[已解决]如何画圆？

qsy78

不用grace.h,如何画圆？

最佳答案

月排行榜 / 总排行榜

人造人

2021-10-14 22:04:28

在数学中怎么画圆，在编程中就怎么画圆

main.c

#include "screen.h"
#include <math.h>

void circle(screen_t *screen, size_t x, size_t y, size_t r) {
    for(double i = 0; i < 2 * M_PI; i += M_PI / 180) {
        screen_putchar(screen, x + (cos(i) * r) * 1.8, y + sin(i) * r, '0');
    }
}

int main(void) {
    screen_t *screen = screen_init(130, 41);
    screen_draw_border(screen, '#');
    circle(screen, screen->width / 2, screen->height / 2, 15);
    screen_refresh(screen, stdout);
    screen_deinit(screen);
    return 0;
}

screen.h

#ifndef _SCREEN_H_
#define _SCREEN_H_

#include <stdio.h>
#include <stddef.h>

typedef struct {
    size_t width, height;
    char *buff;
} screen_t;

screen_t *screen_init(size_t width, size_t height);
void screen_deinit(screen_t *screen);
void screen_putchar(screen_t *screen, size_t x, size_t y, char ch);
void screen_refresh(screen_t *screen, FILE *fp);
void screen_draw_border(screen_t *screen, char ch);

#endif

screen.c

#include "screen.h"
#include <stdlib.h>
#include <string.h>

screen_t *screen_init(size_t width, size_t height) {
    screen_t *screen = malloc(sizeof(*screen));
    *screen = (screen_t){width, height, malloc(width * height)};
    memset(screen->buff, ' ', screen->width * screen->height);
    return screen;
}

void screen_deinit(screen_t *screen) {
    free(screen->buff);
    free(screen);
}

void screen_putchar(screen_t *screen, size_t x, size_t y, char ch) {
    if(x < screen->width && y < screen->height)
        screen->buff[y * screen->width + x] = ch;
}

void screen_refresh(screen_t *screen, FILE *fp) {
    for(size_t y = 0; y < screen->height; ++y) {
        for(size_t x = 0; x < screen->width; ++x) {
            fputc(screen->buff[y * screen->width + x], fp);
        }
        fputc('\n', fp);
    }
}

void screen_draw_border(screen_t *screen, char ch) {
    for(size_t y = 0; y < screen->height; ++y) {
        for(size_t x = 0; x < screen->width; ++x) {
            if(y == 0 || x == 0 || y == screen->height - 1 || x == screen->width - 1)
                screen_putchar(screen, x, y, ch);
        }
    }
}

跳转到最佳答案楼层

人造人

在数学中怎么画圆，在编程中就怎么画圆

main.c

#include "screen.h"
#include <math.h>

void circle(screen_t *screen, size_t x, size_t y, size_t r) {
    for(double i = 0; i < 2 * M_PI; i += M_PI / 180) {
        screen_putchar(screen, x + (cos(i) * r) * 1.8, y + sin(i) * r, '0');
    }
}

int main(void) {
    screen_t *screen = screen_init(130, 41);
    screen_draw_border(screen, '#');
    circle(screen, screen->width / 2, screen->height / 2, 15);
    screen_refresh(screen, stdout);
    screen_deinit(screen);
    return 0;
}

screen.h

#ifndef _SCREEN_H_
#define _SCREEN_H_

#include <stdio.h>
#include <stddef.h>

typedef struct {
    size_t width, height;
    char *buff;
} screen_t;

screen_t *screen_init(size_t width, size_t height);
void screen_deinit(screen_t *screen);
void screen_putchar(screen_t *screen, size_t x, size_t y, char ch);
void screen_refresh(screen_t *screen, FILE *fp);
void screen_draw_border(screen_t *screen, char ch);

#endif

screen.c

#include "screen.h"
#include <stdlib.h>
#include <string.h>

screen_t *screen_init(size_t width, size_t height) {
    screen_t *screen = malloc(sizeof(*screen));
    *screen = (screen_t){width, height, malloc(width * height)};
    memset(screen->buff, ' ', screen->width * screen->height);
    return screen;
}

void screen_deinit(screen_t *screen) {
    free(screen->buff);
    free(screen);
}

void screen_putchar(screen_t *screen, size_t x, size_t y, char ch) {
    if(x < screen->width && y < screen->height)
        screen->buff[y * screen->width + x] = ch;
}

void screen_refresh(screen_t *screen, FILE *fp) {
    for(size_t y = 0; y < screen->height; ++y) {
        for(size_t x = 0; x < screen->width; ++x) {
            fputc(screen->buff[y * screen->width + x], fp);
        }
        fputc('\n', fp);
    }
}

void screen_draw_border(screen_t *screen, char ch) {
    for(size_t y = 0; y < screen->height; ++y) {
        for(size_t x = 0; x < screen->width; ++x) {
            if(y == 0 || x == 0 || y == screen->height - 1 || x == screen->width - 1)
                screen_putchar(screen, x, y, ch);
        }
    }
}

人造人

我就是问一下
不用grace.h,如何画圆？那使用grace.h,如何画圆？

完全没有听说过 grace.h 这个头文件，你是不是又因为不认真写错单词了？
你想写的是这个？
graphics.h