Cocos2d-x Sprite笔记

1.create

auto sprite = Sprite::create("HelloWorld.png");
Sprite* Sprite::create(const std::string& filename)
{
    Sprite *sprite = new (std::nothrow) Sprite();
    if (sprite && sprite->initWithFile(filename))
    {
        sprite->autorelease();
        return sprite;
    }
    CC_SAFE_DELETE(sprite);
    return nullptr;
}
Sprite::Sprite(void)
: _batchNode(nullptr)
, _textureAtlas(nullptr)
, _shouldBeHidden(false)
, _texture(nullptr)
, _spriteFrame(nullptr)
, _insideBounds(true)
{
}

2.init

bool Sprite::initWithFile(const std::string& filename)
{
    if (filename.empty())
    {
        CCLOG("Call Sprite::initWithFile with blank resource filename.");
        return false;
    }

    _fileName = filename;
    _fileType = 0;

    Texture2D *texture = _director->getTextureCache()->addImage(filename);
    if (texture)
    {
        Rect rect = Rect::ZERO;
        rect.size = texture->getContentSize();
        return initWithTexture(texture, rect);
    }

    // don't release here.
    // when load texture failed, it's better to get a "transparent" sprite then a crashed program
    // this->release();
    return false;
}

1）_director->getTextureCache()->addImage(filename)：TextureCache用于管理texture的加载（另开一个线程）
2）rect.size = texture->getContentSize()：用texture content size（像素为单位，window.size也是以像素为单位）作为Sprite的size，如果是一张1024X768的图片，则rect = （0，0，1024，768），这个rect会用来生成Sprite的顶点坐标，比如这个Rect的右上角对应的顶点坐标是（1024 / window.size.w, 768 / window.size.h）

bool Node::init()
{
    return true;
}
bool Sprite::initWithTexture(Texture2D *texture, const Rect& rect, bool rotated)
{
    bool result = false;
    if (Node::init())
    {
        _batchNode = nullptr;

        _recursiveDirty = false;
        setDirty(false);

        _opacityModifyRGB = true;

        _blendFunc = BlendFunc::ALPHA_PREMULTIPLIED;

        _flippedX = _flippedY = false;

        // default transform anchor: center
        setAnchorPoint(Vec2(0.5f, 0.5f));

        // zwoptex default values
        _offsetPosition.setZero();

        // clean the Quad
        memset(&_quad, 0, sizeof(_quad));

        // Atlas: Color
        _quad.bl.colors = Color4B::WHITE;
        _quad.br.colors = Color4B::WHITE;
        _quad.tl.colors = Color4B::WHITE;
        _quad.tr.colors = Color4B::WHITE;

        // update texture (calls updateBlendFunc), set program but not set vertex attrib and uniform
        setTexture(texture);
        // set _quad, _texcoord
        setTextureRect(rect, rotated, rect.size);

        // by default use "Self Render".
        // if the sprite is added to a batchnode, then it will automatically switch to "batchnode Render"
        setBatchNode(nullptr);
        result = true;
    }

    _recursiveDirty = true;
    setDirty(true);

    return result;
}

0）_quad.bl.colors = Color4B::WHITE：默认4个角的颜色为白色
1）_flippedX = _flippedY = false：不需要flip，因为TexCoords按照未flip生成的（y轴向下，OpenGL坐标系y轴向上）
2）setAnchorPoint(Vec2(0.5f, 0.5f))：除了layer类，其他Node类锚点默认在正中间
3）_offsetPosition.setZero()：Node的content size可能和texture size不一样，这样就会产生offset，一般offset都是0。因为使用texture的content size来设置Node的content size的，两者相等，所以没有offset。
4）setTexture(texture)：设置texture，获取GLProgramState，加载编译所有的program，如果texture为nullptr，用一张白色的图片作为texture

void Sprite::setTexture(Texture2D *texture)
{
    setGLProgramState(GLProgramState::getOrCreateWithGLProgramName(GLProgram::SHADER_NAME_POSITION_TEXTURE_COLOR_NO_MVP, texture));

    // If batchnode, then texture id should be the same
    CCASSERT(! _batchNode || (texture &&  texture->getName() == _batchNode->getTexture()->getName()), "CCSprite: Batched sprites should use the same texture as the batchnode");
    // accept texture==nil as argument
    CCASSERT( !texture || dynamic_cast<Texture2D*>(texture), "setTexture expects a Texture2D. Invalid argument");

    if (texture == nullptr)
    {
        // Gets the texture by key firstly.
        texture = _director->getTextureCache()->getTextureForKey(CC_2x2_WHITE_IMAGE_KEY);

        // If texture wasn't in cache, create it from RAW data.
        if (texture == nullptr)
        {
            Image* image = new (std::nothrow) Image();
            bool isOK = image->initWithRawData(cc_2x2_white_image, sizeof(cc_2x2_white_image), 2, 2, 8);
            CC_UNUSED_PARAM(isOK);
            CCASSERT(isOK, "The 2x2 empty texture was created unsuccessfully.");

            texture = _director->getTextureCache()->addImage(image, CC_2x2_WHITE_IMAGE_KEY);
            CC_SAFE_RELEASE(image);
        }
    }

    if (!_batchNode && _texture != texture)
    {
        CC_SAFE_RETAIN(texture);
        CC_SAFE_RELEASE(_texture);
        _texture = texture;
        updateBlendFunc();
    }
}

5）setTextureRect(rect, rotated, rect.size)：setTexCoords（左上为(0,0), 左下为(0.1)，load image不flip，TexCoords实现flip）和setPosition（position没有变，左下为(0,0)）

void Sprite::setTextureRect(const Rect& rect, bool rotated, const Size& untrimmedSize)
{
    _rectRotated = rotated;

    setContentSize(untrimmedSize);
    setVertexRect(rect);
    setTextureCoords(rect);

    float relativeOffsetX = _unflippedOffsetPositionFromCenter.x;
    float relativeOffsetY = _unflippedOffsetPositionFromCenter.y;

    // issue #732
    if (_flippedX)
    {
        relativeOffsetX = -relativeOffsetX;
    }
    if (_flippedY)
    {
        relativeOffsetY = -relativeOffsetY;
    }

    _offsetPosition.x = relativeOffsetX + (_contentSize.width - _rect.size.width) / 2;
    _offsetPosition.y = relativeOffsetY + (_contentSize.height - _rect.size.height) / 2;

    // rendering using batch node
    if (_batchNode)
    {
        // update dirty_, don't update recursiveDirty_
        setDirty(true);
    }
    else
    {
        // self rendering

        // Atlas: Vertex
        float x1 = 0.0f + _offsetPosition.x;
        float y1 = 0.0f + _offsetPosition.y;
        float x2 = x1 + _rect.size.width;
        float y2 = y1 + _rect.size.height;

        // Don't update Z.
        _quad.bl.vertices.set(x1, y1, 0.0f);
        _quad.br.vertices.set(x2, y1, 0.0f);
        _quad.tl.vertices.set(x1, y2, 0.0f);
        _quad.tr.vertices.set(x2, y2, 0.0f);
    }

    _polyInfo.setQuad(&_quad);
}
void Node::setContentSize(const Size & size)
{
    if (! size.equals(_contentSize))
    {
        _contentSize = size;

        _anchorPointInPoints.set(_contentSize.width * _anchorPoint.x, _contentSize.height * _anchorPoint.y);
        _transformUpdated = _transformDirty = _inverseDirty = _contentSizeDirty = true;
    }
}
void Sprite::setVertexRect(const Rect& rect)
{
    _rect = rect;
}
void Sprite::setTextureCoords(const Rect& rectInPoint)
{
    Texture2D *tex = _batchNode ? _textureAtlas->getTexture() : _texture;
    if (tex == nullptr)
    {
        return;
    }

    auto rectInPixels = CC_RECT_POINTS_TO_PIXELS(rectInPoint);

    float atlasWidth = (float)tex->getPixelsWide();
    float atlasHeight = (float)tex->getPixelsHigh();

    float left, right, top, bottom;

    if (_rectRotated)
    {
#if CC_FIX_ARTIFACTS_BY_STRECHING_TEXEL
        left    = (2*rectInPixels.origin.x+1)/(2*atlasWidth);
        right   = left+(rectInPixels.size.height*2-2)/(2*atlasWidth);
        top     = (2*rectInPixels.origin.y+1)/(2*atlasHeight);
        bottom  = top+(rectInPixels.size.width*2-2)/(2*atlasHeight);
#else
        left    = rectInPixels.origin.x/atlasWidth;
        right   = (rectInPixels.origin.x+rectInPixels.size.height) / atlasWidth;
        top     = rectInPixels.origin.y/atlasHeight;
        bottom  = (rectInPixels.origin.y+rectInPixels.size.width) / atlasHeight;
#endif // CC_FIX_ARTIFACTS_BY_STRECHING_TEXEL

        if (_flippedX)
        {
            std::swap(top, bottom);
        }

        if (_flippedY)
        {
            std::swap(left, right);
        }

        _quad.bl.texCoords.u = left;
        _quad.bl.texCoords.v = top;
        _quad.br.texCoords.u = left;
        _quad.br.texCoords.v = bottom;
        _quad.tl.texCoords.u = right;
        _quad.tl.texCoords.v = top;
        _quad.tr.texCoords.u = right;
        _quad.tr.texCoords.v = bottom;
    }
    else
    {
#if CC_FIX_ARTIFACTS_BY_STRECHING_TEXEL
        left    = (2*rectInPixels.origin.x+1)/(2*atlasWidth);
        right    = left + (rectInPixels.size.width*2-2)/(2*atlasWidth);
        top        = (2*rectInPixels.origin.y+1)/(2*atlasHeight);
        bottom    = top + (rectInPixels.size.height*2-2)/(2*atlasHeight);
#else
        left    = rectInPixels.origin.x/atlasWidth;
        right    = (rectInPixels.origin.x + rectInPixels.size.width) / atlasWidth;
        top        = rectInPixels.origin.y/atlasHeight;
        bottom    = (rectInPixels.origin.y + rectInPixels.size.height) / atlasHeight;
#endif // ! CC_FIX_ARTIFACTS_BY_STRECHING_TEXEL

        if(_flippedX)
        {
            std::swap(left, right);
        }

        if(_flippedY)
        {
            std::swap(top, bottom);
        }

        _quad.bl.texCoords.u = left;
        _quad.bl.texCoords.v = bottom;
        _quad.br.texCoords.u = right;
        _quad.br.texCoords.v = bottom;
        _quad.tl.texCoords.u = left;
        _quad.tl.texCoords.v = top;
        _quad.tr.texCoords.u = right;
        _quad.tr.texCoords.v = top;
    }
}
/**The structure of Triangles. */
struct Triangles
{
    /**Vertex data pointer.*/
    V3F_C4B_T2F* verts;
    /**Index data pointer.*/
    unsigned short* indices;
    /**The number of vertices.*/
    int vertCount;
    /**The number of indices.*/
    int indexCount;
};
static unsigned short quadIndices[]={0,1,2, 3,2,1};
void PolygonInfo::setQuad(V3F_C4B_T2F_Quad *quad)
{
    releaseVertsAndIndices();
    isVertsOwner = false;
    triangles.indices = quadIndices;
    triangles.vertCount = 4;
    triangles.indexCount = 6;
    triangles.verts = (V3F_C4B_T2F*)quad;
}

6）init之后，texture，position（未归一化，bl(0,0)，br(0,1024)，tl(0,768)，tr(1024,768)），indices（预定义的{0,1,2, 3,2,1}），TexCoords（flip过的，bl(0,1)，br(1,1)，tl(0,0)，tr(1,0)）

3.setPosition

sprite->setPosition(Vec2(visibleSize / 2) + origin);
void Sprite::setPosition(const Vec2& pos)
{
    Node::setPosition(pos);
    SET_DIRTY_RECURSIVELY();
}
void Node::setPosition(float x, float y)
{
    if (_position.x == x && _position.y == y)
        return;

    _position.x = x;
    _position.y = y;

    _transformUpdated = _transformDirty = _inverseDirty = true;
    _usingNormalizedPosition = false;
}

1）这里的Position是用来生成translate的
2）与移动相关的Action修改的也是这个Position
3）如何由Position到Transform Matrix

const Mat4& Node::getNodeToParentTransform() const
{
    if (_transformDirty)
    {
        // Translate values 0
        float x = _position.x;
        float y = _position.y;
        float z = _positionZ;
        // _ignoreAnchorPointForPosition = false
        if (_ignoreAnchorPointForPosition)
        {
            x += _anchorPointInPoints.x;
            y += _anchorPointInPoints.y;
        }

        bool needsSkewMatrix = ( _skewX || _skewY );


        Vec2 anchorPoint(_anchorPointInPoints.x * _scaleX, _anchorPointInPoints.y * _scaleY);

        // calculate real position 1
        // get real translation
        if (! needsSkewMatrix && !_anchorPointInPoints.isZero())
        {
            x += -anchorPoint.x;
            y += -anchorPoint.y;
        }

        // Build Transform Matrix = translation * rotation * scale
        Mat4 translation;
        // move to anchor point first, then rotate 2
        // will restore after rotate
        Mat4::createTranslation(x + anchorPoint.x, y + anchorPoint.y, z, &translation);

        Mat4::createRotation(_rotationQuat, &_transform);

        if (_rotationZ_X != _rotationZ_Y)
        {
            // Rotation values
            // Change rotation code to handle X and Y
            // If we skew with the exact same value for both x and y then we're simply just rotating
            float radiansX = -CC_DEGREES_TO_RADIANS(_rotationZ_X);
            float radiansY = -CC_DEGREES_TO_RADIANS(_rotationZ_Y);
            float cx = cosf(radiansX);
            float sx = sinf(radiansX);
            float cy = cosf(radiansY);
            float sy = sinf(radiansY);

            float m0 = _transform.m[0], m1 = _transform.m[1], m4 = _transform.m[4], m5 = _transform.m[5], m8 = _transform.m[8], m9 = _transform.m[9];
            _transform.m[0] = cy * m0 - sx * m1, _transform.m[4] = cy * m4 - sx * m5, _transform.m[8] = cy * m8 - sx * m9;
            _transform.m[1] = sy * m0 + cx * m1, _transform.m[5] = sy * m4 + cx * m5, _transform.m[9] = sy * m8 + cx * m9;
        }
        _transform = translation * _transform;
        // move by (-anchorPoint.x, -anchorPoint.y, 0) after rotation 3
        // restore position after rotate
        _transform.translate(-anchorPoint.x, -anchorPoint.y, 0);


        if (_scaleX != 1.f)
        {
            _transform.m[0] *= _scaleX, _transform.m[1] *= _scaleX, _transform.m[2] *= _scaleX;
        }
        if (_scaleY != 1.f)
        {
            _transform.m[4] *= _scaleY, _transform.m[5] *= _scaleY, _transform.m[6] *= _scaleY;
        }
        if (_scaleZ != 1.f)
        {
            _transform.m[8] *= _scaleZ, _transform.m[9] *= _scaleZ, _transform.m[10] *= _scaleZ;
        }

        // FIXME:: Try to inline skew
        // If skew is needed, apply skew and then anchor point
        if (needsSkewMatrix)
        {
            float skewMatArray[16] =
            {
                1, (float)tanf(CC_DEGREES_TO_RADIANS(_skewY)), 0, 0,
                (float)tanf(CC_DEGREES_TO_RADIANS(_skewX)), 1, 0, 0,
                0,  0,  1, 0,
                0,  0,  0, 1
            };
            Mat4 skewMatrix(skewMatArray);

            _transform = _transform * skewMatrix;

            // adjust anchor point
            if (!_anchorPointInPoints.isZero())
            {
                // FIXME:: Argh, Mat4 needs a "translate" method.
                // FIXME:: Although this is faster than multiplying a vec4 * mat4
                _transform.m[12] += _transform.m[0] * -_anchorPointInPoints.x + _transform.m[4] * -_anchorPointInPoints.y;
                _transform.m[13] += _transform.m[1] * -_anchorPointInPoints.x + _transform.m[5] * -_anchorPointInPoints.y;
            }
        }
    }
    // only camera node need this maybe, get additional transform from scene's eyeTransform Matrix
    if (_additionalTransform)
    {
        // This is needed to support both Node::setNodeToParentTransform() and Node::setAdditionalTransform()
        // at the same time. The scenario is this:
        // at some point setNodeToParentTransform() is called.
        // and later setAdditionalTransform() is called every time. And since _transform
        // is being overwritten everyframe, _additionalTransform[1] is used to have a copy
        // of the last "_transform without _additionalTransform"
        if (_transformDirty)
            _additionalTransform[1] = _transform;

        if (_transformUpdated)
            _transform = _additionalTransform[1] * _additionalTransform[0];
    }

    _transformDirty = _additionalTransformDirty = false;

    return _transform;
}

4.visit

void Node::visit(Renderer* renderer, const Mat4 &parentTransform, uint32_t parentFlags)
{
    // quick return if not visible. children won't be drawn.
    if (!_visible)
    {
        return;
    }
    // set transform
    uint32_t flags = processParentFlags(parentTransform, parentFlags);

    // IMPORTANT:
    // To ease the migration to v3.0, we still support the Mat4 stack,
    // but it is deprecated and your code should not rely on it
    _director->pushMatrix(MATRIX_STACK_TYPE::MATRIX_STACK_MODELVIEW);
    _director->loadMatrix(MATRIX_STACK_TYPE::MATRIX_STACK_MODELVIEW, _modelViewTransform);

    bool visibleByCamera = isVisitableByVisitingCamera();

    int i = 0;

    if(!_children.empty())
    {
        sortAllChildren();
        // draw children zOrder < 0
        for( ; i < _children.size(); i++ )
        {
            auto node = _children.at(i);

            if (node && node->_localZOrder < 0)
                node->visit(renderer, _modelViewTransform, flags);
            else
                break;
        }
        // self draw
        if (visibleByCamera)
            this->draw(renderer, _modelViewTransform, flags);

        for(auto it=_children.cbegin()+i; it != _children.cend(); ++it)
            (*it)->visit(renderer, _modelViewTransform, flags);
    }
    else if (visibleByCamera)
    {
        this->draw(renderer, _modelViewTransform, flags);
    }

    _director->popMatrix(MATRIX_STACK_TYPE::MATRIX_STACK_MODELVIEW);

    // FIX ME: Why need to set _orderOfArrival to 0??
    // Please refer to https://github.com/cocos2d/cocos2d-x/pull/6920
    // reset for next frame
    // _orderOfArrival = 0;
}

由Position get _modelViewTransform

uint32_t Node::processParentFlags(const Mat4& parentTransform, uint32_t parentFlags)
{
    // _usingNormalizedPosition = false
    if(_usingNormalizedPosition)
    {
        CCASSERT(_parent, "setNormalizedPosition() doesn't work with orphan nodes");
        if ((parentFlags & FLAGS_CONTENT_SIZE_DIRTY) || _normalizedPositionDirty)
        {
            auto& s = _parent->getContentSize();
            _position.x = _normalizedPosition.x * s.width;
            _position.y = _normalizedPosition.y * s.height;
            _transformUpdated = _transformDirty = _inverseDirty = true;
            _normalizedPositionDirty = false;
        }
    }

    // Fixes Github issue #16100. Basically when having two cameras, one camera might set as dirty the
    // node that is not visited by it, and might affect certain calculations. Besides, it is faster to do this.
    if (!isVisitableByVisitingCamera())
        return parentFlags;

    uint32_t flags = parentFlags;
    flags |= (_transformUpdated ? FLAGS_TRANSFORM_DIRTY : 0);
    flags |= (_contentSizeDirty ? FLAGS_CONTENT_SIZE_DIRTY : 0);

    // true
    if(flags & FLAGS_DIRTY_MASK)
        _modelViewTransform = this->transform(parentTransform);

    _transformUpdated = false;
    _contentSizeDirty = false;

    return flags;
}
Mat4 Node::transform(const Mat4& parentTransform)
{
    return parentTransform * this->getNodeToParentTransform();
}
const Mat4& Node::getNodeToParentTransform() const
{
    if (_transformDirty)
    {
        // Translate values
        float x = _position.x;
        float y = _position.y;
        float z = _positionZ;
        // false
        if (_ignoreAnchorPointForPosition)
        {
            x += _anchorPointInPoints.x;
            y += _anchorPointInPoints.y;
        }

        bool needsSkewMatrix = ( _skewX || _skewY );

        // (1024.0/2, 768.0/2)
        Vec2 anchorPoint(_anchorPointInPoints.x * _scaleX, _anchorPointInPoints.y * _scaleY);

        // calculate real position
        // not ignore AnchorPoint, calculate real translate values
        if (! needsSkewMatrix && !_anchorPointInPoints.isZero())
        {
            x += -anchorPoint.x;
            y += -anchorPoint.y;
        }

        // Build Transform Matrix = translation * rotation * scale
        Mat4 translation;
        //move to anchor point first, then rotate 2
        Mat4::createTranslation(x + anchorPoint.x, y + anchorPoint.y, z, &translation);

        Mat4::createRotation(_rotationQuat, &_transform);

        if (_rotationZ_X != _rotationZ_Y)
        {
            // Rotation values
            // Change rotation code to handle X and Y
            // If we skew with the exact same value for both x and y then we're simply just rotating
            float radiansX = -CC_DEGREES_TO_RADIANS(_rotationZ_X);
            float radiansY = -CC_DEGREES_TO_RADIANS(_rotationZ_Y);
            float cx = cosf(radiansX);
            float sx = sinf(radiansX);
            float cy = cosf(radiansY);
            float sy = sinf(radiansY);

            float m0 = _transform.m[0], m1 = _transform.m[1], m4 = _transform.m[4], m5 = _transform.m[5], m8 = _transform.m[8], m9 = _transform.m[9];
            _transform.m[0] = cy * m0 - sx * m1, _transform.m[4] = cy * m4 - sx * m5, _transform.m[8] = cy * m8 - sx * m9;
            _transform.m[1] = sy * m0 + cx * m1, _transform.m[5] = sy * m4 + cx * m5, _transform.m[9] = sy * m8 + cx * m9;
        }
        _transform = translation * _transform;
        //move by (-anchorPoint.x, -anchorPoint.y, 0) after rotation 3
        _transform.translate(-anchorPoint.x, -anchorPoint.y, 0);


        if (_scaleX != 1.f)
        {
            _transform.m[0] *= _scaleX, _transform.m[1] *= _scaleX, _transform.m[2] *= _scaleX;
        }
        if (_scaleY != 1.f)
        {
            _transform.m[4] *= _scaleY, _transform.m[5] *= _scaleY, _transform.m[6] *= _scaleY;
        }
        if (_scaleZ != 1.f)
        {
            _transform.m[8] *= _scaleZ, _transform.m[9] *= _scaleZ, _transform.m[10] *= _scaleZ;
        }

        // FIXME:: Try to inline skew
        // If skew is needed, apply skew and then anchor point
        if (needsSkewMatrix)
        {
            float skewMatArray[16] =
            {
                1, (float)tanf(CC_DEGREES_TO_RADIANS(_skewY)), 0, 0,
                (float)tanf(CC_DEGREES_TO_RADIANS(_skewX)), 1, 0, 0,
                0,  0,  1, 0,
                0,  0,  0, 1
            };
            Mat4 skewMatrix(skewMatArray);

            _transform = _transform * skewMatrix;

            // adjust anchor point
            if (!_anchorPointInPoints.isZero())
            {
                // FIXME:: Argh, Mat4 needs a "translate" method.
                // FIXME:: Although this is faster than multiplying a vec4 * mat4
                _transform.m[12] += _transform.m[0] * -_anchorPointInPoints.x + _transform.m[4] * -_anchorPointInPoints.y;
                _transform.m[13] += _transform.m[1] * -_anchorPointInPoints.x + _transform.m[5] * -_anchorPointInPoints.y;
            }
        }
    }
    // false
    if (_additionalTransform)
    {
        // This is needed to support both Node::setNodeToParentTransform() and Node::setAdditionalTransform()
        // at the same time. The scenario is this:
        // at some point setNodeToParentTransform() is called.
        // and later setAdditionalTransform() is called every time. And since _transform
        // is being overwritten everyframe, _additionalTransform[1] is used to have a copy
        // of the last "_transform without _additionalTransform"
        if (_transformDirty)
            _additionalTransform[1] = _transform;

        if (_transformUpdated)
            _transform = _additionalTransform[1] * _additionalTransform[0];
    }

    _transformDirty = _additionalTransformDirty = false;

    return _transform;
}

visit就是沿着Node树从root node把transform传递下去，如：scene的translate同样要apply到子children node，并且在apply transform后，按照树关系调用children node的draw()函数add command，Sprite添加TrianglesCommand

5.draw

void Sprite::draw(Renderer *renderer, const Mat4 &transform, uint32_t flags)
{
    if (_texture == nullptr)
    {
        return;
    }

#if CC_USE_CULLING
    // Don't calculate the culling if the transform was not updated
    auto visitingCamera = Camera::getVisitingCamera();
    auto defaultCamera = Camera::getDefaultCamera();
    if (visitingCamera == defaultCamera) {
        _insideBounds = ((flags & FLAGS_TRANSFORM_DIRTY) || visitingCamera->isViewProjectionUpdated()) ? renderer->checkVisibility(transform, _contentSize) : _insideBounds;
    }
    else
    {
        // XXX: this always return true since
        _insideBounds = renderer->checkVisibility(transform, _contentSize);
    }

    if(_insideBounds)
#endif
    {
        _trianglesCommand.init(_globalZOrder, 
            _texture, 
            getGLProgramState(), 
            _blendFunc, 
            _polyInfo.triangles, 
            transform, 
            flags);

        renderer->addCommand(&_trianglesCommand);
    }
}
void TrianglesCommand::init(float globalOrder, GLuint textureID, GLProgramState* glProgramState, BlendFunc blendType, const Triangles& triangles,const Mat4& mv, uint32_t flags)
{
    CCASSERT(glProgramState, "Invalid GLProgramState");
    CCASSERT(glProgramState->getVertexAttribsFlags() == 0, "No custom attributes are supported in QuadCommand");

    RenderCommand::init(globalOrder, mv, flags);

    _triangles = triangles;
    if(_triangles.indexCount % 3 != 0)
    {
        int count = _triangles.indexCount;
        _triangles.indexCount = count / 3 * 3;
        CCLOGERROR("Resize indexCount from %zd to %zd, size must be multiple times of 3", count, _triangles.indexCount);
    }
    _mv = mv;

    if( _textureID != textureID || _blendType.src != blendType.src || _blendType.dst != blendType.dst ||
       _glProgramState != glProgramState ||
       _glProgram != glProgramState->getGLProgram())
    {
        _textureID = textureID;
        _blendType = blendType;
        _glProgramState = glProgramState;
        _glProgram = glProgramState->getGLProgram();

        generateMaterialID();
    }
}
void Renderer::addCommand(RenderCommand* command)
{
    // renderQueue = 0, usual only one renderGroup
    int renderQueue =_commandGroupStack.top();
    addCommand(command, renderQueue);
}

void Renderer::addCommand(RenderCommand* command, int renderQueue)
{
    CCASSERT(!_isRendering, "Cannot add command while rendering");
    CCASSERT(renderQueue >=0, "Invalid render queue");
    CCASSERT(command->getType() != RenderCommand::Type::UNKNOWN_COMMAND, "Invalid Command Type");
    // only have one render groups, but five commands array : GLOBALZ_NEG, OPAQUE_3D ... 
    _renderGroups[renderQueue].push_back(command);
}
enum QUEUE_GROUP
{
    /**Objects with globalZ smaller than 0.*/
    GLOBALZ_NEG = 0,
    /**Opaque 3D objects with 0 globalZ.*/
    OPAQUE_3D = 1,
    /**Transparent 3D objects with 0 globalZ.*/
    TRANSPARENT_3D = 2,
    /**2D objects with 0 globalZ.*/
    GLOBALZ_ZERO = 3,
    /**Objects with globalZ bigger than 0.*/
    GLOBALZ_POS = 4,
    /**Max Queue Count*/
    QUEUE_COUNT = 5,
};
void RenderQueue::push_back(RenderCommand* command)
{
    float z = command->getGlobalOrder();
    if(z < 0)
    {
        _commands[QUEUE_GROUP::GLOBALZ_NEG].push_back(command);
    }
    else if(z > 0)
    {
        _commands[QUEUE_GROUP::GLOBALZ_POS].push_back(command);
    }
    else
    {
        if(command->is3D())
        {
            if(command->isTransparent())
            {
                _commands[QUEUE_GROUP::TRANSPARENT_3D].push_back(command);
            }
            else
            {
                _commands[QUEUE_GROUP::OPAQUE_3D].push_back(command);
            }
        }
        else
        {
            _commands[QUEUE_GROUP::GLOBALZ_ZERO].push_back(command);
        }
    }
}

6.render

void Renderer::render()
{
    //Uncomment this once everything is rendered by new renderer
    //glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    //TODO: setup camera or MVP
    _isRendering = true;

    if (_glViewAssigned)
    {
        //Process render commands
        //1. Sort render commands based on ID
        for (auto &renderqueue : _renderGroups)
        {
            // sort use zorder
            renderqueue.sort();
        }
        // 
        visitRenderQueue(_renderGroups[0]);
    }
    clean();
    _isRendering = false;
}
void RenderQueue::sort()
{
    // Don't sort _queue0, it already comes sorted
    std::sort(std::begin(_commands[QUEUE_GROUP::TRANSPARENT_3D]), std::end(_commands[QUEUE_GROUP::TRANSPARENT_3D]), compare3DCommand);
    std::sort(std::begin(_commands[QUEUE_GROUP::GLOBALZ_NEG]), std::end(_commands[QUEUE_GROUP::GLOBALZ_NEG]), compareRenderCommand);
    std::sort(std::begin(_commands[QUEUE_GROUP::GLOBALZ_POS]), std::end(_commands[QUEUE_GROUP::GLOBALZ_POS]), compareRenderCommand);
}
void Renderer::visitRenderQueue(RenderQueue& queue)
{
    queue.saveRenderState();

    //
    //Process Global-Z < 0 Objects
    //

    //
    //Process Opaque Object
    //

    //
    //Process 3D Transparent object
    //

    //
    //Process Global-Z = 0 Queue
    //
    const auto& zZeroQueue = queue.getSubQueue(RenderQueue::QUEUE_GROUP::GLOBALZ_ZERO);
    if (zZeroQueue.size() > 0)
    {
        // false
        if(_isDepthTestFor2D)
        {
            glEnable(GL_DEPTH_TEST);
            glDepthMask(true);
            glEnable(GL_BLEND);

            RenderState::StateBlock::_defaultState->setDepthTest(true);
            RenderState::StateBlock::_defaultState->setDepthWrite(true);
            RenderState::StateBlock::_defaultState->setBlend(true);
        }
        else
        {
            glDisable(GL_DEPTH_TEST);
            glDepthMask(false);
            glEnable(GL_BLEND);

            RenderState::StateBlock::_defaultState->setDepthTest(false);
            RenderState::StateBlock::_defaultState->setDepthWrite(false);
            RenderState::StateBlock::_defaultState->setBlend(true);
        }
        glDisable(GL_CULL_FACE);
        RenderState::StateBlock::_defaultState->setCullFace(false);

        for (auto it = zZeroQueue.cbegin(); it != zZeroQueue.cend(); ++it)
        {
            processRenderCommand(*it);
        }
        flush();
    }

    //
    //Process Global-Z > 0 Queue
    //

    queue.restoreRenderState();
}
void Renderer::processRenderCommand(RenderCommand* command)
{
    auto commandType = command->getType();
    if( RenderCommand::Type::TRIANGLES_COMMAND == commandType)
    {
        // flush other queues
        flush3D();

        auto cmd = static_cast<TrianglesCommand*>(command);

        // flush own queue when buffer is full
        if(_filledVertex + cmd->getVertexCount() > VBO_SIZE || _filledIndex + cmd->getIndexCount() > INDEX_VBO_SIZE)
        {
            CCASSERT(cmd->getVertexCount()>= 0 && cmd->getVertexCount() < VBO_SIZE, "VBO for vertex is not big enough, please break the data down or use customized render command");
            CCASSERT(cmd->getIndexCount()>= 0 && cmd->getIndexCount() < INDEX_VBO_SIZE, "VBO for index is not big enough, please break the data down or use customized render command");
            drawBatchedTriangles();
        }

        // queue it, draw when vector full or all cmd queued
        _queuedTriangleCommands.push_back(cmd);
        _filledIndex += cmd->getIndexCount();
        _filledVertex += cmd->getVertexCount();
    }
}
void Renderer::flush()
{
    flush2D();
    flush3D();
}
void Renderer::flush2D()
{
    flushTriangles();
}
void Renderer::flushTriangles()
{
    drawBatchedTriangles();
}
void Renderer::fillVerticesAndIndices(const TrianglesCommand* cmd)
{
    memcpy(&_verts[_filledVertex], cmd->getVertices(), sizeof(V3F_C4B_T2F) * cmd->getVertexCount());

    // fill vertex, and convert them to world coordinates
    const Mat4& modelView = cmd->getModelView();
    for(ssize_t i=0; i < cmd->getVertexCount(); ++i)
    {
        modelView.transformPoint(&(_verts[i + _filledVertex].vertices));
    }

    // fill index
    const unsigned short* indices = cmd->getIndices();
    for(ssize_t i=0; i< cmd->getIndexCount(); ++i)
    {
        _indices[_filledIndex + i] = _filledVertex + indices[i];
    }

    _filledVertex += cmd->getVertexCount();
    _filledIndex += cmd->getIndexCount();
}
void Renderer::drawBatchedTriangles()
{
    if(_queuedTriangleCommands.empty())
        return;

    CCGL_DEBUG_INSERT_EVENT_MARKER("RENDERER_BATCH_TRIANGLES");

    _filledVertex = 0;
    _filledIndex = 0;

    /************** 1: Setup up vertices/indices *************/

    _triBatchesToDraw[0].offset = 0;
    _triBatchesToDraw[0].indicesToDraw = 0;
    _triBatchesToDraw[0].cmd = nullptr;

    int batchesTotal = 0;
    int prevMaterialID = -1;
    bool firstCommand = true;

    for(auto it = std::begin(_queuedTriangleCommands); it != std::end(_queuedTriangleCommands); ++it)
    {
        const auto& cmd = *it;
        auto currentMaterialID = cmd->getMaterialID();
        const bool batchable = !cmd->isSkipBatching();

        // fill vertices and indices from cmd, also convert vertices to world coordinates
        fillVerticesAndIndices(cmd);

        // in the same batch ?
        if (batchable && (prevMaterialID == currentMaterialID || firstCommand))
        {
            CC_ASSERT(firstCommand || _triBatchesToDraw[batchesTotal].cmd->getMaterialID() == cmd->getMaterialID() && "argh... error in logic");
            _triBatchesToDraw[batchesTotal].indicesToDraw += cmd->getIndexCount();
            _triBatchesToDraw[batchesTotal].cmd = cmd;
        }
        else
        {
            // is this the first one?
            if (!firstCommand) {
                batchesTotal++;
                _triBatchesToDraw[batchesTotal].offset = _triBatchesToDraw[batchesTotal-1].offset + _triBatchesToDraw[batchesTotal-1].indicesToDraw;
            }

            _triBatchesToDraw[batchesTotal].cmd = cmd;
            _triBatchesToDraw[batchesTotal].indicesToDraw = (int) cmd->getIndexCount();

            // is this a single batch ? Prevent creating a batch group then
            if (!batchable)
                currentMaterialID = -1;
        }

        // capacity full ?
        if (batchesTotal + 1 >= _triBatchesToDrawCapacity) {
            _triBatchesToDrawCapacity *= 1.4;
            _triBatchesToDraw = (TriBatchToDraw*) realloc(_triBatchesToDraw, sizeof(_triBatchesToDraw[0]) * _triBatchesToDrawCapacity);
        }

        prevMaterialID = currentMaterialID;
        firstCommand = false;
    }
    batchesTotal++;

    /************** 2: Copy vertices/indices to GL objects *************/
    // false
    if (conf->supportsShareableVAO() && conf->supportsMapBuffer())
    {
        //Bind VAO
        GL::bindVAO(_buffersVAO);
        //Set VBO data
        glBindBuffer(GL_ARRAY_BUFFER, _buffersVBO[0]);

        // option 1: subdata
//        glBufferSubData(GL_ARRAY_BUFFER, sizeof(_quads[0])*start, sizeof(_quads[0]) * n , &_quads[start] );

        // option 2: data
//        glBufferData(GL_ARRAY_BUFFER, sizeof(_verts[0]) * _filledVertex, _verts, GL_STATIC_DRAW);

        // option 3: orphaning + glMapBuffer
        // FIXME: in order to work as fast as possible, it must "and the exact same size and usage hints it had before."
        //  source: https://www.opengl.org/wiki/Buffer_Object_Streaming#Explicit_multiple_buffering
        // so most probably we won't have any benefit of using it
        glBufferData(GL_ARRAY_BUFFER, sizeof(_verts[0]) * _filledVertex, nullptr, GL_STATIC_DRAW);
        void *buf = glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
        memcpy(buf, _verts, sizeof(_verts[0]) * _filledVertex);
        glUnmapBuffer(GL_ARRAY_BUFFER);

        glBindBuffer(GL_ARRAY_BUFFER, 0);

        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _buffersVBO[1]);
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(_indices[0]) * _filledIndex, _indices, GL_STATIC_DRAW);
    }
    else
    {
        // Client Side Arrays
#define kQuadSize sizeof(_verts[0])
        glBindBuffer(GL_ARRAY_BUFFER, _buffersVBO[0]);

        glBufferData(GL_ARRAY_BUFFER, sizeof(_verts[0]) * _filledVertex , _verts, GL_DYNAMIC_DRAW);

        GL::enableVertexAttribs(GL::VERTEX_ATTRIB_FLAG_POS_COLOR_TEX);

        // vertices
        glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 3, GL_FLOAT, GL_FALSE, kQuadSize, (GLvoid*) offsetof(V3F_C4B_T2F, vertices));

        // colors
        glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_COLOR, 4, GL_UNSIGNED_BYTE, GL_TRUE, kQuadSize, (GLvoid*) offsetof(V3F_C4B_T2F, colors));

        // tex coords
        glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_TEX_COORD, 2, GL_FLOAT, GL_FALSE, kQuadSize, (GLvoid*) offsetof(V3F_C4B_T2F, texCoords));

        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, _buffersVBO[1]);
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(_indices[0]) * _filledIndex, _indices, GL_STATIC_DRAW);
    }

    /************** 3: Draw *************/
    for (int i=0; i<batchesTotal; ++i)
    {
        CC_ASSERT(_triBatchesToDraw[i].cmd && "Invalid batch");
        _triBatchesToDraw[i].cmd->useMaterial();
        glDrawElements(GL_TRIANGLES, (GLsizei) _triBatchesToDraw[i].indicesToDraw, GL_UNSIGNED_SHORT, (GLvoid*) (_triBatchesToDraw[i].offset*sizeof(_indices[0])) );
        _drawnBatches++;
        _drawnVertices += _triBatchesToDraw[i].indicesToDraw;
    }

    /************** 4: Cleanup *************/
    if (Configuration::getInstance()->supportsShareableVAO())
    {
        //Unbind VAO
        GL::bindVAO(0);
    }
    else
    {
        glBindBuffer(GL_ARRAY_BUFFER, 0);
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
    }

    _queuedTriangleCommands.clear();
    _filledVertex = 0;
    _filledIndex = 0;
}
void TrianglesCommand::useMaterial() const
{
    //Set texture
    GL::bindTexture2D(_textureID);

    if (_alphaTextureID > 0)
    { // ANDROID ETC1 ALPHA supports.
        GL::bindTexture2DN(1, _alphaTextureID);
    }
    //set blend mode
    GL::blendFunc(_blendType.src, _blendType.dst);

    _glProgramState->apply(_mv);
}
void GLProgramState::apply(const Mat4& modelView)
{
    applyGLProgram(modelView);

    applyAttributes();

    applyUniforms();
}
void GLProgramState::applyGLProgram(const Mat4& modelView)
{
    CCASSERT(_glprogram, "invalid glprogram");
    updateUniformsAndAttributes();
    // set shader
    _glprogram->use();
    _glprogram->setUniformsForBuiltins(modelView);
}

缺陷：
1）每次render都会重新更新VBO中的vertex data，可能这样比较适合
2）glVertexAttribPointer和GLProgramState分离，GLProgramState并不起作用