Editar desbotamento no TikZ

Question

Eu tenho um filldrawretângulo com esmaecimento personalizado (ou seja, mais do que apenas preenchimento superior = cor1, preenchimento inferior = cor2, por exemplo), que é definido usando a \shadeopção a seguir.publicarpor Tobias Brink.

Existem duas edições que eu gostaria de realizar:

1. Desenhe uma borda que façanãodesaparece com o preenchimento, mas desaparece sempre que a transparência é definida como 100 (ou seja, as partes brancas)
2. Arredondar apenas os cantos nordeste e sudeste? Isso foi respondido nodescomo nestepublicar, mas não consigo fazê-lo funcionar aqui.
3. O texto deve aparecer sem transparência.

MWE

\documentclass[tikz]{standalone} \usetikzlibrary{fadings}

\begin{tikz fadinfrompicture}[name=myfading]   
\clip (0,0) rectangle (2,2);   
\shade [top color=transparent!100, bottom color=transparent!0] (0,0) rectangle (2,0.38);                 
\shade [top color=transparent!10, bottom color=transparent!100] (0,0.68) rectangle (2,0.92);               
\shade [top color=transparent!100, bottom color=transparent!10] (0,0.92) rectangle (2,1.16);                     
\shade [top color=transparent!0, bottom color=transparent!100] (0,1.59) rectangle (2,2);                     
\end{tikzfadingfrompicture}

\begin{document}

\begin{tikzpicture} 
\filldraw [blue, path fading=myfading, draw=black, line width=1mm, text opacity = 1] (10,0) rectangle (19,-11.5) node[pos=.5,text width=8 cm] {Some text without transparency}; 
\end{tikzpicture}

\end{document}

Isso gera a seguinte saída

Answer 1

Para o primeiro ponto, temo que você precise descer um pouco mais. Manter a fronteira normalmente é fácil. Fronteira desbotada, ainda mais fácil. Mas você está pedindo paranão desenhara fronteiraapenasquando o desbotamento é totalmente transparente e não acho que haja uma maneira de fazer isso sem código personalizado.

Para os outros dois:

• Cantos arredondados:Construa o caminho com linhas simples, sem usar rectangle, a tonalidade não deve mudar. Por exemplo:
  \draw (0,0) to[rounded corners] (0,2) to[rounded corners] (2,2) -- (2,0) -- cycle;
• Transparência do texto: text opacityna verdade não funciona aqui, mas você pode simplesmente substituir tudo por um nó e algumas opções personalizadas para seu estilo de borda.

Aqui está o código:

\documentclass[tikz,margin=10pt]{standalone} 

\usetikzlibrary{fadings}
\definecolor{myblue}{RGB}{80,103,173}% my blue is different than yours

\begin{tikzfadingfrompicture}[name=myfading]   
\clip (0,0) rectangle (2,2);   
\shade [top color=transparent!100, bottom color=transparent!0] (0,0) rectangle (2,0.38);                 
\shade [top color=transparent!10, bottom color=transparent!100] (0,0.68) rectangle (2,0.92);               
\shade [top color=transparent!100, bottom color=transparent!10] (0,0.92) rectangle (2,1.16);                     
\shade [top color=transparent!0, bottom color=transparent!100] (0,1.59) rectangle (2,2);                     
\end{tikzfadingfrompicture}

\tikzset{
    special/.style={%
        text=myblue,
        minimum height=10cm,
        minimum width=10cm,
        inner sep=0,
        text width=8cm,
        append after command={% custom border and fill!
            \pgfextra
            \fill[preaction={draw=black,line width=1mm}, myblue, path fading=myfading]
            (\tikzlastnode.south west) to[rounded corners=1cm] 
            (\tikzlastnode.north west) to[rounded corners=1cm] 
            (\tikzlastnode.north east) -- 
            (\tikzlastnode.south east) -- cycle; 
            \endpgfextra 
        }
    }
}

\begin{document}

\begin{tikzpicture} 
    \node[special] at (5,5) {Some text without transparency\\Some text without transparency\\Some text without transparency\\Some text without transparency\\Some text without transparency\\Some text without transparency\\Some text without transparency\\}; 
\end{tikzpicture}

\end{document}

e o resultado:

Answer 2

Após o feedback do abcdefg sobre o \pgfextra, decidi trabalhar em uma solução diferente, que você mesmo pode avaliar. Eu criei o comando

\specrect[ <options> ]{ <position> }{ <text> }

As opções incluem quaisquer opções que você possa aplicar a um nó: text width, text, minimum width / height / sizee assim por diante. A única opção personalizada que você tem aqui é decidir se os cantos são agudos ou arredondados (e em caso afirmativo, quanto), e você os decide nesta ordem (a vírgula é o separador):

set corners={ north west, north east, south west, south east }

Se a opção não for dada, todos os cantos serão rounded corners=0, ou seja, cantos agudos. No meu exemplo abaixo mudei os cantos na parte superior para mostrar como funciona.

Saída

Código

\documentclass[tikz, margin=10pt]{standalone} 

\usetikzlibrary{fadings}
\definecolor{myblue}{RGB}{80,103,173}

\begin{tikzfadingfrompicture}[name=myfading]   
\clip (0,0) rectangle (2,2);   
\shade [top color=transparent!100, bottom color=transparent!0] (0,0) rectangle (2,0.38);                 
\shade [top color=transparent!10, bottom color=transparent!100] (0,0.68) rectangle (2,0.92);               
\shade [top color=transparent!100, bottom color=transparent!10] (0,0.92) rectangle (2,1.16);                     
\shade [top color=transparent!0, bottom color=transparent!100] (0,1.59) rectangle (2,2);                     
\end{tikzfadingfrompicture}

\pgfkeys{/tikz/.cd,% to set the path
    nwcorner/.initial=0,
    nwcorner/.get=\nwcorner,
    nwcorner/.store in=\nwcorner,
    necorner/.initial=0,
    necorner/.get=\necorner,
    necorner/.store in=\necorner,
    swcorner/.initial=0,
    swcorner/.get=\swcorner,
    swcorner/.store in=\swcorner,
    secorner/.initial=0,
    secorner/.get=\secorner,
    secorner/.store in=\secorner,
    set corners/.style args={#1,#2,#3,#4}{nwcorner=#1,necorner=#2,swcorner=#3,secorner=#4},
}

\newcommand\specrect[3][]{%
    \tikzset{nwcorner=0,necorner=0,swcorner=0,secorner=0,set corners={0,0,0,0},#1} 
    \node (specialr) at (#2) {};
    \filldraw[preaction={draw=black, line width=1mm},myblue, path fading=myfading] 
        (specialr.south west) to[rounded corners=\nwcorner] 
        (specialr.north west) to[rounded corners=\necorner] 
        (specialr.north east) to[rounded corners=\swcorner]  
        (specialr.south east) to[rounded corners=\secorner] cycle;
    \node at (#2) {#3};
}

\begin{document}
\begin{tikzpicture}
\specrect[
    text=myblue,
    minimum height=10cm,
    minimum width=10cm,
    inner sep=0,
    text width=8cm,
    set corners={1cm,3cm,0,0}% nw, ne, sw, se
    ]{0,0}{Some text without transparency}
\end{tikzpicture}
\end{document}

Answer 3

Por solicitação: uma versão sem \pgfextra, qual deve sernãousar para operações de caminho. Pode-se usar um path pictureem vez disso. Se alguém quiser um limite, em geral isso pode ser feito apenas adicionando draw. No caso em questão, com cantos arredondados apenas para alguns cantos, pode-se usar append after command. Observe que isso não fornece um nó que "sabe" onde está seu limite, ou seja, ele não desenhará caminhos de conexão nas proximidades dos cantos arredondados corretamente. Para isso, você teria que definir uma nova forma.

\documentclass[tikz]{standalone} 
\usetikzlibrary{calc,fadings}

\begin{tikzfadingfrompicture}[name=myfading]   
\clip (0,0) rectangle (2,2);   
\shade [top color=transparent!100, bottom color=transparent!0] (0,0) rectangle (2,0.38);                 
\shade [top color=transparent!10, bottom color=transparent!100] (0,0.68) rectangle (2,0.92);               
\shade [top color=transparent!100, bottom color=transparent!10] (0,0.92) rectangle (2,1.16);                     
\shade [top color=transparent!0, bottom color=transparent!100] (0,1.59) rectangle (2,2);                     
\end{tikzfadingfrompicture}

\begin{document}

\begin{tikzpicture}[faded/.style={path picture={
\fill[blue, path fading=myfading]
    let \p1=($(path picture bounding box.north east)-(path picture bounding box.south west)$),
     \n1={0.15*min(\x1,\y1)} in [rounded corners=\n1]
            (path picture bounding box.south west) |- 
            (path picture bounding box.north east) [sharp corners] |- cycle;
},append after command={[ultra thick] let
\p1=($(\tikzlastnode.north east)-(\tikzlastnode.south west)$),
     \n1={0.15*min(\x1,\y1)} in 
(\tikzlastnode.south west) edge[ultra thick,line cap=rect,vh path,rounded corners=\n1] (\tikzlastnode.north)
(\tikzlastnode.south east) edge[ultra thick,line cap=rect,vh path,rounded corners=\n1] (\tikzlastnode.north)
(\tikzlastnode.south west) edge[ultra thick,line cap=rect] (\tikzlastnode.south east)
}},vh path/.style={to path={|- (\tikztotarget)}}] 
\path  node[minimum size=10cm,text width=8cm,faded] 
{Some text without transparency}; 
\end{tikzpicture}
\end{document}

Uma versão possivelmente mais limpa é obtida usando oretângulo com cantos arredondados variáveis.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{intersections}
\usetikzlibrary{calc,fadings}

\begin{tikzfadingfrompicture}[name=myfading]   
\clip (0,0) rectangle (2,2);   
\shade [top color=transparent!100, bottom color=transparent!0] (0,0) rectangle (2,0.38);                 
\shade [top color=transparent!10, bottom color=transparent!100] (0,0.68) rectangle (2,0.92);               
\shade [top color=transparent!100, bottom color=transparent!10] (0,0.92) rectangle (2,1.16);                     
\shade [top color=transparent!0, bottom color=transparent!100] (0,1.59) rectangle (2,2);                     
\end{tikzfadingfrompicture}

\begin{document}

\makeatletter
% from https://tex.stackexchange.com/a/118786/228539
\pgfkeys{/pgf/.cd,
  rectangle corner radius north west/.initial=0pt,
  rectangle corner radius north east/.initial=0pt,
  rectangle corner radius south west/.initial=0pt,
  rectangle corner radius south east/.initial=0pt
}
\newif\ifpgf@rectanglewrc@donecorner@
\def\pgf@rectanglewithroundedcorners@docorner#1#2#3#4#5{%
  \edef\pgf@marshal{%
    \noexpand\pgfintersectionofpaths
      {%
        \noexpand\pgfpathmoveto{\noexpand\pgfpoint{\the\pgf@xa}{\the\pgf@ya}}%
        \noexpand\pgfpathlineto{\noexpand\pgfpoint{\the\pgf@x}{\the\pgf@y}}%
      }%
      {%
        \noexpand\pgfpathmoveto{\noexpand\pgfpointadd
          {\noexpand\pgfpoint{\the\pgf@xc}{\the\pgf@yc}}%
          {\noexpand\pgfpoint{#1}{#2}}}%
        \noexpand\pgfpatharc{#3}{#4}{#5}%
      }%
    }%
  \pgf@process{\pgf@marshal\pgfpointintersectionsolution{1}}%
  \pgf@process{\pgftransforminvert\pgfpointtransformed{}}%
  \pgf@rectanglewrc@donecorner@true
}
\pgfdeclareshape{rectangle with rounded corners}
{
  \inheritsavedanchors[from=rectangle] % this is nearly a rectangle
  \inheritanchor[from=rectangle]{north}
  \inheritanchor[from=rectangle]{north west}
  \inheritanchor[from=rectangle]{north east}
  \inheritanchor[from=rectangle]{center}
  \inheritanchor[from=rectangle]{west}
  \inheritanchor[from=rectangle]{east}
  \inheritanchor[from=rectangle]{mid}
  \inheritanchor[from=rectangle]{mid west}
  \inheritanchor[from=rectangle]{mid east}
  \inheritanchor[from=rectangle]{base}
  \inheritanchor[from=rectangle]{base west}
  \inheritanchor[from=rectangle]{base east}
  \inheritanchor[from=rectangle]{south}
  \inheritanchor[from=rectangle]{south west}
  \inheritanchor[from=rectangle]{south east}

  \savedmacro\cornerradiusnw{%
    \edef\cornerradiusnw{\pgfkeysvalueof{/pgf/rectangle corner radius north west}}%
  }
  \savedmacro\cornerradiusne{%
    \edef\cornerradiusne{\pgfkeysvalueof{/pgf/rectangle corner radius north east}}%
  }
  \savedmacro\cornerradiussw{%
    \edef\cornerradiussw{\pgfkeysvalueof{/pgf/rectangle corner radius south west}}%
  }
  \savedmacro\cornerradiusse{%
    \edef\cornerradiusse{\pgfkeysvalueof{/pgf/rectangle corner radius south east}}%
  }

  \backgroundpath{%
    \northeast\advance\pgf@y-\cornerradiusne\relax
    \pgfpathmoveto{}%
    \pgfpatharc{0}{90}{\cornerradiusne}%
    \northeast\pgf@ya=\pgf@y\southwest\advance\pgf@x\cornerradiusnw\relax\pgf@y=\pgf@ya
    \pgfpathlineto{}%
    \pgfpatharc{90}{180}{\cornerradiusnw}%
    \southwest\advance\pgf@y\cornerradiussw\relax
    \pgfpathlineto{}%
    \pgfpatharc{180}{270}{\cornerradiussw}%
    \northeast\pgf@xa=\pgf@x\advance\pgf@xa-\cornerradiusse\southwest\pgf@x=\pgf@xa
    \pgfpathlineto{}%
    \pgfpatharc{270}{360}{\cornerradiusse}%
    \northeast\advance\pgf@y-\cornerradiusne\relax
    \pgfpathlineto{}%
    \pgfpathclose
  }

  \anchor{before north east}{\northeast\advance\pgf@y-\cornerradiusne}
  \anchor{after north east}{\northeast\advance\pgf@x-\cornerradiusne}
  \anchor{before north west}{\southwest\pgf@xa=\pgf@x\advance\pgf@xa\cornerradiusnw
    \northeast\pgf@x=\pgf@xa}
  \anchor{after north west}{\northeast\pgf@ya=\pgf@y\advance\pgf@ya-\cornerradiusnw
    \southwest\pgf@y=\pgf@ya}
  \anchor{before south west}{\southwest\advance\pgf@y\cornerradiussw}
  \anchor{after south west}{\southwest\advance\pgf@x\cornerradiussw}
  \anchor{before south east}{\northeast\pgf@xa=\pgf@x\advance\pgf@xa-\cornerradiusse
    \southwest\pgf@x=\pgf@xa}
  \anchor{after south east}{\southwest\pgf@ya=\pgf@y\advance\pgf@ya\cornerradiusse
    \northeast\pgf@y=\pgf@ya}

  \anchorborder{%
    \pgf@xb=\pgf@x% xb/yb is target
    \pgf@yb=\pgf@y%
    \southwest%
    \pgf@xa=\pgf@x% xa/ya is se
    \pgf@ya=\pgf@y%
    \northeast%
    \advance\pgf@x by-\pgf@xa%
    \advance\pgf@y by-\pgf@ya%
    \pgf@xc=.5\pgf@x% x/y is half width/height
    \pgf@yc=.5\pgf@y%
    \advance\pgf@xa by\pgf@xc% xa/ya becomes center
    \advance\pgf@ya by\pgf@yc%
    \edef\pgf@marshal{%
      \noexpand\pgfpointborderrectangle
      {\noexpand\pgfqpoint{\the\pgf@xb}{\the\pgf@yb}}
      {\noexpand\pgfqpoint{\the\pgf@xc}{\the\pgf@yc}}%
    }%
    \pgf@process{\pgf@marshal}%
    \advance\pgf@x by\pgf@xa% 
    \advance\pgf@y by\pgf@ya%
    \pgfextract@process\borderpoint{}%
    %
    \pgf@rectanglewrc@donecorner@false
    %
    % do southwest corner
    \southwest\pgf@xc=\pgf@x\pgf@yc=\pgf@y
    \advance\pgf@xc\cornerradiussw\relax\advance\pgf@yc\cornerradiussw\relax 
    \borderpoint
    \ifdim\pgf@x<\pgf@xc\relax\ifdim\pgf@y<\pgf@yc\relax
      \pgf@rectanglewithroundedcorners@docorner{-\cornerradiussw}{0pt}{180}{270}{\cornerradiussw}%
    \fi\fi
    %
    % do southeast corner
    \ifpgf@rectanglewrc@donecorner@\else
      \southwest\pgf@yc=\pgf@y\relax\northeast\pgf@xc=\pgf@x\relax
      \advance\pgf@xc-\cornerradiusse\relax\advance\pgf@yc\cornerradiusse\relax
      \borderpoint
      \ifdim\pgf@x>\pgf@xc\relax\ifdim\pgf@y<\pgf@yc\relax
       \pgf@rectanglewithroundedcorners@docorner{0pt}{-\cornerradiusse}{270}{360}{\cornerradiusse}%
      \fi\fi
    \fi
    %
    % do northeast corner
    \ifpgf@rectanglewrc@donecorner@\else
      \northeast\pgf@xc=\pgf@x\relax\pgf@yc=\pgf@y\relax
      \advance\pgf@xc-\cornerradiusne\relax\advance\pgf@yc-\cornerradiusne\relax
      \borderpoint
      \ifdim\pgf@x>\pgf@xc\relax\ifdim\pgf@y>\pgf@yc\relax
       \pgf@rectanglewithroundedcorners@docorner{\cornerradiusne}{0pt}{0}{90}{\cornerradiusne}%
      \fi\fi
    \fi
    %
    % do northwest corner
    \ifpgf@rectanglewrc@donecorner@\else
      \northeast\pgf@yc=\pgf@y\relax\southwest\pgf@xc=\pgf@x\relax
      \advance\pgf@xc\cornerradiusnw\relax\advance\pgf@yc-\cornerradiusnw\relax
      \borderpoint
      \ifdim\pgf@x<\pgf@xc\relax\ifdim\pgf@y>\pgf@yc\relax
       \pgf@rectanglewithroundedcorners@docorner{0pt}{\cornerradiusnw}{90}{180}{\cornerradiusnw}%
      \fi\fi
    \fi
  }
}

\makeatother

\begin{tikzpicture}[faded/.style={path picture={
\fill[blue, path fading=myfading]
            (path picture bounding box.south west) rectangle 
            (path picture bounding box.north east);}}] 
\path node[rectangle with rounded corners,minimum size=10cm,
    text width=8cm,faded,draw,ultra thick,font=\sffamily, 
    rectangle corner radius north west=20pt] 
{Some text without transparency}; 
\end{tikzpicture}
\end{document}