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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 static final MaskFilter sCoarseClipTable = TableMaskFilter.CreateClipTable(0, 200);
     65 
     66     private int[] mTempOffset = new int[2];
     67 
     68     HolographicOutlineHelper() {
     69         mHolographicPaint.setFilterBitmap(true);
     70         mHolographicPaint.setAntiAlias(true);
     71         mBlurPaint.setFilterBitmap(true);
     72         mBlurPaint.setAntiAlias(true);
     73         mErasePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
     74         mErasePaint.setFilterBitmap(true);
     75         mErasePaint.setAntiAlias(true);
     76         MaskFilter alphaClipTable = TableMaskFilter.CreateClipTable(180, 255);
     77         mAlphaClipPaint.setMaskFilter(alphaClipTable);
     78     }
     79 
     80     /**
     81      * Returns the interpolated holographic highlight alpha for the effect we want when scrolling
     82      * pages.
     83      */
     84     public static float highlightAlphaInterpolator(float r) {
     85         float maxAlpha = 0.6f;
     86         return (float) Math.pow(maxAlpha * (1.0f - r), 1.5f);
     87     }
     88 
     89     /**
     90      * Returns the interpolated view alpha for the effect we want when scrolling pages.
     91      */
     92     public static float viewAlphaInterpolator(float r) {
     93         final float pivot = 0.95f;
     94         if (r < pivot) {
     95             return (float) Math.pow(r / pivot, 1.5f);
     96         } else {
     97             return 1.0f;
     98         }
     99     }
    100 
    101     /**
    102      * Apply an outer blur to the given bitmap.
    103      * You should use OUTER_BLUR_RADIUS to ensure that the bitmap is big enough to draw
    104      * the blur without clipping.
    105      */
    106     void applyOuterBlur(Bitmap bitmap, Canvas canvas, int color) {
    107         mBlurPaint.setMaskFilter(sThickOuterBlurMaskFilter);
    108         Bitmap glow = bitmap.extractAlpha(mBlurPaint, mTempOffset);
    109 
    110         // Use the clip table to make the glow heavier closer to the outline
    111         mHolographicPaint.setMaskFilter(sCoarseClipTable);
    112         mHolographicPaint.setAlpha(150);
    113         mHolographicPaint.setColor(color);
    114 
    115         canvas.drawBitmap(glow, mTempOffset[0], mTempOffset[1], mHolographicPaint);
    116         glow.recycle();
    117     }
    118 
    119     /**
    120      * Applies a more expensive and accurate outline to whatever is currently drawn in a specified
    121      * bitmap.
    122      */
    123     void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    124             int outlineColor, int thickness) {
    125         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, mAlphaClipPaint,
    126                 thickness);
    127     }
    128     void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    129             int outlineColor, Paint alphaClipPaint, int thickness) {
    130 
    131         // We start by removing most of the alpha channel so as to ignore shadows, and
    132         // other types of partial transparency when defining the shape of the object
    133         if (alphaClipPaint == null) {
    134             alphaClipPaint = mAlphaClipPaint;
    135         }
    136         Bitmap glowShape = srcDst.extractAlpha(alphaClipPaint, mTempOffset);
    137 
    138         // calculate the outer blur first
    139         BlurMaskFilter outerBlurMaskFilter;
    140         switch (thickness) {
    141             case EXTRA_THICK:
    142                 outerBlurMaskFilter = sExtraThickOuterBlurMaskFilter;
    143                 break;
    144             case THICK:
    145                 outerBlurMaskFilter = sThickOuterBlurMaskFilter;
    146                 break;
    147             case MEDIUM:
    148                 outerBlurMaskFilter = sMediumOuterBlurMaskFilter;
    149                 break;
    150             default:
    151                 throw new RuntimeException("Invalid blur thickness");
    152         }
    153         mBlurPaint.setMaskFilter(outerBlurMaskFilter);
    154         int[] outerBlurOffset = new int[2];
    155         Bitmap thickOuterBlur = glowShape.extractAlpha(mBlurPaint, outerBlurOffset);
    156         if (thickness == EXTRA_THICK) {
    157             mBlurPaint.setMaskFilter(sMediumOuterBlurMaskFilter);
    158         } else {
    159             mBlurPaint.setMaskFilter(sThinOuterBlurMaskFilter);
    160         }
    161 
    162         int[] brightOutlineOffset = new int[2];
    163         Bitmap brightOutline = glowShape.extractAlpha(mBlurPaint, brightOutlineOffset);
    164 
    165         // calculate the inner blur
    166         srcDstCanvas.setBitmap(glowShape);
    167         srcDstCanvas.drawColor(0xFF000000, PorterDuff.Mode.SRC_OUT);
    168         BlurMaskFilter innerBlurMaskFilter;
    169         switch (thickness) {
    170             case EXTRA_THICK:
    171                 innerBlurMaskFilter = sExtraThickInnerBlurMaskFilter;
    172                 break;
    173             case THICK:
    174                 innerBlurMaskFilter = sThickInnerBlurMaskFilter;
    175                 break;
    176             case MEDIUM:
    177                 innerBlurMaskFilter = sMediumInnerBlurMaskFilter;
    178                 break;
    179             default:
    180                 throw new RuntimeException("Invalid blur thickness");
    181         }
    182         mBlurPaint.setMaskFilter(innerBlurMaskFilter);
    183         int[] thickInnerBlurOffset = new int[2];
    184         Bitmap thickInnerBlur = glowShape.extractAlpha(mBlurPaint, thickInnerBlurOffset);
    185 
    186         // mask out the inner blur
    187         srcDstCanvas.setBitmap(thickInnerBlur);
    188         srcDstCanvas.drawBitmap(glowShape, -thickInnerBlurOffset[0],
    189                 -thickInnerBlurOffset[1], mErasePaint);
    190         srcDstCanvas.drawRect(0, 0, -thickInnerBlurOffset[0], thickInnerBlur.getHeight(),
    191                 mErasePaint);
    192         srcDstCanvas.drawRect(0, 0, thickInnerBlur.getWidth(), -thickInnerBlurOffset[1],
    193                 mErasePaint);
    194 
    195         // draw the inner and outer blur
    196         srcDstCanvas.setBitmap(srcDst);
    197         srcDstCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
    198         mHolographicPaint.setColor(color);
    199         srcDstCanvas.drawBitmap(thickInnerBlur, thickInnerBlurOffset[0], thickInnerBlurOffset[1],
    200                 mHolographicPaint);
    201         srcDstCanvas.drawBitmap(thickOuterBlur, outerBlurOffset[0], outerBlurOffset[1],
    202                 mHolographicPaint);
    203 
    204         // draw the bright outline
    205         mHolographicPaint.setColor(outlineColor);
    206         srcDstCanvas.drawBitmap(brightOutline, brightOutlineOffset[0], brightOutlineOffset[1],
    207                 mHolographicPaint);
    208 
    209         // cleanup
    210         srcDstCanvas.setBitmap(null);
    211         brightOutline.recycle();
    212         thickOuterBlur.recycle();
    213         thickInnerBlur.recycle();
    214         glowShape.recycle();
    215     }
    216 
    217     void applyExtraThickExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    218             int outlineColor) {
    219         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, EXTRA_THICK);
    220     }
    221 
    222     void applyThickExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    223             int outlineColor) {
    224         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, THICK);
    225     }
    226 
    227     void applyMediumExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    228             int outlineColor, Paint alphaClipPaint) {
    229         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, alphaClipPaint,
    230                 MEDIUM);
    231     }
    232 
    233     void applyMediumExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
    234             int outlineColor) {
    235         applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, MEDIUM);
    236     }
    237 
    238 }
    239