Question

我有这行代码：

boneHierarchy = BoneHierarchy(Point3D(24.5f,
                                       84.0f + HumanBoundingBox::HEIGHT/2.0f ,24.5f
                                      ),
                              CompassRadians(0.0f),
                              renderingEngine
                             );

BoneHierarchy将一些向量作为私有成员。我获取向量的地址并将它们传递给渲染类。但是当我调用向量的size成员函数时，我正在变垃圾。我正在考虑向量的地址而不是其中的元素。

BoneHierarchy::BoneHierarchy(Point3D const& position,
                             CompassRadians const& heading,
                             Renderer* renderingEngine) : counter(0), renderingEngine(renderingEngine)
{    




    CoordinateSystem bodyCoordSys = CoordinateSystem(
                                                     Vector3D(0.0f,1.0f,0.0f),
                                                     Vector3D(0.0f,0.0f,1.0f));


    map<Normal3D::enumeration, TextureCoordinates> cubeTextureKind;
    Normal3D::enumeration normal;
    for (normal = Normal3D::begin(); normal != Normal3D::end(); ++normal)
    {
        cubeTextureKind[normal] = TextureAtlas::textureAtlasCoordLookup(WOOD);
    }
    Bone body = Bone(
                     Vector3D(0.0f, HumanBoundingBox::HEIGHT/2.0f,0.0f),
                     HumanBoundingBox::DIM,
                     Euler3D(0.0f,0.0f,0.0f),
                     cubeTextureKind,
                     bodyCoordSys);
    //TODO there are two positions for the human, one here and one in mesh vbo, unify these into one.
    body.setPosition(Vector3D(position.getX(),position.getY(),position.getZ()));
    body.setEuler(Euler3D((float) (Math::toDegrees(heading.getValue())),0.0f,0.0f));
    drawBone(body,UPDATE_ALL);
    root = body;


    map<string,Renderer::Buffer> vboVariableMap;
    vboVariableMap["aVertexPosition"] = Renderer::Buffer(verticesBuf);
    vboVariableMap["aTextureCoord"] = Renderer::Buffer(texCoordsBuf);
    vboVariableMap["index"] = Renderer::Buffer(indicesBuf);
    cout << "aBoneIndex " << boneIndexBuf.size() << endl;
    vboVariableMap["aBoneIndex"] = Renderer::Buffer(boneIndexBuf);
    vboVariableMap["uBoneMatrix0"] = Renderer::Buffer(transformMatrixBuf);
    GLuint textureID = 0; 
    Renderer::VBODescription vboDescription = Renderer::VBODescription("boneShader",
                                                                       vboVariableMap,
                                                                       GL_DYNAMIC_DRAW,
                                                                       indicesBuf.size(),
                                                                       textureID);
    bufferID = renderingEngine->registerBuffer(vboDescription);
    cout << "bufferID " << bufferID << endl;
    renderingEngine->printBoneIndexSize();
    cout << &(getBoneIndexBuf()) << endl;
}


Renderer::Buffer::Buffer(vector<GLfloat> const& data):
floatData(&data), ushortData(NULL), target(GL_ARRAY_BUFFER)
{
    printf("pointer: %p, size: %lu\n", floatData, floatData->size());
}

Renderer::Buffer::Buffer(vector<GLushort> const& data):
floatData(NULL), ushortData(&data), target(GL_ELEMENT_ARRAY_BUFFER)
{
}

Answer 1

如果接受BoneHierarchy和Point3D的{{1}}构造函数计算其自己的向量成员的地址，那很好。他们的地址不会改变。

该代码还显示了赋值语句。右侧临时CompassRadians的向量成员的地址将与左侧BoneHierarchy中存储的BoneHierarchy对象的地址不同。确保您没有复制赋值运算符中的地址，否则boneHierarchy对象将最终引用不再存在的临时对象的向量成员。您还需要检查复制构造函数。

Answer 2

他们的地址不会改变。此外，如果您不在初始化列表中，则其内容在整个构建过程中都应该有效。

Answer 3

此处提供的代码不足。假设您只想创建一个实例，请改用这行代码：

 BoneHierarchy boneHierarchy(Point3D(24.5f, 84.0f + HumanBoundingBox::HEIGHT/2.0f ,24.5f), 
 CompassRadians(0.0f), renderingEngine);

这将在本地堆栈中创建一个实例。正如rob指出的那样，你必须调用BoneHierarchy的赋值运算符。

在构造函数中，我可以获取成员的地址并依赖它们保持不变吗？

3 个答案: