public void beforeDrawFrame() {
this.mDrawingFrame = true;
if (this.mFovsChanged || this.mTextureFormatChanged) {
this.updateTextureAndDistortionMesh();
}
GLES20.glGetIntegerv(GLES20.GL_FRAMEBUFFER_BINDING, this.mOriginalFramebufferId);
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, this.mFramebufferId);
}
private void updateTextureAndDistortionMesh() {
final ScreenParams screen = this.mHmd.getScreenParams();
final CardboardDeviceParams cdp = this.mHmd.getCardboardDeviceParams();
if (this.mProgramHolder == null) {
this.mProgramHolder = this.createProgramHolder();
}
if (this.mProgramHolderAberration == null) {
this.mProgramHolderAberration = (ProgramHolderAberration) this.createProgramHolder(true);
}
final float textureWidthTanAngle = this.mLeftEyeViewport.width + this.mRightEyeViewport.width;
final float textureHeightTanAngle =
Math.max(this.mLeftEyeViewport.height, this.mRightEyeViewport.height);
final int[] maxTextureSize = {0};
GLES20.glGetIntegerv(GLES20.GL_MAX_TEXTURE_SIZE, maxTextureSize, 0);
final int textureWidthPx =
Math.min(Math.round(textureWidthTanAngle * this.mXPxPerTanAngle), maxTextureSize[0]);
final int textureHeightPx =
Math.min(Math.round(textureHeightTanAngle * this.mYPxPerTanAngle), maxTextureSize[0]);
float xEyeOffsetTanAngleScreen =
(screen.getWidthMeters() / 2.0f - cdp.getInterLensDistance() / 2.0f)
/ this.mMetersPerTanAngle;
final float yEyeOffsetTanAngleScreen =
(cdp.getVerticalDistanceToLensCenter() - screen.getBorderSizeMeters())
/ this.mMetersPerTanAngle;
this.mLeftEyeDistortionMesh =
this.createDistortionMesh(
this.mLeftEyeViewport,
textureWidthTanAngle,
textureHeightTanAngle,
xEyeOffsetTanAngleScreen,
yEyeOffsetTanAngleScreen);
xEyeOffsetTanAngleScreen =
screen.getWidthMeters() / this.mMetersPerTanAngle - xEyeOffsetTanAngleScreen;
this.mRightEyeDistortionMesh =
this.createDistortionMesh(
this.mRightEyeViewport,
textureWidthTanAngle,
textureHeightTanAngle,
xEyeOffsetTanAngleScreen,
yEyeOffsetTanAngleScreen);
this.setupRenderTextureAndRenderbuffer(textureWidthPx, textureHeightPx);
this.mFovsChanged = false;
}