From 326ce5996117291d7612a587e07a4fe2f979a06e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Foucault?= <foucault.clem@gmail.com>
Date: Wed, 5 Mar 2025 12:05:34 +0100
Subject: [PATCH] Fix #134509: GPU: Add workaround for Intel ARC nodelink
 driver bug

This disables the instancing optimization for this specific
hardware.

Pull Request: https://projects.blender.org/blender/blender/pulls/135458
---
 source/blender/editors/space_node/drawnode.cc         | 3 ++-
 source/blender/gpu/GPU_capabilities.hh                | 1 +
 source/blender/gpu/intern/gpu_capabilities.cc         | 5 +++++
 source/blender/gpu/intern/gpu_capabilities_private.hh | 1 +
 source/blender/gpu/opengl/gl_backend.cc               | 9 +++++++++
 5 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/source/blender/editors/space_node/drawnode.cc b/source/blender/editors/space_node/drawnode.cc
index d1c8fcfed96..7448dc63dc0 100644
--- a/source/blender/editors/space_node/drawnode.cc
+++ b/source/blender/editors/space_node/drawnode.cc
@@ -35,6 +35,7 @@
 
 #include "GPU_batch.hh"
 #include "GPU_batch_presets.hh"
+#include "GPU_capabilities.hh"
 #include "GPU_framebuffer.hh"
 #include "GPU_immediate.hh"
 #include "GPU_matrix.hh"
@@ -2445,7 +2446,7 @@ static void node_draw_link_bezier_ex(const SpaceNode &snode,
     nodelink_batch_init();
   }
 
-  if (g_batch_link.enabled && !draw_config.highlighted) {
+  if (g_batch_link.enabled && !draw_config.highlighted && !GPU_node_link_instancing_workaround()) {
     /* Add link to batch. */
     nodelink_batch_add_link(snode, points, draw_config);
   }
diff --git a/source/blender/gpu/GPU_capabilities.hh b/source/blender/gpu/GPU_capabilities.hh
index 491df447fe4..6b2f713d47e 100644
--- a/source/blender/gpu/GPU_capabilities.hh
+++ b/source/blender/gpu/GPU_capabilities.hh
@@ -46,6 +46,7 @@ int GPU_texture_size_with_limit(int res);
 bool GPU_use_parallel_compilation();
 
 bool GPU_stencil_clasify_buffer_workaround();
+bool GPU_node_link_instancing_workaround();
 bool GPU_mip_render_workaround();
 bool GPU_depth_blitting_workaround();
 bool GPU_use_main_context_workaround();
diff --git a/source/blender/gpu/intern/gpu_capabilities.cc b/source/blender/gpu/intern/gpu_capabilities.cc
index c34b7e9e360..365446475df 100644
--- a/source/blender/gpu/intern/gpu_capabilities.cc
+++ b/source/blender/gpu/intern/gpu_capabilities.cc
@@ -167,6 +167,11 @@ bool GPU_stencil_clasify_buffer_workaround()
   return GCaps.stencil_clasify_buffer_workaround;
 }
 
+bool GPU_node_link_instancing_workaround()
+{
+  return GCaps.node_link_instancing_workaround;
+}
+
 bool GPU_vulkan_render_pass_workaround()
 {
   return GCaps.render_pass_workaround;
diff --git a/source/blender/gpu/intern/gpu_capabilities_private.hh b/source/blender/gpu/intern/gpu_capabilities_private.hh
index bee7d403872..5189b4a7e9b 100644
--- a/source/blender/gpu/intern/gpu_capabilities_private.hh
+++ b/source/blender/gpu/intern/gpu_capabilities_private.hh
@@ -61,6 +61,7 @@ struct GPUCapabilities {
   bool broken_amd_driver = false;
   bool use_hq_normals_workaround = false;
   bool stencil_clasify_buffer_workaround = false;
+  bool node_link_instancing_workaround = false;
 
   /* Vulkan related workarounds. */
   bool render_pass_workaround = false;
diff --git a/source/blender/gpu/opengl/gl_backend.cc b/source/blender/gpu/opengl/gl_backend.cc
index 6b240303186..3ecc0728c52 100644
--- a/source/blender/gpu/opengl/gl_backend.cc
+++ b/source/blender/gpu/opengl/gl_backend.cc
@@ -310,6 +310,7 @@ static void detect_workarounds()
     GCaps.depth_blitting_workaround = true;
     GCaps.mip_render_workaround = true;
     GCaps.stencil_clasify_buffer_workaround = true;
+    GCaps.node_link_instancing_workaround = true;
     GLContext::debug_layer_workaround = true;
     /* Turn off Blender features. */
     GCaps.hdr_viewport_support = false;
@@ -493,6 +494,14 @@ static void detect_workarounds()
     GLContext::multi_bind_image_support = false;
   }
 
+  /* #134509 Intel ARC GPU have a driver bug that break the display of batched nodelinks.
+   * Disabling batching fixes the issue. */
+  if (GPU_type_matches(GPU_DEVICE_INTEL, GPU_OS_ANY, GPU_DRIVER_OFFICIAL)) {
+    if (strstr(renderer, "Arc")) {
+      GCaps.node_link_instancing_workaround = true;
+    }
+  }
+
   /* Multi viewport creates small triangle discard on RDNA2 GPUs with official drivers.
    * Using geometry shader workaround fixes the issue. */
   if (GPU_type_matches(GPU_DEVICE_ATI, GPU_OS_ANY, GPU_DRIVER_OFFICIAL)) {