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 "SkFilterShader.h"
9
10#include "SkColorFilter.h"
11#include "SkReadBuffer.h"
12#include "SkWriteBuffer.h"
13#include "SkShader.h"
14#include "SkString.h"
15
16SkFilterShader::SkFilterShader(SkShader* shader, SkColorFilter* filter) {
17    fShader = shader;
18    shader->ref();
19
20    fFilter = filter;
21    filter->ref();
22}
23
24SkFilterShader::~SkFilterShader() {
25    fFilter->unref();
26    fShader->unref();
27}
28
29SkFlattenable* SkFilterShader::CreateProc(SkReadBuffer& buffer) {
30    SkAutoTUnref<SkShader> shader(buffer.readShader());
31    SkAutoTUnref<SkColorFilter> filter(buffer.readColorFilter());
32    if (!shader.get() || !filter.get()) {
33        return NULL;
34    }
35    return SkNEW_ARGS(SkFilterShader, (shader, filter));
36}
37
38void SkFilterShader::flatten(SkWriteBuffer& buffer) const {
39    buffer.writeFlattenable(fShader);
40    buffer.writeFlattenable(fFilter);
41}
42
43uint32_t SkFilterShader::FilterShaderContext::getFlags() const {
44    const SkFilterShader& filterShader = static_cast<const SkFilterShader&>(fShader);
45
46    uint32_t shaderF = fShaderContext->getFlags();
47    uint32_t filterF = filterShader.fFilter->getFlags();
48
49    // filters don't support 16bit, so clear the matching bit in the shader
50    shaderF &= ~SkShader::kHasSpan16_Flag;
51
52    // if the filter might change alpha, clear the opaque flag in the shader
53    if (!(filterF & SkColorFilter::kAlphaUnchanged_Flag)) {
54        shaderF &= ~SkShader::kOpaqueAlpha_Flag;
55    }
56    return shaderF;
57}
58
59SkShader::Context* SkFilterShader::onCreateContext(const ContextRec& rec, void* storage) const {
60    char* shaderContextStorage = (char*)storage + sizeof(FilterShaderContext);
61    SkShader::Context* shaderContext = fShader->createContext(rec, shaderContextStorage);
62    if (NULL == shaderContext) {
63        return NULL;
64    }
65    return SkNEW_PLACEMENT_ARGS(storage, FilterShaderContext, (*this, shaderContext, rec));
66}
67
68size_t SkFilterShader::contextSize() const {
69    return sizeof(FilterShaderContext) + fShader->contextSize();
70}
71
72SkFilterShader::FilterShaderContext::FilterShaderContext(const SkFilterShader& filterShader,
73                                                         SkShader::Context* shaderContext,
74                                                         const ContextRec& rec)
75    : INHERITED(filterShader, rec)
76    , fShaderContext(shaderContext) {}
77
78SkFilterShader::FilterShaderContext::~FilterShaderContext() {
79    fShaderContext->~Context();
80}
81
82void SkFilterShader::FilterShaderContext::shadeSpan(int x, int y, SkPMColor result[], int count) {
83    const SkFilterShader& filterShader = static_cast<const SkFilterShader&>(fShader);
84
85    fShaderContext->shadeSpan(x, y, result, count);
86    filterShader.fFilter->filterSpan(result, count, result);
87}
88
89#ifndef SK_IGNORE_TO_STRING
90void SkFilterShader::toString(SkString* str) const {
91    str->append("SkFilterShader: (");
92
93    str->append("Shader: ");
94    fShader->toString(str);
95    str->append(" Filter: ");
96    // TODO: add "fFilter->toString(str);" once SkColorFilter::toString is added
97
98    this->INHERITED::toString(str);
99
100    str->append(")");
101}
102#endif
103