image and animation progress

modules/Transform.lua

@@ -0,0 +1,147 @@
+--- Transform module for 2D transformations (rotate, scale, translate, skew)
+---@class Transform
+---@field rotate number? Rotation in radians (default: 0)
+---@field scaleX number? X-axis scale (default: 1)
+---@field scaleY number? Y-axis scale (default: 1)
+---@field translateX number? X translation in pixels (default: 0)
+---@field translateY number? Y translation in pixels (default: 0)
+---@field skewX number? X-axis skew in radians (default: 0)
+---@field skewY number? Y-axis skew in radians (default: 0)
+---@field originX number? Transform origin X (0-1, default: 0.5)
+---@field originY number? Transform origin Y (0-1, default: 0.5)
+local Transform = {}
+Transform.__index = Transform
+
+--- Create a new transform instance
+---@param props TransformProps?
+---@return Transform transform
+function Transform.new(props)
+  props = props or {}
+
+  local self = setmetatable({}, Transform)
+
+  self.rotate = props.rotate or 0
+  self.scaleX = props.scaleX or 1
+  self.scaleY = props.scaleY or 1
+  self.translateX = props.translateX or 0
+  self.translateY = props.translateY or 0
+  self.skewX = props.skewX or 0
+  self.skewY = props.skewY or 0
+  self.originX = props.originX or 0.5
+  self.originY = props.originY or 0.5
+
+  return self
+end
+
+--- Apply transform to LÖVE graphics context
+---@param transform Transform Transform instance
+---@param x number Element x position
+---@param y number Element y position
+---@param width number Element width
+---@param height number Element height
+function Transform.apply(transform, x, y, width, height)
+  if not transform then
+    return
+  end
+
+  -- Calculate transform origin
+  local ox = x + width * transform.originX
+  local oy = y + height * transform.originY
+
+  -- Apply transform in correct order: translate → rotate → scale → skew
+  love.graphics.push()
+  love.graphics.translate(ox, oy)
+
+  if transform.rotate ~= 0 then
+    love.graphics.rotate(transform.rotate)
+  end
+
+  if transform.scaleX ~= 1 or transform.scaleY ~= 1 then
+    love.graphics.scale(transform.scaleX, transform.scaleY)
+  end
+
+  if transform.skewX ~= 0 or transform.skewY ~= 0 then
+    love.graphics.shear(transform.skewX, transform.skewY)
+  end
+
+  love.graphics.translate(-ox, -oy)
+  love.graphics.translate(transform.translateX, transform.translateY)
+end
+
+--- Remove transform from LÖVE graphics context
+function Transform.unapply()
+  love.graphics.pop()
+end
+
+--- Interpolate between two transforms
+---@param from Transform Starting transform
+---@param to Transform Ending transform
+---@param t number Interpolation factor (0-1)
+---@return Transform interpolated
+function Transform.lerp(from, to, t)
+  -- Sanitize inputs
+  if type(from) ~= "table" then
+    from = Transform.new()
+  end
+  if type(to) ~= "table" then
+    to = Transform.new()
+  end
+  if type(t) ~= "number" or t ~= t or t == math.huge or t == -math.huge then
+    t = 0
+  end
+
+  -- Clamp t to 0-1 range
+  t = math.max(0, math.min(1, t))
+
+  return Transform.new({
+    rotate = (from.rotate or 0) * (1 - t) + (to.rotate or 0) * t,
+    scaleX = (from.scaleX or 1) * (1 - t) + (to.scaleX or 1) * t,
+    scaleY = (from.scaleY or 1) * (1 - t) + (to.scaleY or 1) * t,
+    translateX = (from.translateX or 0) * (1 - t) + (to.translateX or 0) * t,
+    translateY = (from.translateY or 0) * (1 - t) + (to.translateY or 0) * t,
+    skewX = (from.skewX or 0) * (1 - t) + (to.skewX or 0) * t,
+    skewY = (from.skewY or 0) * (1 - t) + (to.skewY or 0) * t,
+    originX = (from.originX or 0.5) * (1 - t) + (to.originX or 0.5) * t,
+    originY = (from.originY or 0.5) * (1 - t) + (to.originY or 0.5) * t,
+  })
+end
+
+--- Check if transform is identity (no transformation)
+---@param transform Transform
+---@return boolean isIdentity
+function Transform.isIdentity(transform)
+  if not transform then
+    return true
+  end
+
+  return transform.rotate == 0
+    and transform.scaleX == 1
+    and transform.scaleY == 1
+    and transform.translateX == 0
+    and transform.translateY == 0
+    and transform.skewX == 0
+    and transform.skewY == 0
+end
+
+--- Clone a transform
+---@param transform Transform
+---@return Transform clone
+function Transform.clone(transform)
+  if not transform then
+    return Transform.new()
+  end
+
+  return Transform.new({
+    rotate = transform.rotate,
+    scaleX = transform.scaleX,
+    scaleY = transform.scaleY,
+    translateX = transform.translateX,
+    translateY = transform.translateY,
+    skewX = transform.skewX,
+    skewY = transform.skewY,
+    originX = transform.originX,
+    originY = transform.originY,
+  })
+end
+
+return Transform