我面前有android Hello效果样本。我可以看到它如何在android.opengl.GLSurfaceView上应用不同的效果。一切顺利完成。我想知道如何从GLSurfaceView获取输出位图？
这是代码：
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;
}
}
答案 0 :(得分：0)
在您完成渲染后，但在调用glReadPixels()之前，您可以使用eglSwapBuffers()读取像素。您正在使用GLSurfaceView，它会在onDrawFrame()返回时为您执行缓冲区交换，因此您需要在onDrawFrame()的末尾执行捕获。
您可以找到一个示例，将当前GLES帧缓冲区保存到Grafika中的PNG。请参阅EglSurfaceBase#saveFrame()方法（您可以忽略顶部的mEglCore测试）。
答案 1 :(得分：0)
要从 glSurfaceView 获取输出位图，您需要使用 glReadPixes()。使用 glReadPixels() 时，请确保从渲染器线程调用它。如果你从主线程调用它就行不通了。这是获取输出位图的代码。
public Bitmap createBitmapFromGLSurface(int w, int h) {
w = screenWidth;
h = screenHeight;
int bitmapBuffer[] = new int[w * h];
int bitmapSource[] = new int[w * h];
IntBuffer intBuffer = IntBuffer.wrap(bitmapBuffer);
intBuffer.position(0);
try {
GLES20.glReadPixels(x, y, w, h, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, intBuffer);
int offset1, offset2;
for (int i = 0; i < h; i++) {
offset1 = i * w;
offset2 = (h - i - 1) * w;
for (int j = 0; j < w; j++) {
int texturePixel = bitmapBuffer[offset1 + j];
int blue = (texturePixel >> 16) & 0xff;
int red = (texturePixel << 16) & 0x00ff0000;
int pixel = (texturePixel & 0xff00ff00) | red | blue;
bitmapSource[offset2 + j] = pixel;
}
}
} catch (GLException e) {
e.printStackTrace();
return null;
}
return Bitmap.createBitmap(bitmapSource, w, h, Bitmap.Config.ARGB_8888);
}