lisichkin_alexander

Thanks for the help. Yes, indeed the code: if (not a) or True then work. But why code: var b: boolean; begin b := False; if not b or True then writeln('b not or'); end; work and code: var a: TplFilterValue<Boolean>; begin a := False; if not a or True then writeln('a not or'); end; do not work? I assumed that I did not override for some operator for the record 😕 P.S. I use Delphi 10.2, so I can not use operator assign

Happy New Year, everyone! I create a class(record) with operator overloading. But I got an error: [dcc32 Error] E2015 Operator not applicable to this operand type Which operator did I forget to override? uses System.SysUtils, System.Generics.Collections, System.Rtti, System.TypInfo; type TplFilterValue<T> = record class operator Implicit(AValue: T): TplFilterValue<T>; class operator Implicit(AValue: TplFilterValue<T>): T; class operator LogicalNot(AValue: TplFilterValue<T>): Boolean; class operator LogicalOr(ALeft: TplFilterValue<T>; ARight: TplFilterValue<T>): Boolean; class operator LogicalAnd(ALeft: TplFilterValue<T>; ARight: TplFilterValue<T>): Boolean; private FValue: T; class function AsBoolean(AValue: TplFilterValue<T>): Boolean; static; procedure SetValue(AValue: T); public property Value: T read FValue write SetValue; end; procedure TplFilterValue<T>.SetValue(AValue: T); begin FValue := AValue; end; class operator TplFilterValue<T>.Implicit(AValue: T): TplFilterValue<T>; begin Result.FValue := AValue; end; class operator TplFilterValue<T>.Implicit(AValue: TplFilterValue<T>): T; begin Result := AValue.FValue; end; class function TplFilterValue<T>.AsBoolean(AValue: TplFilterValue<T>): Boolean; var LTypeInfo: PTypeInfo; LValue: TValue; begin LTypeInfo := System.TypeInfo(T); if LTypeInfo^.Name <> 'Boolean' then raise Exception.Create('Unsupported type operation'); LValue := TValue.From<T>(AValue.FValue); Result := LValue.AsBoolean; end; class operator TplFilterValue<T>.LogicalNot(AValue: TplFilterValue<T>): Boolean; begin Result := not AsBoolean(AValue); end; class operator TplFilterValue<T>.LogicalOr(ALeft: TplFilterValue<T>; ARight: TplFilterValue<T>): Boolean; begin Result := AsBoolean(ALeft) or AsBoolean(ARight); end; class operator TplFilterValue<T>.LogicalAnd(ALeft: TplFilterValue<T>; ARight: TplFilterValue<T>): Boolean; begin Result := AsBoolean(ALeft) and AsBoolean(ARight); end; var a: TplFilterValue<Boolean>; begin try a := False; if not a then writeln('not a = True'); if a or True then writeln('a or'); if a and True then writeln('a and'); if not(a) or True then <<--- Error [dcc32 Error] E2015 Operator not applicable to this operand type writeln('a not or'); except on E: Exception do Writeln(E.ClassName, ': ', E.Message); end; end.

l have to explain why I started all this 🙂 There is a Web service, written in Java, that we use to convert and compress images to Png. It was noticed that this service does not correctly convert colors for some Png images. I was given the task of building an algorithm that would determine that two pictures are identical. Moreover, with the condition, that colors are identical - the images themselves are considered the same. I came up with the idea of comparing the illumination histograms of two pictures. And this algorithm worked well, until I find some images with transparency - for which I did not correctly determine the color of some points. The question can be reformulated: how to get the R G B color of a point, taking into account transparency.

Hello! It is required to calculate the illumination of a point in a TPNGImage object, taking into account transparency. I wrote the following algorithm: function GetBrightness(const AImage: TPNGImage; AX, AY: Integer): Integer; var LColor, LTransparentColor: TColor; r, g, b, alpha: Byte; tr, tg, tb: Byte; LDstAlpha: pByteArray; begin LColor := AImage.Pixels[AX, AY]; r := Byte(LColor); g := Byte(LColor shr 8); b := Byte(LColor shr 16); if AImage.Transparent and (LColor <> 0) then begin if (AImage.Header.ColorType in [COLOR_RGBALPHA, COLOR_GRAYSCALEALPHA]) then begin LDstAlpha := AImage.AlphaScanline[AY]; if Assigned(LDstAlpha) then begin alpha := LDstAlpha[AX]; r := Byte(Round(r * alpha/255)); g := Byte(Round(g * alpha/255)); b := Byte(Round(b * alpha/255)); end; end else if AImage.Header.ColorType = COLOR_PALETTE then begin LTransparentColor := AImage.TransparentColor; tr := Byte(LTransparentColor); tg := Byte(LTransparentColor shr 8); tb := Byte(LTransparentColor shr 16); r := Byte(Round(r * tr/255)); g := Byte(Round(g * tg/255)); b := Byte(Round(b * tb/255)); end; end; Result := Round(0.3*r + 0.59*g + 0.11*b); end; Please analyze my algorithm for errors. P.S. Unfortunately, in my test base there are no images with TransparentColor - only with alpha channel. Alexander.

I can make a few assumptions: 1. A 32-bit application works with a database. and for some reason You need to process a large amount of information not on the server, but on the client and the amount of data exceeds 3GB of memory. 2. You want to write a dll library for a 64-bit application (Extended stored procedure) 3.... This is only a 32 to 64 bit transition

It’s not clear what you want to do, I can suggest using Windows API function CreateProcessWithLogonW = function(const lpUsername: PWideChar; const lpDomain: PWideChar; const lpPassword: PWideChar; dwLogonFlags: DWORD; const lpApplicationName: PWideChar; lpCommandLine: PWideChar; dwCreationFlags: DWORD; lpEnvironment: Pointer; const lpCurrentDirectory: PWideChar; lpStartupInfo: PStartupInfo; lpProcessInfo: PProcessInformation): Boolean; stdcall