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Examples: Made example_sdl_opengl3 and example_glfw_opengl3 build with Emscripten. Removed dedicated examples. (#2492, #2494, #3699, #3705)

ocornut 2 năm trước cách đây
mục cha
commit
ce6e6da510

+ 2 - 2
.gitignore

@@ -40,8 +40,8 @@ xcuserdata
 examples/*.o.tmp
 examples/*.out.js
 examples/*.out.wasm
-examples/example_emscripten_glfw_opengl3/web/*
-examples/example_emscripten_opengl3/web/*
+examples/example_glfw_opengl3/web/*
+examples/example_sdl_opengl3/web/*
 examples/example_emscripten_wgpu/web/*
 
 ## JetBrains IDE artifacts

+ 13 - 17
docs/EXAMPLES.md

@@ -104,15 +104,10 @@ OSX + OpenGL2 example. <BR>
 (NB: imgui_impl_osx.mm is currently not as feature complete as other platforms backends.
  You may prefer to use the GLFW Or SDL backends, which will also support Windows and Linux.)
 
-[example_emscripten_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_emscripten_opengl3/) <BR>
-Emcripten + SDL2 + OpenGL3+/ES2/ES3 example. <BR>
-= main.cpp + imgui_impl_sdl.cpp + imgui_impl_opengl3.cpp <BR>
-Note that other examples based on SDL or GLFW + OpenGL could easily be modified to work with Emscripten.
-We provide this to make the Emscripten differences obvious, and have them not pollute all other examples.
-
 [example_emscripten_wgpu/](https://github.com/ocornut/imgui/blob/master/examples/example_emscripten_wgpu/) <BR>
 Emcripten + GLFW + WebGPU example. <BR>
 = main.cpp + imgui_impl_glfw.cpp + imgui_impl_wgpu.cpp
+Note that the 'example_glfw_opengl3' and 'example_sdl_opengl3' examples also supports Emscripten!
 
 [example_glfw_metal/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_metal/) <BR>
 GLFW (Mac) + Metal example. <BR>
@@ -121,18 +116,18 @@ GLFW (Mac) + Metal example. <BR>
 [example_glfw_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_opengl2/) <BR>
 GLFW + OpenGL2 example (legacy, fixed pipeline). <BR>
 = main.cpp + imgui_impl_glfw.cpp + imgui_impl_opengl2.cpp <BR>
-**DO NOT USE THIS IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)** <BR>
+**DO NOT USE THIS IF YOUR CODE/ENGINE IS USING MODERN GL or WEBGL (SHADERS, VBO, VAO, etc.)** <BR>
 This code is mostly provided as a reference to learn about Dear ImGui integration, because it is shorter.
-If your code is using GL3+ context or any semi modern OpenGL calls, using this renderer is likely to
-make things more complicated, will require your code to reset many OpenGL attributes to their initial
+If your code is using GL3+ context or any semi modern GL calls, using this renderer is likely to
+make things more complicated, will require your code to reset many GL attributes to their initial
 state, and might confuse your GPU driver. One star, not recommended.
 
 [example_glfw_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_opengl3/) <BR>
 GLFW (Win32, Mac, Linux) + OpenGL3+/ES2/ES3 example (modern, programmable pipeline). <BR>
 = main.cpp + imgui_impl_glfw.cpp + imgui_impl_opengl3.cpp <BR>
-This uses more modern OpenGL calls and custom shaders. <BR>
-This may actually also work with OpenGL 2.x contexts! <BR>
-Prefer using that if you are using modern OpenGL in your application (anything with shaders).
+This uses more modern GL calls and custom shaders.<BR>
+This support building with Emscripten and targetting WebGL.<BR>
+Prefer using that if you are using modern GL or WebGL in your application.
 
 [example_glfw_vulkan/](https://github.com/ocornut/imgui/blob/master/examples/example_glfw_vulkan/) <BR>
 GLFW (Win32, Mac, Linux) + Vulkan example. <BR>
@@ -163,17 +158,18 @@ SDL2 (Mac) + Metal example. <BR>
 [example_sdl_opengl2/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl_opengl2/) <BR>
 SDL2 (Win32, Mac, Linux etc.) + OpenGL example (legacy, fixed pipeline). <BR>
 = main.cpp + imgui_impl_sdl.cpp + imgui_impl_opengl2.cpp <BR>
-**DO NOT USE OPENGL2 CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)** <BR>
+**DO NOT USE OPENGL2 CODE IF YOUR CODE/ENGINE IS USING GL OR WEBGL (SHADERS, VBO, VAO, etc.)** <BR>
 This code is mostly provided as a reference to learn about Dear ImGui integration, because it is shorter.
-If your code is using GL3+ context or any semi modern OpenGL calls, using this renderer is likely to
-make things more complicated, will require your code to reset many OpenGL attributes to their initial
+If your code is using GL3+ context or any semi modern GL calls, using this renderer is likely to
+make things more complicated, will require your code to reset many GL attributes to their initial
 state, and might confuse your GPU driver. One star, not recommended.
 
 [example_sdl_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl_opengl3/) <BR>
 SDL2 (Win32, Mac, Linux, etc.) + OpenGL3+/ES2/ES3 example. <BR>
 = main.cpp + imgui_impl_sdl.cpp + imgui_impl_opengl3.cpp <BR>
-This uses more modern OpenGL calls and custom shaders. <BR>
-This may actually also work with OpenGL 2.x contexts! <BR>
+This uses more modern GL calls and custom shaders. <BR>
+This support building with Emscripten and targetting WebGL.<BR>
+Prefer using that if you are using modern GL or WebGL in your application.
 
 [example_sdl_sdlrenderer/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl_sdlrenderer/) <BR>
 SDL2 (Win32, Mac, Linux, etc.) + SDL_Renderer (most graphics backends are supported underneath) <BR>

+ 0 - 167
examples/example_emscripten_glfw_opengl3/main.cpp

@@ -1,167 +0,0 @@
-// Dear ImGui: standalone example application for Emscripten, using GLFW + OpenGL3
-// (Emscripten is a C++-to-javascript compiler, used to publish executables for the web. See https://emscripten.org/)
-// 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
-
-// This is mostly the same code as the GLFW + OpenGL3 example, simply with the modifications needed to run on Emscripten.
-// It is possible to combine both code into a single source file that will compile properly on Desktop and using Emscripten.
-// See https://github.com/ocornut/imgui/pull/2492 as an example on how to do just that.
-
-#include "imgui.h"
-#include "imgui_impl_glfw.h"
-#include "imgui_impl_opengl3.h"
-#include <stdio.h>
-#include <emscripten.h>
-#define GL_SILENCE_DEPRECATION
-#if defined(IMGUI_IMPL_OPENGL_ES2)
-#include <GLES2/gl2.h>
-#endif
-#include <GLFW/glfw3.h> // Will drag system OpenGL headers
-
-// Emscripten requires to have full control over the main loop. We're going to store our GLFW book-keeping variables globally.
-// Having a single function that acts as a loop prevents us to store state in the stack of said function. So we need some location for this.
-GLFWwindow*     g_Window = NULL;
-
-static void glfw_error_callback(int error, const char* description)
-{
-    fprintf(stderr, "Glfw Error %d: %s\n", error, description);
-}
-
-// For clarity, our main loop code is declared at the end.
-static void main_loop(void*);
-
-int main(int, char**)
-{
-    // Setup window
-    glfwSetErrorCallback(glfw_error_callback);
-    if (!glfwInit())
-        return 1;
-
-    // For the browser using Emscripten, we are going to use WebGL1 with GL ES2. See the Makefile. for requirement details.
-    // It is very likely the generated file won't work in many browsers. Firefox is the only sure bet, but I have successfully
-    // run this code on Chrome for Android for example.
-    const char* glsl_version = "#version 100";
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
-    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
-    glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
-
-    // Create window with graphics context
-    GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+Emscripten example", NULL, NULL);
-    if (window == NULL)
-        return 1;
-    glfwMakeContextCurrent(window);
-    glfwSwapInterval(1); // Enable vsync
-    g_Window = window;
-
-    // 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
-
-    // 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 = NULL;
-
-    // Setup Dear ImGui style
-    ImGui::StyleColorsDark();
-    //ImGui::StyleColorsLight();
-
-    // Setup Platform/Renderer backends
-    ImGui_ImplGlfw_InitForOpenGL(window, true);
-    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 NULL. 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 \\ !
-    // - Emscripten allows preloading a file or folder to be accessible at runtime. See Makefile for details.
-    //io.Fonts->AddFontDefault();
-#ifndef IMGUI_DISABLE_FILE_FUNCTIONS
-    //io.Fonts->AddFontFromFileTTF("fonts/segoeui.ttf", 18.0f);
-    io.Fonts->AddFontFromFileTTF("fonts/DroidSans.ttf", 16.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/Roboto-Medium.ttf", 16.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/Cousine-Regular.ttf", 15.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/ProggyTiny.ttf", 10.0f);
-    //ImFont* font = io.Fonts->AddFontFromFileTTF("fonts/ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
-    //IM_ASSERT(font != NULL);
-#endif
-
-    // This function call won't return, and will engage in an infinite loop, processing events from the browser, and dispatching them.
-    emscripten_set_main_loop_arg(main_loop, NULL, 0, true);
-}
-
-static void main_loop(void* arg)
-{
-    IM_UNUSED(arg); // We can pass this argument as the second parameter of emscripten_set_main_loop_arg(), but we don't use that.
-
-    // Our state (make them static = more or less global) as a convenience to keep the example terse.
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
-    // 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.
-    glfwPollEvents();
-
-    // Start the Dear ImGui frame
-    ImGui_ImplOpenGL3_NewFrame();
-    ImGui_ImplGlfw_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);
-
-    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
-    {
-        static float f = 0.0f;
-        static int counter = 0;
-
-        ImGui::Begin("Hello, world!");                                // Create a window called "Hello, world!" and append into it.
-
-        ImGui::Text("This is some useful text.");                     // Display some text (you can use a format strings too)
-        ImGui::Checkbox("Demo Window", &show_demo_window);            // Edit bools storing our window open/close state
-        ImGui::Checkbox("Another Window", &show_another_window);
-
-        ImGui::SliderFloat("float", &f, 0.0f, 1.0f);                  // Edit 1 float using a slider from 0.0f to 1.0f
-        ImGui::ColorEdit3("clear color", (float*)&clear_color);       // Edit 3 floats representing a color
-
-        if (ImGui::Button("Button"))                                  // Buttons return true when clicked (most widgets return true when edited/activated)
-            counter++;
-        ImGui::SameLine();
-        ImGui::Text("counter = %d", counter);
-
-        ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-        ImGui::End();
-    }
-
-    // 3. Show another simple window.
-    if (show_another_window)
-    {
-        ImGui::Begin("Another Window", &show_another_window);         // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
-        ImGui::Text("Hello from another window!");
-        if (ImGui::Button("Close Me"))
-            show_another_window = false;
-        ImGui::End();
-    }
-
-    // Rendering
-    ImGui::Render();
-    int display_w, display_h;
-    glfwGetFramebufferSize(g_Window, &display_w, &display_h);
-    glViewport(0, 0, display_w, display_h);
-    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());
-
-    glfwSwapBuffers(g_Window);
-}

+ 0 - 65
examples/example_emscripten_glfw_opengl3/shell_minimal.html

@@ -1,65 +0,0 @@
-<!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>Dear ImGui GLFW+Emscripten example</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;
-        }*/
-        .emscripten { padding-right: 0; margin-left: auto; margin-right: auto; display: block; }
-    </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>

+ 0 - 26
examples/example_emscripten_opengl3/README.md

@@ -1,26 +0,0 @@
-## How to Build
-
-- You need to install Emscripten from https://emscripten.org/docs/getting_started/downloads.html, and have the environment variables set, as described in https://emscripten.org/docs/getting_started/downloads.html#installation-instructions
-
-- Depending on your configuration, in Windows you may need to run `emsdk/emsdk_env.bat` in your console to access the Emscripten command-line tools.
-
-- You may also refer to our [Continuous Integration setup](https://github.com/ocornut/imgui/tree/master/.github/workflows) for Emscripten setup.
-
-- Then build using `make` while in the `example_emscripten_opengl3/` directory.
-
-## How to Run
-
-To run on a local machine:
-- `make serve` will use Python3 to spawn a local webserver, you can then browse http://localhost:8000 to access your build.
-- Otherwise, generally you will need a local webserver:
-  - Quoting [https://emscripten.org/docs/getting_started](https://emscripten.org/docs/getting_started/Tutorial.html#generating-html):<br>
-_"Unfortunately several browsers (including Chrome, Safari, and Internet Explorer) do not support file:// [XHR](https://emscripten.org/docs/site/glossary.html#term-xhr) requests, and can’t load extra files needed by the HTML (like a .wasm file, or packaged file data as mentioned lower down). For these browsers you’ll need to serve the files using a [local webserver](https://emscripten.org/docs/getting_started/FAQ.html#faq-local-webserver) and then open http://localhost:8000/hello.html."_
-  - Emscripten SDK has a handy `emrun` command: `emrun web/example_emscripten_opengl3.html --browser firefox` which will spawn a temporary local webserver (in Firefox). See https://emscripten.org/docs/compiling/Running-html-files-with-emrun.html for details.
-  - You may use Python 3 builtin webserver: `python -m http.server -d web` (this is what `make serve` uses).
-  - You may use Python 2 builtin webserver: `cd web && python -m SimpleHTTPServer`.
-  - If you are accessing the files over a network, certain browsers, such as Firefox, will restrict Gamepad API access to secure contexts only (e.g. https only).
-
-## Obsolete features:
-
-- Emscripten 2.0 (August 2020) obsoleted the fastcomp backend, only llvm is supported.
-- Emscripten 1.39.0 (October 2019) obsoleted the `BINARYEN_TRAP_MODE=clamp` compilation flag which was required with version older than 1.39.0 to avoid rendering artefacts. See [#2877](https://github.com/ocornut/imgui/issues/2877) for details. If you use an older version, uncomment this line in the Makefile: `#EMS += -s BINARYEN_TRAP_MODE=clamp`

+ 0 - 176
examples/example_emscripten_opengl3/main.cpp

@@ -1,176 +0,0 @@
-// Dear ImGui: standalone example application for Emscripten, using SDL2 + OpenGL3
-// (Emscripten is a C++-to-javascript compiler, used to publish executables for the web. See https://emscripten.org/)
-// 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
-
-// This is mostly the same code as the SDL2 + OpenGL3 example, simply with the modifications needed to run on Emscripten.
-// It is possible to combine both code into a single source file that will compile properly on Desktop and using Emscripten.
-// See https://github.com/ocornut/imgui/pull/2492 as an example on how to do just that.
-
-#include "imgui.h"
-#include "imgui_impl_sdl.h"
-#include "imgui_impl_opengl3.h"
-#include <stdio.h>
-#include <emscripten.h>
-#include <SDL.h>
-#include <SDL_opengles2.h>
-
-// Emscripten requires to have full control over the main loop. We're going to store our SDL book-keeping variables globally.
-// Having a single function that acts as a loop prevents us to store state in the stack of said function. So we need some location for this.
-SDL_Window*     g_Window = NULL;
-
-// For clarity, our main loop code is declared at the end.
-static void main_loop(void*);
-
-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;
-    }
-
-    // For the browser using Emscripten, we are going to use WebGL1 with GL ES2. See the Makefile. for requirement details.
-    // It is very likely the generated file won't work in many browsers. Firefox is the only sure bet, but I have successfully
-    // run this code on Chrome for Android for example.
-    const char* glsl_version = "#version 100";
-    //const char* glsl_version = "#version 300 es";
-    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);
-
-    // 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_DisplayMode current;
-    SDL_GetCurrentDisplayMode(0, &current);
-    SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL+Emscripten example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
-    SDL_GLContext gl_context = SDL_GL_CreateContext(window);
-    if (!gl_context)
-    {
-        fprintf(stderr, "Failed to initialize GL context!\n");
-        return 1;
-    }
-    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
-
-    // 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 = NULL;
-
-    // Setup Dear ImGui style
-    ImGui::StyleColorsDark();
-    //ImGui::StyleColorsLight();
-
-    // 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 NULL. 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 \\ !
-    // - Emscripten allows preloading a file or folder to be accessible at runtime. See Makefile for details.
-    //io.Fonts->AddFontDefault();
-#ifndef IMGUI_DISABLE_FILE_FUNCTIONS
-    //io.Fonts->AddFontFromFileTTF("fonts/segoeui.ttf", 18.0f);
-    io.Fonts->AddFontFromFileTTF("fonts/DroidSans.ttf", 16.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/Roboto-Medium.ttf", 16.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/Cousine-Regular.ttf", 15.0f);
-    //io.Fonts->AddFontFromFileTTF("fonts/ProggyTiny.ttf", 10.0f);
-    //ImFont* font = io.Fonts->AddFontFromFileTTF("fonts/ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
-    //IM_ASSERT(font != NULL);
-#endif
-
-    // This function call won't return, and will engage in an infinite loop, processing events from the browser, and dispatching them.
-    g_Window = window;
-    emscripten_set_main_loop_arg(main_loop, NULL, 0, true);
-}
-
-static void main_loop(void* arg)
-{
-    ImGuiIO& io = ImGui::GetIO();
-    IM_UNUSED(arg); // We can pass this argument as the second parameter of emscripten_set_main_loop_arg(), but we don't use that.
-
-    // Our state (make them static = more or less global) as a convenience to keep the example terse.
-    static bool show_demo_window = true;
-    static bool show_another_window = false;
-    static ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
-
-    // 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);
-        // Capture events here, based on io.WantCaptureMouse and io.WantCaptureKeyboard
-    }
-
-    // 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);
-
-    // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
-    {
-        static float f = 0.0f;
-        static int counter = 0;
-
-        ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
-
-        ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
-        ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
-        ImGui::Checkbox("Another Window", &show_another_window);
-
-        ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
-        ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
-
-        if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
-            counter++;
-        ImGui::SameLine();
-        ImGui::Text("counter = %d", counter);
-
-        ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
-        ImGui::End();
-    }
-
-    // 3. Show another simple window.
-    if (show_another_window)
-    {
-        ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
-        ImGui::Text("Hello from another window!");
-        if (ImGui::Button("Close Me"))
-            show_another_window = false;
-        ImGui::End();
-    }
-
-    // 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(g_Window);
-}

+ 2 - 3
examples/example_emscripten_glfw_opengl3/Makefile → examples/example_glfw_opengl3/Makefile.emscripten

@@ -6,7 +6,7 @@
 # This Makefile assumes you have loaded emscripten's environment.
 # (On Windows, you may need to execute emsdk_env.bat or encmdprompt.bat ahead)
 #
-# Running `make` will produce three files:
+# Running `make -f Makefile.emscripten` will produce three files:
 #  - web/index.html
 #  - web/index.js
 #  - web/index.wasm
@@ -32,7 +32,6 @@ EMS =
 ##---------------------------------------------------------------------
 
 # ("EMS" options gets added to both CPPFLAGS and LDFLAGS, whereas some options are for linker only)
-
 EMS += -s DISABLE_EXCEPTION_CATCHING=1
 LDFLAGS += -s USE_GLFW=3 -s WASM=1 -s ALLOW_MEMORY_GROWTH=1 -s NO_EXIT_RUNTIME=0 -s ASSERTIONS=1
 
@@ -60,7 +59,7 @@ endif
 CPPFLAGS += -I$(IMGUI_DIR) -I$(IMGUI_DIR)/backends
 #CPPFLAGS += -g
 CPPFLAGS += -Wall -Wformat -Os $(EMS)
-LDFLAGS += --shell-file shell_minimal.html
+# LDFLAGS += --shell-file ../libs/emscripten/shell_minimal.html
 LDFLAGS += $(EMS)
 
 ##---------------------------------------------------------------------

+ 17 - 0
examples/example_glfw_opengl3/main.cpp

@@ -3,6 +3,8 @@
 // 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
 
+// This example can also compile and run with Emscripten. See Makefile.emscripten for details.
+
 #include "imgui.h"
 #include "imgui_impl_glfw.h"
 #include "imgui_impl_opengl3.h"
@@ -25,6 +27,11 @@ static GLFWwindow* g_AppWindow = NULL;
 
 // Forward declarations of helper functions
 void MainLoopStep();
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+void MainLoopForEmscripten(void*) { MainLoopStep(); }
+#endif
+
 static void glfw_error_callback(int error, const char* description)
 {
     fprintf(stderr, "GLFW Error %d: %s\n", error, description);
@@ -91,6 +98,7 @@ int main(int, char**)
     // - 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);
@@ -100,8 +108,17 @@ int main(int, char**)
     //IM_ASSERT(font != NULL);
 
     // Main loop
+#ifndef __EMSCRIPTEN__
+    // Desktop Build
     while (!glfwWindowShouldClose(window))
         MainLoopStep();
+#else
+    // Emscripten Build
+    // 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 = NULL;
+    emscripten_set_main_loop_arg(MainLoopForEmscripten, NULL, 0, true);
+#endif
 
     // Cleanup
     ImGui_ImplOpenGL3_Shutdown();

+ 2 - 2
examples/example_emscripten_opengl3/Makefile → examples/example_sdl_opengl3/Makefile.emscripten

@@ -6,7 +6,7 @@
 # This Makefile assumes you have loaded emscripten's environment.
 # (On Windows, you may need to execute emsdk_env.bat or encmdprompt.bat ahead)
 #
-# Running `make` will produce three files:
+# Running `make -f Makefile.emscripten` will produce three files:
 #  - web/index.html
 #  - web/index.js
 #  - web/index.wasm
@@ -60,7 +60,7 @@ endif
 CPPFLAGS += -I$(IMGUI_DIR) -I$(IMGUI_DIR)/backends
 #CPPFLAGS += -g
 CPPFLAGS += -Wall -Wformat -Os $(EMS)
-LDFLAGS += --shell-file shell_minimal.html
+LDFLAGS += --shell-file ../libs/emscripten/shell_minimal.html
 LDFLAGS += $(EMS)
 
 ##---------------------------------------------------------------------

+ 34 - 6
examples/example_sdl_opengl3/README.md

@@ -1,12 +1,13 @@
 
 # How to Build
 
-- On Windows with Visual Studio's IDE
+## Windows with Visual Studio's IDE
 
 Use the provided project file (.vcxproj). Add to solution (imgui_examples.sln) if necessary.
 
-- On Windows with Visual Studio's CLI
+## Windows with Visual Studio's CLI
 
+Use build_win32.bat or directly:
 ```
 set SDL2_DIR=path_to_your_sdl2_folder
 cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib opengl32.lib /subsystem:console
@@ -15,15 +16,42 @@ cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_
 cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x64 SDL2.lib SDL2main.lib opengl32.lib /subsystem:console
 ```
 
-- On Linux and similar Unixes
+## Linux and similar Unixes
 
+Use our Makefile or directly:
 ```
-c++ `sdl2-config --cflags` -I .. -I ../.. -I ../../backends main.cpp ../../backends/imgui_impl_sdl.cpp ../../backends/imgui_impl_opengl3.cpp ../../imgui*.cpp `sdl2-config --libs` -lGL -ldl
+c++ `sdl2-config --cflags` -I .. -I ../.. -I ../../backends
+  main.cpp ../../backends/imgui_impl_sdl.cpp ../../backends/imgui_impl_opengl3.cpp ../../imgui*.cpp
+  `sdl2-config --libs` -lGL -ldl
 ```
 
-- On Mac OS X
+## macOS
 
+Use our Makefile or directly:
 ```
 brew install sdl2
-c++ `sdl2-config --cflags` -I .. -I ../.. -I ../../backends main.cpp ../../backends/imgui_impl_sdl.cpp ../../backends/imgui_impl_opengl3.cpp ../../imgui*.cpp `sdl2-config --libs` -framework OpenGl -framework CoreFoundation
+c++ `sdl2-config --cflags` -I .. -I ../.. -I ../../backends
+  main.cpp ../../backends/imgui_impl_sdl.cpp ../../backends/imgui_impl_opengl3.cpp ../../imgui*.cpp
+  `sdl2-config --libs` -framework OpenGl -framework CoreFoundation
 ```
+
+## Emscripten
+
+**Building**
+
+You need to install Emscripten from https://emscripten.org/docs/getting_started/downloads.html, and have the environment variables set, as described in https://emscripten.org/docs/getting_started/downloads.html#installation-instructions
+
+- Depending on your configuration, in Windows you may need to run `emsdk/emsdk_env.bat` in your console to access the Emscripten command-line tools.
+- You may also refer to our [Continuous Integration setup](https://github.com/ocornut/imgui/tree/master/.github/workflows) for Emscripten setup.
+- Then build using `make -f Makefile.emscripten` while in the current directory.
+
+**Running an Emscripten project**
+
+To run on a local machine:
+- `make -f Makefile.emscripten serve` will use Python3 to spawn a local webserver, you can then browse http://localhost:8000 to access your build.
+- Otherwise, generally you will need a local webserver. Quoting [https://emscripten.org/docs/getting_started](https://emscripten.org/docs/getting_started/Tutorial.html#generating-html):<br>
+_"Unfortunately several browsers (including Chrome, Safari, and Internet Explorer) do not support file:// [XHR](https://emscripten.org/docs/site/glossary.html#term-xhr) requests, and can’t load extra files needed by the HTML (like a .wasm file, or packaged file data as mentioned lower down). For these browsers you’ll need to serve the files using a [local webserver](https://emscripten.org/docs/getting_started/FAQ.html#faq-local-webserver) and then open http://localhost:8000/hello.html."_
+- Emscripten SDK has a handy `emrun` command: `emrun web/index.html --browser firefox` which will spawn a temporary local webserver (in Firefox). See https://emscripten.org/docs/compiling/Running-html-files-with-emrun.html for details.
+- You may use Python 3 builtin webserver: `python -m http.server -d web` (this is what `make serve` uses).
+- You may use Python 2 builtin webserver: `cd web && python -m SimpleHTTPServer`.
+- If you are accessing the files over a network, certain browsers, such as Firefox, will restrict Gamepad API access to secure contexts only (e.g. https only).

+ 16 - 0
examples/example_sdl_opengl3/main.cpp

@@ -3,6 +3,8 @@
 // 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
 
+// This example can also compile and run with Emscripten. See Makefile.emscripten for details.
+
 #include "imgui.h"
 #include "imgui_impl_sdl.h"
 #include "imgui_impl_opengl3.h"
@@ -19,6 +21,10 @@ static SDL_Window* g_AppWindow = NULL;
 
 // Forward declarations of helper functions
 bool MainLoopStep();
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+void MainLoopForEmscripten(void*) { MainLoopStep(); }
+#endif
 
 // Main code
 int main(int, char**)
@@ -88,6 +94,7 @@ int main(int, char**)
     // - 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);
@@ -97,11 +104,20 @@ int main(int, char**)
     //IM_ASSERT(font != NULL);
 
     // Main loop
+#ifndef __EMSCRIPTEN__
+    // Desktop Build
     while (true)
     {
         if (!MainLoopStep())
             break;
     }
+#else
+    // Emscripten Build
+    // 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 = NULL;
+    emscripten_set_main_loop_arg(MainLoopForEmscripten, NULL, 0, true);
+#endif
 
     // Cleanup
     ImGui_ImplOpenGL3_Shutdown();

+ 2 - 1
examples/example_emscripten_opengl3/shell_minimal.html → examples/libs/emscripten/shell_minimal.html

@@ -3,9 +3,10 @@
   <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>Dear ImGui SDL+Emscripten example</title>
+    <title>Dear ImGui Emscripten example</title>
     <style>
         body { margin: 0; background-color: black }
+        /* FIXME: with our GLFW example this block seems to break resizing and io.DisplaySize gets stuck */
         .emscripten {
             position: absolute;
             top: 0px;

+ 3 - 0
imgui_demo.cpp

@@ -5994,6 +5994,9 @@ void ImGui::ShowAboutWindow(bool* p_open)
 #endif
 #ifdef __clang_version__
         ImGui::Text("define: __clang_version__=%s", __clang_version__);
+#endif
+#ifdef __EMSCRIPTEN__
+        ImGui::Text("define: __EMSCRIPTEN__");
 #endif
         ImGui::Separator();
         ImGui::Text("io.BackendPlatformName: %s", io.BackendPlatformName ? io.BackendPlatformName : "NULL");