I have android Hello Effect sample in front of me. I can see how it applying different effects on android.opengl.GLSurfaceView. All done successfully. I wonder how can I get the output bitmap from GLSurfaceView?
this is the code:
private GLSurfaceView glSurfaceView;
private int[] mTextures = new int[2];
private EffectContext mEffectContext;
private Effect mEffect;
private TextureRenderer mTexRenderer = new TextureRenderer();
private int mImageWidth;
private int mImageHeight;
private boolean mInitialized = false;
int mCurrentEffect;
public void setCurrentEffect(int effect) {
mCurrentEffect = effect;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
/**
* Initialize the renderer and tell it to only render when
* explicity requested with the RENDERMODE_WHEN_DIRTY option
*/
glSurfaceView = (GLSurfaceView) findViewById(R.id.effectsview);
glSurfaceView.setEGLContextClientVersion(2);
glSurfaceView.setRenderer(this);
glSurfaceView.setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
mCurrentEffect = R.id.none;
}
private void loadTextures() {
// Generate textures
GLES20.glGenTextures(2, mTextures, 0);
// Load input bitmap
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.puppy);
mImageWidth = bitmap.getWidth();
mImageHeight = bitmap.getHeight();
mTexRenderer.updateTextureSize(mImageWidth, mImageHeight);
// Upload to texture
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextures[0]);
GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
// Set texture parameters
GLToolbox.initTexParams();
}
private void initEffect() {
EffectFactory effectFactory = mEffectContext.getFactory();
if (mEffect != null) {
mEffect.release();
}
/**
* Initialize the correct effect based on the selected menu/action item
*/
switch (mCurrentEffect) {
case R.id.none:
break;
case R.id.autofix:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_AUTOFIX);
mEffect.setParameter("scale", 0.5f);
break;
case R.id.bw:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_BLACKWHITE);
mEffect.setParameter("black", .1f);
mEffect.setParameter("white", .7f);
break;
case R.id.brightness:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_BRIGHTNESS);
mEffect.setParameter("brightness", 2.0f);
break;
case R.id.contrast:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_CONTRAST);
mEffect.setParameter("contrast", 1.4f);
break;
case R.id.crossprocess:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_CROSSPROCESS);
break;
case R.id.documentary:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_DOCUMENTARY);
break;
case R.id.duotone:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_DUOTONE);
mEffect.setParameter("first_color", Color.YELLOW);
mEffect.setParameter("second_color", Color.DKGRAY);
break;
case R.id.filllight:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_FILLLIGHT);
mEffect.setParameter("strength", .8f);
break;
case R.id.fisheye:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_FISHEYE);
mEffect.setParameter("scale", .5f);
break;
case R.id.flipvert:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_FLIP);
mEffect.setParameter("vertical", true);
break;
case R.id.fliphor:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_FLIP);
mEffect.setParameter("horizontal", true);
break;
case R.id.grain:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_GRAIN);
mEffect.setParameter("strength", 1.0f);
break;
case R.id.grayscale:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_GRAYSCALE);
break;
case R.id.lomoish:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_LOMOISH);
break;
case R.id.negative:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_NEGATIVE);
break;
case R.id.posterize:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_POSTERIZE);
break;
case R.id.rotate:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_ROTATE);
mEffect.setParameter("angle", 180);
break;
case R.id.saturate:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_SATURATE);
mEffect.setParameter("scale", .5f);
break;
case R.id.sepia:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_SEPIA);
break;
case R.id.sharpen:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_SHARPEN);
break;
case R.id.temperature:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_TEMPERATURE);
mEffect.setParameter("scale", .9f);
break;
case R.id.tint:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_TINT);
mEffect.setParameter("tint", Color.MAGENTA);
break;
case R.id.vignette:
mEffect = effectFactory.createEffect(
EffectFactory.EFFECT_VIGNETTE);
mEffect.setParameter("scale", .5f);
break;
default:
break;
}
}
private void applyEffect() {
mEffect.apply(mTextures[0], mImageWidth, mImageHeight, mTextures[1]);
}
private void renderResult() {
if (mCurrentEffect != R.id.none) {
// if no effect is chosen, just render the original bitmap
mTexRenderer.renderTexture(mTextures[1]);
} else {
// render the result of applyEffect()
mTexRenderer.renderTexture(mTextures[0]);
}
}
@Override
public void onDrawFrame(GL10 gl) {
if (!mInitialized) {
//Only need to do this once
mEffectContext = EffectContext.createWithCurrentGlContext();
mTexRenderer.init();
loadTextures();
mInitialized = true;
}
if (mCurrentEffect != R.id.none) {
//if an effect is chosen initialize it and apply it to the texture
initEffect();
applyEffect();
}
renderResult();
}
@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
if (mTexRenderer != null) {
mTexRenderer.updateViewSize(width, height);
}
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
setCurrentEffect(item.getItemId());
glSurfaceView.requestRender();
return true;
}
}
You can read the pixels back with glReadPixels() after you're done rendering, but before eglSwapBuffers() is called. You're using GLSurfaceView, which does the buffer-swap for you when onDrawFrame() returns, so you'll need to do the capture right at the end of onDrawFrame().
You can find an example that saves the current GLES framebuffer to a PNG in Grafika. See the EglSurfaceBase#saveFrame() method (you can ignore the mEglCore test at the top).