27f, 0.54f, 0.42f, 0.83f);
+  colors[ImGuiCol_TabHovered] = ImVec4(0.34f, 0.68f, 0.53f, 0.83f);
+  colors[ImGuiCol_TabActive] = ImVec4(0.38f, 0.76f, 0.58f, 0.83f);
+}
+
+
+std::tuple<ImFontAtlas*, ImFont*, ImFont*> prepareImGuiFonts() {
+
+  ImGuiIO& io = ImGui::GetIO();
+
+  // outputs
+  ImFontAtlas* globalFontAtlas;
+  ImFont* regularFont;
+  ImFont* monoFont;
+
+  { // add regular font
+    ImFontConfig config;
+    regularFont = io.Fonts->AddFontFromMemoryCompressedTTF(render::getLatoRegularCompressedData(),
+                                                           render::getLatoRegularCompressedSize(), 18.0f, &config);
+  }
+
+  { // add mono font
+    ImFontConfig config;
+    monoFont = io.Fonts->AddFontFromMemoryCompressedTTF(render::getCousineRegularCompressedData(),
+                                                        render::getCousineRegularCompressedSize(), 16.0f, &config);
+  }
+
+  // io.Fonts->AddFontFromFileTTF("test-font-name.ttf", 16);
+
+  io.Fonts->Build();
+  globalFontAtlas = io.Fonts;
+
+  return std::tuple<ImFontAtlas*, ImFont*, ImFont*>{globalFontAtlas, regularFont, monoFont};
+}
+
+} // namespace polyscope

src/options.cpp

@@ -1,5 +1,6 @@
 // Copyright 2017-2019, Nicholas Sharp and the Polyscope contributors. http://polyscope.run.
 #include "polyscope/options.h"
+#include "polyscope/imgui_config.h"
 
 namespace polyscope {
 namespace options {
@@ -16,8 +17,6 @@ bool alwaysRedraw = false;
 bool autocenterStructures = false;
 bool autoscaleStructures = false;
 bool automaticallyComputeSceneExtents = true;
-bool buildGui = true;
-bool openImGuiWindowForUserCallback = true;
 bool invokeUserCallbackForNestedShow = false;
 bool giveFocusOnShow = false;
 
@@ -41,6 +40,14 @@ int ssaaFactor = 1;
 TransparencyMode transparencyMode = TransparencyMode::None;
 int transparencyRenderPasses = 8;
 
+// === Advanced ImGui configuration
+
+bool buildGui = true;
+bool openImGuiWindowForUserCallback = true;
+std::function<void()> configureImGuiStyleCallback = configureImGuiStyle;
+std::function<std::tuple<ImFontAtlas*, ImFont*, ImFont*>()> prepareImGuiFontsCallback = prepareImGuiFonts;
+
+
 // enabled by default in debug mode
 #ifndef NDEBUG
 bool enableRenderErrorChecks = false;

src/polyscope.cpp

@@ -139,7 +139,10 @@ void pushContext(std::function<void()> callbackFunction, bool drawDefaultUI) {
   ImGuiIO& oldIO = ImGui::GetIO(); // used to copy below, see note
   ImGui::SetCurrentContext(newContext);
 
-  render::engine->setImGuiStyle();
+  if (options::configureImGuiStyleCallback) {
+    options::configureImGuiStyleCallback();
+  }
+
   ImGui::GetIO() = oldIO; // Copy all of the old IO values to new. With ImGUI 1.76 (and some previous versions), this
                           // was necessary to fix a bug where keys like delete, etc would break in subcontexts. The
                           // problem was that the key mappings (e.g. GLFW_KEY_BACKSPACE --> ImGuiKey_Backspace) need to
@@ -415,6 +418,10 @@ void renderSceneToScreen() {
   }
 }
 
+auto lastMainLoopIterTime = std::chrono::steady_clock::now();
+
+} // namespace
+
 void buildPolyscopeGui() {
 
   // Create window
@@ -555,6 +562,25 @@ void buildStructureGui() {
   ImGui::End();
 }
 
+void buildPickGui() {
+  if (pick::haveSelection()) {
+
+    ImGui::SetNextWindowPos(ImVec2(view::windowWidth - (rightWindowsWidth + imguiStackMargin),
+                                   2 * imguiStackMargin + lastWindowHeightUser));
+    ImGui::SetNextWindowSize(ImVec2(rightWindowsWidth, 0.));
+
+    ImGui::Begin("Selection", nullptr);
+    std::pair<Structure*, size_t> selection = pick::getSelection();
+
+    ImGui::TextUnformatted((selection.first->typeName() + ": " + selection.first->name).c_str());
+    ImGui::Separator();
+    selection.first->buildPickUI(selection.second);
+
+    rightWindowsWidth = ImGui::GetWindowWidth();
+    ImGui::End();
+  }
+}
+
 void buildUserGuiAndInvokeCallback() {
 
   if (!options::invokeUserCallbackForNestedShow && contextStack.size() > 2) {
@@ -587,29 +613,6 @@ void buildUserGuiAndInvokeCallback() {
   }
 }
 
-void buildPickGui() {
-  if (pick::haveSelection()) {
-
-    ImGui::SetNextWindowPos(ImVec2(view::windowWidth - (rightWindowsWidth + imguiStackMargin),
-                                   2 * imguiStackMargin + lastWindowHeightUser));
-    ImGui::SetNextWindowSize(ImVec2(rightWindowsWidth, 0.));
-
-    ImGui::Begin("Selection", nullptr);
-    std::pair<Structure*, size_t> selection = pick::getSelection();
-
-    ImGui::TextUnformatted((selection.first->typeName() + ": " + selection.first->name).c_str());
-    ImGui::Separator();
-    selection.first->buildPickUI(selection.second);
-
-    rightWindowsWidth = ImGui::GetWindowWidth();
-    ImGui::End();
-  }
-}
-
-auto lastMainLoopIterTime = std::chrono::steady_clock::now();
-
-} // namespace
-
 void draw(bool withUI, bool withContextCallback) {
   processLazyProperties();