Question

#include <iostream>
#include <math.h>
#include <cstdlib>
using namespace std;

void circle(int x, int y, int radius);
void line(int a, int b, int c, int d);
bool buffer[26][81];
char drawSpace[26][81];

int main() {
    int a = 0;
    int b = 0;
    int c = 0;
    int d = 0;
    int x = 0;
    int y = 0;
    int radius = 0;
    char choice;

    cout << "Type 'c' to draw a circle or type 'l' to draw a line." << endl;
    cin >> choice;

    if (choice == 'c'){
        cout << "please enter an x coordinate for the center of the circle \n";
        cin >> x;
        cout << "please enter a y coordinate for the center of the circle \n";
        cin >> y;
        cout << "please enter a value for the radius of the circle \n";
        cin >> radius;
        int moves = (x - radius) / 10;
        for (int s = 0; s < moves; s++){
            circle(x, y, radius);
            system("clear");
            x = x -10;
        }
    }

    else if (choice == 'l'){
        cout << "Please enter the x coordinate for the first point on the line \n";
        cin >> a;
        cout << "Please enter the y coordinate for the first point on the line \n";
        cin >> b;
        cout << "Please enter the x coordinate for the end point on the line \n";
        cin >> c;
        cout << "Please enter the y coordinate for the end point on the line \n";
        cin >> d;
    }

    else
        cout << "you did not enter an appropriate letter, please restart the program and try again."<< endl;

    return 0;
}

void circle(int x, int y, int radius){
    if (x + radius >= 81|| x - radius <= 0 || y + radius >= 26 || y - radius <= 0){
        cout << "the coordinates provided for the circle will not fit on the screen" << endl;
        return;
    }

    for (int i = 0; i < 26; i++) {
        for(int j = 0; j < 81; j++) {
            int a = abs (x - j);
            int b = abs (y - i);
            int distance =  pow(a, 2) + pow(b, 2);
            int realDistance = pow(radius, 2);
            if (abs(realDistance - distance) <= 3){
                buffer[i][j] = true;
            }
        }
    }

    for (int m = 0; m < 26; m++){
        for(int n = 0; n < 81; n++){
            if (buffer[m][n]){
                drawSpace[m][n] = 42;
            }
            else
                drawSpace[m][n] = 32;
        }
    }

    for (int row = 25; row >= 0; row--) {
        for (int col = 0; col < 81; col++) {
            cout << drawSpace[row][col];
        }
        cout << "\n";
    }
}

void line(int a, int b, int c, int d){
    if (a >= 81 || c >= 81 || a <= 0 || c <= 0 || b >= 26 || d >= 26 || b <= 0 || d <= 0){
        return;
    }
    int intercept = 0;
    double rise = d - b;
    double run = c - a;
    double slope = rise/run;
    intercept = b - (slope*a);
    for (int i = 0; i < 26; i++) {
        for(int j = 21; j < 81; j++) {
            if (slope > 0){
                if (j > a && j < c){
                    int newIntercept = i - (slope*j);
                    int test = abs (intercept - newIntercept);
                    if (test <= 0)
                        buffer[i][j] = true;
                else
                    buffer[i][j] = false;
                }
            }
            else if (slope < 0){
                if (j < a && j > c){
                    int newIntercept = i - (slope*j);
                    int test = abs (newIntercept - intercept);
                    if (test <= 0)
                        buffer[i][j] = true;

                }
                else
                    break;
            }
        }
    }

    for (int m = 0; m < 26; m++){
        for(int n = 0; n < 81; n++){
            if (buffer[m][n])
                drawSpace[m][n] = 42;
            else
                drawSpace[m][n] = 32;
        }
    }

    for (int row = 25; row >= 0; row--) {
        for (int col = 0; col < 81; col++) {
            cout << drawSpace[row][col];
        }
        cout << "\n";
    }
}

我为编程分配编写了这段代码，其目标是获取圆或线的坐标和尺寸的输入，并将它们打印到终端，就像它是一个图形一样。第二步是让形状从屏幕右侧移动到左侧。我已开始为圆圈编写此代码，但由于某种原因，系统（“清除”）调用似乎不会清除屏幕，并且它只是打印额外的圆圈而不会删除旧的圆圈。如果有人可以提供帮助，我会非常感激。

Answer 1

尝试：

cout << "\033[2J\033[1;1H";

转到http://en.wikipedia.org/wiki/ANSI_escape_code了解详情。

Answer 2

在Linux（和其他Unix）上，你也可以使用ncurses library输出到终端。

Answer 3

原始海报还没有足够的代表，所以我在这里发帖给他：

我实际上有点偏离基础。我实际使用的system("clear")确实如此工作，我遇到的问题是我没有重置bool 我用来绘制需要绘制的点的数组。感谢您的帮助，我在找到自己的问题之前了解了一些关于如何清除屏幕的事情。

清除终端屏幕

3 个答案: