How do I scale up by a non-integer factor?

[kshitijl]

Hi! I made a software rasterizer and I'm making an interactive story/game with it. The rasterizer outputs (say) 640x480. I'd like to scale that up to whatever the fullscreen resolution is on my laptop. I understand it won't be pixel perfect; I'm okay with some kind of compromise filtering/sampling/smoothing type thing.

I've been using pixels for screen output so far and it's been fine, except for the big black border. I ... just want fullscreen output or a least to take up the full size available on my screen. I know some other libraries work by drawing a textured quad on the screen. Idk if that's what pixels is doing. Naively it seems certainly possible to just do some kind of scaling to get my output to fit on the screen.

What are my options?

Thank you!

[parasyte]

Have you tried ScalingMode::Fill on the (unpublished) main branch?

pixels/src/lib.rs

Lines 58 to 66 in 21bae15

	/// The scaling mode controls the scaling behavior of [`renderers::ScalingRenderer`].
	#[derive(Debug, Copy, Clone)]
	pub enum ScalingMode {
	/// The buffer is scaled up, if needed, to the nearest integer multiple of the buffer size.
	PixelPerfect,
	/// Fill the screen while preserving aspect ratio. The renderer effectively scales the buffer
	/// to the nearest integer multiple first, then linearly interpolates to fit.
	Fill,
	}

pixels/src/lib.rs

Lines 308 to 323 in 21bae15

	/// Set the scaling mode.
	///
	/// Controls how the pixel buffer is scaled to the screen.
	///
	/// ```no_run
	/// # use pixels::{Pixels, ScalingMode};
	/// # let window = pixels_mocks::Window;
	/// # let surface_texture = pixels::SurfaceTexture::new(1920, 1080, &window);
	/// let mut pixels = Pixels::new(640, 480, surface_texture)?;
	/// // Scale the buffer up to fill the screen while preserving aspect ratio.
	/// pixels.set_scaling_mode(ScalingMode::Fill);
	/// # Ok::<(), pixels::Error>(())
	/// ```
	pub fn set_scaling_mode(&mut self, scaling_mode: ScalingMode) {
	self.context.scaling_renderer.scaling_mode = scaling_mode;
	}

You'll have to use a git reference instead of the latest published version (0.15). The only drawbacks are that you don't get automatic patch updates if you pin the revision or you get breaking changes if you don't (assuming you run cargo update), and you cannot publish your own project if any of its dependencies uses a git reference.

[kshitijl]

Wow amazing, that worked! Thank you so much for making this library :)