来自 glSurfaceView 的位图为空
bitmap from glSurfaceView is empty
public Bitmap getBitmapFromGlSurface(int x, int y, int w, int h){
ByteBuffer buff = ByteBuffer.allocate(h * w * 4);
Bitmap bitmap;
try {
GLES20.glReadPixels(x, y, w, h, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, buff);
bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
bitmap.copyPixelsFromBuffer(buff);
Matrix matrix = new Matrix();
matrix.postScale(1, -1, w / 2, h / 2); // We have to flip it upside down because opengl has inverted y axis
bitmap = Bitmap.createBitmap(bitmap, 0, 0, w, h, matrix, true);
} catch (GLException e) {
Log.d(TAG, "createBitmapFromGLSurface: " + e.getMessage(), e);
return null;
}
return bitmap;
}
从 glSurfaceView 的 queueEvent 调用此方法
activity.glSurfaceView.queueEvent(new Runnable() {
@Override
public void run() {
final Bitmap snapshotBitmap = activity.glSurfaceView.getRenderer().getBitmapFromGlSurface(0, 0, activity.glSurfaceView.getWidth(), activity.glSurfaceView.getHeight());
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
bitmapReadyCallbacks.onBitmapReady(snapshotBitmap);
}
});
}
});
这里是glSurfaceView的初始化
setZOrderOnTop(true);
setEGLContextClientVersion(2);
setEGLConfigChooser(8, 8, 8, 8, 0, 0);
getHolder().setFormat(PixelFormat.TRANSLUCENT);
renderer = new WriteGLRenderer(activity,this);
setRenderer(renderer);
setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
setPreserveEGLContextOnPause(true);
因为你在 GLSurfaceView 初始化中使用了 setZOrderTop(true),它不会让你去它的视图并捕获它的像素。
为了获得位图,您必须从 JNI(C++) 端代码 return 字节数组 并将这些像素放入缓冲区。
这是方法
public Bitmap getBitmapFromGlSurface(int w, int h){
Bitmap bitmap;
try {
ByteBuffer buff = ByteBuffer.wrap(WriteViewActivity.getSnapshot());
buff.rewind();
bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
bitmap.copyPixelsFromBuffer(buff);
buff.clear();
Matrix matrix = new Matrix();
matrix.postScale(1, -1, bitmap.getWidth() / 2, bitmap.getHeight() / 2); // We have to flip it upside down because opengl has inverted y axis
bitmap = Bitmap.createBitmap(bitmap, 0, 0, (int)(bitmap.getWidth()), (int)(bitmap.getHeight() ), matrix, true);
} catch (GLException e) {
Log.e(TAG, "createBitmapFromGLSurface: " + e.getMessage(), e);
return null;
}
return bitmap;
}
public Bitmap getBitmapFromGlSurface(int x, int y, int w, int h){
ByteBuffer buff = ByteBuffer.allocate(h * w * 4);
Bitmap bitmap;
try {
GLES20.glReadPixels(x, y, w, h, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, buff);
bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
bitmap.copyPixelsFromBuffer(buff);
Matrix matrix = new Matrix();
matrix.postScale(1, -1, w / 2, h / 2); // We have to flip it upside down because opengl has inverted y axis
bitmap = Bitmap.createBitmap(bitmap, 0, 0, w, h, matrix, true);
} catch (GLException e) {
Log.d(TAG, "createBitmapFromGLSurface: " + e.getMessage(), e);
return null;
}
return bitmap;
}
从 glSurfaceView 的 queueEvent 调用此方法
activity.glSurfaceView.queueEvent(new Runnable() {
@Override
public void run() {
final Bitmap snapshotBitmap = activity.glSurfaceView.getRenderer().getBitmapFromGlSurface(0, 0, activity.glSurfaceView.getWidth(), activity.glSurfaceView.getHeight());
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
bitmapReadyCallbacks.onBitmapReady(snapshotBitmap);
}
});
}
});
这里是glSurfaceView的初始化
setZOrderOnTop(true);
setEGLContextClientVersion(2);
setEGLConfigChooser(8, 8, 8, 8, 0, 0);
getHolder().setFormat(PixelFormat.TRANSLUCENT);
renderer = new WriteGLRenderer(activity,this);
setRenderer(renderer);
setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
setPreserveEGLContextOnPause(true);
因为你在 GLSurfaceView 初始化中使用了 setZOrderTop(true),它不会让你去它的视图并捕获它的像素。 为了获得位图,您必须从 JNI(C++) 端代码 return 字节数组 并将这些像素放入缓冲区。 这是方法
public Bitmap getBitmapFromGlSurface(int w, int h){
Bitmap bitmap;
try {
ByteBuffer buff = ByteBuffer.wrap(WriteViewActivity.getSnapshot());
buff.rewind();
bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
bitmap.copyPixelsFromBuffer(buff);
buff.clear();
Matrix matrix = new Matrix();
matrix.postScale(1, -1, bitmap.getWidth() / 2, bitmap.getHeight() / 2); // We have to flip it upside down because opengl has inverted y axis
bitmap = Bitmap.createBitmap(bitmap, 0, 0, (int)(bitmap.getWidth()), (int)(bitmap.getHeight() ), matrix, true);
} catch (GLException e) {
Log.e(TAG, "createBitmapFromGLSurface: " + e.getMessage(), e);
return null;
}
return bitmap;
}