触摸屏

代码说明：

void gui_fill_circle(u16 x0,u16 y0,u16 r,u16 color) {   u32 i; u32 imax = ((u32)r*707)/1000+1; u32 sqmax = (u32)r*(u32)r+(u32)r/2; u32 x=r; gui_draw_hline(x0-r,y0,2*r,color); for (i=1;isqmax)// draw lines from outside   {   if (x>imax)  { gui_draw_hline (x0-i+1,y0+x,2*(i-1),color); gui_draw_hline (x0-i+1,y0-x,2*(i-1),color); } x--; } // draw lines from inside (center)   gui_draw_hline(x0-x,y0+i,2*x,color); gui_draw_hline(x0-x,y0-i,2*x,color); } }   //两个数之差的绝对值  //x1,x2：需取差值的两个数 //返回值：|x1-x2| u16 my_abs(u16 x1,u16 x2) {   if(x1>x2)return x1-x2; else return x2-x1; }   //画一条粗线 //(x1,y1),(x2,y2):线条的起始坐标 //size：线条的粗细程度 //color：线条的颜色 void lcd_draw