From b2dd4db15dced146f426ea7c7cea00d20d580faf Mon Sep 17 00:00:00 2001
From: Struma <strix@struma.me>
Date: Tue, 18 Jan 2022 03:28:05 -0500
Subject: [PATCH] make pattern subtract blend mode actually subtract

---
 shader/sprite.frag | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/shader/sprite.frag b/shader/sprite.frag
index c6d5282..d9c61f7 100644
--- a/shader/sprite.frag
+++ b/shader/sprite.frag
@@ -51,11 +51,11 @@ vec3 blendAdd(vec3 base, vec3 blend, float opacity) {
 
 // Subtract
 float blendSubtract(float base, float blend) {
-    return max(base+blend-1.0,0.0);
+    return max(base-blend,0.0);
 }
 
 vec3 blendSubtract(vec3 base, vec3 blend) {
-    return max(base+blend-vec3(1.0),vec3(0.0));
+    return max(base-blend,vec3(0.0));
 }
 
 vec3 blendSubtract(vec3 base, vec3 blend, float opacity) {