From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 14 May 2022 22:41:53 +0000 (+0100)
Subject: dice: Adjust circle size to be right for images which are circles
X-Git-Tag: otter-1.1.0~153
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=cdd4531eb89ac938561b5d66118ffb6aebcfa877;p=otter.git

dice: Adjust circle size to be right for images which are circles

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/src/dice.rs b/src/dice.rs
index c77215f7..78a72d8c 100644
--- a/src/dice.rs
+++ b/src/dice.rs
@@ -152,8 +152,16 @@ impl PieceSpec for Spec {
     if_let!{ Some((nfaces,_)) = nfaces;
              else throw!(SpecError::MultipleFacesRequired) };
 
+    let radius = image.bbox_approx()?.size()?.len()? * 0.5;
+    let radius = radius * if image.shape() == Some(Shape::Circle) {
+      // bbox_approx is the diagonal of the enclosing square
+      // go back to the circle
+      0.5f64 .sqrt()
+    } else {
+      1.0
+    };
     let radius = if (0.5 .. 1.5).contains(&self.circle_scale) {
-      image.bbox_approx()?.size()?.len()? * 0.5 * self.circle_scale
+      radius * self.circle_scale
     } else {
       throw!(SpecError::InvalidSizeScale)
     };