class MiniGL::Effect
Represents a visual effect, i.e., a graphic - usually animated - that shows up in the screen, lasts for a given time and “disappears”. You should explicitly dispose of references to effects whose attribute dead
is set to true
.
Attributes
This is true
when the effect’s lifetime has already passed.
The number of times update
has been called for this effect, while it was still active (not dead
).
The lifetime of the effect, in updates, i.e., how many calls to update
must happen before the effect is marked as dead
, since its creation.
Public Class Methods
Creates a new Effect
.
Parameters:
- x
-
The x-coordinate in the screen (or map) where the effect will be drawn. This can be modified later via the
x
attribute. - y
-
The y-coordinate in the screen (or map) where the effect will be drawn. This can be modified later via the
y
attribute. - img
-
The image or spritesheet to use for this effect (see
Sprite
for details on spritesheets). - sprite_cols
-
(see
Sprite
) - sprite_rows
-
(see
Sprite
) - interval
-
The interval between steps of the animation, in updates.
- indices
-
The indices to use in the animation. See
Sprite#animate
for details. Ifnil
, it will be the sequence from 0 tosprite_cols * sprite_rows - 1
. - lifetime
-
The lifetime of the effect, in updates. After
update
is called this number of times, the effect will no longer be visible, even whendraw
is called, and thedead
flag will be set totrue
, so you get to know when to dispose of theEffect
object. Ifnil
, it will be set to@indices.length * interval
, i.e., the exact time needed for one animation cycle to complete. - sound
-
The id of a sound to be played when the effect is created (id must be given in the format specified for the
Res.sound
method). - sound_ext
-
Extension of the sound file, if a sound is given. Default is ‘.wav’.
- sound_volume
-
The volume (from 0 to 1) to play the sound, if any. Default is 1.
Obs.: This method accepts named parameters, but x
, y
and img
are mandatory.
MiniGL::Sprite::new
# File lib/minigl/game_object.rb, line 357 def initialize(x, y = nil, img = nil, sprite_cols = nil, sprite_rows = nil, interval = 10, indices = nil, lifetime = nil, sound = nil, sound_ext = '.wav', sound_volume = 1) if x.is_a? Hash y = x[:y] img = x[:img] sprite_cols = x.fetch(:sprite_cols, nil) sprite_rows = x.fetch(:sprite_rows, nil) interval = x.fetch(:interval, 10) indices = x.fetch(:indices, nil) lifetime = x.fetch(:lifetime, nil) sound = x.fetch(:sound, nil) sound_ext = x.fetch(:sound_ext, '.wav') sound_volume = x.fetch(:sound_volume, 1) x = x[:x] end super x, y, img, sprite_cols, sprite_rows @elapsed_time = 0 if indices @indices = indices else @indices = *(0..(@img.length - 1)) end @interval = interval if lifetime @lifetime = lifetime else @lifetime = @indices.length * interval end Res.sound(sound, false, sound_ext).play(sound_volume) if sound end
Public Instance Methods
MiniGL::Sprite#draw
# File lib/minigl/game_object.rb, line 398 def draw(map = nil, scale_x = 1, scale_y = 1, alpha = 0xff, color = 0xffffff, angle = nil, flip = nil, z_index = 0, round = false) super unless @dead end
The remaining number of calls to update
until the effect is marked dead
.
# File lib/minigl/game_object.rb, line 404 def time_left @lifetime - @elapsed_time end
Updates the effect, animating and counting its remaining lifetime.
# File lib/minigl/game_object.rb, line 390 def update return if @dead animate(@indices, @interval) @elapsed_time += 1 @dead = true if @elapsed_time == @lifetime end