cambridge/tetris/components/piece.lua

167 lines
4.2 KiB
Lua

local Object = require 'libs.classic'
local Piece = Object:extend()
function Piece:new(shape, rotation, position, block_offsets, gravity, lock_delay, skin, colour, big)
self.shape = shape
self.rotation = rotation
self.position = position
self.block_offsets = block_offsets
self.gravity = gravity
self.lock_delay = lock_delay
self.skin = skin
self.colour = colour
self.ghost = false
self.locked = false
self.big = big
end
-- Functions that return a new piece to test in rotation systems.
function Piece:withOffset(offset)
return Piece(
self.shape, self.rotation,
{x = self.position.x + offset.x, y = self.position.y + offset.y},
self.block_offsets, self.gravity, self.lock_delay, self.skin, self.colour, self.big
)
end
function Piece:withRelativeRotation(rot)
local new_rot = self.rotation + rot
while new_rot < 0 do new_rot = new_rot + 4 end
while new_rot >= 4 do new_rot = new_rot - 4 end
return Piece(
self.shape, new_rot, self.position,
self.block_offsets, self.gravity, self.lock_delay, self.skin, self.colour, self.big
)
end
-- Functions that return predicates relative to a grid.
function Piece:getBlockOffsets()
return self.block_offsets[self.shape][self.rotation + 1]
end
function Piece:occupiesSquare(x, y)
local offsets = self:getBlockOffsets()
for index, offset in pairs(offsets) do
local new_offset = {x = self.position.x + offset.x, y = self.position.y + offset.y}
if new_offset.x == x and new_offset.y == y then
return true
end
end
return false
end
function Piece:isMoveBlocked(grid, offset)
local moved_piece = self:withOffset(offset)
return not grid:canPlacePiece(moved_piece)
end
function Piece:isDropBlocked(grid)
return self:isMoveBlocked(grid, { x=0, y=1 })
end
-- Procedures to actually do stuff to pieces.
function Piece:setOffset(offset)
self.position.x = self.position.x + offset.x
self.position.y = self.position.y + offset.y
return self
end
function Piece:setRelativeRotation(rot)
new_rot = self.rotation + rot
while new_rot < 0 do new_rot = new_rot + 4 end
while new_rot >= 4 do new_rot = new_rot - 4 end
self.rotation = new_rot
return self
end
function Piece:moveInGrid(step, squares, grid)
local moved = false
for x = 1, squares do
if grid:canPlacePiece(self:withOffset(step)) then
moved = true
self:setOffset(step)
else
break
end
end
if moved and step.y == 0 then playSE("move") end
return self
end
function Piece:dropSquares(dropped_squares, grid)
self:moveInGrid({ x = 0, y = 1 }, dropped_squares, grid)
end
function Piece:dropToBottom(grid)
local piece_y = self.position.y
self:dropSquares(math.huge, grid)
self.gravity = 0
if self.position.y > piece_y then
-- if it got dropped any, also reset lock delay
if self.ghost == false then playSE("bottom") end
self.lock_delay = 0
end
return self
end
function Piece:lockIfBottomed(grid)
if self:isDropBlocked(grid) then
self.locked = true
end
return self
end
function Piece:addGravity(gravity, grid)
local new_gravity = self.gravity + gravity
if self:isDropBlocked(grid) then
self.gravity = math.min(1, new_gravity)
self.lock_delay = self.lock_delay + 1
else
local dropped_squares = math.floor(new_gravity)
local new_frac_gravity = new_gravity - dropped_squares
self.gravity = new_frac_gravity
self:dropSquares(dropped_squares, grid)
if self:isDropBlocked(grid) then
playSE("bottom")
end
end
return self
end
-- Procedures for drawing.
function Piece:draw(opacity, brightness, grid, partial_das)
if opacity == nil then opacity = 1 end
if brightness == nil then brightness = 1 end
love.graphics.setColor(brightness, brightness, brightness, opacity)
local offsets = self:getBlockOffsets()
local gravity_offset = 0
--if grid ~= nil and not self:isDropBlocked(grid) then
-- gravity_offset = self.gravity * 16
--end
if partial_das == nil then partial_das = 0 end
for index, offset in pairs(offsets) do
local x = self.position.x + offset.x
local y = self.position.y + offset.y
if self.big then
love.graphics.draw(
blocks[self.skin][self.colour],
64+x*32+partial_das*2, 16+y*32+gravity_offset*2,
0, 2, 2
)
else
love.graphics.draw(
blocks[self.skin][self.colour],
64+x*16+partial_das, 16+y*16+gravity_offset
)
end
end
return false
end
return Piece