C语言画图之画个太极图
呵呵昨天花了一个圆，想画个太极图，我知道没啥技术含量，但是挺有意思的，希望各位看官不要鄙视我不务正业，画完此图，不再做这些事情。 先展示下画出来的图像的情况，因为不支持pgm格式的图像，所以我用的 QQ截图：
，二话不说上代码。同时再次致谢Banu前辈。 #include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h> typedef struct { size_t width; size_t height; unsigned char *data; } Image; static Image * image_new (size_t width， size_t height) { Image *image; image = malloc (sizeof *image); image->width = width; image->height = height; image->data = malloc (width * height); return image; } static void image_free (Image *image) { free (image->data); free (image); } static void image_fill (Image *image， unsigned char value) { memset (image->data， value， image->width * image->height); } /** * image_set_pixel: * * Sets a pixel passed in signed (x， y) coordinates， where (0，0) is at * the center of the image. **/ static void image_set_pixel (Image *image， ssize_t x， ssize_t y， unsigned char value) { size_t tx， ty; unsigned char *p; tx = (image->width / 2) + x; ty = (image->height / 2) + y; p = image->data + (ty * image->width) + tx; *p = value; } static void image_save (const Image *image， const char *filename) { FILE *out; out = fopen (filename， "wb"); if (!out) return; fprintf (out， "P5 "); fprintf (out， "%zu %zu "， image->width， image->height); fprintf (out， "255 "); fwrite (image->data， 1， image->width * image->height， out); fclose (out); } static void draw_Taijitu(Image *image，int radius，int value) { int x，y; int rlimit ，llimit; int radius_2 = radius*radius; for(y = -radius;y<radius;y++) for(x= -radius;x<radius;x++) if(x*x+y*y <= radius_2) image_set_pixel(image，x，y，0xff); for(y = -radius;y<0;y++) for(x = 0;x<radius;x++) if((x*x)+(y*y) <= radius_2) image_set_pixel(image，x，y，value); for(y = -radius;y<0;y++) for(x = -(int)sqrt((double)(-radius*y-y*y));x<0;x++) image_set_pixel(image，x，y，value); for(y = 0;y<radius;y++) { llimit = (int)sqrt((double)(radius*y - y*y)); rlimit = (int)sqrt((double)(radius_2 - y*y)); for(x = llimit;x<rlimit;x++) image_set_pixel(image，x，y，value); } for(y = 2*radius/6;y<4*radius/6;y++) { rlimit =(int) sqrt((double)(radius*y-y*y-2*radius_2/9)); llimit = -rlimit; for(x = llimit;x<rlimit;x++) image_set_pixel(image，x，y，value); } for(y = -4*radius/6;y<-2*radius/6;y++) { rlimit = sqrt(-radius*y-y*y-2*radius_2/9); llimit = -rlimit; for(x = llimit;x<rlimit;x++) image_set_pixel(image，x，y，0xff); } return ; } int main (int argc， char *argv[]) { Image *image; image = image_new (800， 800); image_fill (image， 0xaa); draw_Taijitu (image， 300， 0); image_save (image， "taiji_6.pgm"); image_free (image); return 0; }
