!*
 * TANK MODE
 *
 * Drive an ASCII tank around your buffer.
 * Invoke via EIQ[$SCITECOPATH]/tank.tes
 *!
[tank.sprite.0] !* background *!

!* FIXME: Perhaps encode the gun's top in the integer cell *!
[tank.sprite.1]
█▓█▓
╠════○
▓█▓█
[tank.sprite.2]
  █▓█▓
○════╣
  ▓█▓█
[tank.sprite.3]
 ┌┐
▓││█
█││▓
▓┴┴█
[tank.sprite.4]
█┬┬▓
▓││█
█││▓
 └┘

!*
 * f,tM[tank.rand] - LCG pseudo random number generator for values between f and t
 * This is based on the version in the BSD libc.
 *!
::U[tank.rand]
@[tank.rand]{
  U.tU.f
  (1103515245*Q[tank.rand]+12345) & (2^*31-1)U[tank.rand]
  (Q[tank.rand]^/(Q.t-Q.f+1)+Q.f)
}

!* x,yM[tank.goto] -> success|failure *!
@[tank.goto]{
  U.yU.x
  Q.x"< 0 ' Q.y"< 0 '
  J Q.y:L"F 0 '
  Q.x<0A"< I  F> ' 0A-10"= I  F> ' C>
  -1
}

!* x,y,spriteM[tank.blit] *!
@[tank.blit]{
  U.sU.yU.x Q.xU.#x0
  Q.s"N
    10[tank.sprite.0] !* background *!
    %[tank.blit]
  '
  <
    %.iQ[tank.sprite.\.s]U.c Q.c:;
    Q[tank.blit]&1"=
      !* toggle the chain character to simulate movements *!
      Q.c-█"= ▓U.c | Q.c-▓"= █U.c ' '
    '

    Q.c-10"=
      %.y Q.#x0U.x
      Q.s"N 10:[tank.sprite.0] '
    |
      Q.x,Q.yM[tank.goto];
      Q.s"N !* not background sprite *!
        Q.c- "=
          !* space is "transparent" - copy background unmodified *!
          0A"< I  | 0A-10"= I  | C ' '
          -A:[tank.sprite.0]
          %.x F<
        '
        !* "destroy" fields we have touched *!
         U.d
          0A"F 0A-10"N 0A- "N 33,126M[tank.rand]U.d ' ' '
        Q.d:[tank.sprite.0]
      '
      0A"F 0A-10"N D ' ' Q.cI
      %.x
    '
  >
}

@[tank.explode]{
  !!.[explosion]*oO%. 
  .[explosion]✹✸✶✧· 
  :Q.[explosion]<
    0A"F 0A-10"N D ' '
    %.i-1Q.[explosion]IR
  >
}

0U[tank.score]

@[tank.shoot]{
  U.#dr U.yU.x

  !* FIXME: Could also be encoded into a map *!
  Q.#dr-1Oright,left,up,down
  !right!
    6-1%.x %.y
    1U.#dx 0U.#dy
    Oend
  !left!
    %.y
    -U.#dx 0U.#dy
    Oend
  !up!
    2-1%.x
    0U.#dx -U.#dy
    Oend
  !down!
    2-1%.x 3%.y
    0U.#dx 1U.#dy
    !* fall through *!
  !end!
    <
      (Q.#dx%.x),(Q.#dy%.y)M[tank.goto]"F  '
      0A"<  ' Q.#dy"= 0A-10"=  ' '
      0A- "N 0A-10"N 1; ' '
      0A"F 0A-10"N D ' ' I●
       -DI 
    >
    M[tank.explode]

    %[tank.score] 
SCORE: \[tank.score]

}

@[tank.selfdestruct]{
  U.yU.x Q.x+2U.#cx Q.y+2U.#cy
  .[explosion]✹✹✸✸✶✶✧✧· 
  10<
    Q.#cx-10U.x 20<
      Q.x-1"< %.x F> '
      Q.#cy-10U.y 20<
        !* d = sqrt((x - cx)^2 + ((y - cy) * aspect)^2) *!
        (Q.x-Q.#cx)^*2 + ((Q.y-Q.#cy)*2)^*2 U.#d2

        Q.r^*2 - Q.#d2"<
          Q.#d2 - (Q.r+2)^*2"<
            !* on shock wave *!
            Q.x,Q.yM[tank.goto]"F %.y F> '
            -D Q.rQ.[explosion]I
          '
        |
          !* within shock wave *!
          Q.x,Q.yM[tank.goto]"F %.y F> '
          -D I 
        '
      %.y>
    %.x>
    1
  %.r>
  Q.#cx,Q.#cyM[tank.goto]
}

ESGETCOLUMNU.x :-1U.y
Q.xU.#xo Q.yU.#yo

!*
 * Normalize identations to spaces -- assumed by M[goto]
 * FIXME: Will not work well with character representations.
 *!
ESGETTABDRAWMODE-2"N
  J <S^I;
    ESGETCOLUMN-(-1ESGETCOLUMN)U.w
    -D Q.w<I >
  >
'


CONTROL: W A S D. SHOOT: SPACE. QUIT: ESCAPE. PRESS ANY KEY TO START.
 

ESGETCARETSTYLEU.[caretstyle]
0ESSETCARETSTYLE

1U.[sprite]
<
  Q.#xo,Q.#yo,0M[tank.blit] !* redraw background *!
  Q.xU.#xo Q.yU.#yo

  Q.x,Q.y,Q.[sprite]M[tank.blit]
  0 U.c
  :Okey.U.c
    F>
  !key.w!
    Q.y"> -%.y ' 3U.[sprite]
    F>
  !key.a!
    Q.x,Q.y,0M[tank.blit] !* redraw background *!
    Q.x"> -%.x ' 2U.[sprite]
    F>
  !key.s!
    Q.x,Q.y,0M[tank.blit] !* redraw background *!
    %.y 4U.[sprite]
    F>
  !key.d!
    Q.x,Q.y,0M[tank.blit] !* redraw background *!
    %.x 1U.[sprite]
    F>
  !key. !
    !* FIXME: this also scrolls due to  *!
    Q.x,Q.y,Q.[sprite]M[tank.shoot]
    F>
  !key.!
    Q.x,Q.yM[tank.selfdestruct]
    1;
>

Q.[caretstyle]ESSETCARETSTYLE