From 6c8aff01c6a98a9d16cb59a70ce6f5c90a4de6e5 Mon Sep 17 00:00:00 2001
From: Dominic Nancekievill <domjn@google.com>
Date: Mon, 15 Nov 2021 08:02:05 +0000
Subject: [PATCH] Fix bug where rasterize() hangs on Apple silicon

If any edges of the triangle are horizontal or vertical, it's possible
for the raXX variables, and thus d, to get a division by zero leading
to +Inf. On Intel, when +Inf is converted to int and back with
  d = float64(int(d))
the result is a very large negative number which the existing check
converted to zero. On ARM (or at least on Apple Silicon which is where I
ran into the problem) the result is a very large positive number,
causing the function to hang.
---
 context.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/context.go b/context.go
index 38467dd..7098e52 100644
--- a/context.go
+++ b/context.go
@@ -195,6 +195,9 @@ func (dc *Context) rasterize(v0, v1, v2 Vertex, s0, s1, s2 Vector) RasterizeInfo
 		if w02 < 0 && d2 > d {
 			d = d2
 		}
+		if d == math.Inf(1) {
+			d = 0
+		}
 		d = float64(int(d))
 		if d < 0 {
 			// occurs in pathological cases