src/main/java/org/saturnclient/impl/ui/GlassRenderer.java

@@ -48,6 +48,9 @@ public final class GlassRenderer {
             .withLocation(Identifier.of("saturnclient", "pipeline/glass"))
             .withFragmentShader(Identifier.of("saturnclient", "core/glass"))
             .withSampler("Sampler1")
+            // The transforms block ends with LineWidth before 1.21.11 (see glass.fsh).
+            //? if <1.21.11
+            //.withShaderDefine("HAS_LINE_WIDTH")
             .build();
 
     private static final Identifier BLUR = Identifier.ofVanilla("post_effect/blur.json");

src/main/resources/assets/saturnclient/shaders/core/glass.fsh

@@ -3,8 +3,18 @@
 // Saturn's glass: the blurred game behind the screen, cut to a panel's shape. For 1.21.6 and
 // later; glass_pre_1_21_6.fsh (with glass.json, the program 1.21.4 loads) is for older versions.
 
-// Vanilla's own, since its layout changes between versions (1.21.11 dropped LineWidth)
-#moj_import <minecraft:dynamictransforms.glsl>
+// Vanilla's transforms, laid out as the version has them: 1.21.6 to 1.21.10 end with LineWidth, which
+// 1.21.11 dropped (GlassRenderer defines HAS_LINE_WIDTH there). Not imported: the include only exists
+// from 1.21.6, and 1.21.4 and 1.21.5 still read every shader's imports while loading resources.
+layout(std140) uniform DynamicTransforms {
+    mat4 ModelViewMat;
+    vec4 ColorModulator;
+    vec3 ModelOffset;
+    mat4 TextureMat;
+#ifdef HAS_LINE_WIDTH
+    float LineWidth;
+#endif
+};
 
 // The panel's rounded rectangle, the same texture its background is drawn with
 uniform sampler2D Sampler0;