#include <cairo.h> 
 
#define SIZE (640) /* 太極圖大小 */ 
#define CX (SIZE / 2) /* 太極圓中心橫坐標(biāo) */ 
#define CY (SIZE / 2) /* 太極圓中心縱坐標(biāo) */ 
#define R (SIZE / 2) /* 太極圓半徑 */ 
 
/* 把角度轉(zhuǎn)換為所對(duì)應(yīng)的弧度 */ 
#define ANGLE(ang) (ang * 3.1415926 / 180.0) 
 
int main(int argc, char *argv[]) 
{ 
 /* 創(chuàng)建32位RGBA顏色格式的Cairo繪圖環(huán)境，直接在Memory中渲染 */ 
 cairo_surface_t* surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, SIZE + 1, SIZE + 1); 
 cairo_t* cr = cairo_create(surface); 
 
 /* 繪制太極邊框 */ 
 cairo_set_line_width(cr, 2.0); 
 cairo_set_source_rgba(cr, 0, 0, 0, 1); 
 cairo_arc(cr, CX, CY, R, ANGLE(0), ANGLE(360)); 
 cairo_stroke(cr); 
 
 /* 繪制陰陽(yáng)圓 */ 
 cairo_set_source_rgba(cr, 0, 0, 0, 1); 
 cairo_arc(cr, CX, CY, R, ANGLE(90), ANGLE(270)); 
 cairo_fill(cr); 
 cairo_set_source_rgba(cr, 1, 1, 1, 1); 
 cairo_arc(cr, CX, CY, R, ANGLE(-90), ANGLE(90)); 
 cairo_fill(cr); 
 
 /* 繪制陰陽(yáng)線(xiàn) */ 
 cairo_set_source_rgba(cr, 0, 0, 0, 1); 
 cairo_arc(cr, CX, CY - R / 2, R / 2, ANGLE(-90), ANGLE(90)); 
 cairo_fill(cr); 
 cairo_set_source_rgba(cr, 1, 1, 1, 1); 
 cairo_arc(cr, CX, CY + R / 2, R / 2, ANGLE(90), ANGLE(270)); 
 cairo_fill(cr); 
 
 /* 繪制太極眼 */ 
 cairo_set_source_rgba(cr, 1, 1, 1, 1); 
 cairo_arc(cr, CX, CY - R / 2, R / 10, ANGLE(0), ANGLE(360)); 
 cairo_fill(cr); 
 cairo_set_source_rgba(cr, 0, 0, 0, 1); 
 cairo_arc(cr, CX, CY + R / 2, R / 10, ANGLE(0), ANGLE(360)); 
 cairo_fill(cr); 
 
 /* 將Memory的渲染效果存儲(chǔ)到圖片中 */ 
 cairo_surface_write_to_png(surface, "taichi.png"); 
 /* 銷(xiāo)毀并退出Cairo繪圖環(huán)境 */ 
 cairo_destroy(cr); 
 cairo_surface_destroy (surface); 
 
 return 0; 
} 

gcc -o taichi $(pkg-config --cflags --libs cairo) taichi.c