tdf#158125 android: Don't insist on RGB 565 EGL config

As the `eglChooseConfig` doc [1] says:

> eglChooseConfig returns in configs a list of all EGL frame buffer
> configurations that match the attributes specified
> [...]
> Attributes are matched in an attribute-specific manner. Some of the
> attributes, such as EGL_LEVEL, must match the specified value exactly.
> Others, such as, EGL_RED_SIZE must meet or exceed the specified minimum
> values.

The config/attribute list used for Android Viewer specifies
EGL_RED_SIZE=5, EGL_GREEN_SIZE=6, and EGL_BLUE_SIZE=5 and so
far, only configs using exactly those bit sizes were accepted,
causing 1 of the 11 devices used in automated tests in Google Play CI
crashing with this stack trace:

    Exception org.mozilla.gecko.gfx.GLController$GLControllerException: No suitable EGL configuration found
      at org.mozilla.gecko.gfx.GLController.chooseConfig (GLController.java:219)
      at org.mozilla.gecko.gfx.GLController.initEGL (GLController.java:172)
      at org.mozilla.gecko.gfx.GLController.initEGLContext (GLController.java:176)
      at org.mozilla.gecko.gfx.GLController.initGLContext (GLController.java:57)
      at org.mozilla.gecko.gfx.RenderControllerThread.doSurfaceCreated (RenderControllerThread.java:132)
      at org.mozilla.gecko.gfx.RenderControllerThread.execute (RenderControllerThread.java:52)
      at org.mozilla.gecko.gfx.RenderControllerThread.run (RenderControllerThread.java:30)

Since only configs fulfilling the minimium specification
have been returned, I don't see a reason to insist on
having one that uses exactly the specified amount of bits
for the individual color components.

I also didn't see any rendering issues in a quick test (also using
the colorful Calc sheet attachment 188343 from tdf#156182) forcing the
use of a configuration using EGL_RED_SIZE=8, EGL_GREEN_SIZE=8, and
EGL_BLUE_SIZE=8 with an x86_64 AVD and on a Fairphone 3+ (arm64)
using this temporary local change:

    diff --git a/android/source/src/java/org/mozilla/gecko/gfx/GLController.java b/android/source/src/java/org/mozilla/gecko/gfx/GLController.java
    index 45600e9f1e7c..9e7f348e9e72 100644
    --- a/android/source/src/java/org/mozilla/gecko/gfx/GLController.java
    +++ b/android/source/src/java/org/mozilla/gecko/gfx/GLController.java
    @@ -171,7 +171,7 @@ public class GLController {
                 mEGL.eglGetConfigAttrib(mEGLDisplay, config, EGL10.EGL_RED_SIZE, red);
                 mEGL.eglGetConfigAttrib(mEGLDisplay, config, EGL10.EGL_GREEN_SIZE, green);
                 mEGL.eglGetConfigAttrib(mEGLDisplay, config, EGL10.EGL_BLUE_SIZE, blue);
    -            if (red[0] == 5 && green[0] == 6 && blue[0] == 5) {
    +            if (red[0] == 8 && green[0] == 8 && blue[0] == 8) {
                     return config;
                 }
             }

Therefore, fall back to using another config that fulfils the
specification.
(Leave the previously required config as preferred one for now,
maybe it still has advantages, e.g. might be more efficient due
to not wasting extra bits for the color components that are
not needed for the rendering in LibreOffice Viewer. (?))

[1] https://registry.khronos.org/EGL/sdk/docs/man/html/eglChooseConfig.xhtml

Change-Id: I953d292248004bc6f7e9384ceef78c8a88c21e9e
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/159204
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
(cherry picked from commit edc2dc80e1f6f7594722cd79ac6a930352252c90)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/159044
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/android/source/src/java/org/mozilla/gecko/gfx/GLController.java b/android/source/src/java/org/mozilla/gecko/gfx/GLController.java
index e296f4760f68..3dcfbbdfdbff 100644
--- a/android/source/src/java/org/mozilla/gecko/gfx/GLController.java
+++ b/android/source/src/java/org/mozilla/gecko/gfx/GLController.java
@@ -216,7 +216,8 @@ public class GLController {
             }
         }
 
-        throw new GLControllerException("No suitable EGL configuration found");
+        // if there's no 565 RGB configuration, select another one that fulfils the specification
+        return configs[0];
     }
 
     private void createEGLSurface() {