Subversion Repositories openmsp430

#include "spacewar.h"

//************************************************************

// externals

//

extern volatile int xinit, yinit;

extern void cline(int, int);

void set_xy(int, int);

extern void point(rkt_data *);

//************************************************************

//

// rkt2

//

//    draws rocket # 2

//

// pa_x = xd2 + xs2

// pa_y = yd2 + ys2

// pb_x = xd2 - xs2

// pb_y = yd2 - ys2

// pc_x = xd2 - xs2/2

// pc_y = yd2 - ys2/2

// pd_x = (xd2 - xs2) - ys2/2

// pd_y = (yd2 - ys2) + xs2/2

// pf_x = (xd2 - xs2) + ys2/2

// pf_y = (yd2 - ys2) - xs2/2

//

/* Description:

Draws rocket 2 made of five lines.  This rocket looks like an arrowhead

Also draws rocket 2 torpedos as points. On exit leaves the DAC parked at the

center of the screen.

*/

void rocket2(rkt_data *rkt2)

{

int tmp_x, tmp_y;

int half_xs2, half_ys2;

  tmp_x = rkt2->xdisp - rkt2->xsize;    // pb_x = xd2 - xs2

  tmp_y = rkt2->ydisp - rkt2->ysize;    // pb_y = yd2 - ys2

  half_xs2 = rkt2->xsize >> 1;          // xs2/2

  half_ys2 = rkt2->ysize >> 1;          // ys2/2

  xinit = tmp_x;                        // start pb_x

  yinit = tmp_y;                        // start pb_y

  cline(rkt2->xdisp + rkt2->xsize, rkt2->ydisp + rkt2->ysize);  // draw line #1 b->a

  cline(tmp_x + half_ys2, tmp_y - half_xs2); // draw line #2 a->f

  cline(rkt2->xdisp - half_xs2, rkt2->ydisp - half_ys2); // draw line #3 f->c

  cline(tmp_x - half_ys2, tmp_y + half_xs2); // draw line #4 c->d

  cline(rkt2->xdisp + rkt2->xsize, rkt2->ydisp + rkt2->ysize); // draw line #5 d->a

  point(rkt2);                          // update and draw rkt2's torpedoes

  set_xy(center, center);               // park dot at center of screen

}