书名：代码本色：用编程模拟自然体系
作者：Daniel Shiffman
译者：周晗彬
ISBN：978-7-115-36947-5
第7章目录
7.8 面向对象的细胞实现
在背面的工作中，我们将为CA体系添加一些扩展特性，此中许多都涉及细胞的多个属性，比如：让细胞记着迩来的10个状态；在CA体系中加入运动和物理学特性，让细胞能在屏幕中移动，在每一帧里动态地改变它的邻人。叨教，这些特性该怎样实现？
1、Cell类
- 一个细胞对象有哪些属性？
在本例中，每个细胞都有一个位置和巨细，当然尚有状态。
class Cell { float x,y; 位置和尺寸 float w; int state; 细胞的状态是什么？
- 在非面向对象版本中，我们用两个差别的二维数组存放当前和下一代的状态。用对象表示细胞后，每个细胞可以同时生存这两个状态。因此，我们盼望细胞能记着之前的状态（在盘算新状态之前）。
int previous; 之前一代的细胞状态是什么？
- 这让我们能将更多状态厘革信息可视化。比如，我们可以对状态发生厘革细胞赋予差别的颜色
2、示例
代码7-3 面向对象的生命游戏
GOL gol;void setup() { size(640, 360); gol = new GOL();}void draw() { background(255); gol.generate(); gol.display();}// reset board when mouse is pressedvoid mousePressed() { gol.init();}
class Cell { float x, y; float w; int state; int previous; Cell(float x_, float y_, float w_) { x = x_; y = y_; w = w_; state = int(random(2)); previous = state; } void savePrevious() { previous = state; } void newState(int s) { state = s; } void display() { if (previous == 0 && state == 1) fill(0,0,255); else if (state == 1) fill(0); else if (previous == 1 && state == 0) fill(255,0,0); else fill(255); stroke(0); rect(x, y, w, w); }}
class GOL { int w = 8; int columns, rows; // Game of life board Cell[][] board; GOL() { // Initialize rows, columns and set-up arrays columns = width/w; rows = height/w; board = new Cell[columns][rows]; init(); } void init() { for (int i = 0; i < columns; i++) { for (int j = 0; j < rows; j++) { board[j] = new Cell(i*w, j*w, w); } } } // The process of creating the new generation void generate() { for ( int i = 0; i < columns;i++) { for ( int j = 0; j < rows;j++) { board[j].savePrevious(); } } // Loop through every spot in our 2D array and check spots neighbors for (int x = 0; x < columns; x++) { for (int y = 0; y < rows; y++) { // Add up all the states in a 3x3 surrounding grid int neighbors = 0; for (int i = -1; i <= 1; i++) { for (int j = -1; j <= 1; j++) { neighbors += board[(x+i+columns)%columns][(y+j+rows)%rows].previous; } } // A little trick to subtract the current cell's state since // we added it in the above loop neighbors -= board[x][y].previous; // Rules of Life if ((board[x][y].state == 1) && (neighbors < 2)) board[x][y].newState(0); // Loneliness else if ((board[x][y].state == 1) && (neighbors > 3)) board[x][y].newState(0); // Overpopulation else if ((board[x][y].state == 0) && (neighbors == 3)) board[x][y].newState(1); // Reproduction // else do nothing! } } } // This is the easy part, just draw the cells, fill 255 for '1', fill 0 for '0' void display() { for ( int i = 0; i < columns;i++) { for ( int j = 0; j < rows;j++) { board[j].display(); } } }}3、运行结果
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