From a936d0669cb3378559f973899f6c59a2f4bec4c0 Mon Sep 17 00:00:00 2001 From: "Nicolas \"Pixel\" Noble" Date: Sat, 13 Apr 2019 17:25:06 +0200 Subject: [PATCH 1/5] Adding standalone Emscripten example. --- examples/example_emscripten/Makefile | 58 ++++++ examples/example_emscripten/README.md | 8 + examples/example_emscripten/main.cpp | 165 ++++++++++++++++++ .../example_emscripten/shell_minimal.html | 153 ++++++++++++++++ 4 files changed, 384 insertions(+) create mode 100644 examples/example_emscripten/Makefile create mode 100644 examples/example_emscripten/README.md create mode 100644 examples/example_emscripten/main.cpp create mode 100644 examples/example_emscripten/shell_minimal.html diff --git a/examples/example_emscripten/Makefile b/examples/example_emscripten/Makefile new file mode 100644 index 00000000..b97933d6 --- /dev/null +++ b/examples/example_emscripten/Makefile @@ -0,0 +1,58 @@ +# +# Makefile to use with emscripten +# See https://emscripten.org/docs/getting_started/downloads.html +# for installation instructions. This Makefile assumes you have +# loaded emscripten's environment. +# +# Running `make` will produce three files: +# - example_emscripten.html +# - example_emscripten.js +# - example_emscripten.wasm +# +# All three are needed to run the demo. + +CC = emcc +CXX = em++ + +EXE = example_emscripten.html +SOURCES = main.cpp +SOURCES += ../imgui_impl_sdl.cpp ../imgui_impl_opengl3.cpp +SOURCES += ../../imgui.cpp ../../imgui_demo.cpp ../../imgui_draw.cpp ../../imgui_widgets.cpp +OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES)))) +UNAME_S := $(shell uname -s) + +EMS = -s USE_SDL=2 -s USE_WEBGL2=1 -s WASM=1 -s FULL_ES3=1 +EMS += -s ALLOW_MEMORY_GROWTH=1 -s BINARYEN_TRAP_MODE=clamp +EMS += -s DISABLE_EXCEPTION_CATCHING=1 -s EXIT_RUNTIME=1 +EMS += -s ASSERTIONS=1 -s SAFE_HEAP=1 + +CPPFLAGS = -I../ -I../../ +CPPFLAGS += -g -Wall -Wformat -O3 +CPPFLAGS += $(EMS) +LIBS = $(EMS) +LDFLAGS = --shell-file shell_minimal.html + +##--------------------------------------------------------------------- +## BUILD RULES +##--------------------------------------------------------------------- + +%.o:%.cpp + $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c -o $@ $< + +%.o:../%.cpp + $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c -o $@ $< + +%.o:../../%.cpp + $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c -o $@ $< + +%.o:../libs/gl3w/GL/%.c + $(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $< + +all: $(EXE) + @echo Build complete for $(EXE) + +$(EXE): $(OBJS) + $(CXX) -o $@ $^ $(LIBS) $(LDFLAGS) + +clean: + rm -f $(EXE) $(OBJS) *.js *.wasm diff --git a/examples/example_emscripten/README.md b/examples/example_emscripten/README.md new file mode 100644 index 00000000..c607ed73 --- /dev/null +++ b/examples/example_emscripten/README.md @@ -0,0 +1,8 @@ + +# 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 + +``` +em++ -I.. -I../.. main.cpp ../imgui_impl_sdl.cpp ../imgui_impl_opengl3.cpp ../../imgui*.cpp -s USE_SDL=2 -s USE_WEBGL2=1 -s WASM=1 -s FULL_ES3=1 -s ALLOW_MEMORY_GROWTH=1 -s BINARYEN_TRAP_MODE=clamp --shell-file shell_minimal.html -o example-emscripten.html +``` diff --git a/examples/example_emscripten/main.cpp b/examples/example_emscripten/main.cpp new file mode 100644 index 00000000..dd31e7b7 --- /dev/null +++ b/examples/example_emscripten/main.cpp @@ -0,0 +1,165 @@ +// dear imgui: standalone example application for Emscripten, using SDL2 + OpenGL3 +// 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. +// +// If you are new to dear imgui, see examples/README.txt and documentation at the top of imgui.cpp. +// (Emscripten is a C++-to-javascript compiler, used to publish executables for the web. See https://emscripten.org/) + +#include "imgui.h" +#include "imgui_impl_sdl.h" +#include "imgui_impl_opengl3.h" +#include +#include +#include +#include + +// Emscripten requires to have full control over the main loop. We're going to store variables from main() to main_loop() here. +// This will also hold some of our persistent data across loops. Remember: imgui is immediate mode, and doesn't store state. +// 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. +struct MainLoopVars { + SDL_Window* window = NULL; + SDL_GLContext gl_context = NULL; + bool show_demo_window = true; + bool show_another_window = false; + ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f); +}; + +// For clarity, our main loop code is declared at the end. +void main_loop(void*); + +int main(int, char**) +{ + MainLoopVars vars; + + // Setup SDL + if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER) != 0) + { + printf("Error: %s\n", SDL_GetError()); + return -1; + } + + // For the browser using emscripten, we are going to use WebGL2 with GLES3. See the Makefile.emscripten 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 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, 3); + 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, ¤t); + SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI); + vars.window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags); + vars.gl_context = SDL_GL_CreateContext(vars.window); + if (!vars.gl_context) { + fprintf(stderr, "Failed to initialize WebGL context!\n"); + return 1; + } + 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 + + // Setup Dear ImGui style + ImGui::StyleColorsDark(); + //ImGui::StyleColorsClassic(); + + // Setup Platform/Renderer bindings + ImGui_ImplSDL2_InitForOpenGL(vars.window, vars.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. + // - Read 'misc/fonts/README.txt' 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 \\ ! + //io.Fonts->AddFontDefault(); + //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f); + //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f); + //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f); + //io.Fonts->AddFontFromFileTTF("../../misc/fonts/ProggyTiny.ttf", 10.0f); + //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese()); + //IM_ASSERT(font != NULL); + + // 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, &vars, 0, true); +} + +void main_loop(void* arg) { + MainLoopVars* vars = (MainLoopVars*) arg; + ImGuiIO& io = ImGui::GetIO(); + + // 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. + // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application. + // 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(vars->window); + 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 (vars->show_demo_window) + ImGui::ShowDemoWindow(&vars->show_demo_window); + + // 2. Show a simple window that we create ourselves. We use a Begin/End pair to created 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", &vars->show_demo_window); // Edit bools storing our window open/close state + ImGui::Checkbox("Another Window", &vars->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*)&vars->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 (vars->show_another_window) + { + ImGui::Begin("Another Window", &vars->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")) + vars->show_another_window = false; + ImGui::End(); + } + + // Rendering + ImGui::Render(); + SDL_GL_MakeCurrent(vars->window, vars->gl_context); + glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y); + glClearColor(vars->clear_color.x, vars->clear_color.y, vars->clear_color.z, vars->clear_color.w); + glClear(GL_COLOR_BUFFER_BIT); + ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData()); + SDL_GL_SwapWindow(vars->window); +} diff --git a/examples/example_emscripten/shell_minimal.html b/examples/example_emscripten/shell_minimal.html new file mode 100644 index 00000000..3c5ef8ca --- /dev/null +++ b/examples/example_emscripten/shell_minimal.html @@ -0,0 +1,153 @@ + + + + + + Emscripten-Generated Code + + + +
+
emscripten
+
Downloading...
+
+ +
+
+ +
+
+
+ Resize canvas + Lock/hide mouse pointer +     + +
+ +
+ +
+ + {{{ SCRIPT }}} + + From 882d480b5e479898c26971ebdaecece5ae543649 Mon Sep 17 00:00:00 2001 From: omar Date: Mon, 15 Apr 2019 01:01:39 +0200 Subject: [PATCH 2/5] Examples: Removed unused variable (will be used in docking branch tho, undo when merging!) --- examples/imgui_impl_sdl.cpp | 3 --- 1 file changed, 3 deletions(-) diff --git a/examples/imgui_impl_sdl.cpp b/examples/imgui_impl_sdl.cpp index 528dbba3..10f49493 100644 --- a/examples/imgui_impl_sdl.cpp +++ b/examples/imgui_impl_sdl.cpp @@ -51,9 +51,6 @@ #define SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE SDL_VERSION_ATLEAST(2,0,4) #define SDL_HAS_VULKAN SDL_VERSION_ATLEAST(2,0,6) -#if !SDL_HAS_VULKAN -static const Uint32 SDL_WINDOW_VULKAN = 0x10000000; -#endif // Data static SDL_Window* g_Window = NULL; From c1848b185cd9dff997bb0e52981f78b8492f7a17 Mon Sep 17 00:00:00 2001 From: omar Date: Mon, 15 Apr 2019 01:01:44 +0200 Subject: [PATCH 3/5] Examples: Emscripten: Switched to WebGL1/ES2, Added Changelog, Updated links, Added ignore list, Fixed warning with older versions. Removed reliance on C++11 (would warn on some compiler). Improved html template, removed undesirable options, reduced log size. Tweaked main.cpp. (#2494) --- docs/CHANGELOG.txt | 1 + docs/README.md | 7 +- docs/TODO.txt | 3 +- examples/.gitignore | 1 + examples/README.txt | 12 +++- examples/example_emscripten/Makefile | 6 +- examples/example_emscripten/main.cpp | 66 +++++++++---------- .../example_emscripten/shell_minimal.html | 30 ++++----- 8 files changed, 67 insertions(+), 59 deletions(-) diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt index f80d0329..889ca66c 100644 --- a/docs/CHANGELOG.txt +++ b/docs/CHANGELOG.txt @@ -54,6 +54,7 @@ Other Changes: to using the ImGui::MemAlloc()/MemFree() calls directly. - Examples: OpenGL: Added a dummy GL call + comments in ImGui_ImplOpenGL3_Init() to detect uninitialized GL function loaders early, and help users understand what they are missing. (#2421) +- Examples: Emscripten: Added Emscripten+SDL+GLES2 example. (#2494, #2492, #2351, #336) [@nicolasnoble] - Examples: OpenGL3: Minor tweaks + not calling glBindBuffer more than necessary in the render loop. - Examples: Vulkan: Fixed in-flight buffers issues when using multi-viewports. (#2461, #2348, #2378, #2097) - Examples: Vulkan: Added missing support for 32-bit indices (#define ImDrawIdx unsigned int). diff --git a/docs/README.md b/docs/README.md index ba48517e..1b00d2fb 100644 --- a/docs/README.md +++ b/docs/README.md @@ -135,8 +135,7 @@ Languages: (third-party bindings) Frameworks: - Renderers: DirectX 9/10/11/12, Metal, OpenGL2, OpenGL3+/ES2/ES3, Vulkan: [examples/](https://github.com/ocornut/imgui/tree/master/examples) - Platform: GLFW, SDL, Win32, OSX, GLUT: [examples/](https://github.com/ocornut/imgui/tree/master/examples) -- Framework: Allegro 5, Marmalade: [examples/](https://github.com/ocornut/imgui/tree/master/examples) -- Unmerged PR: SDL2 + OpenGLES + Emscripten: [#336](https://github.com/ocornut/imgui/pull/336) +- Framework: Allegro 5, Emscripten, Marmalade: [examples/](https://github.com/ocornut/imgui/tree/master/examples) - Unmerged PR: Android: [#421](https://github.com/ocornut/imgui/pull/421) - Cinder: [Cinder-ImGui](https://github.com/simongeilfus/Cinder-ImGui) - Cocos2d-x: [imguix](https://github.com/c0i/imguix), [#551](https://github.com/ocornut/imgui/issues/551) @@ -221,8 +220,8 @@ Frequently Asked Question (FAQ) This library is poorly documented at the moment and expects of the user to be acquainted with C/C++. - Run the examples/ applications and explore them. - - See demo code in imgui_demo.cpp and particularly the ImGui::ShowDemoWindow() function. - - The demo covers most features of Dear ImGui, so you can read the code and see its output. + - See demo code in imgui_demo.cpp and particularly the ImGui::ShowDemoWindow() function. + - The demo covers most features of Dear ImGui, so you can read the code and see its output. - See documentation and comments at the top of imgui.cpp + effectively imgui.h. - Dozens of standalone example applications using e.g. OpenGL/DirectX are provided in the examples/ folder to explain how to integrate Dear ImGui with your own engine/application. - Your programming IDE is your friend, find the type or function declaration to find comments associated to it. diff --git a/docs/TODO.txt b/docs/TODO.txt index 66fd9459..a837b8b5 100644 --- a/docs/TODO.txt +++ b/docs/TODO.txt @@ -316,8 +316,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i - misc: possible compile-time support for wchar_t instead of char*? - backend: bgfx? https://gist.github.com/RichardGale/6e2b74bc42b3005e08397236e4be0fd0 - - web/emscriptem: refactor some examples to facilitate integration with emscripten main loop system. (#1713, #336) - - web/emscriptem: with refactored examples, we could provide a direct imgui_impl_emscripten platform layer (see eg. https://github.com/floooh/sokol-samples/blob/master/html5/imgui-emsc.cc#L42) + - emscriptem: with refactored examples, we could provide a direct imgui_impl_emscripten platform layer (see eg. https://github.com/floooh/sokol-samples/blob/master/html5/imgui-emsc.cc#L42) - remote: make a system like RemoteImGui first-class citizen/project (#75) diff --git a/examples/.gitignore b/examples/.gitignore index ddfa5ead..54c0a118 100644 --- a/examples/.gitignore +++ b/examples/.gitignore @@ -27,6 +27,7 @@ xcuserdata ## Emscripten output *.out.js *.out.wasm +example_emscripten/example_emscripten.* ## Unix executables example_glfw_opengl2/example_glfw_opengl2 diff --git a/examples/README.txt b/examples/README.txt index 03974745..cd60733c 100644 --- a/examples/README.txt +++ b/examples/README.txt @@ -122,13 +122,15 @@ List of high-level Frameworks Bindings in this repository: (combine Platform + R imgui_impl_allegro5.cpp imgui_impl_marmalade.cpp +Note that Dear ImGui works with Emscripten. +The examples_emscripten/ app uses sdl.cpp + opengl3.cpp but other combinations are possible. Third-party framework, graphics API and languages bindings are listed at: https://github.com/ocornut/imgui/wiki/Bindings Languages: C, C#, ChaiScript, D, Go, Haxe, Java, Lua, Odin, Pascal, PureBasic, Python, Rust, Swift... - Frameworks: Cinder, Cocoa (OSX), Cocos2d-x, Emscripten, SFML, GML/GameMaker Studio, Irrlicht, Ogre, - OpenSceneGraph, openFrameworks, LOVE, NanoRT, Nim Game Lib, Qt3d, SFML, Unreal Engine 4... + Frameworks: Cinder, Cocoa (OSX), Cocos2d-x, SFML, GML/GameMaker Studio, Irrlicht, Ogre, OpenSceneGraph, + openFrameworks, LOVE, NanoRT, Nim Game Lib, Qt3d, SFML, Unreal Engine 4... Miscellaneous: Software Renderer, RemoteImgui, etc. @@ -177,6 +179,12 @@ example_apple_opengl2/ = main.mm + imgui_impl_osx.mm + imgui_impl_opengl2.cpp (NB: you may still want to use GLFW or SDL which will also support Windows, Linux along with OSX.) +example_empscripten: + Emcripten + SDL2 + OpenGL3+/ES2/ES3 example. + = main.cpp + imgui_impl_sdl.cpp + imgui_impl_opengl3.cpp + Note that other examples based on SDL or GLFW + GL 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_glfw_opengl2/ GLFW + OpenGL2 example (legacy, fixed pipeline). = main.cpp + imgui_impl_glfw.cpp + imgui_impl_opengl2.cpp diff --git a/examples/example_emscripten/Makefile b/examples/example_emscripten/Makefile index b97933d6..6c9865ff 100644 --- a/examples/example_emscripten/Makefile +++ b/examples/example_emscripten/Makefile @@ -21,9 +21,9 @@ SOURCES += ../../imgui.cpp ../../imgui_demo.cpp ../../imgui_draw.cpp ../../imgui OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES)))) UNAME_S := $(shell uname -s) -EMS = -s USE_SDL=2 -s USE_WEBGL2=1 -s WASM=1 -s FULL_ES3=1 +EMS = -s USE_SDL=2 -s WASM=1 EMS += -s ALLOW_MEMORY_GROWTH=1 -s BINARYEN_TRAP_MODE=clamp -EMS += -s DISABLE_EXCEPTION_CATCHING=1 -s EXIT_RUNTIME=1 +EMS += -s DISABLE_EXCEPTION_CATCHING=1 -s NO_EXIT_RUNTIME=0 EMS += -s ASSERTIONS=1 -s SAFE_HEAP=1 CPPFLAGS = -I../ -I../../ @@ -55,4 +55,4 @@ $(EXE): $(OBJS) $(CXX) -o $@ $^ $(LIBS) $(LDFLAGS) clean: - rm -f $(EXE) $(OBJS) *.js *.wasm + rm -f $(EXE) $(OBJS) *.js *.wasm *.wasm.pre diff --git a/examples/example_emscripten/main.cpp b/examples/example_emscripten/main.cpp index dd31e7b7..847b505a 100644 --- a/examples/example_emscripten/main.cpp +++ b/examples/example_emscripten/main.cpp @@ -14,24 +14,16 @@ #include #include -// Emscripten requires to have full control over the main loop. We're going to store variables from main() to main_loop() here. -// This will also hold some of our persistent data across loops. Remember: imgui is immediate mode, and doesn't store state. +// 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. -struct MainLoopVars { - SDL_Window* window = NULL; - SDL_GLContext gl_context = NULL; - bool show_demo_window = true; - bool show_another_window = false; - ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f); -}; +SDL_Window* g_Window = NULL; +SDL_GLContext g_GLContext = NULL; // For clarity, our main loop code is declared at the end. void main_loop(void*); int main(int, char**) { - MainLoopVars vars; - // Setup SDL if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER) != 0) { @@ -39,13 +31,14 @@ int main(int, char**) return -1; } - // For the browser using emscripten, we are going to use WebGL2 with GLES3. See the Makefile.emscripten for requirement details. + // 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 300 es"; + 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, 3); + SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2); SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0); // Create window with graphics context @@ -55,9 +48,10 @@ int main(int, char**) SDL_DisplayMode current; SDL_GetCurrentDisplayMode(0, ¤t); SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI); - vars.window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags); - vars.gl_context = SDL_GL_CreateContext(vars.window); - if (!vars.gl_context) { + g_Window = SDL_CreateWindow("Dear ImGui Emscripten example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags); + g_GLContext = SDL_GL_CreateContext(g_Window); + if (!g_GLContext) + { fprintf(stderr, "Failed to initialize WebGL context!\n"); return 1; } @@ -74,7 +68,7 @@ int main(int, char**) //ImGui::StyleColorsClassic(); // Setup Platform/Renderer bindings - ImGui_ImplSDL2_InitForOpenGL(vars.window, vars.gl_context); + ImGui_ImplSDL2_InitForOpenGL(g_Window, g_GLContext); ImGui_ImplOpenGL3_Init(glsl_version); // Load Fonts @@ -93,12 +87,18 @@ int main(int, char**) //IM_ASSERT(font != NULL); // 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, &vars, 0, true); + emscripten_set_main_loop_arg(main_loop, NULL, 0, true); } -void main_loop(void* arg) { - MainLoopVars* vars = (MainLoopVars*) arg; +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. @@ -114,12 +114,12 @@ void main_loop(void* arg) { // Start the Dear ImGui frame ImGui_ImplOpenGL3_NewFrame(); - ImGui_ImplSDL2_NewFrame(vars->window); + ImGui_ImplSDL2_NewFrame(g_Window); 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 (vars->show_demo_window) - ImGui::ShowDemoWindow(&vars->show_demo_window); + 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 created a named window. { @@ -129,11 +129,11 @@ void main_loop(void* arg) { 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", &vars->show_demo_window); // Edit bools storing our window open/close state - ImGui::Checkbox("Another Window", &vars->show_another_window); + 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*)&vars->clear_color); // Edit 3 floats representing a color + 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++; @@ -145,21 +145,21 @@ void main_loop(void* arg) { } // 3. Show another simple window. - if (vars->show_another_window) + if (show_another_window) { - ImGui::Begin("Another Window", &vars->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::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")) - vars->show_another_window = false; + show_another_window = false; ImGui::End(); } // Rendering ImGui::Render(); - SDL_GL_MakeCurrent(vars->window, vars->gl_context); + SDL_GL_MakeCurrent(g_Window, g_GLContext); glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y); - glClearColor(vars->clear_color.x, vars->clear_color.y, vars->clear_color.z, vars->clear_color.w); + glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w); glClear(GL_COLOR_BUFFER_BIT); ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData()); - SDL_GL_SwapWindow(vars->window); + SDL_GL_SwapWindow(g_Window); } diff --git a/examples/example_emscripten/shell_minimal.html b/examples/example_emscripten/shell_minimal.html index 3c5ef8ca..b967b04b 100644 --- a/examples/example_emscripten/shell_minimal.html +++ b/examples/example_emscripten/shell_minimal.html @@ -3,15 +3,19 @@ - Emscripten-Generated Code + Dear ImGui Emscripten example -
emscripten
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+ Example compiled from https://github.com/ocornut/imgui
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- Resize canvas - Lock/hide mouse pointer -     - + +
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