<<>> <> <> <> <<>> DIRECTORY ImagerBrick USING [Brick, BrickShape, BrickSpec], ImagerSample USING [Clear, NewSampleMap, Put, RasterSampleMap], ImagerSys USING [LongMult], ImagerTransformation USING [Cat, Create, InverseTransformVec, Rotate, Scale, Transformation, TransformVec], List USING [Compare, CompareProc, LORA, Sort], Real USING [Round], RealInline USING [MCFix], RealFns USING [CosDeg], SF USING [Vec], Vector2 USING [Add, Cross, Sub, VEC]; ImagerBrickImpl: CEDAR PROGRAM IMPORTS List, ImagerTransformation, Real, RealInline, RealFns, Vector2, ImagerSample, ImagerSys EXPORTS ImagerBrick ~ BEGIN VEC: TYPE ~ Vector2.VEC; Transformation: TYPE ~ ImagerTransformation.Transformation; BrickShape: TYPE ~ ImagerBrick.BrickShape; ExtendedGCD: TYPE ~ RECORD [p, q: INTEGER, g: NAT]; ExtendedEuclid: PROC [u, v: NAT] RETURNS [ExtendedGCD] ~ { <> u1: INTEGER ¬ 1; u2: INTEGER ¬ 0; u3: NAT ¬ u; v1: INTEGER ¬ 0; v2: INTEGER ¬ 1; v3: NAT ¬ v; WHILE v3 # 0 DO quotient: NAT ~ u3/v3; t1: INTEGER ~ u1-(v1*quotient); t2: INTEGER ~ u2-(v2*quotient); t3: INTEGER ~ u3-(v3*quotient); u1 ¬ v1; u2 ¬ v2; u3 ¬ v3; v1 ¬ t1; v2 ¬ t2; v3 ¬ t3; ENDLOOP; RETURN [[p: u1, q: u2, g: u3]] }; Sig: PROC [a, b: INT] RETURNS [INT] ~ {RETURN [IF a < 0 THEN -b ELSE b]}; BrickShapeFromDeltas: PUBLIC PROC [s0, f0, s1, f1: INT] RETURNS [BrickShape] ~ { area: CARD ~ ABS[INT[s0]*INT[f1] - INT[s1]*INT[f0]]; -- cross product to get area gcd: ExtendedGCD ~ ExtendedEuclid[ABS[s0], ABS[s1]]; sSize: CARD ~ gcd.g; fSize: INT ~ area/sSize; phase: INT ¬ Sig[s0, f0]*INT[gcd.p] + Sig[s1, f1]*INT[gcd.q]; WHILE phase < 0 DO phase ¬ phase + fSize ENDLOOP; WHILE phase >= fSize DO phase ¬ phase - fSize ENDLOOP; RETURN [[sSize, fSize, phase]]; }; SqrAbs: PROC [v: VEC] RETURNS [REAL] ~ INLINE {RETURN [v.x*v.x+v.y*v.y]}; SqrLen: PROC [u, v: VEC] RETURNS [REAL] ~ INLINE {RETURN [SqrAbs[Vector2.Sub[u, v]]]}; BrickSpec: TYPE ~ ImagerBrick.BrickSpec; BrickSpecFromTransformedRectangle: PUBLIC PROC [w, h: REAL, clientToDevice: Transformation, allowedRelativeError: REAL, minLevels: CARD] RETURNS [BrickSpec] ~ { v: ARRAY [0..1] OF VEC ~ [ ImagerTransformation.TransformVec[clientToDevice, [w, 0]], ImagerTransformation.TransformVec[clientToDevice, [0, h]] ]; vMul: ARRAY [0..1] OF VEC ¬ v; allowSqr: REAL ~ allowedRelativeError*allowedRelativeError; n0: INT ¬ 1; n1: INT ¬ 1; IF ABS[Vector2.Cross[v[0], v[1]]] < 0.015625 THEN { <> RETURN [[[sSize: 1, fSize: 2, phase: 1], ImagerTransformation.Create[a: 1, b: -1, c: clientToDevice.c, d: 1, e: 1, f: clientToDevice.f]]] }; DO v0x: INT ¬ Real.Round[vMul[0].x]; v0y: INT ¬ Real.Round[vMul[0].y]; v1x: INT ¬ Real.Round[vMul[1].x]; v1y: INT ¬ Real.Round[vMul[1].y]; SELECT TRUE FROM SqrLen[vMul[0], [v0x, v0y]] > SqrAbs[vMul[0]]*allowSqr => { vMul[0] ¬ Vector2.Add[v[0], vMul[0]]; n0 ¬ n0 + 1; }; SqrLen[vMul[1], [v1x, v1y]] > SqrAbs[vMul[1]]*allowSqr => { vMul[1] ¬ Vector2.Add[v[1], vMul[1]]; n1 ¬ n1 + 1; }; ENDCASE => { n0w: REAL ~ REAL[n0]*w; n1h: REAL ~ REAL[n1*h]; bs: BrickShape ~ BrickShapeFromDeltas[v0x, v0y, v1x, v1y]; brickShape: BrickShape ¬ bs; m: Transformation ~ ImagerTransformation.Create[a: v0x/n0w, b: v1x/n1h, c: clientToDevice.c, d: v0y/n0w, e: v1y/n1h, f: clientToDevice.f]; <> <