u_format: fix inv_swizzles generation

[mesa.git] / src / gallium / auxiliary / util / u_format_parse.py

diff --git a/src/gallium/auxiliary/util/u_format_parse.py b/src/gallium/auxiliary/util/u_format_parse.py
index 73a4bcb21000627c9b9bf6621b6302d235b2c5c0..3a39e5ba5242d72380823feeb6a53bf1acd52bae 100755 (executable)
--- a/src/gallium/auxiliary/util/u_format_parse.py
+++ b/src/gallium/auxiliary/util/u_format_parse.py
@@ -196,10 +196,11 @@ class Format:
 
     def inv_swizzles(self):
         '''Return an array[4] of inverse swizzle terms'''
+        '''Only pick the first matching value to avoid l8 getting blue and i8 getting alpha'''
         inv_swizzle = [None]*4
         for i in range(4):
             swizzle = self.swizzles[i]
-            if swizzle < 4:
+            if swizzle < 4 and inv_swizzle[swizzle] == None:
                 inv_swizzle[swizzle] = i
         return inv_swizzle