Clear cache on reload shaders

src/main/java/net/coderbot/iris/pipeline/DeferredWorldRenderingPipeline.java

@@ -45,6 +45,7 @@ import net.coderbot.iris.postprocess.BufferFlipper;
 import net.coderbot.iris.postprocess.CenterDepthSampler;
 import net.coderbot.iris.postprocess.CompositeRenderer;
 import net.coderbot.iris.postprocess.FinalPassRenderer;
+import net.coderbot.iris.postprocess.FullScreenQuadRenderer;
 import net.coderbot.iris.postprocess.ProgramBuildContext;
 import net.coderbot.iris.rendertarget.IRenderTargetExt;
 import net.coderbot.iris.rendertarget.NativeImageBackedSingleColorTexture;
@@ -1028,6 +1029,7 @@ public class DeferredWorldRenderingPipeline implements WorldRenderingPipeline, R
 		BlendModeOverride.restore();
 		AlphaTestOverride.restore();
 
+		FullScreenQuadRenderer.clearLocCache();
 		destroyPasses(table);
 
 		// Destroy the composite rendering pipeline

src/main/java/net/coderbot/iris/postprocess/FullScreenQuadRenderer.java

@@ -78,6 +78,11 @@ public class FullScreenQuadRenderer {
 	/** Per-program cached uniform locations: [mvLoc, projLoc]. Populated on first miss. */
 	private static final Int2ObjectOpenHashMap<int[]> compositeLocCache = new Int2ObjectOpenHashMap<>();
 
+	/** Clear cached uniform locations. Must be called when composite programs are destroyed (e.g. shader reload). */
+	public static void clearLocCache() {
+		compositeLocCache.clear();
+	}
+
 	public static void uploadCompositeMatrices() {
 		final int program = GLStateManager.glGetInteger(GL20.GL_CURRENT_PROGRAM);
 		if (program == 0) return;