SFML community forums
Help => Graphics => Topic started by: JasonLeon on May 09, 2025, 06:53:40 pm
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Hi, I'm implementing a layered UI rendering system in SFML to simulate the RPG Maker XP style window system.
Here's how the rendering pipeline currently works:
I render the window background onto a RenderTexture (let's call it RT1).
I create another RenderTexture (RT2) that acts as a clipping mask for the window content area — it's 32 pixels smaller in both width and height than the background.
I then render the actual window content, such as text, onto a third RenderTexture (RT3).
Next, I draw RT3 onto RT2 to apply the clipping.
Then, I draw both RT1 and RT2 onto a fourth RenderTexture (RT4), which represents the full final UI layer.
Finally, I draw RT4 onto the main application window.
The problem is: this multi-layered rendering process seems to degrade image quality, especially for text. After going through these multiple RenderTexture layers, the final result looks noticeably blurrier, as if it's suffering from a loss of fidelity due to repeated re-rendering.
Is there a recommended way in SFML to preserve sharpness and image quality in multi-pass RenderTexture pipelines like this? Especially when rendering crisp text?
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Hello, is there any solutions?
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The default blending mode is BlendAlpha, meaning for every render with said blend mode, you're multiplying the alpha channels, i.e. the anti-aliased parts of the font and thus it becomes blurrier.
Personally, I'd likely render the text just once at the end on top of everything to ensure a crisp rendering and the correct blending with the background. It additionally would allow for picking the correct font size, in case the view is scaled in anyway. Zooming on text is a bad idea.
Maybe even consider rendering the whole HUD in a separate view at the end.