<div dir="ltr"><div class="gmail_extra">I am trying to paint controls, so I need to eventually Canvas.Draw() to get a graphic onto a control. I've been working on creating a fully featured web browser for Lazarus and have been looking at the underlying widgetset interface code. </div><div class="gmail_extra"><br></div><div class="gmail_extra">Gtk3, which my project currently works great on, uses the now required Cairo system for painting Gtk widgets. I've already had to patch the Gtk3 LCL interface section quite a bit to fix errors and I'll submit those changes when I publish my project.</div><div class="gmail_extra"><br></div><div class="gmail_extra">However, the LCL Gtk2 widgetset is stuck using the Gdk system for drawing, even though that was deprecated early on in the Gtk2 lifetime and Cairo has been recommend for a decade or more. I would like to submit a patch for Gtk2 replacing Gdk with Cairo, but using a swtich setting that could be changed at runtime.</div><div class="gmail_extra"><br></div><div class="gmail_extra">GDI+ has been available for Windows since XP was released in 2001, and Direct2D since Windows 7 in 2009. I think it's about time we upgrade the Windows graphics from GDI to at least GDI+.</div><div class="gmail_extra"><br></div><div class="gmail_extra">I am willing to contribute to these changes, but I would want assurances that we would accept a common interface for the advanced features all these improved graphics back-ends include. They all include alpha blending, gradient brushes, matrix transforms, vector shaped clipping paths, and more. </div><div class="gmail_extra"><br></div><div class="gmail_extra">My recommend approach to adding these features to the core LCL Canvas class would be to:</div><div class="gmail_extra"><br></div><div class="gmail_extra">A) Change the underlying widgetset to operate with these new graphic backends and operate the same as before, but fixing a few problems like allowing Canavs.Draw to work between 32 bits per pixel surfaces correctly.</div><div class="gmail_extra"><br></div><div class="gmail_extra">B) Add an advanced canvas interface for new features like gradient brushes, vector clipping paths and such. Widgetsets can implement the advanced interface and use it in conjunction with the original TCanvas class.</div><div class="gmail_extra"><br></div><div class="gmail_extra">Examples:</div><div class="gmail_extra"><br></div><div class="gmail_extra">Canvas.Matrix.Rotate(PI / 6);</div><div class="gmail_extra">Canvas.AddPath<span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">(Polygon);</span></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">Canvas.Clip;</span><br></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">Canvas.Fill(Gradient);</span></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline"><br></span></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">  TPolygon = array of TPointF;</span></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline"><br></span></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">  IAdvancedCanvas = interface </span></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">    ...</span></div><div class="gmail_extra">    procedure AddPath(Polygon: TPolygon);<br></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">    procedure Clip;</span></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">    procedure Fill(Brush: IBrush);</span></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline"><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">    property Matrix: IMatrix read GetMatrix write SetMatrix;</span></div><div class="gmail_extra">    ....<br></div></span></div><div class="gmail_extra"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">  end;</span></div><div class="gmail_extra"><br></div><div class="gmail_extra">Suggestions?</div></div>