SkImageShader.cpp revision 8515377d8f67b7d4d3edfd669fbc727a007ddab3 
1/*
2 * Copyright 2015 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 "SkBitmapProcShader.h"
9#include "SkBitmapProvider.h"
10#include "SkImage_Base.h"
11#include "SkImageShader.h"
12#include "SkReadBuffer.h"
13#include "SkWriteBuffer.h"
14
15SkImageShader::SkImageShader(const SkImage* img, TileMode tmx, TileMode tmy, const SkMatrix* matrix)
16    : INHERITED(matrix)
17    , fImage(SkRef(img))
18    , fTileModeX(tmx)
19    , fTileModeY(tmy)
20{}
21
22SkFlattenable* SkImageShader::CreateProc(SkReadBuffer& buffer) {
23    const TileMode tx = (TileMode)buffer.readUInt();
24    const TileMode ty = (TileMode)buffer.readUInt();
25    SkMatrix matrix;
26    buffer.readMatrix(&matrix);
27    SkAutoTUnref<SkImage> img(buffer.readImage());
28    if (!img) {
29        return nullptr;
30    }
31    return new SkImageShader(img, tx, ty, &matrix);
32}
33
34void SkImageShader::flatten(SkWriteBuffer& buffer) const {
35    buffer.writeUInt(fTileModeX);
36    buffer.writeUInt(fTileModeY);
37    buffer.writeMatrix(this->getLocalMatrix());
38    buffer.writeImage(fImage);
39}
40
41bool SkImageShader::isOpaque() const {
42    return fImage->isOpaque();
43}
44
45size_t SkImageShader::contextSize() const {
46    return SkBitmapProcShader::ContextSize();
47}
48
49SkShader::Context* SkImageShader::onCreateContext(const ContextRec& rec, void* storage) const {
50    return SkBitmapProcShader::MakeContext(*this, fTileModeX, fTileModeY,
51                                           SkBitmapProvider(fImage), rec, storage);
52}
53
54SkShader* SkImageShader::Create(const SkImage* image, TileMode tx, TileMode ty,
55                                const SkMatrix* localMatrix) {
56    if (!image) {
57        return nullptr;
58    }
59    return new SkImageShader(image, tx, ty, localMatrix);
60}
61
62#ifndef SK_IGNORE_TO_STRING
63void SkImageShader::toString(SkString* str) const {
64    const char* gTileModeName[SkShader::kTileModeCount] = {
65        "clamp", "repeat", "mirror"
66    };
67
68    str->appendf("ImageShader: ((%s %s) ", gTileModeName[fTileModeX], gTileModeName[fTileModeY]);
69    fImage->toString(str);
70    this->INHERITED::toString(str);
71    str->append(")");
72}
73#endif
74
75///////////////////////////////////////////////////////////////////////////////////////////////////
76
77#if SK_SUPPORT_GPU
78
79#include "GrTextureAccess.h"
80#include "SkGr.h"
81#include "SkGrPriv.h"
82#include "effects/GrSimpleTextureEffect.h"
83#include "effects/GrBicubicEffect.h"
84#include "effects/GrSimpleTextureEffect.h"
85
86const GrFragmentProcessor* SkImageShader::asFragmentProcessor(GrContext* context,
87                                                              const SkMatrix& viewM,
88                                                              const SkMatrix* localMatrix,
89                                                              SkFilterQuality filterQuality) const {
90    SkMatrix matrix;
91    matrix.setIDiv(fImage->width(), fImage->height());
92
93    SkMatrix lmInverse;
94    if (!this->getLocalMatrix().invert(&lmInverse)) {
95        return nullptr;
96    }
97    if (localMatrix) {
98        SkMatrix inv;
99        if (!localMatrix->invert(&inv)) {
100            return nullptr;
101        }
102        lmInverse.postConcat(inv);
103    }
104    matrix.preConcat(lmInverse);
105
106    SkShader::TileMode tm[] = { fTileModeX, fTileModeY };
107
108    // Must set wrap and filter on the sampler before requesting a texture. In two places below
109    // we check the matrix scale factors to determine how to interpret the filter quality setting.
110    // This completely ignores the complexity of the drawVertices case where explicit local coords
111    // are provided by the caller.
112    bool doBicubic;
113    GrTextureParams::FilterMode textureFilterMode =
114    GrSkFilterQualityToGrFilterMode(filterQuality, viewM, this->getLocalMatrix(), &doBicubic);
115    GrTextureParams params(tm, textureFilterMode);
116    SkAutoTUnref<GrTexture> texture(as_IB(fImage)->asTextureRef(context, params));
117    if (!texture) {
118        return nullptr;
119    }
120
121    SkAutoTUnref<const GrFragmentProcessor> inner;
122    if (doBicubic) {
123        inner.reset(GrBicubicEffect::Create(texture, matrix, tm));
124    } else {
125        inner.reset(GrSimpleTextureEffect::Create(texture, matrix, params));
126    }
127
128    if (GrPixelConfigIsAlphaOnly(texture->config())) {
129        return SkRef(inner.get());
130    }
131    return GrFragmentProcessor::MulOutputByInputAlpha(inner);
132}
133
134#endif
135