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      1 /*
      2  * Copyright (C) 2008 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.launcher2;
     18 
     19 import android.graphics.Bitmap;
     20 import android.graphics.BlurMaskFilter;
     21 import android.graphics.Canvas;
     22 import android.graphics.MaskFilter;
     23 import android.graphics.Paint;
     24 import android.graphics.PorterDuff;
     25 import android.graphics.PorterDuffXfermode;
     26 import android.graphics.TableMaskFilter;
     27 
     28 public class HolographicOutlineHelper {
     29     private final Paint mHolographicPaint = new Paint();
     30     private final Paint mBlurPaint = new Paint();
     31     private final Paint mErasePaint = new Paint();
     32     private final Paint mAlphaClipPaint = new Paint();
     33 
     34     public static final int MAX_OUTER_BLUR_RADIUS;
     35     public static final int MIN_OUTER_BLUR_RADIUS;
     36 
     37     private static final BlurMaskFilter sExtraThickOuterBlurMaskFilter;
     38     private static final BlurMaskFilter sThickOuterBlurMaskFilter;
     39     private static final BlurMaskFilter sMediumOuterBlurMaskFilter;
     40     private static final BlurMaskFilter sThinOuterBlurMaskFilter;
     41     private static final BlurMaskFilter sThickInnerBlurMaskFilter;
     42     private static final BlurMaskFilter sExtraThickInnerBlurMaskFilter;
     43     private static final BlurMaskFilter sMediumInnerBlurMaskFilter;
     44 
     45     private static final int THICK = 0;
     46     private static final int MEDIUM = 1;
     47     private static final int EXTRA_THICK = 2;
     48 
     49     static {
     50         final float scale = LauncherApplication.getScreenDensity();
     51 
     52         MIN_OUTER_BLUR_RADIUS = (int) (scale * 1.0f);
     53         MAX_OUTER_BLUR_RADIUS = (int) (scale * 12.0f);
     54 
     55         sExtraThickOuterBlurMaskFilter = new BlurMaskFilter(scale * 12.0f, BlurMaskFilter.Blur.OUTER);
     56         sThickOuterBlurMaskFilter = new BlurMaskFilter(scale * 6.0f, BlurMaskFilter.Blur.OUTER);
     57         sMediumOuterBlurMaskFilter = new BlurMaskFilter(scale * 2.0f, BlurMaskFilter.Blur.OUTER);
     58         sThinOuterBlurMaskFilter = new BlurMaskFilter(scale * 1.0f, BlurMaskFilter.Blur.OUTER);
     59         sExtraThickInnerBlurMaskFilter = new BlurMaskFilter(scale * 6.0f, BlurMaskFilter.Blur.NORMAL);
     60         sThickInnerBlurMaskFilter = new BlurMaskFilter(scale * 4.0f, BlurMaskFilter.Blur.NORMAL);
     61         sMediumInnerBlurMaskFilter = new BlurMaskFilter(scale * 2.0f, BlurMaskFilter.Blur.NORMAL);
     62     }
     63 
     64     private int[] mTempOffset = new int[2];
     65 
     66     HolographicOutlineHelper() {
     67         mHolographicPaint.setFilterBitmap(true);
     68         mHolographicPaint.setAntiAlias(true);
     69         mBlurPaint.setFilterBitmap(true);
     70         mBlurPaint.setAntiAlias(true);
     71         mErasePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
     72         mErasePaint.setFilterBitmap(true);
     73         mErasePaint.setAntiAlias(true);
     74         MaskFilter alphaClipTable = TableMaskFilter.CreateClipTable(180, 255);
     75         mAlphaClipPaint.setMaskFilter(alphaClipTable);
     76     }
     77 
     78     /**
     79      * Returns the interpolated holographic highlight alpha for the effect we want when scrolling
     80      * pages.
     81      */
     82     public static float highlightAlphaInterpolator(float r) {
     83         float maxAlpha = 0.6f;
     84         return (float) Math.pow(maxAlpha * (1.0f - r), 1.5f);
     85     }
     86 
     87     /**
     88      * Returns the interpolated view alpha for the effect we want when scrolling pages.
     89      */
     90     public static float viewAlphaInterpolator(float r) {
     91         final float pivot = 0.95f;
     92         if (r < pivot) {
     93             return (float) Math.pow(r / pivot, 1.5f);
     94         } else {
     95             return 1.0f;
     96         }
     97     }
     98 
     99     /**
    100      * Applies a more expensive and accurate outline to whatever is currently drawn in a specified
    101      * bitmap.
    102      */
    103     void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    104             int outlineColor, int thickness) {
    105         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, mAlphaClipPaint,
    106                 thickness);
    107     }
    108     void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    109             int outlineColor, Paint alphaClipPaint, int thickness) {
    110 
    111         // We start by removing most of the alpha channel so as to ignore shadows, and
    112         // other types of partial transparency when defining the shape of the object
    113         if (alphaClipPaint == null) {
    114             alphaClipPaint = mAlphaClipPaint;
    115         }
    116         Bitmap glowShape = srcDst.extractAlpha(alphaClipPaint, mTempOffset);
    117 
    118         // calculate the outer blur first
    119         BlurMaskFilter outerBlurMaskFilter;
    120         switch (thickness) {
    121             case EXTRA_THICK:
    122                 outerBlurMaskFilter = sExtraThickOuterBlurMaskFilter;
    123                 break;
    124             case THICK:
    125                 outerBlurMaskFilter = sThickOuterBlurMaskFilter;
    126                 break;
    127             case MEDIUM:
    128                 outerBlurMaskFilter = sMediumOuterBlurMaskFilter;
    129                 break;
    130             default:
    131                 throw new RuntimeException("Invalid blur thickness");
    132         }
    133         mBlurPaint.setMaskFilter(outerBlurMaskFilter);
    134         int[] outerBlurOffset = new int[2];
    135         Bitmap thickOuterBlur = glowShape.extractAlpha(mBlurPaint, outerBlurOffset);
    136         if (thickness == EXTRA_THICK) {
    137             mBlurPaint.setMaskFilter(sMediumOuterBlurMaskFilter);
    138         } else {
    139             mBlurPaint.setMaskFilter(sThinOuterBlurMaskFilter);
    140         }
    141 
    142         int[] brightOutlineOffset = new int[2];
    143         Bitmap brightOutline = glowShape.extractAlpha(mBlurPaint, brightOutlineOffset);
    144 
    145         // calculate the inner blur
    146         srcDstCanvas.setBitmap(glowShape);
    147         srcDstCanvas.drawColor(0xFF000000, PorterDuff.Mode.SRC_OUT);
    148         BlurMaskFilter innerBlurMaskFilter;
    149         switch (thickness) {
    150             case EXTRA_THICK:
    151                 innerBlurMaskFilter = sExtraThickInnerBlurMaskFilter;
    152                 break;
    153             case THICK:
    154                 innerBlurMaskFilter = sThickInnerBlurMaskFilter;
    155                 break;
    156             case MEDIUM:
    157                 innerBlurMaskFilter = sMediumInnerBlurMaskFilter;
    158                 break;
    159             default:
    160                 throw new RuntimeException("Invalid blur thickness");
    161         }
    162         mBlurPaint.setMaskFilter(innerBlurMaskFilter);
    163         int[] thickInnerBlurOffset = new int[2];
    164         Bitmap thickInnerBlur = glowShape.extractAlpha(mBlurPaint, thickInnerBlurOffset);
    165 
    166         // mask out the inner blur
    167         srcDstCanvas.setBitmap(thickInnerBlur);
    168         srcDstCanvas.drawBitmap(glowShape, -thickInnerBlurOffset[0],
    169                 -thickInnerBlurOffset[1], mErasePaint);
    170         srcDstCanvas.drawRect(0, 0, -thickInnerBlurOffset[0], thickInnerBlur.getHeight(),
    171                 mErasePaint);
    172         srcDstCanvas.drawRect(0, 0, thickInnerBlur.getWidth(), -thickInnerBlurOffset[1],
    173                 mErasePaint);
    174 
    175         // draw the inner and outer blur
    176         srcDstCanvas.setBitmap(srcDst);
    177         srcDstCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
    178         mHolographicPaint.setColor(color);
    179         srcDstCanvas.drawBitmap(thickInnerBlur, thickInnerBlurOffset[0], thickInnerBlurOffset[1],
    180                 mHolographicPaint);
    181         srcDstCanvas.drawBitmap(thickOuterBlur, outerBlurOffset[0], outerBlurOffset[1],
    182                 mHolographicPaint);
    183 
    184         // draw the bright outline
    185         mHolographicPaint.setColor(outlineColor);
    186         srcDstCanvas.drawBitmap(brightOutline, brightOutlineOffset[0], brightOutlineOffset[1],
    187                 mHolographicPaint);
    188 
    189         // cleanup
    190         srcDstCanvas.setBitmap(null);
    191         brightOutline.recycle();
    192         thickOuterBlur.recycle();
    193         thickInnerBlur.recycle();
    194         glowShape.recycle();
    195     }
    196 
    197     void applyExtraThickExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    198             int outlineColor) {
    199         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, EXTRA_THICK);
    200     }
    201 
    202     void applyThickExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    203             int outlineColor) {
    204         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, THICK);
    205     }
    206 
    207     void applyMediumExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    208             int outlineColor, Paint alphaClipPaint) {
    209         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, alphaClipPaint,
    210                 MEDIUM);
    211     }
    212 
    213     void applyMediumExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    214             int outlineColor) {
    215         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, MEDIUM);
    216     }
    217 
    218 }
    219