how does this drawtank function draws a rectangular tank?

how does this drawtank function draws a rectangular tank?

b aryal

Member #17,071

April 2019

void drawtank(int num)
{
int x = tanks[num].x;
int y = tanks[num].y;
int dir = tanks[num].dir;
//draw tank body and turret
rectfill(screen, x-11, y-11, x+11, y+11, tanks[num].color);
rectfill(screen, x-6, y-6, x+6, y+6, 7);
//draw the treads based on orientation
if (dir == 0 || dir == 2)
{
rectfill(screen, x-16, y-16, x-11, y+16, 8);
rectfill(screen, x+11, y-16, x+16, y+16, 8);
}
else
if (dir == 1 || dir == 3)
{
rectfill(screen, x-16, y-16, x+16, y-11, 8);
rectfill(screen, x-16, y+16, x+16, y+11, 8);
}
//draw the turret based on direction
switch (dir)
{
case 0:
rectfill(screen, x-1, y, x+1, y-16, 8);
break;
case 1:
rectfill(screen, x, y-1, x+16, y+1, 8);
break;
case 2:
rectfill(screen, x-1, y, x+1, y+16, 8);
break;
case 3:
rectfill(screen, x, y-1, x-16, y+1, 8);
break;
}
}

Edgar Reynaldo

Major Reynaldo

May 2007

That is allegro 4 code. It draws a tank using filled rectangles only.

Eagle and Allegro 5 binaries | Older Allegro 4 and 5 binaries | Allegro 5 compile guide
King Piccolo will make it so Then I could just flip it with some sweet, sweet matrix math. In either case, I’ll ride this wagon until the wheels fall off. Thanks to those that keep it running

b aryal

Member #17,071

April 2019

0: Move toward the northwest
1: Move toward the southwest
2: Move toward the northeast
3: Move toward the southeast
is this how directions work in allegro everytime..

context-: if (dir==0...and so on)

Edgar Reynaldo

Major Reynaldo

May 2007

0 is north.

You've got to learn how to read code for yourself that's the true mark of a coder, being able to read someone else's code.

It has nothing to do with allegro, except that y decreases going up the screen.

EDIT
Welcome to allegro by the way.

If you use <code>code goes here</code> tags, you can highlight your code, and it will provide (outdated) links to the manual, like so :

#SelectExpand
  1void drawtank(int num)
  2{
  3int x = tanks[num].x;
  4int y = tanks[num].y;
  5int dir = tanks[num].dir;
  6//draw tank body and turret
  7rectfill(screen, x-11, y-11, x+11, y+11, tanks[num].color);
  8rectfill(screen, x-6, y-6, x+6, y+6, 7);
  9//draw the treads based on orientation
 10if (dir == 0 || dir == 2)
 11{
 12rectfill(screen, x-16, y-16, x-11, y+16, 8);
 13rectfill(screen, x+11, y-16, x+16, y+16, 8);
 14}
 15else
 16if (dir == 1 || dir == 3)
 17{
 18rectfill(screen, x-16, y-16, x+16, y-11, 8);
 19rectfill(screen, x-16, y+16, x+16, y+11, 8);
 20}
 21//draw the turret based on direction
 22switch (dir)
 23{
 24case 0:
 25rectfill(screen, x-1, y, x+1, y-16, 8);
 26break;
 27case 1:
 28rectfill(screen, x, y-1, x+16, y+1, 8);
 29break;
 30case 2:
 31rectfill(screen, x-1, y, x+1, y+16, 8);
 32break;
 33case 3:
 34rectfill(screen, x, y-1, x-16, y+1, 8);
 35break;
 36}
 37}