From 191b89b50cfc44754eca3246b8e694e413ab094e Mon Sep 17 00:00:00 2001
From: Ryan Oldenburg <guzba8@gmail.com>
Date: Mon, 8 Feb 2021 16:39:24 -0600
Subject: [PATCH] mask applyOpacity

---
 src/pixie/masks.nim | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/pixie/masks.nim b/src/pixie/masks.nim
index 101336d..c600409 100644
--- a/src/pixie/masks.nim
+++ b/src/pixie/masks.nim
@@ -109,5 +109,11 @@ proc getValueSmooth*(mask: Mask, x, y: float32): uint8 =
 
   lerp(bottomMix, topMix, diffY)
 
+proc applyOpacity*(mask: Mask, opacity: float32) =
+  ## Multiplies the values of the mask by opacity.
+  let opacity = round(255 * opacity).uint32
+  for value in mask.data.mitems:
+    value = ((value * opacity) div 255).uint8
+
 when defined(release):
   {.pop.}