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Showing content with the highest reputation on 05/23/22 in all areas

  1. angusj

    Rounded polygon

    Here's my GetSmoothPath() routine. It requires no specific graphics library to use, just a few extra functions (also included below). This function generates an array of control points that's very easily converted into a flattened cubic bezier path using just about any 2D graphics library. (nb: The code below has been written with simplicity as the focus rather than performance.) uses SysUtils, Math; type TPointD = record X, Y: double; end; TPathD = array of TPointD; TArrayOfDouble = array of double; function DistanceSqrd(const pt1, pt2: TPointD): double; begin result := Sqr(pt1.X - pt2.X) + Sqr(pt1.Y - pt2.Y); end; function Distance(const pt1, pt2: TPointD): double; begin Result := Sqrt(DistanceSqrd(pt1, pt2)); end; function OffsetPoint(const pt: TPointD; dx, dy: double): TPointD; begin result.x := pt.x + dx; result.y := pt.y + dy; end; function GetAvgUnitVector(const vec1, vec2: TPointD): TPointD; var inverseHypot: Double; begin Result.X := (vec1.X + vec2.X) * 0.5; Result.y := (vec1.Y + vec2.Y) * 0.5; inverseHypot := 1 / Hypot(Result.X, Result.Y); Result.X := Result.X * inverseHypot; Result.Y := Result.Y * inverseHypot; end; procedure MakeSymmetric(var val1, val2: double); begin val1 := (val1 + val2) * 0.5; val2 := val1; end; function GetUnitVector(const pt1, pt2: TPointD): TPointD; var dx, dy, inverseHypot: Double; begin if (pt1.x = pt2.x) and (pt1.y = pt2.y) then begin Result.X := 0; Result.Y := 0; Exit; end; dx := (pt2.X - pt1.X); dy := (pt2.Y - pt1.Y); inverseHypot := 1 / Hypot(dx, dy); dx := dx * inverseHypot; dy := dy * inverseHypot; Result.X := dx; Result.Y := dy; end; // GetSmoothPath - returns cubic bezier control points // parameters: 1. path for smoothing // 2. whether or not the smoothed path will closed // 3. percent smoothness (0..100) // 4. maximum dist control pts from path pts (0 = no limit) // 5. symmetric vs asymmmetric control pts function GetSmoothPath(const path: TPathD; pathIsClosed: Boolean; percentOffset, maxCtrlOffset: double; symmetric: Boolean): TPathD; var i, len, prev: integer; vec: TPointD; pl: TArrayOfDouble; unitVecs: TPathD; d, d1,d2: double; begin Result := nil; len := Length(path); if len < 3 then Exit; d := Max(0, Min(100, percentOffset))/200; if maxCtrlOffset <= 0 then maxCtrlOffset := MaxDouble; SetLength(Result, len *3 +1); prev := len-1; SetLength(pl, len); SetLength(unitVecs, len); for i := 0 to len -1 do begin pl[i] := Distance(path[prev], path[i]); unitVecs[i] := GetUnitVector(path[prev], path[i]); prev := i; end; Result[len*3] := path[0]; for i := 0 to len -1 do begin if i = len -1 then begin vec := GetAvgUnitVector(unitVecs[i], unitVecs[0]); d2 := pl[0]*d; end else begin vec := GetAvgUnitVector(unitVecs[i], unitVecs[i+1]); d2 := pl[i+1]*d; end; d1 := pl[i]*d; if symmetric then MakeSymmetric(d1, d2); if i = 0 then Result[len*3-1] := OffsetPoint(path[i], -vec.X * Min(maxCtrlOffset, d1), -vec.Y * Min(maxCtrlOffset, d1)) else Result[i*3-1] := OffsetPoint(path[i], -vec.X * Min(maxCtrlOffset, d1), -vec.Y * Min(maxCtrlOffset, d1)); Result[i*3] := path[i]; Result[i*3+1] := OffsetPoint(path[i], vec.X * Min(maxCtrlOffset, d2), vec.Y * Min(maxCtrlOffset, d2)); end; if not pathIsClosed then begin Result[1] := Result[0]; dec(len); Result[len*3-1] := Result[len*3]; SetLength(Result, Len*3 +1); end; end; And here's what it produces ... the path to smooth (black), the cubic bezier control path produced by GetSmoothPath() (blue) and the flattened cubic bezier path (2D graphics library of you choice required) (red). var TPathD path; begin path := MakePath([190,120, 260,270, 560,120, 190,490]); path := GetSmoothPath(path, true, 20, 0, false); path := ThirdParty2DGraphicsLibrary.FlattenCBezier(path); end; var TPathD path; begin path := MakePath([190,120, 260,270, 560,120, 190,490]); path := GetSmoothPath(path, true, 80, 0, false); path := ThirdParty2DGraphicsLibrary.FlattenCBezier(path); end; Edit: The best way to avoid intersections is to make sure you have enough data points before generating your curves.
  2. SwiftExpat

    Android: Opening files in external application

    Mustafa, Great job putting together that readme for your github repo. I like the inline samples and android version cross references.
  3. Mustafa ֍zgun

    Android: Opening files in external application

    Hi kindly check https://github.com/emozgun/delphi-android-SAF
  4. Vincent Parrett

    New Delphi job opportunity

    Ah the drop bears, those are reserved for hot Swedish tourists -
  5. Uwe Raabe

    Delphi 11.1 - a month later

    This is standard for D11 and it works quite well when you use the scaled designer, too. Unfortunately that will change your DFM files often in an unwanted way. As long as you are the only one working with these files it might be acceptable, but in mixed environments it is often not really usable in the moment. Seems that Embarcadero itself doesn't make use of the scaled designer: All PixelsPerInch in the form resources of CoreIDE280.bpl are 96 DPI.