Janitor: Replace float comparison dance with approx_eq from euclid

Sixtyfps uses euclid already, so let's use euclid for float comparisons
as well.

I changed the code to decide whether a number is a positive integer to
make do without a comparison along the way.

sixtyfps_compiler/passes/lower_layout.rs

@@ -493,12 +493,11 @@ fn eval_const_expr(
 ) -> Option<u16> {
     match expression {
         Expression::NumberLiteral(v, Unit::None) => {
-            let r = *v as u16;
-            if (r as f32 - *v as f32).abs() > f32::EPSILON {
+            if *v < 0. || *v > u16::MAX as f64 || v.trunc() != *v {
                 diag.push_error(format!("'{}' must be a positive integer", name), span);
                 None
             } else {
-                Some(r)
+                Some(*v as u16)
             }
         }
         Expression::Cast { from, .. } => eval_const_expr(from, name, span, diag),

sixtyfps_runtime/rendering_backends/gl/lib.rs

@@ -20,6 +20,7 @@ use std::cell::RefCell;
 use std::pin::Pin;
 use std::rc::Rc;
 
+use euclid::approxeq::ApproxEq;
 use sixtyfps_corelib::graphics::{
     Brush, Color, FontRequest, Image, IntRect, Point, Rect, RenderingCache, Size,
 };
@@ -457,9 +458,7 @@ fn rect_with_radius_to_path(rect: Rect, border_radius: f32) -> femtovg::Path {
     // If we're drawing a circle, use directly connected bezier curves instead of
     // ones with intermediate LineTo verbs, as `rounded_rect` creates, to avoid
     // rendering artifacts due to those edges.
-    if (width - height).abs() < 10.0 * f32::EPSILON
-        && (border_radius * 2. - width).abs() < 10.0 * f32::EPSILON
-    {
+    if width.approx_eq(&height) && (border_radius * 2.).approx_eq(&width) {
         path.circle(x + border_radius, y + border_radius, border_radius);
     } else {
         path.rounded_rect(x, y, width, height, border_radius);

sixtyfps_runtime/rendering_backends/qt/qt_window.rs

@@ -9,6 +9,7 @@
 LICENSE END */
 
 use cpp::*;
+use euclid::approxeq::ApproxEq;
 use items::{ImageFit, TextHorizontalAlignment, TextVerticalAlignment};
 use sixtyfps_corelib::graphics::{Brush, FontRequest, Image, Point, Rect, RenderingCache, Size};
 use sixtyfps_corelib::input::{InternalKeyCode, KeyEvent, KeyEventType, MouseEvent};
@@ -889,8 +890,8 @@ impl QtItemRenderer<'_> {
                 rect.is_valid()
                     && (rect.x != 0.
                         || rect.y != 0.
-                        || (rect.width - target_width).abs() > 100. * f64::EPSILON
-                        || (rect.height - target_height).abs() > 100. * f64::EPSILON)
+                        || rect.width.approx_eq(&target_width)
+                        || rect.height.approx_eq(&target_height))
             });
             let source_size = if !has_source_clipping {
                 Some(qttypes::QSize { width: target_width as u32, height: target_height as u32 })

tools/figma_import/src/figmatypes.rs

@@ -11,7 +11,6 @@ LICENSE END */
 #![allow(unused)]
 
 use std::collections::HashMap;
-use std::f32::EPSILON;
 
 use derive_more::*;
 use serde::Deserialize;
@@ -77,7 +76,7 @@ pub struct Color {
 
 impl Color {
     pub fn is_transparent(&self) -> bool {
-        self.a <= f32::EPSILON
+        self.a.approx_eq(&0.)
     }
 }
 

tools/lsp/Cargo.toml

@@ -24,6 +24,7 @@ sixtyfps-rendering-backend-default = { version = "=0.1.0", path="../../sixtyfps_
 lsp-types = "0.89"
 lsp-server = "0.5"
 crossbeam-channel = "0.5"  # must match the version used by lsp-server
+euclid = "0.22"
 serde_json = "1.0.60"
 serde = "1.0.118"
 spin_on = "0.1"

tools/lsp/main.rs

@@ -14,6 +14,7 @@ mod lsp_ext;
 mod preview;
 mod util;
 
+use euclid::approxeq::ApproxEq;
 use std::collections::HashMap;
 use structopt::StructOpt;
 
@@ -271,7 +272,7 @@ fn handle_request(
         // representation.
         let requested_color = params.color;
 
-        let color_literal = if (requested_color.alpha - 1.).abs() > 10.0 * f32::EPSILON {
+        let color_literal = if requested_color.alpha.approx_eq(&1.) {
             format!(
                 "#{:0>2x}{:0>2x}{:0>2x}{:0>2x}",
                 (requested_color.red * 255.) as u8,