/*
贪吃蛇
by eleqian

按键：
上下左右：改变方向
左软键：开始/暂停
右软键：退出/加速
触屏：
自己体验
*/

#include <base.h>
#include <exb.h>
#define sw SCRW
#define sh SCRH-50
#define s 300 //速度(定时器时长)
#define js 80 //加速速度
#define v 20 //蛇，食物像素大小

/*全局变量*/
int arr[50];
int linc, colc, xside, yside;
int food, last, slen, maxl, state,l,n;
int32 timer;
char txt[4];

int init()
{
setTextSize(1,36);
maxl = 50;

xside = (SCRW % 10) / 2;
if(0 == xside)
 {
xside = 10;
}
xside = xside + 10;
yside = (sh % 10) / 2;
if(0 == yside)
 {
yside = 10;
}
yside = yside + 10;

colc = (SCRW - xside * 2) / v;
linc = (sh - yside * 2) / v;
timer=timercreate();
inits();
return 0;
}

void inits()
{
int m;

m = (linc / 2) *colc + colc / 2;
arr[0]=m;
arr[1]= m + colc;
arr[2]= m + colc * 2;

slen = 3;
state = 0;
last = _UP;

dform();
dsnake(slen);
dfood();
xs();
}

void go(int s)
{
int j, l;

l = arr[slen - 1];
for(j = slen - 1; j > 0; j = j - 1)
{
arr[j]= arr[j - 1];
}
arr[0]= arr[0] + s;
if(0 != isself())
 {
gameover();
}
eat(l);
dsnake(2);
}

void eat(int l)
{
 if(arr[0] == food)
 {
  if(slen < maxl)
  {
  arr[slen]=l;
  slen = slen + 1;
  xs();
  }
  else
  {
  dclub(l, 0, 0, 0);
  }
  dfood();

 }
 else
 {
dclub(l, 0, 0, 0);
}
}

int isself()
{
int i, j, r;

i = arr[0];
r = 0;

for(j = 1; j < slen; j = j + 1)
 {
 if(arr[j] == i)
  {
  r = 1;
  j = slen;
  }
 }
return r;
}

int isate()
{
int i, r;
r = 0;
for(i = 0; i < slen; i = i + 1)
 {
 if(arr[i] == food)
  {
  r = 1;
  i = slen;
  }
 }
return r;
}

void dform()
{
cls(0, 0, 0);
drect(xside - 2, yside, 2, sh-yside*2, 200, 200, 200);
drect(SCRW - xside, yside, 2, sh-yside*2, 200, 200, 200);
drect(xside, yside - 2, sw-xside*2, 2, 200, 200, 200);
drect(xside, sh - yside, sw-xside*2, 2, 200, 200, 200);
ref(0, 0, SCRW, SCRH);
}

void dfood()
{
sand(getuptime());
do
 {
 food = rand() % (colc *linc);
 }
while(0 != isate());

dclub(food, 255, 0, 0);
}

void dsnake(int dl)
{
int i;

dclub(arr[0], 0, 255, 255);

for(i = 1; i < dl; i = i + 1)
 {
 dclub(arr[i], 0, 255, 0);
 }
}


void dclub(int i, int r, int g, int b)
{
int x, y;

x = v *(i % colc) + xside;
y = v *(i / colc) + yside;
drect(x, y, v, v, r / 2, g / 2, b / 2);
drect(x + 1, y + 1, v-2, v-2, r, g, b);
ref(x, y, v, v);
}

void gameover()
{
stop();
inits();
}

void cd(int k)
{
if(k == _LEFT)
 {
 if(last != _RIGHT)
  {
  last = k;
  }
 }
if(k == _RIGHT)
 {
 if(last != _LEFT)
  {
  last = k;
  }
 }
if(k == _UP)
 {
 if(last != _DOWN)
  {
  last = k;
  }
 }
if(k == _DOWN)
 {
 if(last != _UP)
  {
  last = k;
  }
 }

if(last == k)
 {
 stop();
 _timer(0);
 start();
 }
}

int event(int t, int a, int b)
{
 if(t==MS_DOWN)
 {
  if(state)
  {
   if(a>0&&a<sw&&b>0&&b<sh)
   { fx(a,b);}
   if(a>sw/2&&a<sw&&b>sh&&b<SCRH)
   { event(KY_DOWN,18,0);}
  }
 }

 if(t==MS_UP)
 {
  if(a>0&&a<sw&&b>sh&&b<SCRH)
  {
   if(a<sw/2)
   { event(KY_UP,17,0);}
   else
   { event(KY_UP,18,0);}
  }
 }

 if(t == KY_DOWN)
 {
  if(state == 1)
  {
   if(a==18)
   timersettime(timer,js);
   cd(a);
  }
 }

 if(t == KY_UP)
 {
  if(a == _SLEFT)
  {
   if(0 == state)
   {
 start();
}
   else
   {
stop();
}
   xs();
  }
  if(a == _SRIGHT)
  {
   if(state==1)
   timersettime(timer,s);
   else
   {
timerdel(timer);
exit();
}
  }
 }
 return 0;
}


//触屏方向控制

void fx(int x,int y)
{
 l=last;
 if(x<sw/2)
  if(y<sh/2) cd(l==14||l==15?12:14);
  else cd(l==14||l==15?13:14);
 if(x>=sw/2)
 if(y<sh/2) cd(l==14||l==15?12:15);
 else cd(l==14||l==15?13:15);
}

//底部按键显示
void xs()
{
 drect(0,sh,sw,50,0,0,0);
 dtext(state==0?"开始":"暂停",5,sh+5,200,200,200,0,1);
 dtext(state==0?"退出":"加速",sw-75,sh+5,200,200,200,0,1);
 sprintf(txt,"%d",slen-3);
 dtext(txt,sw/2,sh+5,200,200,200,0,1);
 ref(0,sh,sw,50);
}

void start()
{
timerstart(timer, s, 0, "_timer", TRUE);
state = 1;
}

void stop()
{
timerstop(timer);
state = 0;
}

void _timer(int32 data)
{
if(last == _LEFT)
{
if(0 == arr[0] % colc)
{
gameover();
}
else
{
go( - 1);
}
return ;
}
if(last == _DOWN)
{
if(arr[0] >= (linc - 1) *colc)
{
gameover();
}
else
{
go(colc);
}
return ;
}
if(last == _RIGHT)
{
if((colc - 1) == arr[0] % colc)
{
gameover();
}
else
{
go(1);
}
return ;
}
if(last == _UP)
{
if(arr[0] < colc)
{
gameover();
}
else
{
go( - colc);
}
return ;
}
}


int pause()
{
return 0;
}
int resume()
{
return 0;
}