源码地址： https://github.com/jackfengji/glcoverflow
public class CoverFlowOpenGL extends GLSurfaceView implements
GLSurfaceView.Renderer {
private static final int TOUCH_MINIMUM_MOVE = 5;
private static final int IMAGE_SIZE = 128;
private static final int MAX_TILES = 48;
// the visble tiles left and right
private static final int VISIBLE_TILES = 1;
private static final float SCALE = 0.7f;
private static final float SPREAD_IMAGE = 0.14f;
private static final float FLANK_SPREAD = 0.4f;
private static final float FRICTION = 10.0f;
private static final float MAX_SPEED = 6.0f;
private static final float[] GVertices = new float[] { -1.0f, -1.0f, 0.0f,
1.0f, -1.0f, 0.0f, -1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, };
private static final float[] GTextures = new float[] { 0.0f, 1.0f, 1.0f,
1.0f, 0.0f, 0.0f, 1.0f, 0.0f, };
private GL10 mGLContext;
private FloatBuffer mVerticesBuffer;
private FloatBuffer mTexturesBuffer;
private float[] mMatrix;
private int mBgTexture;
private FloatBuffer mBgVerticesBuffer;
private FloatBuffer mBgTexturesBuffer;
private int mBgBitmapId;
private boolean mInitBackground;
private float mOffset;
private int mLastOffset;
private RectF mTouchRect;
private int mWidth;
private boolean mTouchMoved;
private float mTouchStartPos;
private float mTouchStartX;
private float mTouchStartY;
private float mStartOffset;
private long mStartTime;
private float mStartSpeed;
private float mDuration;
private Runnable mAnimationRunnable;
private VelocityTracker mVelocity;
private CoverFlowListener mListener;
private DataCache<Integer, CoverFlowRecord> mCache;
public CoverFlowOpenGL(Context context) {
super(context);
setEGLConfigChooser(8, 8, 8, 8, 16, 0);
setRenderer(this);
setRenderMode(RENDERMODE_WHEN_DIRTY);
getHolder().setFormat(PixelFormat.TRANSLUCENT);
mCache = new DataCache<Integer, CoverFlowRecord>(MAX_TILES);
mLastOffset = 0;
mOffset = 0;
mInitBackground = false;
mBgBitmapId = 0;
}
public void setCoverFlowListener(CoverFlowListener listener) {
mListener = listener;
}
public void setSelection(int position) {
endAnimation();
mOffset = position;
requestRender();
}
private int getActuallyPosition(int position) {
int max = mListener.getCount(this);
while (position < 0 || position >= max) {
if (position < 0)
position += max;
else if (position >= max)
position -= max;
}
return position;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
touchBegan(event);
return true;
case MotionEvent.ACTION_MOVE:
touchMoved(event);
return true;
case MotionEvent.ACTION_UP:
touchEnded(event);
return true;
}
return false;
}
private void touchBegan(MotionEvent event) {
endAnimation();
float x = event.getX();
mTouchStartX = x;
mTouchStartY = event.getY();
mStartTime = System.currentTimeMillis();
mStartOffset = mOffset;
mTouchMoved = false;
mTouchStartPos = (x / mWidth) * 10 - 5;
mTouchStartPos /= 2;
mVelocity = VelocityTracker.obtain();
mVelocity.addMovement(event);
}
private void touchMoved(MotionEvent event) {
float pos = (event.getX() / mWidth) * 10 - 5;
pos /= 2;
if (!mTouchMoved) {
float dx = Math.abs(event.getX() - mTouchStartX);
float dy = Math.abs(event.getY() - mTouchStartY);
if (dx < TOUCH_MINIMUM_MOVE && dy < TOUCH_MINIMUM_MOVE)
return;
mTouchMoved = true;
}
mOffset = mStartOffset + mTouchStartPos - pos;
requestRender();
mVelocity.addMovement(event);
}
private void touchEnded(MotionEvent event) {
float pos = (event.getX() / mWidth) * 10 - 5;
pos /= 2;
if (mTouchMoved) {
mStartOffset += mTouchStartPos - pos;
mOffset = mStartOffset;
mVelocity.addMovement(event);
mVelocity.computeCurrentVelocity(1000);
double speed = mVelocity.getXVelocity();
speed = (speed / mWidth) * 10;
if (speed > MAX_SPEED)
speed = MAX_SPEED;
else if (speed < -MAX_SPEED)
speed = -MAX_SPEED;
startAnimation(-speed);
} else {
if (mTouchRect.contains(event.getX(), event.getY())) {
mListener.topTileClicked(this,
getActuallyPosition((int) (mOffset + 0.01)));
}
}
}
private void startAnimation(double speed) {
if (mAnimationRunnable != null)
return;
double delta = speed * speed / (FRICTION * 2);
if (speed < 0)
delta = -delta;
double nearest = mStartOffset + delta;
nearest = Math.floor(nearest + 0.5);
mStartSpeed = (float) Math.sqrt(Math.abs(nearest - mStartOffset)
* FRICTION * 2);
if (nearest < mStartOffset)
mStartSpeed = -mStartSpeed;
mDuration = Math.abs(mStartSpeed / FRICTION);
mStartTime = AnimationUtils.currentAnimationTimeMillis();
mAnimationRunnable = new Runnable() {
@Override
public void run() {
driveAnimation();
}
};
post(mAnimationRunnable);
}
private void driveAnimation() {
float elapsed = (AnimationUtils.currentAnimationTimeMillis() - mStartTime) / 1000.0f;
if (elapsed >= mDuration)
endAnimation();
else {
updateAnimationAtElapsed(elapsed);
post(mAnimationRunnable);
}
}
private void endAnimation() {
if (mAnimationRunnable != null) {
mOffset = (float) Math.floor(mOffset + 0.5);
requestRender();
removeCallbacks(mAnimationRunnable);
mAnimationRunnable = null;
}
}
private void updateAnimationAtElapsed(float elapsed) {
if (elapsed > mDuration)
elapsed = mDuration;
float delta = Math.abs(mStartSpeed) * elapsed - FRICTION * elapsed
* elapsed / 2;
if (mStartSpeed < 0)
delta = -delta;
mOffset = mStartOffset + delta;
requestRender();
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
mCache.clear();
mGLContext = gl;
mVerticesBuffer = makeFloatBuffer(GVertices);
mTexturesBuffer = makeFloatBuffer(GTextures);
}
@Override
public void onSurfaceChanged(GL10 gl, int w, int h) {
mWidth = w;
float imagew = w * 0.45f / SCALE / 2.0f;
float imageh = h * 0.45f / SCALE / 2.0f;
mTouchRect = new RectF(w / 2 - imagew, h / 2 - imageh, w / 2 + imagew,
h / 2 + imageh);
gl.glViewport(0, 0, w, h);
float ratio = ((float) w) / h;
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
gl.glOrthof(-ratio * SCALE, ratio * SCALE, -1 * SCALE, 1 * SCALE, 1, 3);
float[] vertices = new float[] { -ratio * SCALE, -SCALE, 0,
ratio * SCALE, -SCALE, 0, -ratio * SCALE, SCALE, 0,
ratio * SCALE, SCALE, 0 };
mBgVerticesBuffer = makeFloatBuffer(vertices);
}
public void setBackgroundTexture(int res) {
mBgBitmapId = res;
mInitBackground = true;
}
public void clearTileCache() {
mCache.clear();
}
private void initBg() {
mInitBackground = false;
if (mBgBitmapId != 0) {
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
mBgBitmapId);
mBgBitmapId = 0;
int tmp = 1;
int w = bitmap.getWidth();
int h = bitmap.getHeight();
while (w > tmp || h > tmp) {
tmp <<= 1;
}
int width = tmp;
int height = tmp;
Bitmap bm = Bitmap.createBitmap(width, height,
Bitmap.Config.RGB_565);
Canvas cv = new Canvas(bm);
int left = (width - w) / 2;
int top = (height - h) / 2;
cv.drawBitmap(bitmap, left, top, new Paint());
GL10 gl = mGLContext;
int[] tex = new int[1];
gl.glGenTextures(1, tex, 0);
mBgTexture = tex[0];
gl.glBindTexture(GL10.GL_TEXTURE_2D, mBgTexture);
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bm, 0);
bitmap.recycle();
bm.recycle();
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER,
GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
GL10.GL_CLAMP_TO_EDGE);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
GL10.GL_CLAMP_TO_EDGE);
gl.glTexEnvf(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE,
GL10.GL_REPLACE);
float[] textcoor = new float[] { (tmp - w) / 2.0f / tmp,
(tmp - h) / 2.0f / tmp, (tmp + w) / 2.0f / tmp,
(tmp - h) / 2.0f / tmp, (tmp - w) / 2.0f / tmp,
(tmp + h) / 2.0f / tmp, (tmp + w) / 2.0f / tmp,
(tmp + h) / 2.0f / tmp };
mBgTexturesBuffer = makeFloatBuffer(textcoor);
}
}
@Override
public void onDrawFrame(GL10 gl) {
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
GLU.gluLookAt(gl, 0, 0, 2, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
gl.glDisable(GL10.GL_DEPTH_TEST);
gl.glClearColor(0, 0, 0, 0);
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
drawBg(gl);
draw(gl);
}
public void drawBg(GL10 gl) {
if (mInitBackground)
initBg();
if (mBgTexture != 0) {
gl.glPushMatrix();
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mBgVerticesBuffer);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, mBgTexturesBuffer);
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glBindTexture(GL10.GL_TEXTURE_2D, mBgTexture);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
gl.glPopMatrix();
}
}
private void draw(GL10 gl) {
gl.glPushMatrix();
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mVerticesBuffer);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, mTexturesBuffer);
gl.glEnable(GL10.GL_TEXTURE_2D);
gl.glEnable(GL10.GL_BLEND);
gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
final float offset = mOffset;
int i = 0;
int mid = (int) Math.floor(offset + 0.5);
// draw the left tiles
int iStartPos = mid - VISIBLE_TILES;
for (i = iStartPos; i < mid; ++i) {
drawTile(i, i - offset, gl);
}
// draw the right tiles
int iEndPos = mid + VISIBLE_TILES;
for (i = iEndPos; i >= mid; --i) {
drawTile(i, i - offset, gl);
}
if (mLastOffset != (int) offset) {
mListener.tileOnTop(this, getActuallyPosition((int) offset));
mLastOffset = (int) offset;
}
gl.glPopMatrix();
}
private void drawTile(int position, float off, GL10 gl) {
final CoverFlowRecord fcr = getTileAtIndex(position, gl);
if (fcr != null && fcr.mTexture != 0) {
if (mMatrix == null) {
mMatrix = new float[16];
mMatrix[15] = 1;
mMatrix[10] = 1;
mMatrix[5] = 1;
mMatrix[0] = 1;
}
float trans = off * SPREAD_IMAGE;
float f = off * FLANK_SPREAD;
if (f > FLANK_SPREAD)
f = FLANK_SPREAD;
else if (f < -FLANK_SPREAD)
f = -FLANK_SPREAD;
mMatrix[3] = -f;
mMatrix[0] = 1 - Math.abs(f);
float sc = 0.38f * mMatrix[0];
trans += f * 1;
gl.glPushMatrix();
gl.glBindTexture(GL10.GL_TEXTURE_2D, fcr.mTexture);
// draw bitmap
gl.glTranslatef(trans, 0, 0);
gl.glScalef(sc, sc, 1.0f);
gl.glMultMatrixf(mMatrix, 0);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
// draw the reflection
gl.glTranslatef(0, -2, 0);
gl.glScalef(1, -1, 1);
gl.glColor4f(1f, 1f, 1f, 0.5f);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
gl.glColor4f(1, 1, 1, 1);
gl.glPopMatrix();
}
}
private CoverFlowRecord getTileAtIndex(int position, GL10 gl) {
synchronized (this) {
position = getActuallyPosition(position);
CoverFlowRecord fcr = mCache.objectForKey(position);
if (fcr == null) {
Bitmap bm = mListener.getImage(this, position);
if (bm == null)
return null;
int texture = imageToTexture(bm, gl);
fcr = new CoverFlowRecord(texture, gl);
mCache.putObjectForKey(position, fcr);
}
return fcr;
}
}
private static Bitmap createTextureBitmap(Bitmap bitmap) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
final Bitmap bm = Bitmap.createBitmap(IMAGE_SIZE, IMAGE_SIZE,
Bitmap.Config.ARGB_8888);
Canvas cv = new Canvas(bm);
if (width > IMAGE_SIZE || height > IMAGE_SIZE) {
// scale the bitmap, make the width or height to the IMAGE_SIZE
Rect src = new Rect(0, 0, width, height);
float scale = 1.0f;
if (width > height)
scale = ((float) IMAGE_SIZE) / width;
else
scale = ((float) IMAGE_SIZE) / height;
width = (int) (width * scale);
height = (int) (height * scale);
float left = (IMAGE_SIZE - width) / 2.0f;
float top = (IMAGE_SIZE - height) / 2.0f;
RectF dst = new RectF(left, top, left + width, top + height);
cv.drawBitmap(bitmap, src, dst, new Paint());
} else {
float left = (IMAGE_SIZE - width) / 2.0f;
float top = (IMAGE_SIZE - height) / 2.0f;
cv.drawBitmap(bitmap, left, top, new Paint());
}
return bm;
}
private int imageToTexture(Bitmap bitmap, GL10 gl) {
// generate texture
int[] texture = new int[1];
gl.glGenTextures(1, texture, 0);
gl.glBindTexture(GL10.GL_TEXTURE_2D, texture[0]);
final Bitmap bm = createTextureBitmap(bitmap);
bitmap.recycle();
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bm, 0); // draw the bitmap in
// the texture
bm.recycle();
// some texture settings
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER,
GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
GL10.GL_CLAMP_TO_EDGE);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
GL10.GL_CLAMP_TO_EDGE);
gl.glTexEnvf(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE,
GL10.GL_MODULATE);
return texture[0];
}
private static FloatBuffer makeFloatBuffer(final float[] arr) {
ByteBuffer bb = ByteBuffer.allocateDirect(arr.length * 4);
bb.order(ByteOrder.nativeOrder());
FloatBuffer fb = bb.asFloatBuffer();
fb.put(arr);
fb.position(0);
return fb;
}
public static class CoverFlowRecord {
private int mTexture;
private GL10 gl;
public CoverFlowRecord(int texture, GL10 gl) {
mTexture = texture;
this.gl = gl;
}
@Override
protected void finalize() throws Throwable {
if (mTexture != 0) {
gl.glDeleteTextures(1, new int[] { mTexture }, 0);
}
super.finalize();
}
}
public static interface CoverFlowListener {
public int getCount(CoverFlowOpenGL view);
public Bitmap getImage(CoverFlowOpenGL anotherCoverFlow, int position);
public void tileOnTop(CoverFlowOpenGL view, int position);
public void topTileClicked(CoverFlowOpenGL view, int position);
}
}
public class DataCache<K, E> {
private int mCapacity;
private LinkedHashMap<K, E> mCache;
private final ReadWriteLock mReadWriteLock = new ReentrantReadWriteLock();
public DataCache(int capacity) {
mCapacity = capacity;
mCache = new LinkedHashMap<K, E>(mCapacity) {
private static final long serialVersionUID = -9165777183357349715L;
@Override
protected boolean removeEldestEntry(Entry<K, E> eldest) {
if (size() > mCapacity) {
mReadWriteLock.writeLock().lock();
remove(eldest.getKey());
mReadWriteLock.writeLock().unlock();
}
return false;
}
};
}
public E objectForKey(K key) {
mReadWriteLock.readLock().lock();
final E result = mCache.get(key);
mReadWriteLock.readLock().unlock();
return result;
}
public void putObjectForKey(final K key, final E value) {
if (key != null && value != null) {
mReadWriteLock.writeLock().lock();
mCache.put(key, value);
mReadWriteLock.writeLock().unlock();
}
}
public boolean containsKey(final K key) {
mReadWriteLock.readLock().lock();
final boolean result = mCache.containsKey(key);
mReadWriteLock.readLock().unlock();
return result;
}
public void clear() {
mReadWriteLock.writeLock().lock();
mCache.clear();
mReadWriteLock.writeLock().unlock();
}
public void setCapacity(int capacity) {
mCapacity = capacity;
}
}
使用时
private static int[] SAMPLE_IMAGES = new int[] {
R.drawable.gallery_photo_1, R.drawable.gallery_photo_2,
R.drawable.gallery_photo_3, R.drawable.gallery_photo_4,
R.drawable.gallery_photo_5, R.drawable.gallery_photo_6,
R.drawable.gallery_photo_7, R.drawable.gallery_photo_8 };
mCoverFlow = new CoverFlowOpenGL(this);
mCoverFlow.setCoverFlowListener(new CoverFlowOpenGL.CoverFlowListener() {
@Override
public int getCount(CoverFlowOpenGL view) {
return SAMPLE_IMAGES_2.length;
}
@Override
public View getView(CoverFlowOpenGL anotherCoverFlow,
int position) {
return BitmapFactory.decodeResource(getResources(),
SAMPLE_IMAGES_2[position]);
}
@Override
public void tileOnTop(CoverFlowOpenGL view, int position) {
// you can control what will happen when one image is in
// middle
}
@Override
public void topTileClicked(CoverFlowOpenGL view,
int position) {
// you can control what will happen when the image in
// middle is clicked
}
});