Bug 1021: Add GenericStereoDevice* Supporting custom configurations; Hook-in oculusvr-sdk java distortion-mesh calculation if available

StereoDeviceFactory support new GenericStereoDeviceFactory, with it's GenericStereoDevice and GenericStereoDeviceRenderer.

GenericStereoDevice maintains different configurations, triggered either by passing a GenericStereoDevice.Config
instance directly or by the device-index parameter:

  - 0: monoscopi device: No post-processing

  - 1: stereoscopic device SBS: No post-processing

  - 2: stereoscopic device SBS + Lenses: Distortion post-processing
       (only available w/ oculusvr-sdk sub-module)

Producing a 'GenericStereoDevice.Config' instance is self containing
and may extend if supporting more device types like top-bottom, interlaced etc.

StereoDemo01 handles all use-cases and may be used as a test-bed
to add and experiment with stereoscopy, devices and settings.

4 files changed, 152 insertions, 68 deletions

diff --git a/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDevice.java b/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDevice.java
index 09a348c46..2832012e4 100644
--- a/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDevice.java
+++ b/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDevice.java
@@ -42,19 +42,50 @@ import com.jogamp.oculusvr.ovrSizei;
 import com.jogamp.opengl.math.FovHVHalves;
 import com.jogamp.opengl.util.stereo.StereoDevice;
 import com.jogamp.opengl.util.stereo.StereoDeviceRenderer;
+import com.jogamp.opengl.util.stereo.StereoUtil;
 
 public class OVRStereoDevice implements StereoDevice {
+    /** 1.6 up, 5 forward */
+    private static final float[] DEFAULT_EYE_POSITION_OFFSET = { 0.0f, 1.6f, -5.0f };
+
     public final OvrHmdContext handle;
     public final int deviceIndex;
     public final ovrHmdDesc hmdDesc;
+    private final FovHVHalves[] defaultEyeFov;
 
     private boolean sensorsStarted = false;
+    private final int[] eyeRenderOrder;
+    private final int supportedDistortionBits, recommendedDistortionBits, minimumDistortionBits;
 
     public OVRStereoDevice(final OvrHmdContext nativeContext, final int deviceIndex) {
         this.handle = nativeContext;
         this.deviceIndex = deviceIndex;
         this.hmdDesc = ovrHmdDesc.create();
         OVR.ovrHmd_GetDesc(handle, hmdDesc);
+        final ovrFovPort[] defaultOVREyeFov = hmdDesc.getDefaultEyeFov(0, new ovrFovPort[hmdDesc.getEyeRenderOrderArrayLength()]);
+        defaultEyeFov = new FovHVHalves[defaultOVREyeFov.length];
+        for(int i=0; i<defaultEyeFov.length; i++) {
+            defaultEyeFov[i] = OVRUtil.getFovHV(defaultOVREyeFov[i]);
+        }
+        eyeRenderOrder = new int[hmdDesc.getEyeRenderOrderArrayLength()];
+        hmdDesc.getEyeRenderOrder(0, eyeRenderOrder);
+        supportedDistortionBits = OVRUtil.ovrDistCaps2DistBits(hmdDesc.getDistortionCaps());
+        recommendedDistortionBits = supportedDistortionBits & ~StereoDeviceRenderer.DISTORTION_TIMEWARP;
+        minimumDistortionBits = StereoDeviceRenderer.DISTORTION_BARREL;
+    }
+
+    @Override
+    public final String toString() {
+        final StringBuilder sb = new StringBuilder();
+        sb.append("OVRStereoDevice[product "+hmdDesc.getProductNameAsString());
+        sb.append(", vendor "+hmdDesc.getManufacturerAsString());
+        sb.append(", device "+hmdDesc.getDisplayDeviceNameAsString());
+        sb.append(", surfaceSize "+getSurfaceSize());
+        sb.append(", surfacePos "+getPosition());
+        sb.append(", distortionBits[supported ["+StereoUtil.distortionBitsToString(getSupportedDistortionBits())+
+                      "], recommended ["+StereoUtil.distortionBitsToString(getRecommendedDistortionBits())+
+                      "], minimum ["+StereoUtil.distortionBitsToString(getMinimumDistortionBits())+"]]]");
+        return sb.toString();
     }
 
     @Override
@@ -73,12 +104,13 @@ public class OVRStereoDevice implements StereoDevice {
     }
 
     @Override
+    public float[] getDefaultEyePositionOffset() {
+        return DEFAULT_EYE_POSITION_OFFSET;
+    }
+
+    @Override
     public final FovHVHalves[] getDefaultFOV() {
-        final ovrFovPort[] defaultEyeFov = hmdDesc.getDefaultEyeFov(0, new ovrFovPort[2]);
-        final FovHVHalves[] eyeFov = new FovHVHalves[2];
-        eyeFov[0] = OVRUtil.getFovHV(defaultEyeFov[0]);
-        eyeFov[1] = OVRUtil.getFovHV(defaultEyeFov[1]);
-        return eyeFov;
+        return defaultEyeFov;
     }
 
     @Override
@@ -104,7 +136,27 @@ public class OVRStereoDevice implements StereoDevice {
         }
     }
     @Override
-    public boolean getSensorsStarted() { return sensorsStarted; }
+    public final boolean getSensorsStarted() { return sensorsStarted; }
+
+    @Override
+    public final int[] getEyeRenderOrder() {
+        return eyeRenderOrder;
+    }
+
+    @Override
+    public final int getSupportedDistortionBits() {
+        return supportedDistortionBits;
+    };
+
+    @Override
+    public final int getRecommendedDistortionBits() {
+        return recommendedDistortionBits;
+    }
+
+    @Override
+    public final int getMinimumDistortionBits() {
+        return minimumDistortionBits;
+    }
 
     @Override
     public final StereoDeviceRenderer createRenderer(final int distortionBits,
diff --git a/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDeviceFactory.java b/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDeviceFactory.java
index 06454e443..ebd3699e1 100644
--- a/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDeviceFactory.java
+++ b/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDeviceFactory.java
@@ -31,6 +31,7 @@ import com.jogamp.oculusvr.OVR;
 import com.jogamp.oculusvr.OVRVersion;
 import com.jogamp.oculusvr.OvrHmdContext;
 import com.jogamp.opengl.util.stereo.StereoDevice;
+import com.jogamp.opengl.util.stereo.StereoDevice.Config;
 import com.jogamp.opengl.util.stereo.StereoDeviceFactory;
 
 public class OVRStereoDeviceFactory extends StereoDeviceFactory {
@@ -40,7 +41,7 @@ public class OVRStereoDeviceFactory extends StereoDeviceFactory {
     }
 
     @Override
-    public final StereoDevice createDevice(final int deviceIndex, final boolean verbose) {
+    public final StereoDevice createDevice(final int deviceIndex, Config config, final boolean verbose) {
         final OvrHmdContext hmdCtx = OVR.ovrHmd_Create(deviceIndex);
         final OVRStereoDevice ctx = new OVRStereoDevice(hmdCtx, deviceIndex);
         if( verbose ) {
diff --git a/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDeviceRenderer.java b/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDeviceRenderer.java
index 012ad183d..39736217c 100644
--- a/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDeviceRenderer.java
+++ b/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRStereoDeviceRenderer.java
@@ -67,7 +67,7 @@ import com.jogamp.opengl.util.stereo.StereoDeviceRenderer;
 import com.jogamp.opengl.util.stereo.StereoUtil;
 
 /**
- * OculusVR Distortion Data and OpenGL Renderer Utility
+ * OculusVR Stereo Device Distortion and OpenGL Renderer Utility
  */
 public class OVRStereoDeviceRenderer implements StereoDeviceRenderer {
     private static final String shaderPrefix01 = "dist01";
@@ -140,12 +140,34 @@ public class OVRStereoDeviceRenderer implements StereoDeviceRenderer {
 
             updateEyePose(hmdCtx); // 1st init
 
+            // Setup: eyeToSourceUVScale, eyeToSourceUVOffset
+            {
+                final ovrVector2f[] uvScaleOffsetOut = new ovrVector2f[2];
+                uvScaleOffsetOut[0] = ovrVector2f.create(); // FIXME: remove ctor / double check
+                uvScaleOffsetOut[1] = ovrVector2f.create();
+
+                final ovrRecti ovrEyeRenderViewport = OVRUtil.createOVRRecti(eyeViewport);
+                OVR.ovrHmd_GetRenderScaleAndOffset(ovrEyeFov, ovrTextureSize, ovrEyeRenderViewport, uvScaleOffsetOut);
+                if( StereoDevice.DEBUG ) {
+                    System.err.println("XXX."+eyeName+": eyeParam      "+eyeParameter);
+                    System.err.println("XXX."+eyeName+": uvScale       "+OVRUtil.toString(uvScaleOffsetOut[0]));
+                    System.err.println("XXX."+eyeName+": uvOffset      "+OVRUtil.toString(uvScaleOffsetOut[1]));
+                    System.err.println("XXX."+eyeName+": textureSize   "+OVRUtil.toString(ovrTextureSize));
+                    System.err.println("XXX."+eyeName+": viewport      "+OVRUtil.toString(ovrEyeRenderViewport));
+                }
+                final FloatBuffer eyeToSourceUVScaleFB = eyeToSourceUVScale.floatBufferValue();
+                eyeToSourceUVScaleFB.put(0, uvScaleOffsetOut[0].getX());
+                eyeToSourceUVScaleFB.put(1, uvScaleOffsetOut[0].getY());
+                final FloatBuffer eyeToSourceUVOffsetFB = eyeToSourceUVOffset.floatBufferValue();
+                eyeToSourceUVOffsetFB.put(0, uvScaleOffsetOut[1].getX());
+                eyeToSourceUVOffsetFB.put(1, uvScaleOffsetOut[1].getY());
+            }
+
             final ovrDistortionMesh meshData = ovrDistortionMesh.create();
-            final ovrFovPort fov = eyeDesc.getFov();
 
             final int ovrDistortionCaps = distBits2OVRDistCaps(distortionBits);
-            if( !OVR.ovrHmd_CreateDistortionMesh(hmdCtx, eyeName, fov, ovrDistortionCaps, meshData) ) {
-                throw new OVRException("Failed to create meshData for eye "+eyeName+", "+OVRUtil.toString(fov)+" and "+StereoUtil.distortionBitsToString(distortionBits));
+            if( !OVR.ovrHmd_CreateDistortionMesh(hmdCtx, eyeName, ovrEyeFov, ovrDistortionCaps, meshData) ) {
+                throw new OVRException("Failed to create meshData for eye "+eyeName+", "+OVRUtil.toString(ovrEyeFov)+" and "+StereoUtil.distortionBitsToString(distortionBits));
             }
             vertexCount = meshData.getVertexCount();
             indexCount = meshData.getIndexCount();
@@ -168,29 +190,6 @@ public class OVRStereoDeviceRenderer implements StereoDeviceRenderer {
             }
             indices = GLArrayDataServer.createData(1, GL.GL_SHORT, indexCount, GL.GL_STATIC_DRAW, GL.GL_ELEMENT_ARRAY_BUFFER);
 
-            // Setup: eyeToSourceUVScale, eyeToSourceUVOffset
-            {
-                final ovrVector2f[] uvScaleOffsetOut = new ovrVector2f[2];
-                uvScaleOffsetOut[0] = ovrVector2f.create(); // FIXME: remove ctor / double check
-                uvScaleOffsetOut[1] = ovrVector2f.create();
-
-                final ovrRecti ovrEyeRenderViewport = OVRUtil.createOVRRecti(eyeViewport);
-                OVR.ovrHmd_GetRenderScaleAndOffset(fov, ovrTextureSize, ovrEyeRenderViewport, uvScaleOffsetOut);
-                if( StereoDevice.DEBUG ) {
-                    System.err.println("XXX."+eyeName+": fov "+OVRUtil.toString(fov));
-                    System.err.println("XXX."+eyeName+": uvScale "+OVRUtil.toString(uvScaleOffsetOut[0]));
-                    System.err.println("XXX."+eyeName+": uvOffset "+OVRUtil.toString(uvScaleOffsetOut[1]));
-                    System.err.println("XXX."+eyeName+": textureSize "+OVRUtil.toString(ovrTextureSize));
-                    System.err.println("XXX."+eyeName+": viewport "+OVRUtil.toString(ovrEyeRenderViewport));
-                }
-                final FloatBuffer eyeToSourceUVScaleFB = eyeToSourceUVScale.floatBufferValue();
-                eyeToSourceUVScaleFB.put(0, uvScaleOffsetOut[0].getX());
-                eyeToSourceUVScaleFB.put(1, uvScaleOffsetOut[0].getY());
-                final FloatBuffer eyeToSourceUVOffsetFB = eyeToSourceUVOffset.floatBufferValue();
-                eyeToSourceUVOffsetFB.put(0, uvScaleOffsetOut[1].getX());
-                eyeToSourceUVOffsetFB.put(1, uvScaleOffsetOut[1].getY());
-            }
-
             /** 2+2+2+2+2: { vec2 position, vec2 color, vec2 texCoordR, vec2 texCoordG, vec2 texCoordB } */
             final FloatBuffer iVBOFB = (FloatBuffer)iVBO.getBuffer();
             final ovrDistortionVertex[] ovRes = new ovrDistortionVertex[1];
@@ -200,46 +199,76 @@ public class OVRStereoDeviceRenderer implements StereoDeviceRenderer {
                 final ovrDistortionVertex ov = meshData.getPVertexData(vertNum, ovRes)[0];
                 ovrVector2f v;
 
+                if( StereoDevice.DUMP_DATA ) {
+                    System.err.println("XXX."+eyeName+": START VERTEX "+vertNum+" / "+vertexCount);
+                }
                 // pos
                 v = ov.getPos();
+                if( StereoDevice.DUMP_DATA ) {
+                    System.err.println("XXX."+eyeName+": pos "+OVRUtil.toString(v));
+                }
                 iVBOFB.put(v.getX());
                 iVBOFB.put(v.getY());
 
                 // params
                 if( useVignette ) {
+                    if( StereoDevice.DUMP_DATA ) {
+                        System.err.println("XXX."+eyeName+": vignette "+ov.getVignetteFactor());
+                    }
                     iVBOFB.put(ov.getVignetteFactor());
                 } else {
                     iVBOFB.put(1.0f);
                 }
+                if( StereoDevice.DUMP_DATA ) {
+                    System.err.println("XXX."+eyeName+": timewarp "+ov.getTimeWarpFactor());
+                }
                 iVBOFB.put(ov.getTimeWarpFactor());
 
                 // texCoordR
                 v = ov.getTexR();
+                if( StereoDevice.DUMP_DATA ) {
+                    System.err.println("XXX."+eyeName+": texR "+OVRUtil.toString(v));
+                }
                 iVBOFB.put(v.getX());
                 iVBOFB.put(v.getY());
 
                 if( useChromatic ) {
                     // texCoordG
                     v = ov.getTexG();
+                    if( StereoDevice.DUMP_DATA ) {
+                        System.err.println("XXX."+eyeName+": texG "+OVRUtil.toString(v));
+                    }
                     iVBOFB.put(v.getX());
                     iVBOFB.put(v.getY());
 
                     // texCoordB
                     v = ov.getTexB();
+                    if( StereoDevice.DUMP_DATA ) {
+                        System.err.println("XXX."+eyeName+": texB "+OVRUtil.toString(v));
+                    }
                     iVBOFB.put(v.getX());
                     iVBOFB.put(v.getY());
                 }
             }
-            if( StereoDevice.DEBUG ) {
+            if( StereoDevice.DUMP_DATA ) {
                 System.err.println("XXX."+eyeName+": iVBO "+iVBO);
             }
             {
                 final ShortBuffer in = meshData.getPIndexData();
+                if( StereoDevice.DUMP_DATA ) {
+                    System.err.println("XXX."+eyeName+": idx "+indices+", count "+indexCount);
+                    for(int i=0; i< indexCount; i++) {
+                        if( 0 == i % 16 ) {
+                            System.err.printf("%n%5d: ", i);
+                        }
+                        System.err.printf("%5d, ", (int)in.get(i));
+                    }
+                    System.err.println();
+                }
                 final ShortBuffer out = (ShortBuffer) indices.getBuffer();
                 out.put(in);
             }
             if( StereoDevice.DEBUG ) {
-                System.err.println("XXX."+eyeName+": idx "+indices);
                 System.err.println("XXX."+eyeName+": "+this);
             }
             OVR.ovrHmd_DestroyDistortionMesh(meshData);
@@ -247,34 +276,34 @@ public class OVRStereoDeviceRenderer implements StereoDeviceRenderer {
 
         private void linkData(final GL2ES2 gl, final ShaderProgram sp) {
             if( 0 > vboPos.setLocation(gl, sp.program()) ) {
-                throw new OVRException("Couldn't locate "+vboPos);
+                throw new GLException("Couldn't locate "+vboPos);
             }
             if( 0 > vboParams.setLocation(gl, sp.program()) ) {
-                throw new OVRException("Couldn't locate "+vboParams);
+                throw new GLException("Couldn't locate "+vboParams);
             }
             if( 0 > vboTexCoordsR.setLocation(gl, sp.program()) ) {
-                throw new OVRException("Couldn't locate "+vboTexCoordsR);
+                throw new GLException("Couldn't locate "+vboTexCoordsR);
             }
             if( StereoUtil.usesChromaticDistortion(distortionBits) ) {
                 if( 0 > vboTexCoordsG.setLocation(gl, sp.program()) ) {
-                    throw new OVRException("Couldn't locate "+vboTexCoordsG);
+                    throw new GLException("Couldn't locate "+vboTexCoordsG);
                 }
                 if( 0 > vboTexCoordsB.setLocation(gl, sp.program()) ) {
-                    throw new OVRException("Couldn't locate "+vboTexCoordsB);
+                    throw new GLException("Couldn't locate "+vboTexCoordsB);
                 }
             }
             if( 0 > eyeToSourceUVScale.setLocation(gl, sp.program()) ) {
-                throw new OVRException("Couldn't locate "+eyeToSourceUVScale);
+                throw new GLException("Couldn't locate "+eyeToSourceUVScale);
             }
             if( 0 > eyeToSourceUVOffset.setLocation(gl, sp.program()) ) {
-                throw new OVRException("Couldn't locate "+eyeToSourceUVOffset);
+                throw new GLException("Couldn't locate "+eyeToSourceUVOffset);
             }
             if( StereoUtil.usesTimewarpDistortion(distortionBits) ) {
                 if( 0 > eyeRotationStart.setLocation(gl, sp.program()) ) {
-                    throw new OVRException("Couldn't locate "+eyeRotationStart);
+                    throw new GLException("Couldn't locate "+eyeRotationStart);
                 }
                 if( 0 > eyeRotationEnd.setLocation(gl, sp.program()) ) {
-                    throw new OVRException("Couldn't locate "+eyeRotationEnd);
+                    throw new GLException("Couldn't locate "+eyeRotationEnd);
                 }
             }
             iVBO.seal(gl, true);
@@ -368,17 +397,17 @@ public class OVRStereoDeviceRenderer implements StereoDeviceRenderer {
 
 
     private static int distBits2OVRDistCaps(final int distortionBits) {
-        int bits = 0;
+        int caps = 0;
         if( StereoUtil.usesTimewarpDistortion(distortionBits) ) {
-            bits |= OVR.ovrDistortionCap_TimeWarp;
+            caps |= OVR.ovrDistortionCap_TimeWarp;
         }
         if( StereoUtil.usesChromaticDistortion(distortionBits) ) {
-            bits |= OVR.ovrDistortionCap_Chromatic;
+            caps |= OVR.ovrDistortionCap_Chromatic;
         }
         if( StereoUtil.usesVignetteDistortion(distortionBits) ) {
-            bits |= OVR.ovrDistortionCap_Vignette;
+            caps |= OVR.ovrDistortionCap_Vignette;
         }
-        return bits;
+        return caps;
     }
 
     /* pp */ OVRStereoDeviceRenderer(final OVRStereoDevice context, final int distortionBits,
@@ -390,7 +419,7 @@ public class OVRStereoDeviceRenderer implements StereoDeviceRenderer {
         }
         this.context = context;
         this.eyes = new OVREye[2];
-        this.distortionBits = distortionBits | StereoDeviceRenderer.DISTORTION_BARREL /* always */;
+        this.distortionBits = ( distortionBits | context.getMinimumDistortionBits() ) & context.getSupportedDistortionBits();
         this.textureCount = textureCount;
         this.singleTextureSize = singleTextureSize;
         this.totalTextureSize = totalTextureSize;
@@ -428,7 +457,7 @@ public class OVRStereoDeviceRenderer implements StereoDeviceRenderer {
     public final int getTextureUnit() { return texUnit0.intValue(); }
 
     @Override
-    public final boolean ppRequired() { return true; }
+    public final boolean ppAvailable() { return 0 != distortionBits; }
 
     @Override
     public final void init(final GL gl) {
@@ -555,21 +584,6 @@ public class OVRStereoDeviceRenderer implements StereoDeviceRenderer {
     }
 
     @Override
-    public final void ppBothEyes(final GL gl) {
-        final GL2ES2 gl2es2 = gl.getGL2ES2();
-        for(int eyeNum=0; eyeNum<2; eyeNum++) {
-            final OVREye eye = eyes[eyeNum];
-            if( StereoUtil.usesTimewarpDistortion(distortionBits) ) {
-                eye.updateTimewarp(context.handle, eye.ovrEyePose, mat4Tmp1, mat4Tmp2);
-            }
-            eye.updateUniform(gl2es2, sp);
-            eye.enableVBO(gl2es2, true);
-            gl2es2.glDrawElements(GL.GL_TRIANGLES, eye.indexCount, GL.GL_UNSIGNED_SHORT, 0);
-            eyes[eyeNum].enableVBO(gl2es2, false);
-        }
-    }
-
-    @Override
     public final void ppOneEye(final GL gl, final int eyeNum) {
         final OVREye eye = eyes[eyeNum];
         if( StereoUtil.usesTimewarpDistortion(distortionBits) ) {
diff --git a/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRUtil.java b/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRUtil.java
index 48222ea97..44ec728fc 100644
--- a/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRUtil.java
+++ b/src/oculusvr/classes/jogamp/opengl/oculusvr/OVRUtil.java
@@ -33,6 +33,7 @@ import javax.media.nativewindow.util.Point;
 import javax.media.nativewindow.util.PointImmutable;
 import javax.media.nativewindow.util.RectangleImmutable;
 
+import com.jogamp.oculusvr.OVR;
 import com.jogamp.oculusvr.ovrEyeRenderDesc;
 import com.jogamp.oculusvr.ovrFovPort;
 import com.jogamp.oculusvr.ovrQuatf;
@@ -43,6 +44,7 @@ import com.jogamp.oculusvr.ovrVector2i;
 import com.jogamp.oculusvr.ovrVector3f;
 import com.jogamp.opengl.math.FovHVHalves;
 import com.jogamp.opengl.math.Quaternion;
+import com.jogamp.opengl.util.stereo.StereoDeviceRenderer;
 
 /**
  * OculusVR Data Conversion Helper Functions
@@ -122,7 +124,7 @@ public class OVRUtil {
     }
     public static ovrFovPort getOVRFovPort(final FovHVHalves fovHVHalves) {
         final ovrFovPort tanHalfFov = ovrFovPort.create();
-        final FovHVHalves fovHVHalvesTan = fovHVHalves.getInTangents();
+        final FovHVHalves fovHVHalvesTan = fovHVHalves.toTangents();
         tanHalfFov.setLeftTan(fovHVHalvesTan.left);
         tanHalfFov.setRightTan(fovHVHalvesTan.right);
         tanHalfFov.setUpTan(fovHVHalvesTan.top);
@@ -130,6 +132,21 @@ public class OVRUtil {
         return tanHalfFov;
     }
 
+    public static int ovrDistCaps2DistBits(final int ovrDistortionCaps) {
+        int bits = StereoDeviceRenderer.DISTORTION_BARREL;
+        if( 0 != ( OVR.ovrDistortionCap_TimeWarp & ovrDistortionCaps ) ) {
+            bits |= StereoDeviceRenderer.DISTORTION_TIMEWARP;
+        }
+        if( 0 != ( OVR.ovrDistortionCap_Chromatic & ovrDistortionCaps ) ) {
+            bits |= StereoDeviceRenderer.DISTORTION_CHROMATIC;
+        }
+        if( 0 != ( OVR.ovrDistortionCap_Vignette & ovrDistortionCaps ) ) {
+            bits |= StereoDeviceRenderer.DISTORTION_VIGNETTE;
+        }
+        return bits;
+    }
+
+
     public static String toString(final ovrFovPort fov) {
         return "["+fov.getLeftTan()+" l, "+fov.getRightTan()+" r, "+
                    fov.getUpTan()+" u, "+fov.getDownTan()+" d]";