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#include "qsgdefaultinternalimagenode_p.h"
#include <private/qsgmaterialshader_p.h>
#include <private/qsgtexturematerial_p.h>
#include <QtGui/qopenglfunctions.h>
#include <QtCore/qmath.h>

QT_BEGIN_NAMESPACE

class SmoothTextureMaterialShader : public QSGTextureMaterialShader
{
public:
    SmoothTextureMaterialShader();

    void updateState(const RenderState &state, QSGMaterial *newEffect, QSGMaterial *oldEffect) override;
    char const *const *attributeNames() const override;

protected:
    void initialize() override;

    int m_pixelSizeLoc;
};


QSGSmoothTextureMaterial::QSGSmoothTextureMaterial()
{
    setFlag(RequiresFullMatrixExceptTranslate, true);
    setFlag(Blending, true);
}

void QSGSmoothTextureMaterial::setTexture(QSGTexture *texture)
{
    m_texture = texture;
}

QSGMaterialType *QSGSmoothTextureMaterial::type() const
{
    static QSGMaterialType type;
    return &type;
}

QSGMaterialShader *QSGSmoothTextureMaterial::createShader() const
{
    return new SmoothTextureMaterialShader;
}

SmoothTextureMaterialShader::SmoothTextureMaterialShader()
{
    setShaderSourceFile(QOpenGLShader::Vertex, QStringLiteral(":/qt-project.org/scenegraph/shaders/smoothtexture.vert"));
    setShaderSourceFile(QOpenGLShader::Fragment, QStringLiteral(":/qt-project.org/scenegraph/shaders/smoothtexture.frag"));
}

void SmoothTextureMaterialShader::updateState(const RenderState &state, QSGMaterial *newEffect, QSGMaterial *oldEffect)
{
    if (oldEffect == nullptr) {
        // The viewport is constant, so set the pixel size uniform only once.
        QRect r = state.viewportRect();
        program()->setUniformValue(m_pixelSizeLoc, 2.0f / r.width(), 2.0f / r.height());
    }
    QSGTextureMaterialShader::updateState(state, newEffect, oldEffect);
}

char const *const *SmoothTextureMaterialShader::attributeNames() const
{
    static char const *const attributes[] = {
        "vertex",
        "multiTexCoord",
        "vertexOffset",
        "texCoordOffset",
        nullptr
    };
    return attributes;
}

void SmoothTextureMaterialShader::initialize()
{
    m_pixelSizeLoc = program()->uniformLocation("pixelSize");
    QSGTextureMaterialShader::initialize();
}

QSGDefaultInternalImageNode::QSGDefaultInternalImageNode()
{
    setMaterial(&m_materialO);
    setOpaqueMaterial(&m_material);
}

void QSGDefaultInternalImageNode::setFiltering(QSGTexture::Filtering filtering)
{
    if (m_material.filtering() == filtering)
        return;

    m_material.setFiltering(filtering);
    m_materialO.setFiltering(filtering);
    m_smoothMaterial.setFiltering(filtering);
    markDirty(DirtyMaterial);
}

void QSGDefaultInternalImageNode::setMipmapFiltering(QSGTexture::Filtering filtering)
{
    if (m_material.mipmapFiltering() == filtering)
        return;

    m_material.setMipmapFiltering(filtering);
    m_materialO.setMipmapFiltering(filtering);
    m_smoothMaterial.setMipmapFiltering(filtering);
    markDirty(DirtyMaterial);
}

void QSGDefaultInternalImageNode::setVerticalWrapMode(QSGTexture::WrapMode wrapMode)
{
    if (m_material.verticalWrapMode() == wrapMode)
        return;

    m_material.setVerticalWrapMode(wrapMode);
    m_materialO.setVerticalWrapMode(wrapMode);
    m_smoothMaterial.setVerticalWrapMode(wrapMode);
    markDirty(DirtyMaterial);
}

void QSGDefaultInternalImageNode::setHorizontalWrapMode(QSGTexture::WrapMode wrapMode)
{
    if (m_material.horizontalWrapMode() == wrapMode)
        return;

    m_material.setHorizontalWrapMode(wrapMode);
    m_materialO.setHorizontalWrapMode(wrapMode);
    m_smoothMaterial.setHorizontalWrapMode(wrapMode);
    markDirty(DirtyMaterial);
}

void QSGDefaultInternalImageNode::updateMaterialAntialiasing()
{
    if (m_antialiasing) {
        setMaterial(&m_smoothMaterial);
        setOpaqueMaterial(nullptr);
    } else {
        setMaterial(&m_materialO);
        setOpaqueMaterial(&m_material);
    }
}

void QSGDefaultInternalImageNode::setMaterialTexture(QSGTexture *texture)
{
    m_material.setTexture(texture);
    m_materialO.setTexture(texture);
    m_smoothMaterial.setTexture(texture);
}

QSGTexture *QSGDefaultInternalImageNode::materialTexture() const
{
    return m_material.texture();
}

bool QSGDefaultInternalImageNode::updateMaterialBlending()
{
    const bool alpha = m_material.flags() & QSGMaterial::Blending;
    if (materialTexture() && alpha != materialTexture()->hasAlphaChannel()) {
        m_material.setFlag(QSGMaterial::Blending, !alpha);
        return true;
    }
    return false;
}

inline static bool isPowerOfTwo(int x)
{
    // Assumption: x >= 1
    return x == (x & -x);
}

bool QSGDefaultInternalImageNode::supportsWrap(const QSize &size) const
{
    bool wrapSupported = true;

    QOpenGLContext *ctx = QOpenGLContext::currentContext();
#ifndef QT_OPENGL_ES_2
    if (ctx->isOpenGLES())
#endif
    {
        bool npotSupported = ctx->functions()->hasOpenGLFeature(QOpenGLFunctions::NPOTTextureRepeat);
        const bool isNpot = !isPowerOfTwo(size.width()) || !isPowerOfTwo(size.height());
        wrapSupported = npotSupported || !isNpot;
    }

    return wrapSupported;
}

QT_END_NAMESPACE
