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Only resize when clicking on the triangle part

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This commit is contained in:
Robbert van der Helm 2022-03-29 17:00:00 +02:00
parent beb66e46c3
commit 7db6101aea
1 changed files with 47 additions and 9 deletions
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56
nih_plug_vizia/src/widgets/resize_handle.rs
View file

@ -39,15 +39,26 @@ impl View for ResizeHandle {
if let Some(window_event) = event.message.downcast() {
match *window_event {
WindowEvent::MouseDown(MouseButton::Left) => {
cx.capture();
cx.current.set_active(cx, true);
// The handle is a triangle, so we should also interac twith it as if it was a
// triangle
if intersects_triangle(
cx.cache.get_bounds(cx.current),
(cx.mouse.cursorx, cx.mouse.cursory),
) {
cx.capture();
cx.current.set_active(cx, true);
self.drag_active = true;
self.start_scale_factor = cx.user_scale_factor;
self.start_physical_coordinates = (
cx.mouse.cursorx * cx.style.dpi_factor as f32,
cx.mouse.cursory * cx.style.dpi_factor as f32,
);
self.drag_active = true;
self.start_scale_factor = cx.user_scale_factor;
self.start_physical_coordinates = (
cx.mouse.cursorx * cx.style.dpi_factor as f32,
cx.mouse.cursory * cx.style.dpi_factor as f32,
);
event.consume();
} else {
// TODO: The click should be forwarded to the element behind the triangle
}
}
WindowEvent::MouseUp(MouseButton::Left) => {
if self.drag_active {
@ -58,7 +69,12 @@ impl View for ResizeHandle {
}
}
WindowEvent::MouseMove(x, y) => {
// TODO: Filter the hover color and dragging to the actual triangle
if !intersects_triangle(cx.cache.get_bounds(cx.current), (x, y)) {
cx.current.set_hover(cx, false);
} else {
cx.current.set_hover(cx, true);
}
if self.drag_active {
// We need to convert our measurements into physical pixels relative to the
// initial drag to be able to keep a consistent ratio. This 'relative to the
@ -188,3 +204,25 @@ impl View for ResizeHandle {
canvas.fill_path(&mut path, paint);
}
}
/// Test whether a point intersects with the triangle of this resize handle.
fn intersects_triangle(bounds: BoundingBox, (x, y): (f32, f32)) -> bool {
// We could also compute Barycentric coordinates, but this is simple and I like not having to
// think. Just check if (going clockwise), the point is on the right of each of all of the
// triangle's edges. We can compute this using the determinant of the 2x2 matrix formed by two
// column ve vectors, aka the perp dot product, aka the wedge product.
// NOTE: Since this element is positioned in the bottom right corner we would technically only
// have to calculate this for `v1`, checking the other two vectors is redundant but for
// now we'll do it anyways
let (p1x, p1y) = bounds.bottom_left();
let (p2x, p2y) = bounds.top_right();
let (p3x, p3y) = bounds.bottom_right();
let (v1x, v1y) = (p2x - p1x, p2y - p1y);
let (v2x, v2y) = (p3x - p2x, p3y - p2y);
let (v3x, v3y) = (p1x - p3x, p1y - p3y);
((x - p1x) * v1y) - ((y - p1y) * v1x) <= 0.0
&& ((x - p2x) * v2y) - ((y - p2y) * v2x) <= 0.0
&& ((x - p3x) * v3y) - ((y - p3y) * v3x) <= 0.0
}