/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "src/gpu/GrBitmapTextureMaker.h"

#include "include/core/SkBitmap.h"
#include "include/core/SkPixelRef.h"
#include "include/private/GrRecordingContext.h"
#include "src/core/SkMipMap.h"
#include "src/gpu/GrGpuResourcePriv.h"
#include "src/gpu/GrProxyProvider.h"
#include "src/gpu/GrRecordingContextPriv.h"
#include "src/gpu/GrSurfaceContext.h"
#include "src/gpu/SkGr.h"

static GrImageInfo get_image_info(GrRecordingContext* context, const SkBitmap& bitmap) {
    GrColorType ct = SkColorTypeToGrColorType(bitmap.info().colorType());
    GrBackendFormat format = context->priv().caps()->getDefaultBackendFormat(ct, GrRenderable::kNo);
    if (!format.isValid()) {
        ct = GrColorType::kRGBA_8888;
    }
    return {ct, bitmap.alphaType(), bitmap.refColorSpace(), bitmap.dimensions()};
}

GrBitmapTextureMaker::GrBitmapTextureMaker(GrRecordingContext* context, const SkBitmap& bitmap,
                                           Cached cached, SkBackingFit fit, bool useDecal)
        : INHERITED(context, get_image_info(context, bitmap), useDecal)
        , fBitmap(bitmap)
        , fFit(fit) {
    if (!bitmap.isVolatile() && cached == Cached::kYes) {
        SkIPoint origin = bitmap.pixelRefOrigin();
        SkIRect subset = SkIRect::MakeXYWH(origin.fX, origin.fY, bitmap.width(),
                                           bitmap.height());
        GrMakeKeyFromImageID(&fOriginalKey, bitmap.pixelRef()->getGenerationID(), subset);
    }
}

sk_sp<GrTextureProxy> GrBitmapTextureMaker::refOriginalTextureProxy(bool willBeMipped,
                                                                    AllowedTexGenType onlyIfFast) {
    if (AllowedTexGenType::kCheap == onlyIfFast) {
        return nullptr;
    }

    GrProxyProvider* proxyProvider = this->context()->priv().proxyProvider();
    sk_sp<GrTextureProxy> proxy;

    if (fOriginalKey.isValid()) {
        auto colorType = SkColorTypeToGrColorType(fBitmap.colorType());
        proxy = proxyProvider->findOrCreateProxyByUniqueKey(fOriginalKey, colorType,
                                                            kTopLeft_GrSurfaceOrigin);
        if (proxy && (!willBeMipped || GrMipMapped::kYes == proxy->mipMapped())) {
            return proxy;
        }
    }

    if (!proxy) {
        if (this->colorType() != SkColorTypeToGrColorType(fBitmap.info().colorType())) {
            SkASSERT(this->colorType() == GrColorType::kRGBA_8888);
            SkBitmap copy8888;
            if (!copy8888.tryAllocPixels(fBitmap.info().makeColorType(kRGBA_8888_SkColorType)) ||
                !fBitmap.readPixels(copy8888.pixmap())) {
                return nullptr;
            }
            copy8888.setImmutable();
            proxy = proxyProvider->createProxyFromBitmap(
                    copy8888, willBeMipped ? GrMipMapped::kYes : GrMipMapped::kNo, fFit);
        } else {
            proxy = proxyProvider->createProxyFromBitmap(
                    fBitmap, willBeMipped ? GrMipMapped::kYes : GrMipMapped::kNo, fFit);
        }
        if (proxy) {
            if (fOriginalKey.isValid()) {
                proxyProvider->assignUniqueKeyToProxy(fOriginalKey, proxy.get());
            }
            if (!willBeMipped || GrMipMapped::kYes == proxy->mipMapped()) {
                SkASSERT(proxy->origin() == kTopLeft_GrSurfaceOrigin);
                if (fOriginalKey.isValid()) {
                    GrInstallBitmapUniqueKeyInvalidator(
                            fOriginalKey, proxyProvider->contextID(), fBitmap.pixelRef());
                }
                return proxy;
            }
        }
    }

    if (proxy) {
        SkASSERT(willBeMipped);
        SkASSERT(GrMipMapped::kNo == proxy->mipMapped());
        // We need a mipped proxy, but we either found a proxy earlier that wasn't mipped or
        // generated a non mipped proxy. Thus we generate a new mipped surface and copy the original
        // proxy into the base layer. We will then let the gpu generate the rest of the mips.
        GrColorType srcColorType = SkColorTypeToGrColorType(fBitmap.colorType());
        if (auto mippedProxy = GrCopyBaseMipMapToTextureProxy(this->context(), proxy.get(),
                                                              srcColorType)) {
            SkASSERT(mippedProxy->origin() == kTopLeft_GrSurfaceOrigin);
            if (fOriginalKey.isValid()) {
                // In this case we are stealing the key from the original proxy which should only
                // happen when we have just generated mipmaps for an originally unmipped
                // proxy/texture. This means that all future uses of the key will access the
                // mipmapped version. The texture backing the unmipped version will remain in the
                // resource cache until the last texture proxy referencing it is deleted at which
                // time it too will be deleted or recycled.
                SkASSERT(proxy->getUniqueKey() == fOriginalKey);
                proxyProvider->removeUniqueKeyFromProxy(proxy.get());
                proxyProvider->assignUniqueKeyToProxy(fOriginalKey, mippedProxy.get());
                GrInstallBitmapUniqueKeyInvalidator(fOriginalKey, proxyProvider->contextID(),
                                                    fBitmap.pixelRef());
            }
            return mippedProxy;
        }
        // We failed to make a mipped proxy with the base copied into it. This could have
        // been from failure to make the proxy or failure to do the copy. Thus we will fall
        // back to just using the non mipped proxy; See skbug.com/7094.
        return proxy;
    }
    return nullptr;
}

void GrBitmapTextureMaker::makeCopyKey(const CopyParams& copyParams, GrUniqueKey* copyKey) {
    // Destination color space is irrelevant - we always upload the bitmap's contents as-is
    if (fOriginalKey.isValid()) {
        MakeCopyKeyFromOrigKey(fOriginalKey, copyParams, copyKey);
    }
}

void GrBitmapTextureMaker::didCacheCopy(const GrUniqueKey& copyKey, uint32_t contextUniqueID) {
    GrInstallBitmapUniqueKeyInvalidator(copyKey, contextUniqueID, fBitmap.pixelRef());
}