GLES configuration: request EGL_STENCIL_SIZE 1, and if there are no matching configs, request EGL_STENCIL_SIZE 0.

Previously, we were requesting 1 on non-emulators, and 0 on emulators, because emulators use Android's software GLES implementation that doesn't support stencil.
That meant the app wouldn't run on devices without stencil support.

This should fix #94

Author: ericwa

document-viewer/src/main/java/org/ebookdroid/EBookDroidApp.java

@@ -60,8 +60,6 @@ public void onCreate() {
         onAppSettingsChanged(null, AppSettings.current(), null);
         onBackupSettingsChanged(null, BackupSettings.current(), null);
 
-        GLConfiguration.stencilRequired = !IS_EMULATOR;
-
         initialized.set();
     }
 

document-viewer/src/main/java/org/emdev/ui/gl/BaseEGLConfigChooser.java

@@ -29,21 +29,39 @@ public class BaseEGLConfigChooser implements EGLConfigChooser {
     private static final LogContext LCTX = LogManager.root().lctx("GLConfiguration");
 
     private final int mConfigSpec[] = new int[] { EGL10.EGL_RED_SIZE, 5, EGL10.EGL_GREEN_SIZE, 6, EGL10.EGL_BLUE_SIZE,
-            5, EGL10.EGL_ALPHA_SIZE, 0, EGL10.EGL_STENCIL_SIZE, GLConfiguration.stencilRequired ? 1 : 0, EGL10.EGL_NONE };
+            5, EGL10.EGL_ALPHA_SIZE, 0, EGL10.EGL_STENCIL_SIZE, 1, EGL10.EGL_NONE };
 
     private static final int[] ATTR_ID = { EGL10.EGL_RED_SIZE, EGL10.EGL_GREEN_SIZE, EGL10.EGL_BLUE_SIZE,
             EGL10.EGL_ALPHA_SIZE, EGL10.EGL_DEPTH_SIZE, EGL10.EGL_STENCIL_SIZE, EGL10.EGL_CONFIG_ID,
             EGL10.EGL_CONFIG_CAVEAT };
 
     private static final String[] ATTR_NAME = { "R", "G", "B", "A", "D", "S", "ID", "CAVEAT" };
 
+    private void setConfigValue(int key, int value) {
+        for (int i = 0; i < mConfigSpec.length; i += 2)  {
+            if (mConfigSpec[i] == key) {
+                mConfigSpec[i + 1] = value;
+                break;
+            }
+        }
+    }
+
     @Override
     public EGLConfig chooseConfig(final EGL10 egl, final EGLDisplay display) {
         final int[] numConfig = new int[1];
         if (!egl.eglChooseConfig(display, mConfigSpec, null, 0, numConfig)) {
             throw new RuntimeException("eglChooseConfig failed");
         }
 
+        if (numConfig[0] <= 0) {
+            LCTX.i("No configurations found. Trying EGL_STENCIL_SIZE 0");
+            setConfigValue(EGL10.EGL_STENCIL_SIZE, 0);
+
+            if (!egl.eglChooseConfig(display, mConfigSpec, null, 0, numConfig)) {
+                throw new RuntimeException("eglChooseConfig failed");
+            }
+        }
+
         if (numConfig[0] <= 0) {
             throw new RuntimeException("Your device cannot support required GLES configuration");
         }

document-viewer/src/main/java/org/emdev/ui/gl/GLConfiguration.java

@@ -8,8 +8,6 @@
 
 public class GLConfiguration {
 
-    public static boolean stencilRequired = true;
-
     public static boolean use8888 = false;
 
     private static BaseEGLConfigChooser chooser;