Rendering of Meshes seems to break depending on the order they are added

[edwloef]

Is your issue REALLY a bug?

• My issue is indeed a bug!
• I am not crazy! I will not fill out this form just to ask a question or request a feature. Pinky promise.

Is there an existing issue for this?

• I have searched the existing issues.

Is this issue related to iced?

• My hardware is compatible and my graphics drivers are up-to-date.

What happened?

If a Mesh that has a clip bound with a dimension below 1 pixel is drawn before another Mesh with a larger clip bound, the second is not drawn.

Minimum example:

use iced::{
    advanced::{
        graphics::{
            color,
            mesh::{self, Renderer as _, SolidVertex2D},
            Mesh,
        },
        layout::{Limits, Node},
        renderer::Style,
        widget::Tree,
        Layout, Widget,
    },
    mouse::Cursor,
    Length, Rectangle, Renderer, Size, Theme, Transformation,
};

fn main() {
    iced::application("", App::update, App::view).run().unwrap();
}

struct App;

#[derive(Debug)]
enum Message {}

impl App {
    fn new() -> Self {
        Self
    }

    fn update(&mut self, _: Message) {}

    fn view(&self) -> iced::Element<'_, Message> {
        iced::Element::new(Test)
    }
}

impl Default for App {
    fn default() -> Self {
        Self::new()
    }
}

struct Test;

impl Widget<Message, Theme, Renderer> for Test {
    fn size(&self) -> Size<Length> {
        Size::new(Length::Fill, Length::Fill)
    }

    fn layout(&self, _tree: &mut Tree, _renderer: &Renderer, limits: &Limits) -> Node {
        Node::new(Size::new(limits.max().width, limits.max().height))
    }

    fn draw(
        &self,
        _tree: &Tree,
        renderer: &mut Renderer,
        theme: &Theme,
        _style: &Style,
        _layout: Layout<'_>,
        _cursor: Cursor,
        _viewport: &Rectangle,
    ) {
        let mesh1 = Mesh::Solid {
            buffers: mesh::Indexed {
                vertices: vec![
                    SolidVertex2D {
                        position: [0.0, 0.0],
                        color: color::pack(theme.extended_palette().secondary.base.text),
                    },
                    SolidVertex2D {
                        position: [0.0, 100.0],
                        color: color::pack(theme.extended_palette().secondary.base.text),
                    },
                    SolidVertex2D {
                        position: [100.0, 100.0],
                        color: color::pack(theme.extended_palette().secondary.base.text),
                    },
                ],
                indices: vec![0, 1, 2],
            },
            transformation: Transformation::IDENTITY,
            clip_bounds: Rectangle {
                x: 0.0,
                y: 0.0,
                width: 100.0,
                height: 0.9999999,
            },
        };

        let mesh2 = Mesh::Solid {
            buffers: mesh::Indexed {
                vertices: vec![
                    SolidVertex2D {
                        position: [0.0, 100.0],
                        color: color::pack(theme.extended_palette().secondary.base.text),
                    },
                    SolidVertex2D {
                        position: [0.0, 200.0],
                        color: color::pack(theme.extended_palette().secondary.base.text),
                    },
                    SolidVertex2D {
                        position: [100.0, 200.0],
                        color: color::pack(theme.extended_palette().secondary.base.text),
                    },
                ],
                indices: vec![0, 1, 2],
            },
            transformation: Transformation::IDENTITY,
            clip_bounds: Rectangle {
                x: 0.0,
                y: 100.0,
                width: 100.0,
                height: 100.0,
            },
        };

        renderer.draw_mesh(mesh1);
        renderer.draw_mesh(mesh2);
    }
}

mesh2 doesn't render here. Swapping the two draw_mesh calls makes mesh2 render correctly.

This affects both this release and the master branch.

What is the expected behavior?

The mesh with the large clip bound is rendered.

Version

crates.io release

Operating System

Linux

Do you have any log output?

No response