Hello Alexander,

We made an additional discussion in the team and I would like to follow back with some information about the feedback item.

The issue as it is logged only affects RadRichTextEditor. Please check the LetterSpacing.png my colleague attached when creating the item. As I stated in my reply on 19.07.2017, RadRichTextEditor uses native rendering from the gdi32.dll. The control is not affected by the UseCompatibleTextRendering property and this behavior is by design. On the other hand our other controls are respecting the property and they are using the GDI+ engine for rendering the text. 

As you already know, GDI and GDI+ can be easily switched via the UseCompatibleTextRendering property on the controls. Globally you can set it to false only once with the static UseCompatibleTextRenderingDefaultValue property: 

RadControl.UseCompatibleTextRenderingDefaultValue = false;

In this respect the title of the feedback item will be reverted to only mention RadRichTextEditor. I also understand that you might be experiencing rendering issues with the text in other controls so please open up a support ticket with detailed information how they can be observed.

Regards,
Hristo
Progress Telerik

Hello, Alexander,

I have updated the title and description of this feedback item indicating that it is generally related to the Telerik Presentation Framework and the text rendering.

We also have a documentation article explaining how the text is being rendered in the TPF: https://docs.telerik.com/devtools/winforms/telerik-presentation-framework/text-rendering  The TextRenderingHint allows you to control the quality of the text rendering in the TextPrimitive contained in most RadControls.

If you need any further assistance please don't hesitate to contact me. 

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik

Hello,

Your feedback is greatly appreciated. However, as my colleague, Hristo, had previously explained we have no control on how native GDI is working internally and how the characters are painted. Changing the whole text rendering mechanism in RadRichTextEditor is a very massive task and it may affect existing customers' applications. It should be planned very precisely and consider all possible options for improving the text before addressing it. Feel free to track its progress and subscribe for status changes.

Hi Thomas,

GDI and GDI+ can be switched and each has its pros and cons. For our controls we have decided that by default we will use GDI+. We have no control on how these Windows API are working internally and how the characters are painted. Some detailed information and comparisons are available here: https://theartofdev.com/2014/04/21/text-rendering-methods-comparison-or-gdi-vs-gdi-revised/. The Graphics class in GDI+ is significantly faster than the TextRenderer used by GDI. 

The described issue in RadRichTextEditor is actually not at all related to the GDI+. RadRichTextEditor is a complex control and we have decided to use native GDI rendering for the text(not GDI or GDI+). For the purpose we are using the gdi32.dll and its TextOut function: https://msdn.microsoft.com/en-us/library/dd145133(v=vs.85).aspx.