创建一个用于生成柱面的java类

Question

我应该创建一个从SObject扩展的新类SCylinder，它构建一个圆柱模型。期望类SCylinder的工作方式类似于为渲染球体而提供的类SSphere，除了SCylinder用于渲染圆柱体。 我知道我必须更改genData（），以便我可以创建一个圆柱但不知道从哪里开始。任何建议和提示将不胜感激。

package Objects;
public class SCylinder extends SObject{
private float radius;
    private float height;
private int slices;
private int stacks;

public SCylinder(){ 
    super();
    init();
    update();
}

public SCylinder(float radius){
    super();
    init();
    this.radius = radius;
    update();
}

public SCylinder(float radius, float height,int slices, int stacks){
    super();
    this.radius = radius;
            this.height=height;
    this.slices = slices;
    this.stacks = stacks;

    update();
}

private void init(){
    this.radius = 1;
    this.slices = 20;
    this.stacks = 20;
}

@Override
protected void genData() {
    int i,j,k;

    double deltaLong=PI*2/slices;
    double deltaLat= PI/stacks;

    // Generate vertices coordinates, normal values, and texture coordinates
    numVertices = (slices+1)*(stacks-1)+2; 
    vertices = new float[numVertices*3];
    normals = new float[numVertices*3];
    textures = new float[numVertices*2];

    //North pole point
    normals[0] = 0; normals[1] = 0; normals[2] = 1;
    vertices[0] = 0; vertices[1] = 0; vertices[2] = radius;
    textures[0]= 0.5f; textures[1] = 1.0f;

    k = 1;
    //vertices on the main body
    for(i=1;i<stacks;i++){
        for(j=0;j<=slices;j++){
            normals[3*k] = sin(deltaLat*i)*cos(deltaLong*j);
            normals[3*k+1] = sin(deltaLat*i)*sin(deltaLong*j);
            normals[3*k+2] = cos(deltaLat*i);
            vertices[3*k] = radius*normals[3*k];
            vertices[3*k+1] = radius*normals[3*k+1];
            vertices[3*k+2] = radius*normals[3*k+2];
            textures[2*k] = (float) j/slices;
            textures[2*k+1] = 1-(float) i/stacks;
            k++;
        }
    }

    //South pole point
    normals[3*k] = 0; normals[3*k+1] = 0; normals[3*k+2] = -1;
    vertices[3*k] = 0; vertices[3*k+1] = 0; vertices[3*k+2] = -radius;      
    textures[2*k] = 0.5f; textures[2*k+1] = 0.0f;  k++;


    // Generate indices for triangular mesh
    numIndices = (stacks-1)*slices*6;
    indices = new int[numIndices];

    k = 0;
    //North Pole, numElement:slices*3   
    for(j=1;j<=slices;j++){
        indices[k++] = 0;
        indices[k++] = j;
        indices[k++] = j+1;
    }

    //South Pole, numElement:slices*3 
    int temp = numVertices-1;
    for(j=temp-1;j>temp-slices-1;j--){
        indices[k++] = temp;
        indices[k++] = j;
        indices[k++] = j-1;
    }

    //Main body, numElement:(stacks-2)*slices*6 
    for(i=1;i<stacks-1;i++){
        for(j=1;j<=slices;j++){
            //each quad gives two triangles
            //triangle one
            indices[k++] = (i-1)*(slices+1)+j;
            indices[k++] = i*(slices+1)+j;
            indices[k++] = i*(slices+1)+j+1;
            //triangle two
            indices[k++] = (i-1)*(slices+1)+j;
            indices[k++] = i*(slices+1)+j+1;
            indices[k++] = (i-1)*(slices+1)+j+1;
        }
    }
}   

public void setRadius(float radius){
    this.radius = radius;
    updated = false;
}

public void setSlices(int slices){
    this.slices = slices;
    updated = false;
}

public void setStacks(int stacks){
    this.stacks = stacks;
    updated = false;
}

public float getRadius(){
    return radius;
}

public int getSlices(){
    return slices;
}

public int getStacks(){
    return stacks;
}   
}