Examples: Emscripten: Removed BINARYEN_TRAP_MODE=clamp from Makefile which was removed in Emscripten 1.39.0 but required prior to 1.39.0, making life easier for absolutely no-one. (#2877, #2878) [@podsvirov]

docs/CHANGELOG.txt

@@ -75,6 +75,8 @@ Other Changes:
 - Metrics: Expose basic details of each window key/value state storage.
 - Examples: DX12: Using IDXGIDebug1::ReportLiveObjects() when DX12_ENABLE_DEBUG_LAYER is enabled.
 - Examples: Emscripten: Removed NO_FILESYSTEM from Makefile, seems to fail on some setup. (#2734) [@Funto]
+- Examples: Emscripten: Removed BINARYEN_TRAP_MODE=clamp from Makefile which was removed in Emscripten 1.39.0
+  but required prior to 1.39.0, making life easier for absolutely no-one. (#2877, #2878) [@podsvirov]
 - Backends: OpenGL3: Fix building with pre-3.2 GL loaders which do not expose glDrawElementsBaseVertex(),
   using runtime GL version to decide if we set ImGuiBackendFlags_RendererHasVtxOffset. (#2866, #2852) [@dpilawa]
 - Backends: OSX: Fix using Backspace key. (#2578, #2817, #2818) [@DiligentGraphics]

examples/example_emscripten/README.md

@@ -3,6 +3,10 @@
 
 - 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
-```
+- 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.
+
+- Then build using `make` while in the `example_emscripten/` directory.
+
+- Note that 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`