65 lines
2.1 KiB
Lua
65 lines
2.1 KiB
Lua
local Object = require "lib/classic"
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---@class Frame
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---@field sprite number The index of the sprite in the atlas.
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---@field duration? number The duration (in seconds) of this frame.
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---@field atlas? Atlas The sprite atlas this frame is drawn from.
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---@class Animation
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---A timed sequence of sprites.
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local Animation = Object:extend()
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---Creates a new animation.
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---@param frames Frame[] A list of frames.
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---@param duration? number The default duration to use for this animation. Defaults to 15 FPS.
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---@param atlas? Atlas The default atlas to use for this animation.
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function Animation:new(frames, duration, atlas)
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local default_duration = duration or (1.0 / 15.0)
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---The list of frames.
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self.frames = {}
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local total_duration = 0
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for idx, frame in ipairs(frames) do
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total_duration = total_duration + (frame.duration or default_duration)
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self.frames[idx] = {
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sprite = frame.sprite,
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duration = frame.duration or duration,
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atlas = frame.atlas or atlas or error("Missing default atlas"),
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}
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end
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---The total duration of this animation.
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self.duration = total_duration
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end
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---Creates a new animation from the sprites between start and end indices, plus an atlas.
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---@param atlas Atlas The atlas that the sprites are from.
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---@param start_idx number The first sprite index in the animation.
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---@param end_idx number The last sprite index in the animation.
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---@param duration? number The duration of each frame. Defaults to 15 FPS.
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---@return Animation
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function Animation:new_spanned(atlas, start_idx, end_idx, duration)
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local duration = duration or (1.0 / 15.0)
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local frames = {}
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for sprite = start_idx, end_idx do
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frames[#frames + 1] = { sprite = sprite, atlas = atlas, duration = duration }
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end
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return Animation(frames)
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end
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---Draws a frame of this animation.
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---@param index number The index of the frame.
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---@param x number The X position to draw at.
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---@param y number The Y position to draw at.
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function Animation:draw(index, x, y)
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local frame = self.frames[index]
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frame.atlas:draw(frame.sprite, x, y)
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end
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return Animation
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