Class: MiniGL::Effect
Overview
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
.
Instance Attribute Summary collapse
-
#dead ⇒ Object
readonly
This is
true
when the effect’s lifetime has already passed. -
#elapsed_time ⇒ Object
readonly
The number of times
update
has been called for this effect, while it was still active (notdead
). -
#lifetime ⇒ Object
readonly
The lifetime of the effect, in updates, i.e., how many calls to
update
must happen before the effect is marked asdead
, since its creation.
Attributes inherited from Sprite
#img, #img_index, #x, #y
Instance Method Summary collapse
- #draw(map = nil, scale_x = 1, scale_y = 1, alpha = 0xff, color = 0xffffff, angle = nil, flip = nil, z_index = 0, round = false) ⇒ Object
-
#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) ⇒ Effect
constructor
Creates a new Effect.
-
#time_left ⇒ Object
The remaining number of calls to
update
until the effect is markeddead
. -
#update ⇒ Object
Updates the effect, animating and counting its remaining lifetime.
Methods inherited from Sprite
#animate, #animate_once, #set_animation, #visible?
Constructor Details
#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) ⇒ Effect
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. If
nil
, 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 the Effect 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.
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# File 'lib/minigl/game_object.rb', line 349 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 |
Instance Attribute Details
#dead ⇒ Object (readonly)
This is true
when the effect’s lifetime has already passed.
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# File 'lib/minigl/game_object.rb', line 308 def dead @dead end |
#elapsed_time ⇒ Object (readonly)
The number of times update
has been called for this effect, while it was still active (not dead
).
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# File 'lib/minigl/game_object.rb', line 316 def elapsed_time @elapsed_time end |
#lifetime ⇒ Object (readonly)
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.
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# File 'lib/minigl/game_object.rb', line 312 def lifetime @lifetime end |
Instance Method Details
#draw(map = nil, scale_x = 1, scale_y = 1, alpha = 0xff, color = 0xffffff, angle = nil, flip = nil, z_index = 0, round = false) ⇒ Object
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# File 'lib/minigl/game_object.rb', line 390 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 |
#time_left ⇒ Object
The remaining number of calls to update
until the effect is marked dead
.
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# File 'lib/minigl/game_object.rb', line 396 def time_left @lifetime - @elapsed_time end |
#update ⇒ Object
Updates the effect, animating and counting its remaining lifetime.
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# File 'lib/minigl/game_object.rb', line 382 def update return if @dead animate(@indices, @interval) @elapsed_time += 1 @dead = true if @elapsed_time == @lifetime end |