This was always a documented restriction, but was not enforced by the runtime until now.
Until now, if you passed in some other kind of buffer, it would sometimes work, and
sometimes fail. The failures happened when the Java VM moved the buffer data while
OpenGL was still holding a pointer to it.
Now we throw an exception rather than leaving the system in a potentially bad state.
This is just plumbing. The Java APIs existed already, but there were no C APIs to hook the Java APIs
up to. Now there are C APIs, so we can call them.
Of course, whether or not the C APIs actually work when you call them depend upon the
capabilities of the active OpenGL driver, which must be checked at run time.
Also, while we're here, make the glGetString method static. It was always supposed to be static,
but was accidentally implemented as non-static, because the code was copied from the non-static
OpenGL ES classes.
This change adds four new public classes that expose a static OpenGL ES 1.1 API:
android.opengl.GLES10
android.opengl.GLES10Ext
android.opengl.GLES11
android.opengl.GLES11Ext
Benefits:
+ The static API is slightly faster (1% to 4%) than the existing Interface based JSR239 API.
+ The static API is similar to the C API, which should make it easier to import C-based
example code.
+ The static API provides a clear path for adding new OpenGL ES 1.1 extensions
and OpenGL ES 2.0 APIs, neither of which currently have a JSR standard.
Example:
import static android.opengl.GLES10.*;
...
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
Note that it is possible to mix-and-match calls to both the static and JSR239 APIs.
This works because neither API maintains state. They both call through to the same underlying
C OpenGL ES APIs.
Implementation details:
This change enhances the "glgen" "gen" script to generate both the original JSR239 and
new static OpenGL ES APIs. The contents of the generated JSR239 classes remained the same as before,
so there is no need to check in new versions of the generated JSR239 classes.
As part of this work the gen script was updated to be somewhat more robust, and to
work with git instead of perforce. The script prints out commands to git add the generated files,
but leaves it up to the script runner to actually execute those commands.
