C语言不调用库函数画直线

昨天写了一个代码，使用C语言画三角形，既然写了那个，那就继续画一条直线，这个也很有意思。

C语言不调用库函数画一个三角形

直线的方程是

如下图所示

— — 斜率的范围

(-∞,+∞)

既然知道公式了，我们就直接上代码吧，之前有人评论说 putchar函数可以修改下，这次我们就修改下。

还有，我这次就不用浮点型了，直接用int来做计算。

#include "stdio.h"

typedef struct {
        int x,y;
} Vec;
/*y=kx+b*/
int judge(Vec p,int k,int b){
    int tmp = p.y - k*p.x -b;
    if(tmp == 0)
        return 1;
    return 0;
}

int main(){
    Vec p;
    int k = 1;
    int b = 16;
    for(p.y = 50;p.y>= -50;p.y -=2,putchar('\n'))
        for(p.x = -50;p.x <= 50;p.x++)
            putchar(judge(p,k,b)?'@':'.');
}

用图片来更直观的来感受下输出

如果坐标系更大，就会更细腻

—— 程序输出

weiqifa@bsp-ubuntu1804:~/c$ gcc elsfk.c && ./a.out
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