
/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "GrStencilBuffer.h"

#include "GrContext.h"
#include "GrGpu.h"
#include "GrResourceCache.h"

SK_DEFINE_INST_COUNT(GrStencilBuffer)
GR_DEFINE_RESOURCE_CACHE_TYPE(GrStencilBuffer)

void GrStencilBuffer::transferToCache() {
    GrAssert(NULL == this->getCacheEntry());

    this->getGpu()->getContext()->addStencilBuffer(this);
}

namespace {
// we should never have more than one stencil buffer with same combo of
// (width,height,samplecount)
void gen_stencil_key_values(int width,
                            int height,
                            int sampleCnt,
                            GrCacheID* cacheID) {
    cacheID->fPublicID = GrCacheID::kDefaultPublicCacheID;
    cacheID->fResourceSpecific32 = width | (height << 16);
    cacheID->fDomain = GrCacheData::kScratch_ResourceDomain;

    GrAssert(sampleCnt >= 0 && sampleCnt < 256);
    cacheID->fResourceSpecific16 = sampleCnt << 8;

    // last 8 bits of 'fResourceSpecific16' is free for flags
}
}

GrResourceKey GrStencilBuffer::ComputeKey(int width,
                                          int height,
                                          int sampleCnt) {
    GrCacheID id(GrStencilBuffer::GetResourceType());
    gen_stencil_key_values(width, height, sampleCnt, &id);

    uint32_t v[4];
    id.toRaw(v);
    return GrResourceKey(v);
}