NeoForge/patches/com/mojang/renderpearl/backend/opengl/GlCommandEncoder.java.patch

--- a/com/mojang/renderpearl/backend/opengl/GlCommandEncoder.java
+++ b/com/mojang/renderpearl/backend/opengl/GlCommandEncoder.java
@@ -274,6 +_,24 @@
     }
 
     @Override
+    public void clearStencilTexture(GpuTexture texture, int value) {
+        GL33C.glClearStencil(value);
+        GlStateManager._stencilMask(-1);
+        GlStateManager._depthMask(true);
+        GlStateManager._disableScissorTest();
+
+        for (int i = 0; i < texture.getMipLevels(); i++) {
+            this.device.directStateAccess().bindFrameBufferTextures(this.drawFbo, 0, 0, 0, GlConst.GL_FRAMEBUFFER, ((GlTexture)texture).id, i);
+            GL33C.glDrawBuffer(GlConst.GL_NONE);
+            GlStateManager._clear(GL33C.GL_STENCIL_BUFFER_BIT);
+        }
+
+        GL33C.glDrawBuffer(GlConst.GL_COLOR_ATTACHMENT0);
+        GlStateManager._glFramebufferTexture2D(GlConst.GL_FRAMEBUFFER, GL33C.GL_STENCIL_ATTACHMENT, GlConst.GL_TEXTURE_2D, 0, 0);
+        GlStateManager._glBindFramebuffer(GlConst.GL_FRAMEBUFFER, 0);
+    }
+
+    @Override
     public void writeToBuffer(GpuBufferSlice slice, ByteBuffer data) {
         GlBuffer buffer = (GlBuffer)slice.buffer();
         buffer.checkCanBeUsed();
@@ -396,11 +_,22 @@
         boolean isDepth = source.getFormat().hasDepthAspect();
         int sourceId = ((GlTexture)source).glId();
         int destId = ((GlTexture)destination).glId();
-        this.device.directStateAccess().bindFrameBufferTextures(this.readFbo, isDepth ? 0 : sourceId, isDepth ? sourceId : 0, mipLevel, 0);
-        this.device.directStateAccess().bindFrameBufferTextures(this.drawFbo, isDepth ? 0 : destId, isDepth ? destId : 0, mipLevel, 0);
+        boolean hasStencil = source.getFormat().hasStencilAspect();
+        this.device.directStateAccess().bindFrameBufferTextures(this.readFbo, (isDepth || hasStencil) ? 0 : sourceId, isDepth ? sourceId : 0, 0, 0, hasStencil ? sourceId : 0, 0);
+        this.device.directStateAccess().bindFrameBufferTextures(this.drawFbo, (isDepth || hasStencil) ? 0 : destId, isDepth ? destId : 0, 0, 0, hasStencil ? destId : 0, 0);
+        int bufferMask = 0;
+        if (source.getFormat().hasColorAspect()) {
+            bufferMask |= GlConst.GL_COLOR_BUFFER_BIT;
+        }
+        if (source.getFormat().hasDepthAspect()) {
+            bufferMask |= GlConst.GL_DEPTH_BUFFER_BIT;
+        }
+        if (source.getFormat().hasStencilAspect()) {
+            bufferMask |= GL33C.GL_STENCIL_BUFFER_BIT;
+        }
         this.device
             .directStateAccess()
-            .blitFrameBuffers(this.readFbo, this.drawFbo, sourceX, sourceY, width, height, destX, destY, width, height, isDepth ? 256 : 16384, 9728);
+                .blitFrameBuffers(this.readFbo, this.drawFbo, sourceX, sourceY, width, height, destX, destY, width, height, bufferMask, 9728);
         int error = GlStateManager._getError();
         if (error != 0) {
             throw new IllegalStateException(