Add permissive rotation system

tetris/rulesets/prs.lua

@@ -0,0 +1,34 @@
+local SRS = require 'tetris.rulesets.standard'
+
+local PRS = SRS:extend()
+
+PRS.name = "Permissive Rotation System"
+PRS.hash = "PRS"
+PRS.world = true
+
+function PRS:attemptWallkicks(piece, newpiece, rot_dir, grid)
+    for y=0,5 do
+        for x=0,5 do
+            local offset = {x=x, y=y}
+            kicked_piece = newpiece:withOffset(offset)
+            if grid:canPlacePiece(kicked_piece) then
+                piece:setRelativeRotation(rot_dir)
+                piece:setOffset(offset)
+                self:onPieceRotate(piece, grid)
+                return
+            end
+        end
+        for x=0,5 do
+            local offset = {x=-x, y=y}
+            kicked_piece = newpiece:withOffset(offset)
+            if grid:canPlacePiece(kicked_piece) then
+                piece:setRelativeRotation(rot_dir)
+                piece:setOffset(offset)
+                self:onPieceRotate(piece, grid)
+                return
+            end
+        end
+    end
+end
+
+return PRS