/*
 * Copyright 2014 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "SkLocalMatrixShader.h"

#if SK_SUPPORT_GPU
#include "GrFragmentProcessor.h"
#endif

#if SK_SUPPORT_GPU
sk_sp<GrFragmentProcessor> SkLocalMatrixShader::asFragmentProcessor(const AsFPArgs& args) const {
    SkMatrix tmp = this->getLocalMatrix();
    if (args.fLocalMatrix) {
        tmp.preConcat(*args.fLocalMatrix);
    }
    return fProxyShader->asFragmentProcessor(AsFPArgs(
        args.fContext, args.fViewMatrix, &tmp, args.fFilterQuality, args.fDstColorSpace));
}
#endif

sk_sp<SkFlattenable> SkLocalMatrixShader::CreateProc(SkReadBuffer& buffer) {
    SkMatrix lm;
    buffer.readMatrix(&lm);
    auto baseShader(buffer.readShader());
    if (!baseShader) {
        return nullptr;
    }
    return baseShader->makeWithLocalMatrix(lm);
}

void SkLocalMatrixShader::flatten(SkWriteBuffer& buffer) const {
    buffer.writeMatrix(this->getLocalMatrix());
    buffer.writeFlattenable(fProxyShader.get());
}

SkShader::Context* SkLocalMatrixShader::onCreateContext(const ContextRec& rec,
                                                        void* storage) const {
    ContextRec newRec(rec);
    SkMatrix tmp;
    if (rec.fLocalMatrix) {
        tmp.setConcat(*rec.fLocalMatrix, this->getLocalMatrix());
        newRec.fLocalMatrix = &tmp;
    } else {
        newRec.fLocalMatrix = &this->getLocalMatrix();
    }
    return fProxyShader->createContext(newRec, storage);
}

#ifndef SK_IGNORE_TO_STRING
void SkLocalMatrixShader::toString(SkString* str) const {
    str->append("SkLocalMatrixShader: (");

    fProxyShader->toString(str);

    this->INHERITED::toString(str);

    str->append(")");
}
#endif

sk_sp<SkShader> SkShader::makeWithLocalMatrix(const SkMatrix& localMatrix) const {
    if (localMatrix.isIdentity()) {
        return sk_ref_sp(const_cast<SkShader*>(this));
    }

    const SkMatrix* lm = &localMatrix;

    sk_sp<SkShader> baseShader;
    SkMatrix otherLocalMatrix;
    sk_sp<SkShader> proxy(this->makeAsALocalMatrixShader(&otherLocalMatrix));
    if (proxy) {
        otherLocalMatrix.preConcat(localMatrix);
        lm = &otherLocalMatrix;
        baseShader = proxy;
    } else {
        baseShader = sk_ref_sp(const_cast<SkShader*>(this));
    }

    return sk_make_sp<SkLocalMatrixShader>(std::move(baseShader), *lm);
}