<> <> <> <> <> DIRECTORY CDOrient, Basics, CDInline, CD; CDOrientImpl: CEDAR PROGRAM IMPORTS Basics, CDOrient EXPORTS CDOrient = BEGIN OPEN CDOrient; <<-- Orientation Transformations>> <<-- x increases to the right, y increases downward. Y later changed to increase upward>> <<-- An CD.Orientation idx is composed of two parts:>> <<-- a clockwise rotation of (idx/2)*45 degrees,>> <<-- followed by a reflection in x if (idx MOD 2)#0.>> <<-- Odd multiples of 45 degrees are not yet supported.>> MapRect: PUBLIC PROC [itemInCell: CD.Rect, cellSize: CD.Position, cellInstOrient: CD.Orientation, cellInstPos: CD.Position _ [0,0]] RETURNS [itemInWorld: CD.Rect] = <<-- Given an item in a prototype cell, and the>> <<-- size of the prototype cell, both in "cell" co-ordinates, and>> <<-- the position and orientation index of an instance of that cell in "world">> <<-- co-ordinates, this procedure returns the world>> <<-- co-ordinates of the instance of the item.>> BEGIN x1, y1, x2, y2, sizeX, sizeY, t: CD.Number; <<-- most common case>> IF cellInstOrient=original THEN RETURN[CD.Rect[ x1: cellInstPos.x+itemInCell.x1, x2: cellInstPos.x+itemInCell.x2, y1: cellInstPos.y+itemInCell.y1, y2: cellInstPos.y+itemInCell.y2 ]]; [x: sizeX, y: sizeY] _ cellSize; [x1: x1, x2: x2, y1: y1, y2: y2] _ itemInCell; SELECT ConcentrateOnRotate90[cellInstOrient] FROM original => NULL; rotate90 => { -- 90 degrees clockwise t _ y1; y1 _ x1; x1 _ sizeY-y2; y2 _ x2; x2 _ sizeY-t; sizeX _ sizeY; }; rotate180 => { -- 180 degrees clockwise t _ sizeX-x1; x1 _ sizeX-x2; x2 _ t; t _ sizeY-y1; y1 _ sizeY-y2; y2 _ t; }; rotate270 => { -- 270 degrees clockwise t _ x1; x1 _ y1; y1 _ sizeX-x2; x2 _ y2; y2 _ sizeX-t; sizeX _ sizeY; }; ENDCASE; IF IncludesMirrorX[cellInstOrient] THEN { -- mirror in x t _ sizeX-x1; x1 _ sizeX-x2; x2 _ t }; itemInWorld _ [x1: cellInstPos.x+x1, -- translate by cellInstPos y1: cellInstPos.y+y1, x2: cellInstPos.x+x2, y2: cellInstPos.y+y2]; END; DeMapRect: PUBLIC PROC [itemInWorld: CD.Rect, cellSize: CD.Position, cellInstOrient: CD.Orientation, cellInstPos: CD.Position _ [0,0]] RETURNS [itemInCell: CD.Rect] = BEGIN <<-- Given an item in world co-ordinates, and the>> <<-- size of a prototype cell, both in "cell" co-ordinates, and>> <<-- the position and orientation index of an instance of that cell in "world">> <<-- co-ordinates, this procedure returns the cell prototype>> <<-- co-ordinates of that item.>> inverseOrient: CD.Orientation = InverseOrient[cellInstOrient]; itemInCell _ MapRect[ itemInCell: [ x1: itemInWorld.x1-cellInstPos.x, y1: itemInWorld.y1-cellInstPos.y, x2: itemInWorld.x2-cellInstPos.x, y2: itemInWorld.y2-cellInstPos.y ], cellInstOrient: inverseOrient, cellSize: CDOrient.OrientedSize[size: cellSize, orient: inverseOrient] ]; END; MapPosition: PUBLIC PROC [itemInCell: CD.Rect, cellSize: CD.Position, cellInstOrient: CD.Orientation, cellInstPos: CD.Position _ [0,0]] RETURNS [posInWorld: CD.Position] = <<-- Given an position in a prototype cell, and the>> <<-- size of the prototype cell, both in "cell" co-ordinates, and>> <<-- the position and orientation index of an instance of that cell in "world">> <<-- co-ordinates, this procedure returns the world>> <<-- co-ordinates of the position.>> <<-- This procedure is only speed up from MapRect>> BEGIN x1, y1, x2, y2, sizeX, sizeY, t: CD.Number; IF cellInstOrient=original THEN -- most common case RETURN[[ x: cellInstPos.x+itemInCell.x1, y: cellInstPos.y+itemInCell.y1 ]]; [x: sizeX, y: sizeY] _ cellSize; [x1: x1, x2: x2, y1: y1, y2: y2] _ itemInCell; SELECT ConcentrateOnRotate90[cellInstOrient] FROM original => NULL; rotate90 => { -- 90 degrees clockwise t _ y1; y1 _ x1; x1 _ sizeY-y2; x2 _ sizeY-t; sizeX _ sizeY; }; rotate180 => { -- 180 degrees clockwise t _ sizeX-x1; x1 _ sizeX-x2; x2 _ t; y1 _ sizeY-y2; }; rotate270 => { -- 270 degrees clockwise x1 _ y1; y1 _ sizeX-x2; x2 _ y2; sizeX _ sizeY; }; ENDCASE; IF IncludesMirrorX[cellInstOrient] THEN {x1 _ sizeX-x2}; posInWorld _ [x: cellInstPos.x+x1, y: cellInstPos.y+y1]; END; ComposeOrient: PUBLIC PROC [ itemOrientInCell, cellOrientInWorld: CD.Orientation] RETURNS [itemOrientInWorld: CD.Orientation] = BEGIN <<-- This procedure produces the composite orientation>> <<-- obtained by first doing itemOrientInCell and then>> <<-- doing cellOrientInWorld. It uses the observation>> <<-- that a reflection in x followed by a z-degree clockwise>> <<-- rotation is the same as a (360-z)-degree clockwise rotation>> <<-- followed by a reflection in x. Thus if itemOrientInCell>> <<-- contains a final reflection, then cellOrientInWorld's rotation>> <<-- operates in reverse.>> refl1: [0..1] ~ Basics.BITAND[itemOrientInCell, 1]; rot2: [0..14] _ LOOPHOLE[Basics.BITAND[cellOrientInWorld, 14]]; IF refl1#0 AND rot2#0 THEN rot2 _ 16-rot2; itemOrientInWorld _ Basics.BITAND[LOOPHOLE[Basics.BITAND[itemOrientInCell, 14], CARDINAL]+ rot2+LOOPHOLE[Basics.BITXOR[refl1, Basics.BITAND[cellOrientInWorld, 1]], CARDINAL], 15]; END; InverseOrient: PUBLIC PROC [orient: CD.Orientation] RETURNS [inverse: CD.Orientation] = BEGIN <<-- For all orientationIndexes o1, ComposeOrient[o1, InverseOrient[o1]] = 0.>> <<-- A reflection in x followed by a z-degree clockwise>> <<-- rotation is the same as a (360-z)-degree clockwise rotation>> <<-- followed by a reflection in x. Thus if orient>> <<-- contains a final reflection, then the inverse rotation>> <<-- operates in the same direction as the forward one.>> refl: [0..1] ~ Basics.BITAND[orient, 1]; rot: [0..14] _ Basics.BITAND[orient, 14]; IF refl=0 AND rot#0 THEN rot _ 16-rot; inverse _ rot+refl; END; DecomposeOrient: PUBLIC PROC [ itemOrientInWorld, cellOrientInWorld: CD.Orientation] RETURNS [itemOrientInCell: CD.Orientation] = BEGIN <<-- For all orientationIndexes o1 and o2,>> <<-- DecomposeOrient[cellOrientInWorld: o1, itemOrientInWorld:>> <<-- ComposeOrient[cellOrientInWorld: o1, itemOrientInCell: o2]] = o2.>> RETURN[ComposeOrient[ itemOrientInCell: itemOrientInWorld, cellOrientInWorld: InverseOrient[cellOrientInWorld]] ]; END; <<-- Certification tests, can be commented out for speed of startup>> <> <> <> <> <> <> <> <<>> END.