Ben Polinsky
b15211474d
With the default DYNAMIC_EXECUTION=1, embind generates its invokers at runtime with new Function(). A Content-Security-Policy without 'unsafe-eval' blocks this, so the transcoder and encoder fail to start with an EvalError. Add two CMake options to webgl/transcoder and webgl/encoder: - NO_DYNAMIC_EXECUTION (default OFF) adds -s DYNAMIC_EXECUTION=0. - EMBIND_AOT (default ON, only used with NO_DYNAMIC_EXECUTION) adds -s EMBIND_AOT=1. This generates the invokers at build time, so embind calls stay as fast as with the default build. The default build does not change. The .wasm output is byte-identical in all configurations; only the JS glue changes. Fixes #464
basisu_wrappers.cpp contains our JavaScript API (implemented via emscripten bindings), which is a thin layer above our encoder and transcoder's C++ API's. As of Basis Universal v2.0 it supports optional WASM multithreading and WASM64.
Prebuilt versions of basis_transcoder.js and basis_transcoder.wasm are included in the build/ folder, and are sufficient for local demos. To build the transcoder yourself, first install emscripten (tutorial) and cmake (download). Then run:
cd webgl/transcoder/build/
emcmake cmake ../
make
Strict Content-Security-Policy (no unsafe-eval)
By default, the generated JavaScript glue uses new Function() to build its
embind bindings at runtime. A Content-Security-Policy without 'unsafe-eval'
blocks this, and module startup fails with an EvalError. To build glue that
never calls eval() or new Function(), add -DNO_DYNAMIC_EXECUTION=ON:
emcmake cmake ../ -DNO_DYNAMIC_EXECUTION=ON
make
This adds -s DYNAMIC_EXECUTION=0 -s EMBIND_AOT=1 to the link flags. The
.wasm file does not change. EMBIND_AOT generates the bindings at build
time, so JavaScript-to-WASM calls stay as fast as in the default build. The
page still needs 'wasm-unsafe-eval' in script-src to compile the
WebAssembly module. Use -DEMBIND_AOT=OFF to get the smaller, generic
bindings, which are slower per call.