Question

我目前在大脑中有一个关于如何正确地逐行初始化GLFloats 数组的结。据我所知，数组可以这样写：

int a[2][2] = {{1,2},{3,4}}

在我的情况下，我有数组

GLfloat targetVertices[10][72];

表示立方体六边的顶点（十个立方体，确切地说）。立方体坐标存储在

中

float targetX[10], targetY[10], targetZ[10];

阵列。我想像这样初始化它：

for(iii = 0; iii <= 9; iii++) {
    targetVertices[iii] = {                  /*Side 1*/
                           targetX[iii]-1, targetY[iii]-1, targetZ[iii]-1,
                           targetX[iii]-1, targetY[iii]-1, targetZ[iii]+1,
                           targetX[iii]-1, targetY[iii]+1, targetZ[iii]+1,
                           targetX[iii]-1, targetY[iii]+1, targetZ[iii]-1,
                                             /*Side 2*/
                           targetX[iii]+1, targetY[iii]-1, targetZ[iii]-1,
                           targetX[iii]+1, targetY[iii]-1, targetZ[iii]+1,
                           targetX[iii]+1, targetY[iii]+1, targetZ[iii]+1,
                           targetX[iii]+1, targetY[iii]+1, targetZ[iii]-1,
                                             /*Side 3*/
                           targetX[iii]-1, targetY[iii]-1, targetZ[iii]-1,
                           targetX[iii]-1, targetY[iii]-1, targetZ[iii]+1,
                           targetX[iii]+1, targetY[iii]-1, targetZ[iii]+1,
                           targetX[iii]+1, targetY[iii]-1, targetZ[iii]-1,
                                             /*Side 4*/
                           targetX[iii]-1, targetY[iii]+1, targetZ[iii]-1,
                           targetX[iii]-1, targetY[iii]+1, targetZ[iii]+1,
                           targetX[iii]+1, targetY[iii]+1, targetZ[iii]+1,
                           targetX[iii]+1, targetY[iii]+1, targetZ[iii]-1,
                                             /*Side 5*/
                           targetX[iii]-1, targetY[iii]-1, targetZ[iii]-1,
                           targetX[iii]-1, targetY[iii]+1, targetZ[iii]-1,
                           targetX[iii]+1, targetY[iii]+1, targetZ[iii]-1,
                           targetX[iii]+1, targetY[iii]-1, targetZ[iii]-1,
                                             /*Side 6*/
                           targetX[iii]-1, targetY[iii]-1, targetZ[iii]+1,
                           targetX[iii]-1, targetY[iii]+1, targetZ[iii]+1,
                           targetX[iii]+1, targetY[iii]+1, targetZ[iii]+1,
                           targetX[iii]+1, targetY[iii]-1, targetZ[iii]+1
                          };
}

不幸的是，我总是被告知有关第一个波浪形支架（C2059和C2143，但那些对我没有任何意义）的语法错误。我希望我的问题很明确，有人可以帮助我。我在这个或任何其他网站上找不到与我的问题类似的东西。

提前致谢！

Answer 1

你的语法问题是说targetVertices [iii]你引用的是数组的iiith索引，而不是整个列。 2D数组存储为1D数组，但提供[] []以进行简单访问。您可以将它们称为单维或双维。

这是一种更可重用的方法。

void addVertex(std::vector<GLfloat> &data, GLfloat x, GLfloat y, GLfloat z)
{
    data.push_back(x);
    data.push_back(y);
    data.push_back(z);
}

void addCube(std::vector<GLfloat> &data, GLfloat x, GLfloat y, GLfloat z)
{
    addVertex(data, x-1, y-1, z-1);
    addVertex(data, x-1, y-1, z+1);
    addVertex(data, x-1, y+1, z+1);
    addVertex(data, x-1, y+1, z-1);

    addVertex(data, x+1, y-1, z-1);
    addVertex(data, x+1, y-1, z+1);
    addVertex(data, x+1, y+1, z+1);
    addVertex(data, x+1, y+1, z-1);

    addVertex(data, x-1, y-1, z-1);
    addVertex(data, x-1, y-1, z+1);
    addVertex(data, x+1, y-1, z+1);
    addVertex(data, x+1, y-1, z-1);

    addVertex(data, x-1, y+1, z-1);
    addVertex(data, x-1, y+1, z+1);
    addVertex(data, x+1, y+1, z+1);
    addVertex(data, x+1, y+1, z-1);

    addVertex(data, x-1, y-1, z-1);
    addVertex(data, x-1, y+1, z-1);
    addVertex(data, x+1, y+1, z-1);
    addVertex(data, x+1, y-1, z-1);

    addVertex(data, x-1, y-1, z+1);
    addVertex(data, x-1, y+1, z+1);
    addVertex(data, x+1, y+1, z+1);
    addVertex(data, x+1, y-1, z+1);
}

void makeCubes(std::vector<GLfloat> &data)
{
    float targetX[10], targetY[10], targetZ[10];
            data.clear();
            data.reserve(720);

    //...initialize the above arrays...

    for (int i=0; i<10; i++)
    {
        std::vector<GLfloat> newData;
        addCube(newData, targetX[i], targetY[i], targetZ[i]);
        data.insert(data.begin(), newData.begin(), newData.end());
    }
}

您可以通过引用第一个元素轻松将其转换为C数组：

std::vector<GLfloat> data;
makeCubes(data);
GLfloat *cArray = &data[0];

可以像这样调用glBufferData：

glBufferData(GL_ARRAY_BUFFER,
             data.size()*sizeof(GLfloat),
             &data[0],
             GL_STREAM_DRAW);

在C ++中初始化GLfloats的多维数组

1 个答案: