/* * Copyright (C) 2008 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.example.android.apis.graphics;import com.example.android.apis.R;import android.content.Context;import android.graphics.*;import android.os.Bundle;import android.view.*;import android.util.FloatMath;public class BitmapMesh extends GraphicsActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(new SampleView(this));    }        private static class SampleView extends View {        private static final int WIDTH = 20;        private static final int HEIGHT = 20;        private static final int COUNT = (WIDTH + 1) * (HEIGHT + 1);                private final Bitmap mBitmap;        private final float[] mVerts = new float[COUNT*2];        private final float[] mOrig = new float[COUNT*2];                private final Matrix mMatrix = new Matrix();        private final Matrix mInverse = new Matrix();        private static void setXY(float[] array, int index, float x, float y) {            array[index*2 + 0] = x;            array[index*2 + 1] = y;        }        public SampleView(Context context) {            super(context);            setFocusable(true);            mBitmap = BitmapFactory.decodeResource(getResources(),                                                     R.drawable.beach);                        float w = mBitmap.getWidth();            float h = mBitmap.getHeight();            // construct our mesh            int index = 0;            for (int y = 0; y <= HEIGHT; y++) {                float fy = h * y / HEIGHT;                for (int x = 0; x <= WIDTH; x++) {                    float fx = w * x / WIDTH;                                        setXY(mVerts, index, fx, fy);                    setXY(mOrig, index, fx, fy);                    index += 1;                }            }                        mMatrix.setTranslate(10, 10);            mMatrix.invert(mInverse);        }                @Override protected void onDraw(Canvas canvas) {            canvas.drawColor(0xFFCCCCCC);            canvas.concat(mMatrix);            canvas.drawBitmapMesh(mBitmap, WIDTH, HEIGHT, mVerts, 0,                                  null, 0, null);        }                private void warp(float cx, float cy) {            final float K = 10000;            float[] src = mOrig;            float[] dst = mVerts;            for (int i = 0; i < COUNT*2; i += 2) {                float x = src[i+0];                float y = src[i+1];                float dx = cx - x;                float dy = cy - y;                float dd = dx*dx + dy*dy;                float d = FloatMath.sqrt(dd);                float pull = K / (dd + 0.000001f);                                pull /= (d + 0.000001f);             //   android.util.Log.d("skia", "index " + i + " dist=" + d + " pull=" + pull);                if (pull >= 1) {                    dst[i+0] = cx;                    dst[i+1] = cy;                } else {                    dst[i+0] = x + dx * pull;                    dst[i+1] = y + dy * pull;                }            }        }        private int mLastWarpX = -9999; // don't match a touch coordinate        private int mLastWarpY;        @Override public boolean onTouchEvent(MotionEvent event) {            float[] pt = { event.getX(), event.getY() };            mInverse.mapPoints(pt);                        int x = (int)pt[0];            int y = (int)pt[1];            if (mLastWarpX != x || mLastWarpY != y) {                mLastWarpX = x;                mLastWarpY = y;                warp(pt[0], pt[1]);                invalidate();            }            return true;        }    }}