<> <> <> <> DIRECTORY Basics USING [DoubleShiftRight], CD USING [Number, Position, Rect]; CDVScale: CEDAR DEFINITIONS IMPORTS Basics = BEGIN <> <<>> <<-- Scaling must be real fast, therefore the crazyness.>> <<-- Design -> Viewer is the most speed critical operation done, used for drawing >> <<-- every rectangle...>> <<-- Viewer -> Design is speed critical for cursor tracking>> <<-- This interface is thought as an implementation module and freely recompiled to improve the>> <<-- inline procedures. Do never copy code from this module, because this module changes to>> <<-- often, but if new need for scaling appears, include it here.>> <<-- Analyzing compiler generated code showed that it is feasible to have a full record as >> <<-- parameter, since the optimization will get rid of copying the record.>> scaleNum: CARDINAL = 22; ScaleRange: TYPE = [0..scaleNum); <<--A type describing scales; increasing a scale number means viewing a bigger part of the>> <<--chip in a viewer; (more overview, less detail).>> ScaleRec: TYPE = RECORD [ <<--data in this record must be gridded correctly, such that the origin of >> <<--the viewer lies on a grid point; otherwise the gridding would>> <<--require more complex and slower arithmetic.>> off: CD.Position, xx: PRIVATE INT, useMultiply: PRIVATE BOOL, sS: PRIVATE NAT, sA, sB, sC, sD: PRIVATE CARDINAL, designToViewerFactor: PRIVATE REAL, grid: INTEGER, --in DesignCoordinates nscale: INTEGER ]; ArithmeticShiftRight: PROC [x: INT, by: NAT] RETURNS [INT] = INLINE BEGIN IF x>=0 THEN RETURN [LOOPHOLE[Basics.DoubleShiftRight[LOOPHOLE[x], by]]] ELSE RETURN [LOOPHOLE[ LAST[LONG CARDINAL] - LOOPHOLE[ Basics.DoubleShiftRight[ LOOPHOLE[ LAST[LONG CARDINAL] - LOOPHOLE[x, LONG CARDINAL] ], by ], LONG CARDINAL ] ]] END; DesignToViewerFactor: PROC [scale: ScaleRec] RETURNS [REAL] ~ INLINE { <<--without translation>> RETURN [scale.designToViewerFactor] }; DesignToViewerScalar: PROC [scale: ScaleRec, n: CD.Number] RETURNS [CD.Number] ~ INLINE { <<--without translation>> RETURN [IF scale.useMultiply THEN n*scale.xx ELSE ArithmeticShiftRight[n, scale.sS]]; }; <<>> DesignToViewerPosition: PROC[scale: ScaleRec, designPos: CD.Position] RETURNS [viewerPos: CD.Position] ~ INLINE { <<--Including translation to viewer origin>> <<--Caller must make sure that the designRect is only little outside the viewer clip rect>> RETURN[ IF scale.useMultiply THEN CD.Position[ (designPos.x-scale.off.x)*scale.xx, (designPos.y-scale.off.y)*scale.xx ] ELSE CD.Position[ ArithmeticShiftRight[designPos.x-scale.off.x, scale.sS], ArithmeticShiftRight[designPos.y-scale.off.y, scale.sS] ] ] }; DesignToViewerRect: PROC[scale: ScaleRec, designRect: CD.Rect] RETURNS [CD.Rect] ~ INLINE { <<--Including translation to viewer origin.>> <<--Caller must make sure that the designRect is only little outside the viewer clip rect.>> RETURN[ IF scale.useMultiply THEN CD.Rect[ x1: (designRect.x1-scale.off.x)*scale.xx, y1: (designRect.y1-scale.off.y)*scale.xx, x2: (designRect.x2-scale.off.x)*scale.xx, y2: (designRect.y2-scale.off.y)*scale.xx ] ELSE CD.Rect[ x1: ArithmeticShiftRight[designRect.x1-scale.off.x, scale.sS], y1: ArithmeticShiftRight[designRect.y1-scale.off.y, scale.sS], x2: ArithmeticShiftRight[designRect.x2-scale.off.x, scale.sS], y2: ArithmeticShiftRight[designRect.y2-scale.off.y, scale.sS] ] ] }; UngriddedViewerToDesignScalar: PROC [scale: ScaleRec, v: LONG CARDINAL] RETURNS [CD.Number] = INLINE { <<--without translation, without grid>> IF scale.useMultiply THEN RETURN [LOOPHOLE[(v*scale.sA+scale.xx-1)/scale.xx, CD.Number]] ELSE RETURN [LOOPHOLE[(v*scale.sA), CD.Number]] }; ViewerToDesignScalar: PROC [scale: ScaleRec, v: LONG CARDINAL] RETURNS [CD.Number] = INLINE { <<--without translation, but gridded to the current grid>> RETURN [LOOPHOLE[(v*scale.sA+scale.sB)/scale.sC*scale.sD, CD.Number]] }; ViewerToDesignPosition: PROC[scale: ScaleRec, viewerPos: CD.Position] RETURNS [designPos: CD.Position] = INLINE { <<--with offset and grid>> RETURN[CD.Position[ ViewerToDesignScalar[scale, viewerPos.x]+scale.off.x, ViewerToDesignScalar[scale, viewerPos.y]+scale.off.y] ] }; MakeScale: PROC [off: CD.Position_[0, 0], nscale: ScaleRange_4, grid: INTEGER_-1] RETURNS [ScaleRec]; <<--given the grid, offset and nscale; makes a correctly gridded and initialized ScaleRec>> GetClipRecord: PROC [scale: ScaleRec, highX, highY: CARDINAL] RETURNS [CD.Rect]; <<--given the index of the (high-most) pixel in the viewer, compute an outside clipping >> <<--rectangle in design coordinates; (such that all outside the clipping area is invisible).>> END.