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      1 /*
      2  * Copyright 2013 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "SkDropShadowImageFilter.h"
      9 
     10 #include "SkBitmap.h"
     11 #include "SkBlurImageFilter.h"
     12 #include "SkCanvas.h"
     13 #include "SkColorMatrixFilter.h"
     14 #include "SkDevice.h"
     15 #include "SkReadBuffer.h"
     16 #include "SkWriteBuffer.h"
     17 
     18 SkDropShadowImageFilter::SkDropShadowImageFilter(SkScalar dx, SkScalar dy,
     19                                                  SkScalar sigmaX, SkScalar sigmaY, SkColor color,
     20                                                  ShadowMode shadowMode, SkImageFilter* input,
     21                                                  const CropRect* cropRect)
     22     : INHERITED(1, &input, cropRect)
     23     , fDx(dx)
     24     , fDy(dy)
     25     , fSigmaX(sigmaX)
     26     , fSigmaY(sigmaY)
     27     , fColor(color)
     28     , fShadowMode(shadowMode)
     29 {
     30 }
     31 
     32 SkFlattenable* SkDropShadowImageFilter::CreateProc(SkReadBuffer& buffer) {
     33     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
     34     SkScalar dx = buffer.readScalar();
     35     SkScalar dy = buffer.readScalar();
     36     SkScalar sigmaX = buffer.readScalar();
     37     SkScalar sigmaY = buffer.readScalar();
     38     SkColor color = buffer.readColor();
     39     ShadowMode shadowMode = buffer.isVersionLT(SkReadBuffer::kDropShadowMode_Version) ?
     40                             kDrawShadowAndForeground_ShadowMode :
     41                             static_cast<ShadowMode>(buffer.readInt());
     42     return Create(dx, dy, sigmaX, sigmaY, color, shadowMode, common.getInput(0),
     43                   &common.cropRect());
     44 }
     45 
     46 void SkDropShadowImageFilter::flatten(SkWriteBuffer& buffer) const {
     47     this->INHERITED::flatten(buffer);
     48     buffer.writeScalar(fDx);
     49     buffer.writeScalar(fDy);
     50     buffer.writeScalar(fSigmaX);
     51     buffer.writeScalar(fSigmaY);
     52     buffer.writeColor(fColor);
     53     buffer.writeInt(static_cast<int>(fShadowMode));
     54 }
     55 
     56 bool SkDropShadowImageFilter::onFilterImageDeprecated(Proxy* proxy, const SkBitmap& source,
     57                                                       const Context& ctx,
     58                                                       SkBitmap* result, SkIPoint* offset) const {
     59     SkBitmap src = source;
     60     SkIPoint srcOffset = SkIPoint::Make(0, 0);
     61     if (!this->filterInputDeprecated(0, proxy, source, ctx, &src, &srcOffset))
     62         return false;
     63 
     64     SkIRect srcBounds = src.bounds();
     65     srcBounds.offset(srcOffset);
     66     SkIRect bounds;
     67     if (!this->applyCropRect(ctx, srcBounds, &bounds)) {
     68         return false;
     69     }
     70 
     71     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
     72     if (nullptr == device.get()) {
     73         return false;
     74     }
     75     SkCanvas canvas(device.get());
     76 
     77     SkVector sigma = SkVector::Make(fSigmaX, fSigmaY);
     78     ctx.ctm().mapVectors(&sigma, 1);
     79     sigma.fX = SkMaxScalar(0, sigma.fX);
     80     sigma.fY = SkMaxScalar(0, sigma.fY);
     81     SkAutoTUnref<SkImageFilter> blurFilter(SkBlurImageFilter::Create(sigma.fX, sigma.fY));
     82     SkAutoTUnref<SkColorFilter> colorFilter(
     83         SkColorFilter::CreateModeFilter(fColor, SkXfermode::kSrcIn_Mode));
     84     SkPaint paint;
     85     paint.setImageFilter(blurFilter.get());
     86     paint.setColorFilter(colorFilter.get());
     87     paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
     88     SkVector offsetVec = SkVector::Make(fDx, fDy);
     89     ctx.ctm().mapVectors(&offsetVec, 1);
     90     canvas.translate(SkIntToScalar(srcOffset.fX - bounds.fLeft),
     91                      SkIntToScalar(srcOffset.fY - bounds.fTop));
     92     canvas.drawBitmap(src, offsetVec.fX, offsetVec.fY, &paint);
     93     if (fShadowMode == kDrawShadowAndForeground_ShadowMode) {
     94         canvas.drawBitmap(src, 0, 0);
     95     }
     96     *result = device->accessBitmap(false);
     97     offset->fX = bounds.fLeft;
     98     offset->fY = bounds.fTop;
     99     return true;
    100 }
    101 
    102 void SkDropShadowImageFilter::computeFastBounds(const SkRect& src, SkRect* dst) const {
    103     if (getInput(0)) {
    104         getInput(0)->computeFastBounds(src, dst);
    105     } else {
    106         *dst = src;
    107     }
    108 
    109     SkRect shadowBounds = *dst;
    110     shadowBounds.offset(fDx, fDy);
    111     shadowBounds.outset(SkScalarMul(fSigmaX, SkIntToScalar(3)),
    112                         SkScalarMul(fSigmaY, SkIntToScalar(3)));
    113     if (fShadowMode == kDrawShadowAndForeground_ShadowMode) {
    114         dst->join(shadowBounds);
    115     } else {
    116         *dst = shadowBounds;
    117     }
    118 }
    119 
    120 void SkDropShadowImageFilter::onFilterNodeBounds(const SkIRect& src, const SkMatrix& ctm,
    121                                                  SkIRect* dst, MapDirection direction) const {
    122     *dst = src;
    123     SkVector offsetVec = SkVector::Make(fDx, fDy);
    124     if (kReverse_MapDirection == direction) {
    125         offsetVec.negate();
    126     }
    127     ctm.mapVectors(&offsetVec, 1);
    128     dst->offset(SkScalarCeilToInt(offsetVec.x()),
    129                 SkScalarCeilToInt(offsetVec.y()));
    130     SkVector sigma = SkVector::Make(fSigmaX, fSigmaY);
    131     ctm.mapVectors(&sigma, 1);
    132     dst->outset(SkScalarCeilToInt(SkScalarMul(sigma.x(), SkIntToScalar(3))),
    133                 SkScalarCeilToInt(SkScalarMul(sigma.y(), SkIntToScalar(3))));
    134     if (fShadowMode == kDrawShadowAndForeground_ShadowMode) {
    135         dst->join(src);
    136     }
    137 }
    138 
    139 #ifndef SK_IGNORE_TO_STRING
    140 void SkDropShadowImageFilter::toString(SkString* str) const {
    141     str->appendf("SkDropShadowImageFilter: (");
    142 
    143     str->appendf("dX: %f ", fDx);
    144     str->appendf("dY: %f ", fDy);
    145     str->appendf("sigmaX: %f ", fSigmaX);
    146     str->appendf("sigmaY: %f ", fSigmaY);
    147 
    148     str->append("Color: ");
    149     str->appendHex(fColor);
    150 
    151     static const char* gModeStrings[] = {
    152         "kDrawShadowAndForeground", "kDrawShadowOnly"
    153     };
    154 
    155     static_assert(kShadowModeCount == SK_ARRAY_COUNT(gModeStrings), "enum_mismatch");
    156 
    157     str->appendf(" mode: %s", gModeStrings[fShadowMode]);
    158 
    159     str->append(")");
    160 }
    161 #endif
    162