Create a texture exactly under the mouse?

[tseli0s]

Create a texture exactly under the mouse?

I know this may not be the ideal place to ask, but I couldn't find much on the examples. If I want to create a new texture (4x4, each pixel a bit different) that is placed under the mouse cursor, how would I go about it? Currently I have a simple buffer sent every frame that clears the window and nothing more.

Also I apologize if this question could be pretty obvious. I've only worked with SDL's renderer and raw OpenGL coordinates :P.

[parasyte]

I'm not sure exactly what your goal is. A "texture" has a very specific meaning in graphics APIs and positioning them requires applying a transformation matrix to it in a shader. pixels does not give you access to textures and shaders in the traditional graphics model. You are only given an array of bytes and it is up to you to plot pixels within the array. The reason for this is because pixels is designed for writing emulators and software renderers. I can't be certain if you intend to plot pixels, but it's safest to not make assumptions.

So, with that out of the way, do you actually want to plot pixels? Or do you want a higher-level abstraction that gives you control over concepts like textures and transformation matrices?

If you want to plot pixels, then you can use the Pixels::window_pos_to_pixel method to convert a mouse cursor position (e.g. from winit) to a pixel location that can be plotted within the pixel buffer. The conway example shows exactly how to do this:

pixels/examples/conway/src/main.rs

Lines 76 to 98 in 41063db

	// Handle mouse. This is a bit involved since support some simple
	// line drawing (mostly because it makes nice looking patterns).
	let (mouse_cell, mouse_prev_cell) = input
	.mouse()
	.map(|(mx, my)| {
	let (dx, dy) = input.mouse_diff();
	let prev_x = mx - dx;
	let prev_y = my - dy;
	let (mx_i, my_i) = pixels
	.window_pos_to_pixel((mx, my))
	.unwrap_or_else(|pos| pixels.clamp_pixel_pos(pos));
	let (px_i, py_i) = pixels
	.window_pos_to_pixel((prev_x, prev_y))
	.unwrap_or_else(|pos| pixels.clamp_pixel_pos(pos));
	(
	(mx_i as isize, my_i as isize),
	(px_i as isize, py_i as isize),
	)
	})
	.unwrap_or_default();

[tseli0s]

Pretty much the answer I was looking for. Also sorry for the confusion, I meant to say SurfaceTexture. Actually the only part I need is the window_pos_to_pixel() one, I didn't know what it did.