/*

 * Copyright (C) 2009 Apple Inc. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#include "config.h"

#if ENABLE(3D_CANVAS)

#include "WebGLTexture.h"

#include "WebGLRenderingContext.h"

namespace WebCore {

PassRefPtr<WebGLTexture> WebGLTexture::create(WebGLRenderingContext* ctx)

{

    return adoptRef(new WebGLTexture(ctx));

}

WebGLTexture::WebGLTexture(WebGLRenderingContext* ctx)

    : CanvasObject(ctx)

    , cubeMapRWrapModeInitialized(false)

    , m_target(0)

    , m_minFilter(GraphicsContext3D::NEAREST_MIPMAP_LINEAR)

    , m_magFilter(GraphicsContext3D::LINEAR)

    , m_wrapS(GraphicsContext3D::REPEAT)

    , m_wrapT(GraphicsContext3D::REPEAT)

    , m_isNPOT(false)

    , m_isComplete(false)

    , m_needToUseBlackTexture(false)

{

    setObject(context()->graphicsContext3D()->createTexture());

}

void WebGLTexture::setTarget(unsigned long target, int maxLevel)

{

    if (!object())

        return;

    // Target is finalized the first time bindTexture() is called.

    if (m_target)

        return;

    switch (target) {

    case GraphicsContext3D::TEXTURE_2D:

        m_target = target;

        m_info.resize(1);

        m_info[0].resize(maxLevel);

        break;

    case GraphicsContext3D::TEXTURE_CUBE_MAP:

        m_target = target;

        m_info.resize(6);

        for (int ii = 0; ii < 6; ++ii)

            m_info[ii].resize(maxLevel);

        break;

    }

}

void WebGLTexture::setParameteri(unsigned long pname, int param)

{

    if (!object() || !m_target)

        return;

    switch (pname) {

    case GraphicsContext3D::TEXTURE_MIN_FILTER:

        switch (param) {

        case GraphicsContext3D::NEAREST:

        case GraphicsContext3D::LINEAR:

        case GraphicsContext3D::NEAREST_MIPMAP_NEAREST:

        case GraphicsContext3D::LINEAR_MIPMAP_NEAREST:

        case GraphicsContext3D::NEAREST_MIPMAP_LINEAR:

        case GraphicsContext3D::LINEAR_MIPMAP_LINEAR:

            m_minFilter = param;

            break;

        }

        break;

    case GraphicsContext3D::TEXTURE_MAG_FILTER:

        switch (param) {

        case GraphicsContext3D::NEAREST:

        case GraphicsContext3D::LINEAR:

            m_magFilter = param;

            break;

        }

        break;

    case GraphicsContext3D::TEXTURE_WRAP_S:

        switch (param) {

        case GraphicsContext3D::CLAMP_TO_EDGE:

        case GraphicsContext3D::MIRRORED_REPEAT:

        case GraphicsContext3D::REPEAT:

            m_wrapS = param;

            break;

        }

        break;

    case GraphicsContext3D::TEXTURE_WRAP_T:

        switch (param) {

        case GraphicsContext3D::CLAMP_TO_EDGE:

        case GraphicsContext3D::MIRRORED_REPEAT:

        case GraphicsContext3D::REPEAT:

            m_wrapT = param;

            break;

        }

        break;

    default:

        return;

    }

    update();

}

void WebGLTexture::setParameterf(unsigned long pname, float param)

{

    if (!object() || !m_target)

        return;

    int iparam = static_cast<int>(param);

    setParameteri(pname, iparam);

}

void WebGLTexture::setLevelInfo(unsigned long target, int level, unsigned long internalFormat, int width, int height, unsigned long type)

{

    if (!object() || !m_target)

        return;

    // We assume level, internalFormat, width, height, and type have all been

    // validated already.

    int index = mapTargetToIndex(target);

    if (index < 0)

        return;

    m_info[index][level].setInfo(internalFormat, width, height, type);

    update();

}

void WebGLTexture::generateMipmapLevelInfo()

{

    if (!object() || !m_target)

        return;

    if (!canGenerateMipmaps())

        return;

    if (m_isComplete)

        return;

    for (size_t ii = 0; ii < m_info.size(); ++ii) {

        const LevelInfo& info0 = m_info[ii][0];

        int width = info0.width;

        int height = info0.height;

        int levelCount = computeLevelCount(width, height);

        for (int level = 1; level < levelCount; ++level) {

            width = std::max(1, width >> 1);

            height = std::max(1, height >> 1);

            LevelInfo& info = m_info[ii][level];

            info.setInfo(info0.internalFormat, width, height, info0.type);

        }

    }

    m_isComplete = true;

}

unsigned long WebGLTexture::getInternalFormat() const

{

    if (!object() || !m_target)

        return 0;

    return m_info[0][0].internalFormat;

}

bool WebGLTexture::isNPOT(unsigned width, unsigned height)

{

    if (!width || !height)

        return false;

    if ((width & (width - 1)) || (height & (height - 1)))

        return true;

    return false;

}

bool WebGLTexture::isNPOT() const

{

    if (!object())

        return false;

    return m_isNPOT;

}

bool WebGLTexture::needToUseBlackTexture() const

{

    if (!object())

        return false;

    return m_needToUseBlackTexture;

}

void WebGLTexture::_deleteObject(Platform3DObject object)

{

    context()->graphicsContext3D()->deleteTexture(object);

}

int WebGLTexture::mapTargetToIndex(unsigned long target)

{

    if (m_target == GraphicsContext3D::TEXTURE_2D) {

        if (target == GraphicsContext3D::TEXTURE_2D)

            return 0;

    } else if (m_target == GraphicsContext3D::TEXTURE_CUBE_MAP) {

        switch (target) {

        case GraphicsContext3D::TEXTURE_CUBE_MAP_POSITIVE_X:

            return 0;

        case GraphicsContext3D::TEXTURE_CUBE_MAP_NEGATIVE_X:

            return 1;

        case GraphicsContext3D::TEXTURE_CUBE_MAP_POSITIVE_Y:

            return 2;

        case GraphicsContext3D::TEXTURE_CUBE_MAP_NEGATIVE_Y:

            return 3;

        case GraphicsContext3D::TEXTURE_CUBE_MAP_POSITIVE_Z:

            return 4;

        case GraphicsContext3D::TEXTURE_CUBE_MAP_NEGATIVE_Z:

            return 5;

        }

    }

    return -1;

}

bool WebGLTexture::canGenerateMipmaps()

{

    if (isNPOT())

        return false;

    const LevelInfo& first = m_info[0][0];

    for (size_t ii = 0; ii < m_info.size(); ++ii) {

        const LevelInfo& info = m_info[ii][0];

        if (!info.valid

            || info.width != first.width || info.height != first.height

            || info.internalFormat != first.internalFormat || info.type != first.type)

            return false;

    }

    return true;

}

int WebGLTexture::computeLevelCount(int width, int height)

{

    // return 1 + log2Floor(std::max(width, height));

    int n = std::max(width, height);

    if (n <= 0)

        return 0;

    int log = 0;

    int value = n;

    for (int ii = 4; ii >= 0; --ii) {

        int shift = (1 << ii);

        int x = (value >> shift);

        if (x) {

            value = x;

            log += shift;

        }

    }

    ASSERT(value == 1);

    return log + 1;

}

void WebGLTexture::update()

{

    m_isNPOT = false;

    for (size_t ii = 0; ii < m_info.size(); ++ii) {

        if (isNPOT(m_info[ii][0].width, m_info[ii][0].height)) {

            m_isNPOT = true;

            break;

        }

    }

    m_isComplete = true;

    const LevelInfo& first = m_info[0][0];

    int levelCount = computeLevelCount(first.width, first.height);

    if (levelCount < 1)

        m_isComplete = false;

    else {

        for (size_t ii = 0; ii < m_info.size() && m_isComplete; ++ii) {

            const LevelInfo& info0 = m_info[ii][0];

            if (!info0.valid

                || info0.width != first.width || info0.height != first.height

                || info0.internalFormat != first.internalFormat || info0.type != first.type) {

                m_isComplete = false;

                break;

            }

            int width = info0.width;

            int height = info0.height;

            for (int level = 1; level < levelCount; ++level) {

                width = std::max(1, width >> 1);

                height = std::max(1, height >> 1);

                const LevelInfo& info = m_info[ii][level];

                if (!info.valid

                    || info.width != width || info.height != height

                    || info.internalFormat != info0.internalFormat || info.type != info0.type) {

                    m_isComplete = false;

                    break;

                }

            }

        }

    }

    m_needToUseBlackTexture = false;

    // NPOT

    if (m_isNPOT && ((m_minFilter != GraphicsContext3D::NEAREST && m_minFilter != GraphicsContext3D::LINEAR)

                     || m_wrapS != GraphicsContext3D::CLAMP_TO_EDGE || m_wrapT != GraphicsContext3D::CLAMP_TO_EDGE))

        m_needToUseBlackTexture = true;

    // Completeness

    if (!m_isComplete && m_minFilter != GraphicsContext3D::NEAREST && m_minFilter != GraphicsContext3D::LINEAR)

        m_needToUseBlackTexture = true;

}

}

#endif // ENABLE(3D_CANVAS)