Initial commit

9 months ago · 585f3e522c
11 changed files with 777 additions and 0 deletions
--- a/.clang-format
+++ b/.clang-format
@ -0,0 +1,178 @@
				@@ -0,0 +1,178 @@
+---
+Language: Cpp
+# BasedOnStyle: Chromium
+AccessModifierOffset: -2
+AlignAfterOpenBracket: Align
+AlignConsecutiveMacros: false
+AlignConsecutiveAssignments: false
+AlignConsecutiveBitFields: false
+AlignConsecutiveDeclarations: false
+AlignEscapedNewlines: DontAlign
+AlignOperands: DontAlign
+AlignTrailingComments: false
+AllowAllArgumentsOnNextLine: true
+AllowAllConstructorInitializersOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortEnumsOnASingleLine: false
+AllowShortBlocksOnASingleLine: Empty
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: Inline
+AllowShortLambdasOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: true
+AlwaysBreakTemplateDeclarations: Yes
+BinPackArguments: false
+BinPackParameters: false
+BraceWrapping:
+  AfterCaseLabel: false
+  AfterClass: true
+  AfterControlStatement: MultiLine
+  AfterEnum: true
+  AfterFunction: true
+  AfterNamespace: true
+  AfterObjCDeclaration: false
+  AfterStruct: true
+  AfterUnion: true
+  AfterExternBlock: true
+  BeforeCatch: false
+  BeforeElse: false
+  BeforeLambdaBody: true
+  BeforeWhile: false
+  IndentBraces: false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBinaryOperators: NonAssignment
+BreakBeforeBraces: Custom
+# BreakBeforeInheritanceComma: true
+BreakInheritanceList: BeforeComma
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: true
+BreakConstructorInitializers: BeforeComma
+BreakAfterJavaFieldAnnotations: true
+BreakStringLiterals: true
+ColumnLimit: 80
+CommentPragmas: '^ IWYU pragma:'
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DeriveLineEnding: false
+DerivePointerAlignment: false
+DisableFormat: false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+ForEachMacros:
+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+IncludeBlocks: Regroup
+IncludeCategories:
+  # Standard library headers come before anything else
+  - Regex: '^<[a-z_]+>'
+    Priority: -1
+  - Regex: '^<.+\.h(pp)?>'
+    Priority: 1
+  - Regex: '^<.*'
+    Priority: 2
+  - Regex: '.*'
+    Priority: 3
+IncludeIsMainRegex: ''
+IncludeIsMainSourceRegex: ''
+IndentCaseLabels: true
+IndentCaseBlocks: false
+IndentGotoLabels: true
+IndentPPDirectives: AfterHash
+IndentExternBlock: NoIndent
+IndentWidth: 2
+IndentWrappedFunctionNames: false
+InsertTrailingCommas: Wrapped
+JavaScriptQuotes: Double
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: false
+MacroBlockBegin: ''
+MacroBlockEnd: ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBinPackProtocolList: Never
+ObjCBlockIndentWidth: 2
+ObjCBreakBeforeNestedBlockParam: true
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakAssignment: 2
+PenaltyBreakBeforeFirstCallParameter: 1
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyBreakTemplateDeclaration: 10
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 200
+PointerAlignment: Left
+RawStringFormats:
+  - Language: Cpp
+    Delimiters:
+      - cc
+      - CC
+      - cpp
+      - Cpp
+      - CPP
+      - 'c++'
+      - 'C++'
+    CanonicalDelimiter: ''
+    BasedOnStyle: google
+  - Language: TextProto
+    Delimiters:
+      - pb
+      - PB
+      - proto
+      - PROTO
+    EnclosingFunctions:
+      - EqualsProto
+      - EquivToProto
+      - PARSE_PARTIAL_TEXT_PROTO
+      - PARSE_TEST_PROTO
+      - PARSE_TEXT_PROTO
+      - ParseTextOrDie
+      - ParseTextProtoOrDie
+      - ParseTestProto
+      - ParsePartialTestProto
+    CanonicalDelimiter: ''
+    BasedOnStyle: google
+ReflowComments: true
+SortIncludes: true
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: false
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: true
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatementsExceptForEachMacros
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceInEmptyBlock: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 2
+SpacesInAngles: false
+SpacesInConditionalStatement: false
+SpacesInContainerLiterals: false
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+SpaceBeforeSquareBrackets: false
+Standard: Auto
+StatementMacros:
+  - Q_UNUSED
+  - QT_REQUIRE_VERSION
+TabWidth: 8
+UseCRLF: false
+UseTab: Never
+WhitespaceSensitiveMacros:
+  - STRINGIZE
+  - PP_STRINGIZE
+  - BOOST_PP_STRINGIZE
+...
--- a/.clang-tidy
+++ b/.clang-tidy
@ -0,0 +1,17 @@
				@@ -0,0 +1,17 @@
+---
+# Enable ALL the things! Except not really
+# misc-non-private-member-variables-in-classes: the options don't do anything
+# modernize-use-nodiscard: too aggressive, attribute is situationally useful
+Checks: "*,\
+  -google-readability-todo,\
+  -altera-*,\
+  -fuchsia-*,\
+  -modernize-*,\
+  fuchsia-multiple-inheritance,\
+  -llvm-header-guard,\
+  -llvm-include-order,\
+  -llvmlibc-*,\
+  -modernize-use-nodiscard,\
+  -misc-non-private-member-variables-in-classes"
+WarningsAsErrors: ''
+---
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -0,0 +1,115 @@
				@@ -0,0 +1,115 @@
+cmake_minimum_required(VERSION 3.14)
+
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+if(NOT compile-target) 
+    #set(compile-target "-target x86_64-linux-gnu")
+    set(compile-target "")
+else ()
+    message("using compile-target: " compile-target)
+    set(compile-target "-target compile-target")
+endif()
+
+set(BUILD_SHARED_LIBS OFF)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+set(CMAKE_C_FLAGS "CMAKE_C_FLAGS -g")
+set(CMAKE_CXX_FLAGS "CMAKE_CXX_FLAGS -g -fpermissive -Wno-error ")
+
+
+project(
+    chipgui 
+    VERSION 0.1.0
+    DESCRIPTION "CHIP emulator visualiser"
+    HOMEPAGE_URL "https://example.com/"
+    LANGUAGES CXX
+)
+
+include(cmake/emscripten.cmake)
+include(cmake/CPM.cmake)
+include(FetchContent)
+
+CPMAddPackage("gh:onqtam/doctest@2.4.9")
+
+CPMAddPackage("gh:nlohmann/json@3.10.5")
+
+CPMAddPackage("gh:ocornut/imgui#docking")
+
+CPMAddPackage("gh:gabime/spdlog@1.8.2")
+
+CPMAddPackage("gh:fmtlib/fmt#7.1.3")
+
+FetchContent_Declare(SDL2
+  GIT_REPOSITORY https://github.com/libsdl-org/SDL
+  GIT_TAG release-2.26.4
+  OVERRIDE_FIND_PACKAGE
+)
+FetchContent_MakeAvailable(SDL2)
+
+find_package(SDL2 REQUIRED)
+
+# https://github.com/cpm-cmake/CPM.cmake/issues/368
+add_library(imgui STATIC
+    imgui_SOURCE_DIR/imgui.cpp
+    imgui_SOURCE_DIR/imgui_demo.cpp # optionally comment this out
+    imgui_SOURCE_DIR/imgui_draw.cpp
+    imgui_SOURCE_DIR/imgui_widgets.cpp
+    imgui_SOURCE_DIR/imgui_tables.cpp
+    imgui_SOURCE_DIR/backends/imgui_impl_opengl3.cpp
+    imgui_SOURCE_DIR/backends/imgui_impl_sdl2.cpp
+    imgui_SOURCE_DIR/imgui_demo.cpp # optionally comment this out
+)
+target_include_directories(imgui PUBLIC imgui_SOURCE_DIR)
+target_compile_definitions(imgui PUBLIC -DIMGUI_DISABLE_OBSOLETE_FUNCTIONS) # optional imgui setting
+target_link_libraries(imgui PUBLIC SDL2::SDL2-static)
+
+
+add_executable(main_exe source/main.cpp)
+add_executable(main::exe ALIAS main_exe)
+
+
+set(CMAKE_C_FLAGS_DEBUG
+    "CMAKE_C_FLAGS_DEBUG -Og -g -Werror -fsanitize=undefined -fsanitize=address -fsanitize=leak"
+)
+set(CMAKE_CXX_FLAGS_DEBUG
+    "CMAKE_CXX_FLAGS_DEBUG -Og -g -Werror -fsanitize=undefined -fsanitize=address -fsanitize=leak"
+)
+
+set(CMAKE_C_FLAGS_RELEASE "CMAKE_C_FLAGS_RELEASE -O2 -fstack-protector")
+set(CMAKE_CXX_FLAGS_RELEASE "CMAKE_CXX_FLAGS_RELEASE -O2 -fstack-protector")
+
+
+
+
+set_property(TARGET main_exe PROPERTY OUTPUT_NAME main)
+
+target_compile_features(main_exe PRIVATE cxx_std_20)
+
+if (EMSCRIPTEN) 
+    hello_imgui_platform_customization(main_exe)
+endif()
+
+
+target_link_libraries(main_exe PRIVATE 
+    fmt::fmt 
+    SDL2::SDL2-static
+    spdlog
+    imgui
+    nlohmann_json::nlohmann_json
+)
+
+if (EMSCRIPTEN)
+    target_link_libraries(imgui PUBLIC SDL2::SDL2-static GLESv2)
+endif()
+
+if (LINUX) 
+    target_link_libraries(imgui PUBLIC SDL2::SDL2-static OpenGL)
+endif()
+
+if (WIN32) 
+    set(CMAKE_EXE_LINKER_FLAGS "-static -fstack-protector")
+    target_link_libraries(imgui PUBLIC SDL2::SDL2-static opengl32)
+    target_link_libraries(main_exe PRIVATE SDL2::SDL2main iconv ssp opengl32)
+endif()
+
--- a/cmake/CPM.cmake
+++ b/cmake/CPM.cmake
@ -0,0 +1,33 @@
				@@ -0,0 +1,33 @@
+set(CPM_DOWNLOAD_VERSION 0.38.2)
+
+if(CPM_SOURCE_CACHE)
+  set(CPM_DOWNLOAD_LOCATION "${CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+elseif(DEFINED ENV{CPM_SOURCE_CACHE})
+  set(CPM_DOWNLOAD_LOCATION "$ENV{CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+else()
+  set(CPM_DOWNLOAD_LOCATION "${CMAKE_BINARY_DIR}/cmake/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
+endif()
+
+# Expand relative path. This is important if the provided path contains a tilde (~)
+get_filename_component(CPM_DOWNLOAD_LOCATION ${CPM_DOWNLOAD_LOCATION} ABSOLUTE)
+
+function(download_cpm)
+  message(STATUS "Downloading CPM.cmake to ${CPM_DOWNLOAD_LOCATION}")
+  file(DOWNLOAD
+       https://github.com/cpm-cmake/CPM.cmake/releases/download/v${CPM_DOWNLOAD_VERSION}/CPM.cmake
+       ${CPM_DOWNLOAD_LOCATION}
+  )
+endfunction()
+
+if(NOT (EXISTS ${CPM_DOWNLOAD_LOCATION}))
+  download_cpm()
+else()
+  # resume download if it previously failed
+  file(READ ${CPM_DOWNLOAD_LOCATION} check)
+  if("${check}" STREQUAL "")
+    download_cpm()
+  endif()
+  unset(check)
+endif()
+
+include(${CPM_DOWNLOAD_LOCATION})
--- a/cmake/emscripten.cmake
+++ b/cmake/emscripten.cmake
@ -0,0 +1,60 @@
				@@ -0,0 +1,60 @@
+# https://github.com/pthom/hello_imgui/blob/master/hello_imgui_cmake/emscripten/hello_imgui_emscripten.cmake
+
+if (EMSCRIPTEN)
+
+# Also see global emscripten flags in hello_imgui_cmake/emscripten/hello_imgui_emscripten_global_options.cmake
+
+function(hello_imgui_emscripten_set_shell_file app_name)
+    if (EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/shell.emscripten.html)
+        set(shell_template_file ${CMAKE_CURRENT_SOURCE_DIR}/shell.emscripten.html)
+    endif()
+
+    message(${shell_template_file})
+
+    get_property(runtime_output_directory TARGET ${app_name} PROPERTY RUNTIME_OUTPUT_DIRECTORY)
+    if ("${runtime_output_directory}" STREQUAL "")
+        set(real_output_directory ${CMAKE_CURRENT_BINARY_DIR})
+    else()
+        set(real_output_directory ${runtime_output_directory})
+    endif()
+
+    set(shell_file ${real_output_directory}/shell.emscripten.in.html)
+    configure_file(
+        ${shell_template_file}
+        ${shell_file}
+        @ONLY
+    )
+    target_link_options(
+        ${app_name} 
+        PRIVATE
+        "SHELL:--shell-file ${shell_file}"
+    )
+
+    set_target_properties(
+        ${app_name} 
+        PROPERTIES
+        SUFFIX .html
+        )
+endfunction()
+
+
+function(hello_imgui_emscripten_target_compile_options app_name)
+    target_link_options(${app_name} PRIVATE -sUSE_SDL=2 -sASSERTIONS)
+    if (NOT HELLOIMGUI_EMSCRIPTEN_PTHREAD OR HELLOIMGUI_EMSCRIPTEN_PTHREAD_ALLOW_MEMORY_GROWTH)
+        target_link_options(${app_name} PRIVATE -sALLOW_MEMORY_GROWTH)
+    endif()
+endfunction()
+
+
+function(hello_imgui_set_emscripten_target_initial_memory_megabytes app_name nb_megabytes)
+    math(EXPR nb_bytes "1048576 * ${nb_megabytes}")
+    target_link_options(${app_name} PRIVATE -sINITIAL_MEMORY=${nb_bytes})
+endfunction()
+
+
+function(hello_imgui_platform_customization app_name)
+    hello_imgui_emscripten_set_shell_file(${app_name})
+    hello_imgui_emscripten_target_compile_options(${app_name})
+endfunction()
+
+endif (EMSCRIPTEN)
--- a/cmake/windows-cross-clang.cmake
+++ b/cmake/windows-cross-clang.cmake
@ -0,0 +1,8 @@
				@@ -0,0 +1,8 @@
+#set(CMAKE_SYSTEM_NAME Windows)
+
+set(triple x86_64-win32-gnu)
+
+set(CMAKE_C_COMPILER clang)
+set(CMAKE_C_COMPILER_TARGET ${triple})
+set(CMAKE_CXX_COMPILER clang++)
+set(CMAKE_CXX_COMPILER_TARGET ${triple})
--- a/cmake/windows-cross-toolchain.cmake
+++ b/cmake/windows-cross-toolchain.cmake
@ -0,0 +1,13 @@
				@@ -0,0 +1,13 @@
+set(CMAKE_SYSTEM_NAME Windows)
+set(CMAKE_SYSTEM_PROCESSOR x86_64)
+
+find_program(CMAKE_C_COMPILER NAMES x86_64-w64-mingw32-gcc)
+find_program(CMAKE_CXX_COMPILER NAMES x86_64-w64-mingw32-g++)
+
+if(NOT CMAKE_C_COMPILER)
+	message(FATAL_ERROR "Failed to find CMAKE_C_COMPILER.")
+endif()
+
+if(NOT CMAKE_CXX_COMPILER)
+	message(FATAL_ERROR "Failed to find CMAKE_CXX_COMPILER.")
+endif()
--- a/readme.md
+++ b/readme.md
@ -0,0 +1,32 @@
				@@ -0,0 +1,32 @@
+
+# chipgui
+
+CHIP emulator visualiser
+
+A cross-splatform application using OpenGL ES and Dear ImGui.
+
+Build native
+
+```
+cmake -B build .
+cmake --build build
+```
+
+Build for web
+
+```
+emcmake cmake -B bweb 
+emmake cmake --build bweb 
+```
+
+Cross-compile for windows
+
+```
+cmake -DCMAKE_TOOLCHAIN_FILE=cmake/windows-cross-toolchain.cmake -B bwin .
+cmake --build bwin
+```
+
+
+
+
+
--- a/shell.emscripten.html
+++ b/shell.emscripten.html
@ -0,0 +1,64 @@
				@@ -0,0 +1,64 @@
+<!doctype html>
+<html lang="en-us">
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no"/>
+    <title>@HELLO_IMGUI_ICON_DISPLAY_NAME@</title>
+    <style>
+        body { margin: 0; background-color: black }
+        .emscripten {
+            position: absolute;
+            top: 0px;
+            left: 0px;
+            margin: 0px;
+            border: 0;
+            width: 100%;
+            height: 100%;
+            overflow: hidden;
+            display: block;
+            image-rendering: optimizeSpeed;
+            image-rendering: -moz-crisp-edges;
+            image-rendering: -o-crisp-edges;
+            image-rendering: -webkit-optimize-contrast;
+            image-rendering: optimize-contrast;
+            image-rendering: crisp-edges;
+            image-rendering: pixelated;
+            -ms-interpolation-mode: nearest-neighbor;
+        }
+    </style>
+</head>
+<body>
+<canvas class="emscripten" id="canvas" oncontextmenu="event.preventDefault()"></canvas>
+<script type='text/javascript'>
+    var Module = {
+        preRun: [],
+        postRun: [],
+        print: (function() {
+            return function(text) {
+                text = Array.prototype.slice.call(arguments).join(' ');
+                console.log(text);
+            };
+        })(),
+        printErr: function(text) {
+            text = Array.prototype.slice.call(arguments).join(' ');
+            console.error(text);
+        },
+        canvas: (function() {
+            var canvas = document.getElementById('canvas');
+            //canvas.addEventListener("webglcontextlost", function(e) { alert('FIXME: WebGL context lost, please reload the page'); e.preventDefault(); }, false);
+            return canvas;
+        })(),
+        setStatus: function(text) {
+            console.log("status: " + text);
+        },
+        monitorRunDependencies: function(left) {
+            // no run dependencies to log
+        }
+    };
+    window.onerror = function() {
+        console.log("onerror: " + event);
+    };
+</script>
+{{{ SCRIPT }}}
+</body>
+</html> 
--- a/source/main.cpp
+++ b/source/main.cpp
@ -0,0 +1,203 @@
				@@ -0,0 +1,203 @@
+
+// Dear ImGui: standalone example application for SDL2 + OpenGL
+// (SDL is a cross-platform general purpose library for handling windows,
+// inputs, OpenGL/Vulkan/Metal graphics context creation, etc.) If you are new
+// to Dear ImGui, read documentation from the docs/ folder + read the top of
+// imgui.cpp. Read online: https://github.com/ocornut/imgui/tree/master/docs
+// https://github.com/ocornut/imgui/tree/master/examples/example_sdl2_opengl3
+
+#include <fstream>
+
+#include <SDL.h>
+#include <backends/imgui_impl_opengl3.h>
+#include <backends/imgui_impl_sdl2.h>
+#include <fmt/format.h>
+#include <imgui.h>
+#include <stdio.h>
+#if defined(IMGUI_IMPL_OPENGL_ES2)
+#  include <SDL_opengles2.h>
+#else
+#  include <SDL_opengl.h>
+#endif
+
+#ifdef __EMSCRIPTEN__
+#  include "mainloop_stub.hpp"
+#endif
+
+int main(int, char**)
+{
+  // Setup SDL
+  if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
+  {
+    printf("Error: %s\n", SDL_GetError());
+    return -1;
+  }
+
+  // Decide GL+GLSL versions
+#if defined(IMGUI_IMPL_OPENGL_ES2)
+  // GL ES 2.0 + GLSL 100
+  const char* glsl_version = "#version 100";
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
+#elif defined(__APPLE__)
+  // GL 3.2 Core + GLSL 150
+  const char* glsl_version = "#version 150";
+  SDL_GL_SetAttribute(
+      SDL_GL_CONTEXT_FLAGS,
+      SDL_GL_CONTEXT_FORWARD_COMPATIBLE_FLAG);  // Always required on Mac
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
+#else
+  // GL 3.0 + GLSL 130
+  const char* glsl_version = "#version 130";
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+  SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
+#endif
+
+  // From 2.0.18: Enable native IME.
+#ifdef SDL_HINT_IME_SHOW_UI
+  SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
+#endif
+
+  // Create window with graphics context
+  SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+  SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
+  SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
+  SDL_WindowFlags window_flags =
+      (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE
+                        | SDL_WINDOW_ALLOW_HIGHDPI);
+  SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example",
+                                        SDL_WINDOWPOS_CENTERED,
+                                        SDL_WINDOWPOS_CENTERED,
+                                        1280,
+                                        720,
+                                        window_flags);
+  SDL_GLContext gl_context = SDL_GL_CreateContext(window);
+  SDL_GL_MakeCurrent(window, gl_context);
+  SDL_GL_SetSwapInterval(1);  // Enable vsync
+
+  // Setup Dear ImGui context
+  IMGUI_CHECKVERSION();
+  ImGui::CreateContext();
+  ImGuiIO& io = ImGui::GetIO();
+  (void)io;
+  io.ConfigFlags |=
+      ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+  io.ConfigFlags |=
+      ImGuiConfigFlags_NavEnableGamepad;  // Enable Gamepad Controls
+  io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;  // Enable Docking
+
+  // Setup Dear ImGui style
+  ImGui::StyleColorsDark();
+
+  // Setup Platform/Renderer backends
+  ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
+  ImGui_ImplOpenGL3_Init(glsl_version);
+
+  // Load Fonts
+  // - If no fonts are loaded, dear imgui will use the default font. You can
+  // also load multiple fonts and use ImGui::PushFont()/PopFont() to select
+  // them.
+  // - AddFontFromFileTTF() will return the ImFont* so you can store it if you
+  // need to select the font among multiple.
+  // - If the file cannot be loaded, the function will return a nullptr. Please
+  // handle those errors in your application (e.g. use an assertion, or display
+  // an error and quit).
+  // - The fonts will be rasterized at a given size (w/ oversampling) and stored
+  // into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which
+  // ImGui_ImplXXXX_NewFrame below will call.
+  // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype
+  // for higher quality font rendering.
+  // - Read 'docs/FONTS.md' for more instructions and details.
+  // - Remember that in C/C++ if you want to include a backslash \ in a string
+  // literal you need to write a double backslash \\ !
+  // - Our Emscripten build process allows embedding fonts to be accessible at
+  // runtime from the "fonts/" folder. See Makefile.emscripten for details.
+  // io.Fonts->AddFontDefault();
+  // io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
+  // io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
+  // io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
+  // io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
+  // ImFont* font =
+  // io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f,
+  // nullptr, io.Fonts->GetGlyphRangesJapanese()); IM_ASSERT(font != nullptr);
+
+  // Our state
+  bool show_demo_window = true;
+  bool show_another_window = true;
+  ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+
+  // Main loop
+  bool done = false;
+#ifdef __EMSCRIPTEN__
+  // For an Emscripten build we are disabling file-system access, so let's not
+  // attempt to do a fopen() of the imgui.ini file. You may manually call
+  // LoadIniSettingsFromMemory() to load settings from your own storage.
+  io.IniFilename = nullptr;
+  EMSCRIPTEN_MAINLOOP_BEGIN
+#else
+  while (!done)
+#endif
+  {
+    // Poll and handle events (inputs, window resize, etc.)
+    // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to
+    // tell if dear imgui wants to use your inputs.
+    // - When io.WantCaptureMouse is true, do not dispatch mouse input data to
+    // your main application, or clear/overwrite your copy of the mouse data.
+    // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input
+    // data to your main application, or clear/overwrite your copy of the
+    // keyboard data. Generally you may always pass all inputs to dear imgui,
+    // and hide them from your application based on those two flags.
+    SDL_Event event;
+    while (SDL_PollEvent(&event)) {
+      ImGui_ImplSDL2_ProcessEvent(&event);
+      if (event.type == SDL_QUIT)
+        done = true;
+      if (event.type == SDL_WINDOWEVENT
+          && event.window.event == SDL_WINDOWEVENT_CLOSE
+          && event.window.windowID == SDL_GetWindowID(window))
+        done = true;
+    }
+
+    // Start the Dear ImGui frame
+    ImGui_ImplOpenGL3_NewFrame();
+    ImGui_ImplSDL2_NewFrame();
+    ImGui::NewFrame();
+
+    // 1. Show the big demo window (Most of the sample code is in
+    // ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear
+    // ImGui!).
+    if (show_demo_window)
+      ImGui::ShowDemoWindow(&show_demo_window);
+
+    // Rendering
+    ImGui::Render();
+    glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
+    glClearColor(clear_color.x * clear_color.w,
+                 clear_color.y * clear_color.w,
+                 clear_color.z * clear_color.w,
+                 clear_color.w);
+    glClear(GL_COLOR_BUFFER_BIT);
+    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+    SDL_GL_SwapWindow(window);
+  }
+#ifdef __EMSCRIPTEN__
+  EMSCRIPTEN_MAINLOOP_END;
+#endif
+
+  // Cleanup
+  ImGui_ImplOpenGL3_Shutdown();
+  ImGui_ImplSDL2_Shutdown();
+  ImGui::DestroyContext();
+
+  SDL_GL_DeleteContext(gl_context);
+  SDL_DestroyWindow(window);
+  SDL_Quit();
+
+  return 0;
+}
--- a/source/mainloop_stub.hpp
+++ b/source/mainloop_stub.hpp
@ -0,0 +1,54 @@
				@@ -0,0 +1,54 @@
+// What does this file solves?
+// - Since Dear ImGui 1.00 we took pride that most of our examples applications
+// had their entire
+//   main-loop inside the main() function. That's because:
+//   - It makes the examples easier to read, keeping the code sequential.
+//   - It permit the use of local variables, making it easier to try things and
+//   perform quick
+//     changes when someone needs to quickly test something (vs having to
+//     structure the example in order to pass data around). This is very
+//     important because people use those examples to craft easy-to-past repro
+//     when they want to discuss features or report issues.
+//   - It conveys at a glance that this is a no-BS framework, it won't take your
+//   main loop away from you.
+//   - It is generally nice and elegant.
+// - However, comes Emscripten... it is a wonderful and magical tech but it
+// requires a "main loop" function.
+// - Only some of our examples would run on Emscripten. Typically the ones
+// rendering with GL or WGPU ones.
+// - I tried to refactor those examples but felt it was problematic that other
+// examples didn't follow the
+//   same layout. Why would the SDL+GL example be structured one way and the
+//   SGL+DX11 be structured differently? Especially as we are trying hard to
+//   convey that using a Dear ImGui backend in an *existing application* should
+//   requires only a few dozens lines of code, and this should be consistent and
+//   symmetrical for all backends.
+// - So the next logical step was to refactor all examples to follow that layout
+// of using a "main loop" function.
+//   This worked, but it made us lose all the nice things we had...
+
+// Since only about 3 examples really need to run with Emscripten, here's our
+// solution:
+// - Use some weird macros and capturing lambda to turn a loop in main() into a
+// function.
+// - Hide all that crap in this file so it doesn't make our examples unusually
+// ugly.
+//   As a stance and principle of Dear ImGui development we don't use C++
+//   headers and we don't want to suggest to the newcomer that we would ever use
+//   C++ headers as this would affect the initial judgment of many of our target
+//   audience.
+// - Technique is based on this idea:
+// https://github.com/ocornut/imgui/pull/2492/
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#include <functional>
+static std::function<void()> MainLoopForEmscriptenP;
+static void MainLoopForEmscripten() { MainLoopForEmscriptenP(); }
+#define EMSCRIPTEN_MAINLOOP_BEGIN MainLoopForEmscriptenP = [&]()
+#define EMSCRIPTEN_MAINLOOP_END                                                \
+  ;                                                                            \
+  emscripten_set_main_loop(MainLoopForEmscripten, 0, true)
+#else
+#define EMSCRIPTEN_MAINLOOP_BEGIN
+#define EMSCRIPTEN_MAINLOOP_END
+#endif