Use constants as bad boys and girls seem to be shadowing the global variables :p

wadsrc/static/shaders/scene/binding_textures.glsl

@@ -1,23 +1,23 @@
 
 layout(set = 2, binding = 0) uniform sampler2D textures[];
 
-#define tex 0
-#define texture2 1
-#define texture3 2
-#define texture4 3
-#define texture5 4
-#define texture6 5
-#define texture7 6
-#define texture8 7
-#define texture9 8
-#define texture10 9
-#define texture11 10
-#define texture12 11
-#define texture13 12
-#define texture14 13
-#define texture15 14
-#define texture16 15
-#define texture17 16
-#define texture18 17
-#define texture19 18
-#define texture20 19
+const int tex = 0;
+const int texture2 = 1;
+const int texture3 = 2;
+const int texture4 = 3;
+const int texture5 = 4;
+const int texture6 = 5;
+const int texture7 = 6;
+const int texture8 = 7;
+const int texture9 = 8;
+const int texture10 = 9;
+const int texture11 = 10;
+const int texture12 = 11;
+const int texture13 = 12;
+const int texture14 = 13;
+const int texture15 = 14;
+const int texture16 = 15;
+const int texture17 = 16;
+const int texture18 = 17;
+const int texture19 = 18;
+const int texture20 = 19;