This bug was introduced when lighting computations was changed from eye-space to object-space.
The light position need to be transformed back to object-space each time the modelview matrix changes which requires us to compute the inverse of the modelview matrix. This computation was done with the assumption that normals where transformed (which was the case when the computation was made in eye-space), however, normals only require the inverse of the upper 3x3 matrix while transforming positions requires the inverse of the whole matrix.
This caused the interesting behavior that lights were more-or-less transformed properly, but not translated at all, which caused improper lighting with directional lights in particular.
There was also another smaller bug affecting directional lights: when vertices are read, only the active component are read, the other ones are ignored, later, the transformation operations are set up to ignore the unset values, howver, in the case of lighting, we use the vertex in object space (that is, before it is transformed), and therefore were using uninitalized values; in particular w.
we now look for a config file in /system/lib/egl/egl.cfg that describes the association of a display to a driver.
these drivers are named: /system/lib/egl/lib{[EGL|GLESv1_CM|GLESv2] | GLES}_$TAG.so
ANDROID_swap_rectangle allows to specify the rectangle affected by eglSwapBuffers(), anything outside of this rectangle is unchanged. in particular EGL_BUFFER_DESTROYED only applies to that rectangle. This extension as well as EGL_BUFFER_PRESERVED allow major optimizations on surfaceflinger, which can redraw only the dirty area during compositing.
However, ANDROID_swap_rectangle allows further optimizations in EGL by reducing the amount of copy-back needed. ANDROID_swap_rectangle is particularily important for software implementations.
- Currently the lock/unlock path is naive and is done for each drawing operation (glDrawElements and glDrawArrays). this should be improved eventually.
- factor all the lock/unlock code in SurfaceBuffer.
- fixed "showupdate" so it works even when we don't have preserving eglSwapBuffers().
- improved the situation with the dirty-region and fixed a problem that caused GL apps to not update.
- make use of LightRefBase() where needed, instead of duplicating its implementation
- add LightRefBase::getStrongCount()
- renamed EGLNativeWindowSurface.cpp to FramebufferNativeWindow.cpp
- disabled copybits test, since it clashes with the new gralloc api
- Camera/Video will be fixed later when we rework the overlay apis
