#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/* 图形绘制隐形的架构
很多种类型的图元，我要绘制它们。
*/
// 图元的类型
enum SHAPE_TYPE {
SHAPE_TRIANGLE = 0,
SHAPE_RECT = 1,
SHAPE_CIRCLE = 2,
SHAPE_NUM
};
struct point {
float x;
float y;
};
struct shape {
// int type;
enum SHAPE_TYPE type;
union {
struct {
struct point t0;
struct point t1;
struct point t2;
}triangle;
struct {
float x;
float y;
float w;
float h;
}rect;
struct {
float c_x;
float c_y;
float r;
}circle;
}u;
};
void init_circle_shape(struct shape* s, float c_x, float c_y, float r) {
s->type = SHAPE_CIRCLE;
s->u.circle.c_x = c_x;
s->u.circle.c_y = c_y;
s->u.circle.r = r;
}
void init_rect_shape(struct shape* s, float x, float y, float w, float h) {
s->type = SHAPE_RECT;
s->u.rect.x = x;
s->u.rect.y = y;
s->u.rect.w = w;
s->u.rect.h = h;
}
void draw_shapes(struct shape* shapes, int count) {
int i;
for (i = 0; i < count; i++) {
switch (shapes[i].type) {
case SHAPE_CIRCLE:{
printf("circle %f, %f, %f\n",
shapes[i].u.circle.c_x, shapes[i].u.circle.c_y,
shapes[i].u.circle.r);
}
break;
case SHAPE_TRIANGLE: {
printf("triangle %f, %f, %f, %f, %f, %f\n",
shapes[i].u.triangle.t0.x, shapes[i].u.triangle.t0.y,
shapes[i].u.triangle.t1.x, shapes[i].u.triangle.t1.y,
shapes[i].u.triangle.t2.x, shapes[i].u.triangle.t2.y);
}
break;
case SHAPE_RECT: {
printf("rect %f, %f, %f, %f\n",
shapes[i].u.rect.x, shapes[i].u.rect.y, shapes[i].u.rect.w, shapes[i].u.rect.h);
}
break;
default: {
printf("Warning Not a valid shape !!!!\n");
}
break;
}
}
}
void init_triangle_shape(struct shape* s, float x0, float y0, float x1, float y1, float x2, float y2) {
s->type = SHAPE_TRIANGLE;
s->u.triangle.t0.x = x0;
s->u.triangle.t0.y = y0;
s->u.triangle.t1.x = x1;
s->u.triangle.t1.y = y1;
s->u.triangle.t2.x = x2;
s->u.triangle.t2.y = y2;
}
int main(int argc, char** argv) {
struct shape shapes_set[3];
init_triangle_shape(&shapes_set[0], 100, 100, 200, 200, 300, 300);
init_rect_shape(&shapes_set[1], 100, 100, 200, 200);
init_circle_shape(&shapes_set[2], 100, 100, 200);
draw_shapes(shapes_set, 3);
system("pause");
return 0;
}
上面案例就是使用结构体 。联合体 ，枚举的一个综合案例，可以使用一个结构体 就能做3个功能，
struct person{
char name[64];
int age;
int sex;
};
struct person p; //这样声明可以通过 p.name,p.age,p.sex来访问和赋值
struct person* p; //声明指针类型的，可以通过p->name,p->age,p->sex来访问和赋值
枚举：
如果没有指定枚举值 ，默认第一个从0开始 ，下一个是上一个加1
enum WEAPON_TYPE{
JIN_TYPE,
MU_TYPE,
SHUI_TYPE=100,
HUO_TYPE,
TU_TYPE,
};
JIN_TYPE = 0
MU_TYPE = 1
SHUI_TYPE=100 //指定了值
HUO_TYPE = 101
TU_TYPE = 102