Add support for RGB565 images - #12915
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RGB565 is the native format of most embedded displays and of the software renderer's Rgb565Pixel target. Add Image::from_rgb565(SharedPixelBuffer<Rgb565Pixel>) and a SharedImageBuffer::RGB565 variant so such buffers can be displayed without converting them to RGB8 first. The software renderer draws RGB565 textures directly, with no per-pixel conversion at all when the target pixel is also RGB565 (new TargetPixel::from_rgb565, identity for Rgb565Pixel). Qt uploads as QImage::Format_RGB16 (zero-copy), Skia uses ColorType::RGB565, femtovg and anyrender expand to RGB(A)8 at texture upload. Rgb565Pixel moves from i-slint-renderer-software to i-slint-core (the old path keeps a re-export), and in C++ from slint-platform.h to the slint namespace (slint::platform::Rgb565Pixel stays as an alias). SharedPixelBuffer::as_bytes' bound is relaxed from rgb::ComponentBytes to rgb::Pod with bytemuck casting, so pixel types outside the rgb crate can use it. Same file-by-file structure as the pending Gray8 support (slint-ui#11331). ChangeLog: Added `Image::from_rgb565` to create images from RGB565 pixel buffers Fixes slint-ui#12830
R-Cramer4
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Aug 17, 2026
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R-Cramer4
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I was looking into implementing this myself a while ago so I'm happy to see it is getting worked on. I just have one minor nit with it, but otherwise it looks solid.
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| ((value & 0xf800) >> 8) as u8, | ||
| ((value & 0x07e0) >> 3) as u8, | ||
| ((value & 0x001f) << 3) as u8, |
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This should probably use R_MASK, G_MASK, and B_MASK instead of raw hex values
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Good point. I went one step further and used the Rgb565Pixel accessors, which removes the masks from this spot entirely.
…efault Review feedback: the open-coded masks duplicated what the accessors already do.
cspell parses 0xffu8 as the unknown word "xffu". Write the literals like the existing rgb565 test in the software renderer does.
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RGB565 is the native format of most embedded displays and of the software renderer's Rgb565Pixel target. Add
Image::from_rgb565(SharedPixelBuffer) and a SharedImageBuffer::RGB565 variant so such buffers can be displayed without converting them to RGB8 first.
The software renderer draws RGB565 textures directly, with no per-pixel conversion at all when the target pixel is also RGB565 (new TargetPixel::from_rgb565, identity for Rgb565Pixel). Qt uploads as QImage::Format_RGB16 (zero-copy), Skia uses ColorType::RGB565, femtovg and anyrender expand to RGB(A)8 at texture upload.
Rgb565Pixel moves from i-slint-renderer-software to i-slint-core (the old path keeps a re-export), and in C++ from slint-platform.h to the slint namespace (slint::platform::Rgb565Pixel stays as an alias). SharedPixelBuffer::as_bytes' bound is relaxed from rgb::ComponentBytes to rgb::Pod with bytemuck casting, so pixel types outside the rgb crate can use it.
Same file-by-file structure as the pending Gray8 support (#11331).
Fixes #12830