asteroids.eve

= Asteroids =
An Asteroids clone created by porting Asteroids.hs (:link:)

This is not a faithful clone. The only way to control the ship is to shoot
by clicking somewhere on the play field. This will move the ship due to
kickback.

The program starts with a chapter to set up the global state and draw
the initial canvas followed by a the main game chapter and finishing with
a game over screen chapter.

== Global set up and boilerplate ==

=== Set up global state + constants ===
```
match
  [#session-connect]
commit
  [@world screen: "game"]
```
=== Set up canvas ===
```
match
  [#session-connect]
commit
  [#div style: [
    user-select: "none" -webkit-user-select: "none"
    -moz-user-select: "none" 
      background-color: "black" min-width: "550px"] children:
    [#svg @game-window viewBox: "0 0 550 550", width: 550]]
```

== Main game ==
This chapter is divided into sections for each type of game object:
rocks, the player ship & player bullets. Each of these is futher
divided into initialisation section, a control step if applicable, a
simulation step and a draw step.

=== Rocks ===
==== Init ====
```
match
  [#session-connect]
commit
  [#rock x: 150 y: 150 size: 45 vx: 2 vy: 6 frame: 0]
  [#rock x: -45 y: 201 size: 45 vx: 13 vy: -8 frame: 0]
  [#rock x: 45 y: 22 size: 25 vx: -2 vy: 8 frame: 0]
  [#rock x: -210 y: -15 size: 30 vx: -2 vy: -8 frame: 0]
  [#rock x: -45 y: -201 size: 25 vx: 8 vy: 2 frame: 0]
```
==== Simulation ====
```
match
  [#time frames]
  world = [@world screen: "game"]
  rock = [#rock x y vx vy frame != frames]
  new_x = rock.x + rock.vx / 60
  adj_new_x =
    if new_x > 550 then new_x - 550
   else if new_x < 0 then 550 - new_x
    else new_x
  new_y = rock.y + rock.vy / 60
  adj_new_y =
    if new_y > 550 then new_y - 550
   else if new_y < 0 then 550 - new_y
    else new_y
commit
  rock.x := adj_new_x
  rock.y := adj_new_y
  rock.frame := frames
```
==== Draw ====
```
match
  svg = [@game-window]
  rock = [#rock x y size]
bind
  sprite = [#circle rock stroke: "orange"]
  sprite.cx := x
  sprite.cy := y
  sprite.r := size
  svg.children += sprite
```
=== Ship ===
```
```
==== Init ====

==== Control ====

==== Simulation ====

==== Draw ====

=== Bullet ===

==== Init ====

==== Control ====

==== Simulation ====

==== Draw ====

== Game over screen ==