glNormal3f only works in immediate mode

[TheBrokenRail]

When using LEGACY_GL_EMULATION, glNormal3f crashes when not using glBegin/End. When not using immediate mode, glNormal3f should behave similarly to glColor4f.

Version of emscripten/emsdk:

emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 4.0.7 (8dc91db45bf96c174531006839472a3924d105aa)
clang version 21.0.0git (https:/github.com/llvm/llvm-project 57025b42c43b2f14f7e58692bc19cd53d1b8a45e)
Target: wasm32-unknown-emscripten
Thread model: posix

Full link command and output with -v appended:

em++  -Wno-pthreads-mem-growth -sALLOW_MEMORY_GROWTH=1 -pthread -sEXPORTED_FUNCTIONS=_main,_resize_from_js -sEXPORTED_RUNTIME_METHODS=ccall --use-preload-plugins --preload-file /home/connor/Documents/ReMinecraftPE/game@/ -sMIN_WEBGL_VERSION=2 -sMAX_WEBGL_VERSION=2 -sLEGACY_GL_EMULATION -sGL_FFP_ONLY -sUSE_ZLIB=1 -sUSE_SDL=2 platforms/sdl/CMakeFiles/reminecraftpe.dir/main.cpp.o platforms/sdl/CMakeFiles/reminecraftpe.dir/base/AppPlatform_sdl_base.cpp.o platforms/sdl/CMakeFiles/reminecraftpe.dir/emscripten/AppPlatform_sdl.cpp.o -o reminecraftpe.js  source/libreminecraftpe-core.a  platforms/sound/openal/libreminecraftpe-sound.a  source/libreminecraftpe-core.a  source/raknet/libraknet.a  -lGL  -lopenal

[sbc100]

If you have a proposed fix then a PR would be most welcome. I'm not sure how easy this would be but perhaps you are right and it could be made to work in a similar fashion to glColor4f?

@kainino0x and @juj may know more.

[kainino0x]

Unfortunately I don't know anything about the Desktop GL implementation (LEGACY_GL_EMULATION).

[juj]

When not using immediate mode, glNormal3f should behave similarly to glColor4f.

I presume the idea is that there would be a single constant normal value that all vertices would share? In your link, that is what glColor4f without glBegin() seems to do:

emscripten/src/lib/libglemu.js

Lines 3238 to 3246 in d4a7433

	} else {
	GLImmediate.clientColor[0] = r;
	GLImmediate.clientColor[1] = g;
	GLImmediate.clientColor[2] = b;
	GLImmediate.clientColor[3] = a;
	#if GL_FFP_ONLY
	GLctx.vertexAttrib4fv(GLImmediate.COLOR, GLImmediate.clientColor);
	#endif
	}

The original authors of GL emulation path from Mozilla have long moved on, and the legacy GL emulation path does not have a maintainer. If you are interested in trying to develop a fix, then I'm sure we would be able to merge it - though there's not much activity with the legacy GL path in general.

There is a Regal port that might work better than the JS based legacy GL emulation: https://github.com/emscripten-ports/regal although that hasn't been updated in 6 years. It seems like the Regal website no longer exists either.

[kripken]

There is also gl4es:

https://github.com/ptitSeb/gl4es

It mentions it has Emscripten support there, but I haven't tried it myself.