<> <> <> <> <> <> DIRECTORY CDOrient, Basics, CD; CDOrientImpl: CEDAR PROGRAM IMPORTS Basics, CDOrient EXPORTS CDOrient = BEGIN OPEN CDOrient; <<-- Orientation Transformations>> <<-- x increases to the right, y increases upward. >> <<-- An CD.Orientation idx is composed of two parts:>> <<-- a clockwise rotation of (idx/2)*90 degrees,>> <<-- followed by a reflection in x if (idx MOD 2)#0.>> <> <> <> <<>> <<-- 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.>> <<>> <> <> <<-- most common case>> <> <> <> <> <> <> <<]];>> <<>> <<[x: sizeX, y: sizeY] _ cellSize;>> <<[x1: x1, x2: x2, y1: y1, y2: y2] _ itemInCell;>> <<>> <> < { -- 90 degrees clockwise>> <> <> <> <> <> <> <<};>> < { -- 180 degrees clockwise>> <> <> <<};>> < { -- 270 degrees clockwise>> <> <> <> <> <> <> <<};>> < NULL;>> <> <<>> <> <> <<};>> <<>> <> <> <> <> <<>> <<>> MapRect: PUBLIC PROC [itemInCell: CD.Rect, cellSize: CD.Position, cellInstOrient: CD.Orientation, cellInstPos: CD.Position _ [0,0]] RETURNS [itemInWorld: CD.Rect_TRASH] = <<-- 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 SELECT cellInstOrient FROM original => RETURN[CD.Rect[ x1: cellInstPos.x+itemInCell.x1, x2: cellInstPos.x+itemInCell.x2, y1: cellInstPos.y+itemInCell.y1, y2: cellInstPos.y+itemInCell.y2 ]]; 1 => -- reflection in x RETURN[CD.Rect[ x1: cellInstPos.x+cellSize.x-itemInCell.x2, x2: cellInstPos.x+cellSize.x-itemInCell.x1, y1: cellInstPos.y+itemInCell.y1, y2: cellInstPos.y+itemInCell.y2 ]]; rotate90 => { -- 90 degrees clockwise RETURN[CD.Rect[ x1: cellInstPos.x+cellSize.y-itemInCell.y2, y1: cellInstPos.y+itemInCell.x1, x2: cellInstPos.x+cellSize.y-itemInCell.y1, y2: cellInstPos.y+itemInCell.x2]]; }; 3 => { -- 90 degrees clockwise followed by reflection in x RETURN[CD.Rect[ x1: cellInstPos.x+itemInCell.y1, y1: cellInstPos.y+itemInCell.x1, x2: cellInstPos.x+itemInCell.y2, y2: cellInstPos.y+itemInCell.x2]]; }; rotate180 => { -- 180 degrees clockwise RETURN[CD.Rect[ x1: cellInstPos.x+cellSize.x-itemInCell.x2, y1: cellInstPos.y+cellSize.y-itemInCell.y2, x2: cellInstPos.x+cellSize.x-itemInCell.x1, y2: cellInstPos.y+cellSize.y-itemInCell.y1]]; }; 5 => { -- 180 degrees clockwise followed by reflection in x RETURN[CD.Rect[ x1: cellInstPos.x+itemInCell.x1, y1: cellInstPos.y+cellSize.y-itemInCell.y2, x2: cellInstPos.x+itemInCell.x2, y2: cellInstPos.y+cellSize.y-itemInCell.y1]]; }; rotate270 => { -- 270 degrees clockwise RETURN[CD.Rect[ x1: cellInstPos.x+itemInCell.y1, y1: cellInstPos.y+cellSize.x-itemInCell.x2, x2: cellInstPos.x+itemInCell.y2, y2: cellInstPos.y+cellSize.x-itemInCell.x1]]; }; 7 => { -- 270 degrees clockwise followed by reflection in x RETURN[CD.Rect[ x1: cellInstPos.x+cellSize.y-itemInCell.y2, y1: cellInstPos.y+cellSize.x-itemInCell.x2, x2: cellInstPos.x+cellSize.y-itemInCell.y1, y2: cellInstPos.y+cellSize.x-itemInCell.x1]]; }; ENDCASE; 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 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; }; original => NULL; 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.>> itemOrientInWorld _ composeTable[itemOrientInCell][cellOrientInWorld] 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..6] _ Basics.BITAND[orient, 6]; IF refl=0 AND rot#0 THEN rot _ 8-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[ composeTable[itemOrientInWorld][InverseOrient[cellOrientInWorld]] ] END; ReallyComposeOrient: 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..6] _ LOOPHOLE[Basics.BITAND[cellOrientInWorld, 6]]; IF refl1#0 AND rot2#0 THEN rot2 _ 8-rot2; itemOrientInWorld _ Basics.BITAND[LOOPHOLE[Basics.BITAND[itemOrientInCell, 6], CARDINAL]+ rot2+LOOPHOLE[Basics.BITXOR[refl1, Basics.BITAND[cellOrientInWorld, 1]], CARDINAL], 7]; END; <<-- Certification tests, can be commented out for speed of startup>> <> <> <> <> <> <> <> <<>> composeTable: ARRAY CD.Orientation OF ARRAY CD.Orientation OF CD.Orientation; FOR o1: CD.Orientation IN CD.Orientation DO FOR o2: CD.Orientation IN CD.Orientation DO composeTable[o1][o2] _ ReallyComposeOrient[o1, o2]; ENDLOOP; ENDLOOP; END.