Get access to over 100 FireMonkey cross platform samples for Android, IOS, OSX, Windows, and Linux!

AndroidAppmethodCode SnippetDelphiFiremonkeyIOS

Perfect Line Thickness Using TCanvas DrawLine With Delphi XE5 Firemonkey On Android And IOS

Dlphi XE5 Firemonkey Clean LinesIf you’re using Delphi XE5 Firemonkey to do any kind of drawing on TCanvas with DrawLine you may have run into this issue. The problem is that when you draw a one pixel line what you end up with doesn’t appear as a one pixel line. I believe this issue exists on both Android and IOS. Roman Yankovsky has a blog post demonstrating the problem and showing the solution. Here is an example of DrawLine where the problem manifests:

Canvas.DrawLine(PointF(50 + I * 25, 0), PointF(50 + I * 25, ClientHeight), 1);

And here is the an example of DrawLine with the extra code that fixes the problem:

Canvas.DrawLine(PointF(50 + I * 25 – (Canvas.Stroke.Thickness / 2), 0),
PointF(50 + I * 25 – (Canvas.Stroke.Thickness / 2), ClientHeight), 1);

Roman has much more comprehensive example code on his blog and even a second method for correcting the problem.

Head over to read the full blog post about correcting DrawLine on TCanvas.

close

Have Delphi Firemonkey questions? Ask and get answers on StackOverflow.

Related posts
AndroidC++BuilderDelphiFiremonkeyIOSOSXWindows

FireMonkey 10.4.2 Features Updated iOS 14, Android 11, And macOS 11 Support Plus Hundreds Of Fixes

DelphiIDEShowcaseWindows

Ryzen 9 5950x: One Billion Lines Of Delphi Code Compiled In ~5 Minutes On 16 Cores

DelphiFiremonkeyIDEIOSOSXWindows

DelphiCon 2020 FireMonkey Sessions Available Starting November 19

AndroidC++BuilderDelphiDemoFiremonkeyWindows

Powerful Commercial Gorilla3D Framework Upgraded For Delphi FireMonkey On Windows And Android

Sign up for our Newsletter and
stay informed

Leave a Reply