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Merge pull request #271 from armansito/pr-conflation-examples

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Introduce test scenes that demonstrate conflation artifacts
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Arman Uguray 2023-02-06 15:24:38 -08:00 committed by GitHub
parent ef44c17f92 97e6e12799
commit 2690c3602d
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168
examples/scenes/src/test_scenes.rs
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@ -30,6 +30,8 @@ pub fn test_scenes() -> SceneSet {
scene!(animated_text: animated),
scene!(brush_transform: animated),
scene!(blend_grid),
scene!(conflation_artifacts),
scene!(labyrinth),
];
#[cfg(target_arch = "wasm32")]
scenes.push(ExampleScene {
@ -403,6 +405,172 @@ fn blend_square(blend: BlendMode) -> SceneFragment {
fragment
}
fn conflation_artifacts(sb: &mut SceneBuilder, _: &mut SceneParams) {
use PathEl::*;
const N: f64 = 50.0;
const S: f64 = 4.0;
let scale = Affine::scale(S);
let x = N + 0.5; // Fractional pixel offset reveals the problem on axis-aligned edges.
let mut y = N;
let bg_color = Color::rgb8(255, 194, 19);
let fg_color = Color::rgb8(12, 165, 255);
// Two adjacent triangles touching at diagonal edge with opposing winding numbers
sb.fill(
Fill::NonZero,
Affine::translate((x, y)) * scale,
fg_color,
None,
&[
// triangle 1
MoveTo((0.0, 0.0).into()),
LineTo((N, N).into()),
LineTo((0.0, N).into()),
LineTo((0.0, 0.0).into()),
// triangle 2
MoveTo((0.0, 0.0).into()),
LineTo((N, N).into()),
LineTo((N, 0.0).into()),
LineTo((0.0, 0.0).into()),
],
);
// Adjacent rects, opposite winding
y += S * N + 10.0;
sb.fill(
Fill::EvenOdd,
Affine::translate((x, y)) * scale,
bg_color,
None,
&Rect::new(0.0, 0.0, N, N),
);
sb.fill(
Fill::EvenOdd,
Affine::translate((x, y)) * scale,
fg_color,
None,
&[
// left rect
MoveTo((0.0, 0.0).into()),
LineTo((0.0, N).into()),
LineTo((N * 0.5, N).into()),
LineTo((N * 0.5, 0.0).into()),
// right rect
MoveTo((N * 0.5, 0.0).into()),
LineTo((N, 0.0).into()),
LineTo((N, N).into()),
LineTo((N * 0.5, N).into()),
],
);
// Adjacent rects, same winding
y += S * N + 10.0;
sb.fill(
Fill::EvenOdd,
Affine::translate((x, y)) * scale,
bg_color,
None,
&Rect::new(0.0, 0.0, N, N),
);
sb.fill(
Fill::EvenOdd,
Affine::translate((x, y)) * scale,
fg_color,
None,
&[
// left rect
MoveTo((0.0, 0.0).into()),
LineTo((0.0, N).into()),
LineTo((N * 0.5, N).into()),
LineTo((N * 0.5, 0.0).into()),
// right rect
MoveTo((N * 0.5, 0.0).into()),
LineTo((N * 0.5, N).into()),
LineTo((N, N).into()),
LineTo((N, 0.0).into()),
],
);
}
fn labyrinth(sb: &mut SceneBuilder, _: &mut SceneParams) {
use PathEl::*;
let rows: &[[u8; 12]] = &[
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
[0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1],
[1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0],
[0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1],
[1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0],
[0, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0],
[1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1],
[0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1],
[0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0],
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
];
let cols: &[[u8; 10]] = &[
[1, 1, 1, 1, 0, 1, 1, 1, 1, 1],
[0, 0, 1, 0, 0, 0, 1, 1, 1, 0],
[0, 1, 1, 0, 1, 1, 1, 0, 0, 1],
[1, 1, 0, 0, 0, 0, 1, 0, 1, 0],
[0, 0, 1, 0, 1, 0, 0, 0, 0, 1],
[0, 0, 1, 1, 1, 0, 0, 0, 1, 0],
[0, 1, 0, 1, 1, 1, 0, 0, 0, 0],
[1, 1, 1, 0, 1, 1, 1, 0, 1, 0],
[1, 1, 0, 1, 1, 0, 0, 0, 1, 0],
[0, 0, 1, 0, 0, 0, 0, 0, 0, 1],
[0, 0, 1, 1, 0, 0, 0, 0, 1, 0],
[0, 0, 0, 0, 0, 0, 1, 0, 0, 1],
[1, 1, 1, 1, 1, 1, 0, 1, 1, 1],
];
let mut path = BezPath::new();
for (y, row) in rows.iter().enumerate() {
for (x, flag) in row.iter().enumerate() {
let x = x as f64;
let y = y as f64;
if *flag == 1 {
path.push(MoveTo((x - 0.1, y + 0.1).into()));
path.push(LineTo((x + 1.1, y + 0.1).into()));
path.push(LineTo((x + 1.1, y - 0.1).into()));
path.push(LineTo((x - 0.1, y - 0.1).into()));
// The above is equivalent to the following stroke with width 0.2 and square
// caps.
//path.push(MoveTo((x, y).into()));
//path.push(LineTo((x + 1.0, y).into()));
}
}
}
for (x, col) in cols.iter().enumerate() {
for (y, flag) in col.iter().enumerate() {
let x = x as f64;
let y = y as f64;
if *flag == 1 {
path.push(MoveTo((x - 0.1, y - 0.1).into()));
path.push(LineTo((x - 0.1, y + 1.1).into()));
path.push(LineTo((x + 0.1, y + 1.1).into()));
path.push(LineTo((x + 0.1, y - 0.1).into()));
// The above is equivalent to the following stroke with width 0.2 and square
// caps.
//path.push(MoveTo((x, y).into()));
//path.push(LineTo((x, y + 1.0).into()));
}
}
}
// Note the artifacts are clearly visible at a fractional pixel offset/translation. They
// disappear if the translation amount below is a whole number.
sb.fill(
Fill::NonZero,
Affine::translate((20.5, 20.5)) * Affine::scale(80.0),
Color::rgba8(0x70, 0x80, 0x80, 0xff),
None,
&path,
)
}
fn around_center(xform: Affine, center: Point) -> Affine {
Affine::translate(center.to_vec2()) * xform * Affine::translate(-center.to_vec2())
}