/*
 * 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 "GrContext.h"
#include "GrCaps.h"
#include "GrGpu.h"
#include "GrResourceKey.h"
#include "GrRenderTarget.h"
#include "GrRenderTargetPriv.h"
#include "GrTexture.h"
#include "GrTexturePriv.h"
#include "GrTypes.h"
#include "SkMath.h"
#include "SkMipMap.h"
#include "SkTypes.h"

void GrTexture::dirtyMipMaps(bool mipMapsDirty) {
    if (mipMapsDirty) {
        if (kValid_MipMapsStatus == fMipMapsStatus) {
            fMipMapsStatus = kAllocated_MipMapsStatus;
        }
    } else {
        const bool sizeChanged = kNotAllocated_MipMapsStatus == fMipMapsStatus;
        fMipMapsStatus = kValid_MipMapsStatus;
        if (sizeChanged) {
            // This must not be called until after changing fMipMapsStatus.
            this->didChangeGpuMemorySize();
            // TODO(http://skbug.com/4548) - The desc and scratch key should be
            // updated to reflect the newly-allocated mipmaps.
        }
    }
}

size_t GrTexture::onGpuMemorySize() const {
    size_t textureSize;

    if (GrPixelConfigIsCompressed(fDesc.fConfig)) {
        textureSize = GrCompressedFormatDataSize(fDesc.fConfig, fDesc.fWidth, fDesc.fHeight);
    } else {
        textureSize = (size_t) fDesc.fWidth * fDesc.fHeight * GrBytesPerPixel(fDesc.fConfig);
    }

    if (this->texturePriv().hasMipMaps()) {
        // We don't have to worry about the mipmaps being a different size than
        // we'd expect because we never change fDesc.fWidth/fHeight.
        textureSize += textureSize/3;
    }

    SkASSERT(!SkToBool(fDesc.fFlags & kRenderTarget_GrSurfaceFlag));
    SkASSERT(textureSize <= WorseCaseSize(fDesc));

    return textureSize;
}

void GrTexture::validateDesc() const {
    if (this->asRenderTarget()) {
        // This texture has a render target
        SkASSERT(0 != (fDesc.fFlags & kRenderTarget_GrSurfaceFlag));
        SkASSERT(fDesc.fSampleCnt == this->asRenderTarget()->numColorSamples());
    } else {
        SkASSERT(0 == (fDesc.fFlags & kRenderTarget_GrSurfaceFlag));
        SkASSERT(0 == fDesc.fSampleCnt);
    }
}

//////////////////////////////////////////////////////////////////////////////

namespace {

// FIXME:  This should be refactored with the code in gl/GrGLGpu.cpp.
GrSurfaceOrigin resolve_origin(const GrSurfaceDesc& desc) {
    // By default, GrRenderTargets are GL's normal orientation so that they
    // can be drawn to by the outside world without the client having
    // to render upside down.
    bool renderTarget = 0 != (desc.fFlags & kRenderTarget_GrSurfaceFlag);
    if (kDefault_GrSurfaceOrigin == desc.fOrigin) {
        return renderTarget ? kBottomLeft_GrSurfaceOrigin : kTopLeft_GrSurfaceOrigin;
    } else {
        return desc.fOrigin;
    }
}
}

//////////////////////////////////////////////////////////////////////////////
GrTexture::GrTexture(GrGpu* gpu, LifeCycle lifeCycle, const GrSurfaceDesc& desc,
                     GrSLType samplerType, bool wasMipMapDataProvided)
    : INHERITED(gpu, lifeCycle, desc)
    , fSamplerType(samplerType) {
    if (!this->isExternal() && !GrPixelConfigIsCompressed(desc.fConfig)) {
        GrScratchKey key;
        GrTexturePriv::ComputeScratchKey(desc, &key);
        this->setScratchKey(key);
    }

    if (wasMipMapDataProvided) {
        fMipMapsStatus = kValid_MipMapsStatus;
        fMaxMipMapLevel = SkMipMap::ComputeLevelCount(fDesc.fWidth, fDesc.fHeight);
    } else {
        fMipMapsStatus = kNotAllocated_MipMapsStatus;
        fMaxMipMapLevel = 0;
    }
}

void GrTexturePriv::ComputeScratchKey(const GrSurfaceDesc& desc, GrScratchKey* key) {
    static const GrScratchKey::ResourceType kType = GrScratchKey::GenerateResourceType();

    GrSurfaceOrigin origin = resolve_origin(desc);
    uint32_t flags = desc.fFlags & ~kCheckAllocation_GrSurfaceFlag;

    // make sure desc.fConfig fits in 5 bits
    SkASSERT(sk_float_log2(kLast_GrPixelConfig) <= 5);
    SkASSERT(static_cast<int>(desc.fConfig) < (1 << 5));
    SkASSERT(desc.fSampleCnt < (1 << 8));
    SkASSERT(flags < (1 << 10));
    SkASSERT(static_cast<int>(origin) < (1 << 8));

    GrScratchKey::Builder builder(key, kType, 3);
    builder[0] = desc.fWidth;
    builder[1] = desc.fHeight;
    builder[2] = desc.fConfig | (desc.fIsMipMapped << 5) | (desc.fSampleCnt << 6) | (flags << 14)
                 | (origin << 24);
}