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

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ocornut
2023-02-02 18:08:17 +01:00
parent 96ab68eee0
commit ce6e6da510
13 changed files with 91 additions and 465 deletions
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167
examples/example_emscripten_glfw_opengl3/main.cpp
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// 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);
}

65
examples/example_emscripten_glfw_opengl3/shell_minimal.html
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@ -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>

26
examples/example_emscripten_opengl3/README.md
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@ -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`

176
examples/example_emscripten_opengl3/main.cpp
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@ -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);
}

5
examples/example_emscripten_glfw_opengl3/Makefile → examples/example_glfw_opengl3/Makefile.emscripten
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@ -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
examples/example_glfw_opengl3/main.cpp
View File

@ -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();

4
examples/example_emscripten_opengl3/Makefile → examples/example_sdl_opengl3/Makefile.emscripten
View File

@ -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)
##---------------------------------------------------------------------

40
examples/example_sdl_opengl3/README.md
View File

@ -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
examples/example_sdl_opengl3/main.cpp
View File

@ -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();

3
examples/example_emscripten_opengl3/shell_minimal.html → examples/libs/emscripten/shell_minimal.html
View File

@ -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;