Static WebGL image. (#25)

* starting the web.

* expand the gitignore.

* clear the canvas to blue.

* tool advice.

* web-lesson-01 completed

* Update book_src/web_stuff/index.md

Co-authored-by: Joe Clay <27cupsofcoffee@gmail.com>

* note that wasm-bindgen is the common crate in this domain.

* don't say "before we begin" twice.

* make the inability to use file:// more obvious

* canvas tag inside the body.

* expand in the GLintptr note.

Co-authored-by: Joe Clay <27cupsofcoffee@gmail.com>

Author: Lokathor

.gitignore

@@ -4,3 +4,5 @@
 # Added by cargo
 
 /target
+
+web_crate/target/

book_src/SUMMARY.md

@@ -6,5 +6,7 @@
   * [Win32 Cleanup](opening_a_window/win32_cleanup.md)
 * [Loading OpenGL](loading_opengl/index.md)
   * [Win32](loading_opengl/win32.md)
+* [Web Stuff](web_stuff/index.md)
+  * [WebGL with bare WASM](web_stuff/web_gl_with_bare_wasm.md)
 * [Appendix](appendix/index.md)
   * [UTF-16 Literals](appendix/utf16_literals.md)

book_src/web_stuff/index.md

@@ -0,0 +1,20 @@
+
+# Web Nonsense
+
+People really like to run stuff in the browser.
+It's very nice to end users if they can just open a web page and not have to install a whole thing.
+
+If you want to run Rust code in a browser you compile it to [WebAssembly](https://en.wikipedia.org/wiki/WebAssembly),
+or WASM for short,
+which is an output target the same as compiling for windows x86_64,
+or linux arm,
+or any other target.
+
+Even then, Wasm is strongly sandboxed, and it cannot directly interact with the world.
+Not only do you have to bind to some external functions on the Rust side,
+you have to *write those external functions yourself* in javascript.
+This is a bit of a bother,
+and so,
+*for this one target platform*,
+we'll first see how to do it ourselves,
+and then we'll see how to leverage the most common crate for targeting wasm.