如何在处理过程中使用2DArray创建类？是否强制使用括号符号？

Question

我从几个小时以来一直坐在我的立方体教室里。我想创造一个可转换的立方体。为此，我需要点和线，我可以转换与矩阵乘法。

因此，首先我声明我的数组，然后用值构造它们。我要用括号符号吗？我的错误在哪里？

然后，我实现了setter函数来更改数组，并实现了一个转换函数，它为转换后的顶点生成一个新的数组。你将如何正确地实现它？有什么建议吗？

class Cube {
  private Vertex[] vertArray = new Vertex[8];
    // create 8 vertexes for cube
    vertArray[0] = new Vertex(50.0, 50.0, 0.0, 1.0);
    vertArray[1] = new Vertex(150.0, 50.0, 0.0, 1.0);
    vertArray[2] = new Vertex(150.0, 150.0, 0.0, 1.0);
    vertArray[3] = new Vertex(50.0, 150.0, 0.0, 1.0);
    vertArray[4] = new Vertex(50.0, 50.0, -100.0, 1.0);
    vertArray[5] = new Vertex(150.0, 50.0, -100.0, 1.0);
    vertArray[6] = new Vertex(150.0, 150.0, -100.0, 1.0);
    vertArray[7] = new Vertex(50.0, 150.0, -100.0, 1.0);
  private Line[] lineArray = new Line[12];
    // 12 lines out of 8 vertexes
    // clockwise arrangement from top left, first front then back
    lineArray[0] = new Line(vertArray[0], vertArray[1]);
    lineArray[1] = new Line(vertArray[1], vertArray[2]);
    lineArray[2] = new Line(vertArray[2], vertArray[3]);
    lineArray[3] = new Line(vertArray[3], vertArray[0]);
    lineArray[4] = new Line(vertArray[0], vertArray[4]);
    lineArray[5] = new Line(vertArray[1], vertArray[5]);
    lineArray[6] = new Line(vertArray[2], vertArray[6]);
    lineArray[7] = new Line(vertArray[3], vertArray[7]);
    lineArray[8] = new Line(vertArray[4], vertArray[5]);
    lineArray[9] = new Line(vertArray[5], vertArray[6]);
    lineArray[10] = new Line(vertArray[6], vertArray[7]);
    lineArray[11] = new Line(vertArray[7], vertArray[4]);
  private Float[][] transfArray;
  private Vertex[] newVertArray;

  Cube() {
    this.setVertArray(this.vertArray);
    this.setLineArray(this.lineArray);
  }

  void setVertArray(Float vertArray[]) {
    this.vertArray = vertArray;
  }

  void setLineArray(Float lineArray[]) {
    this.lineArray = lineArray;
  }

  void setTransfArray(Float[][] transfArray) {
    this.transfArray = transfArray;   
  }

  void display() {
    for (int i=0; i<lineArray.length; i++) {
      lineArray[i].display();
    }
  }

  void transform() {
    // new vertex-array for transformed vertexes
    newVertArray = new Vertex[vertArray.length];
    // count rows of transformation matrix
    int transfColumns = this.transfArray[0].length;
    // check if matrix-multiplication is possible
    if (transfColumns != 4) {
      println("transformation Array " + transfColumns + " did not match homogenous coordinate.");
    }
    for (int h=0; h<vertArray.length; h++) {
      // iterate through vertArray
      // return new vertArray
      Float[] newCoordinateArray = new Float[4];
      for (int i=0; i<4; i++) {
        // iterate through each row of transfArray
        // return new Vertex
        float newCoordinate = 0.0;
        for (int j=0; j<4; j++) {
          // iterate through each value of transfArray-Row 
          // and multiply with Vertex, add to newCoordinate
          newCoordinate += (transfArray[i][0] * vertArray[h].x);
          newCoordinate += (transfArray[i][1] * vertArray[h].y);
          newCoordinate += (transfArray[i][2] * vertArray[h].z);
          newCoordinate += (transfArray[i][3] * vertArray[h].t);
        }
        newCoordinateArray[i] = newCoordinate;
        //print("newCoordinate = " + newCoordinate);
      }
      // asign values of newCoordinateArray to x, y, z or t
      Vertex newVertex = new Vertex(
        newCoordinateArray[0], // assign to x
        newCoordinateArray[1], // assign to y
        newCoordinateArray[2], // assign to z
        newCoordinateArray[3]  // assign to t
      );
      print(" newVertex = " + newVertex.x + " " +
        newVertex.y + " " + newVertex.z + " " + newVertex.t);
      newVertArray[h] = newVertex;
    }
    //print("newVertArray = " + newVertArray);
  }
}

Eclipse和ProcessingIDE都抱怨数组的构造。其他一切都在建造中。提前感谢！

Answer 1

将像vertArray[0] = new Vertex(50.0, 50.0, 0.0, 1.0);这样的行放入构造函数中。

或者，以这种方式对vertArray进行非关税化：

// create 8 vertexes for cube
private Vertex[] vertArray = new Vertex[8] {
  new Vertex(50.0, 50.0, 0.0, 1.0),
  new Vertex(150.0, 50.0, 0.0, 1.0),
  new Vertex(150.0, 150.0, 0.0, 1.0),
  new Vertex(50.0, 150.0, 0.0, 1.0),
  new Vertex(50.0, 50.0, -100.0, 1.0),
  new Vertex(150.0, 50.0, -100.0, 1.0),
  new Vertex(150.0, 150.0, -100.0, 1.0),
  new Vertex(50.0, 150.0, -100.0, 1.0)
};