diff options
| -rw-r--r-- | src/library_gl.js | 24 | ||||
| -rw-r--r-- | src/settings.js | 2 |
2 files changed, 25 insertions, 1 deletions
diff --git a/src/library_gl.js b/src/library_gl.js index 6f99969e..29e8423f 100644 --- a/src/library_gl.js +++ b/src/library_gl.js @@ -1,4 +1,26 @@ -//"use strict"; +/* + * GL support. + * + * Emscripten supports the WebGL-friendly subset of OpenGL, basically what + * maps directly to WebGL. This includes almost all of OpenGL ES 2.0, + * except for client-side arrays. The reason they are missing from WebGL + * is because they are less efficient than properly using GPU-side data. + * Similarly, if we emulated client-side arrays here, we would end up + * with very bad performance, since we would need to upload the data + * on each call to glDrawArrays etc. (Even if there are two calls one + * after the other, we can't know the data did not change!) So in + * practical terms full OpenGL ES 2.0 emulation would be convenient, + * but lead to bad performance so in practice you would need to properly + * rewrite your code to a WebGL-friendly subset anyhow. + * + * Thankfully, rewriting to that subset is general fairly easy. See + * the files in tests/glbook for some simple examples ported to that + * subset. + * + * Regarding OpenGL aspects present on desktop GL or on OpenGL ES prior + * to 2.0, we also do not support immediate mode (glBegin/glEnd), GL_QUADS, + * etc. Some of these might make sense to emulate, some might not. + */ var LibraryGL = { $GL: { diff --git a/src/settings.js b/src/settings.js index 901812b6..7df86c90 100644 --- a/src/settings.js +++ b/src/settings.js @@ -101,7 +101,9 @@ var SAFE_HEAP_LOG = 0; // Log out all SAFE_HEAP operations var LABEL_DEBUG = 0; // Print out labels and functions as we enter them var EXCEPTION_DEBUG = 1; // Print out exceptions in emscriptened code var LIBRARY_DEBUG = 0; // Print out when we enter a library call (library*.js) + var GL_DEBUG = 0; // Print out all calls into WebGL + var DISABLE_EXCEPTION_CATCHING = 0; // Disables generating code to actually catch exceptions. If the code you // are compiling does not actually rely on catching exceptions (but the // compiler generates code for it, maybe because of stdlibc++ stuff), |