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Diffstat (limited to 'src/com/android/camera/support/glrenderer/NinePatchTexture.java')
| -rw-r--r-- | src/com/android/camera/support/glrenderer/NinePatchTexture.java | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/src/com/android/camera/support/glrenderer/NinePatchTexture.java b/src/com/android/camera/support/glrenderer/NinePatchTexture.java new file mode 100644 index 000000000..c69afd682 --- /dev/null +++ b/src/com/android/camera/support/glrenderer/NinePatchTexture.java @@ -0,0 +1,408 @@ +package com.android.camera.support.glrenderer; + +import java.nio.ByteBuffer; +import java.nio.ByteOrder; +import java.nio.FloatBuffer; + +import android.content.Context; +import android.graphics.Bitmap; +import android.graphics.BitmapFactory; +import android.graphics.Rect; + +import com.android.camera.support.common.Utils; + +// NinePatchTexture is a texture backed by a NinePatch resource. +// +// getPaddings() returns paddings specified in the NinePatch. +// getNinePatchChunk() returns the layout data specified in the NinePatch. +// +public class NinePatchTexture extends ResourceTexture { + @SuppressWarnings("unused") + private static final String TAG = "NinePatchTexture"; + private NinePatchChunk mChunk; + private SmallCache<NinePatchInstance> mInstanceCache + = new SmallCache<NinePatchInstance>(); + + public NinePatchTexture(Context context, int resId) { + super(context, resId); + } + + @Override + protected Bitmap onGetBitmap() { + if (mBitmap != null) return mBitmap; + + BitmapFactory.Options options = new BitmapFactory.Options(); + options.inPreferredConfig = Bitmap.Config.ARGB_8888; + Bitmap bitmap = BitmapFactory.decodeResource( + mContext.getResources(), mResId, options); + mBitmap = bitmap; + setSize(bitmap.getWidth(), bitmap.getHeight()); + byte[] chunkData = bitmap.getNinePatchChunk(); + mChunk = chunkData == null + ? null + : NinePatchChunk.deserialize(bitmap.getNinePatchChunk()); + if (mChunk == null) { + throw new RuntimeException("invalid nine-patch image: " + mResId); + } + return bitmap; + } + + public Rect getPaddings() { + // get the paddings from nine patch + if (mChunk == null) onGetBitmap(); + return mChunk.mPaddings; + } + + public NinePatchChunk getNinePatchChunk() { + if (mChunk == null) onGetBitmap(); + return mChunk; + } + + // This is a simple cache for a small number of things. Linear search + // is used because the cache is small. It also tries to remove less used + // item when the cache is full by moving the often-used items to the front. + private static class SmallCache<V> { + private static final int CACHE_SIZE = 16; + private static final int CACHE_SIZE_START_MOVE = CACHE_SIZE / 2; + private int[] mKey = new int[CACHE_SIZE]; + private V[] mValue = (V[]) new Object[CACHE_SIZE]; + private int mCount; // number of items in this cache + + // Puts a value into the cache. If the cache is full, also returns + // a less used item, otherwise returns null. + public V put(int key, V value) { + if (mCount == CACHE_SIZE) { + V old = mValue[CACHE_SIZE - 1]; // remove the last item + mKey[CACHE_SIZE - 1] = key; + mValue[CACHE_SIZE - 1] = value; + return old; + } else { + mKey[mCount] = key; + mValue[mCount] = value; + mCount++; + return null; + } + } + + public V get(int key) { + for (int i = 0; i < mCount; i++) { + if (mKey[i] == key) { + // Move the accessed item one position to the front, so it + // will less likely to be removed when cache is full. Only + // do this if the cache is starting to get full. + if (mCount > CACHE_SIZE_START_MOVE && i > 0) { + int tmpKey = mKey[i]; + mKey[i] = mKey[i - 1]; + mKey[i - 1] = tmpKey; + + V tmpValue = mValue[i]; + mValue[i] = mValue[i - 1]; + mValue[i - 1] = tmpValue; + } + return mValue[i]; + } + } + return null; + } + + public void clear() { + for (int i = 0; i < mCount; i++) { + mValue[i] = null; // make sure it's can be garbage-collected. + } + mCount = 0; + } + + public int size() { + return mCount; + } + + public V valueAt(int i) { + return mValue[i]; + } + } + + private NinePatchInstance findInstance(GLCanvas canvas, int w, int h) { + int key = w; + key = (key << 16) | h; + NinePatchInstance instance = mInstanceCache.get(key); + + if (instance == null) { + instance = new NinePatchInstance(this, w, h); + NinePatchInstance removed = mInstanceCache.put(key, instance); + if (removed != null) { + removed.recycle(canvas); + } + } + + return instance; + } + + @Override + public void draw(GLCanvas canvas, int x, int y, int w, int h) { + if (!isLoaded()) { + mInstanceCache.clear(); + } + + if (w != 0 && h != 0) { + findInstance(canvas, w, h).draw(canvas, this, x, y); + } + } + + @Override + public void recycle() { + super.recycle(); + GLCanvas canvas = mCanvasRef; + if (canvas == null) return; + int n = mInstanceCache.size(); + for (int i = 0; i < n; i++) { + NinePatchInstance instance = mInstanceCache.valueAt(i); + instance.recycle(canvas); + } + mInstanceCache.clear(); + } +} + +// This keeps data for a specialization of NinePatchTexture with the size +// (width, height). We pre-compute the coordinates for efficiency. +class NinePatchInstance { + + @SuppressWarnings("unused") + private static final String TAG = "NinePatchInstance"; + + // We need 16 vertices for a normal nine-patch image (the 4x4 vertices) + private static final int VERTEX_BUFFER_SIZE = 16 * 2; + + // We need 22 indices for a normal nine-patch image, plus 2 for each + // transparent region. Current there are at most 1 transparent region. + private static final int INDEX_BUFFER_SIZE = 22 + 2; + + private FloatBuffer mXyBuffer; + private FloatBuffer mUvBuffer; + private ByteBuffer mIndexBuffer; + + // Names for buffer names: xy, uv, index. + private int mXyBufferName = -1; + private int mUvBufferName; + private int mIndexBufferName; + + private int mIdxCount; + + public NinePatchInstance(NinePatchTexture tex, int width, int height) { + NinePatchChunk chunk = tex.getNinePatchChunk(); + + if (width <= 0 || height <= 0) { + throw new RuntimeException("invalid dimension"); + } + + // The code should be easily extended to handle the general cases by + // allocating more space for buffers. But let's just handle the only + // use case. + if (chunk.mDivX.length != 2 || chunk.mDivY.length != 2) { + throw new RuntimeException("unsupported nine patch"); + } + + float divX[] = new float[4]; + float divY[] = new float[4]; + float divU[] = new float[4]; + float divV[] = new float[4]; + + int nx = stretch(divX, divU, chunk.mDivX, tex.getWidth(), width); + int ny = stretch(divY, divV, chunk.mDivY, tex.getHeight(), height); + + prepareVertexData(divX, divY, divU, divV, nx, ny, chunk.mColor); + } + + /** + * Stretches the texture according to the nine-patch rules. It will + * linearly distribute the strechy parts defined in the nine-patch chunk to + * the target area. + * + * <pre> + * source + * /--------------^---------------\ + * u0 u1 u2 u3 u4 u5 + * div ---> |fffff|ssssssss|fff|ssssss|ffff| ---> u + * | div0 div1 div2 div3 | + * | | / / / / + * | | / / / / + * | | / / / / + * |fffff|ssss|fff|sss|ffff| ---> x + * x0 x1 x2 x3 x4 x5 + * \----------v------------/ + * target + * + * f: fixed segment + * s: stretchy segment + * </pre> + * + * @param div the stretch parts defined in nine-patch chunk + * @param source the length of the texture + * @param target the length on the drawing plan + * @param u output, the positions of these dividers in the texture + * coordinate + * @param x output, the corresponding position of these dividers on the + * drawing plan + * @return the number of these dividers. + */ + private static int stretch( + float x[], float u[], int div[], int source, int target) { + int textureSize = Utils.nextPowerOf2(source); + float textureBound = (float) source / textureSize; + + float stretch = 0; + for (int i = 0, n = div.length; i < n; i += 2) { + stretch += div[i + 1] - div[i]; + } + + float remaining = target - source + stretch; + + float lastX = 0; + float lastU = 0; + + x[0] = 0; + u[0] = 0; + for (int i = 0, n = div.length; i < n; i += 2) { + // Make the stretchy segment a little smaller to prevent sampling + // on neighboring fixed segments. + // fixed segment + x[i + 1] = lastX + (div[i] - lastU) + 0.5f; + u[i + 1] = Math.min((div[i] + 0.5f) / textureSize, textureBound); + + // stretchy segment + float partU = div[i + 1] - div[i]; + float partX = remaining * partU / stretch; + remaining -= partX; + stretch -= partU; + + lastX = x[i + 1] + partX; + lastU = div[i + 1]; + x[i + 2] = lastX - 0.5f; + u[i + 2] = Math.min((lastU - 0.5f)/ textureSize, textureBound); + } + // the last fixed segment + x[div.length + 1] = target; + u[div.length + 1] = textureBound; + + // remove segments with length 0. + int last = 0; + for (int i = 1, n = div.length + 2; i < n; ++i) { + if ((x[i] - x[last]) < 1f) continue; + x[++last] = x[i]; + u[last] = u[i]; + } + return last + 1; + } + + private void prepareVertexData(float x[], float y[], float u[], float v[], + int nx, int ny, int[] color) { + /* + * Given a 3x3 nine-patch image, the vertex order is defined as the + * following graph: + * + * (0) (1) (2) (3) + * | /| /| /| + * | / | / | / | + * (4) (5) (6) (7) + * | \ | \ | \ | + * | \| \| \| + * (8) (9) (A) (B) + * | /| /| /| + * | / | / | / | + * (C) (D) (E) (F) + * + * And we draw the triangle strip in the following index order: + * + * index: 04152637B6A5948C9DAEBF + */ + int pntCount = 0; + float xy[] = new float[VERTEX_BUFFER_SIZE]; + float uv[] = new float[VERTEX_BUFFER_SIZE]; + for (int j = 0; j < ny; ++j) { + for (int i = 0; i < nx; ++i) { + int xIndex = (pntCount++) << 1; + int yIndex = xIndex + 1; + xy[xIndex] = x[i]; + xy[yIndex] = y[j]; + uv[xIndex] = u[i]; + uv[yIndex] = v[j]; + } + } + + int idxCount = 1; + boolean isForward = false; + byte index[] = new byte[INDEX_BUFFER_SIZE]; + for (int row = 0; row < ny - 1; row++) { + --idxCount; + isForward = !isForward; + + int start, end, inc; + if (isForward) { + start = 0; + end = nx; + inc = 1; + } else { + start = nx - 1; + end = -1; + inc = -1; + } + + for (int col = start; col != end; col += inc) { + int k = row * nx + col; + if (col != start) { + int colorIdx = row * (nx - 1) + col; + if (isForward) colorIdx--; + if (color[colorIdx] == NinePatchChunk.TRANSPARENT_COLOR) { + index[idxCount] = index[idxCount - 1]; + ++idxCount; + index[idxCount++] = (byte) k; + } + } + + index[idxCount++] = (byte) k; + index[idxCount++] = (byte) (k + nx); + } + } + + mIdxCount = idxCount; + + int size = (pntCount * 2) * (Float.SIZE / Byte.SIZE); + mXyBuffer = allocateDirectNativeOrderBuffer(size).asFloatBuffer(); + mUvBuffer = allocateDirectNativeOrderBuffer(size).asFloatBuffer(); + mIndexBuffer = allocateDirectNativeOrderBuffer(mIdxCount); + + mXyBuffer.put(xy, 0, pntCount * 2).position(0); + mUvBuffer.put(uv, 0, pntCount * 2).position(0); + mIndexBuffer.put(index, 0, idxCount).position(0); + } + + private static ByteBuffer allocateDirectNativeOrderBuffer(int size) { + return ByteBuffer.allocateDirect(size).order(ByteOrder.nativeOrder()); + } + + private void prepareBuffers(GLCanvas canvas) { + mXyBufferName = canvas.uploadBuffer(mXyBuffer); + mUvBufferName = canvas.uploadBuffer(mUvBuffer); + mIndexBufferName = canvas.uploadBuffer(mIndexBuffer); + + // These buffers are never used again. + mXyBuffer = null; + mUvBuffer = null; + mIndexBuffer = null; + } + + public void draw(GLCanvas canvas, NinePatchTexture tex, int x, int y) { + if (mXyBufferName == -1) { + prepareBuffers(canvas); + } + canvas.drawMesh(tex, x, y, mXyBufferName, mUvBufferName, mIndexBufferName, mIdxCount); + } + + public void recycle(GLCanvas canvas) { + if (mXyBuffer == null) { + canvas.deleteBuffer(mXyBufferName); + canvas.deleteBuffer(mUvBufferName); + canvas.deleteBuffer(mIndexBufferName); + mXyBufferName = -1; + } + } +}
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