7 files changed, 36 insertions, 8 deletions
diff --git a/source/blender/gpu/GPU_compute.h b/source/blender/gpu/GPU_compute.h
index 437b0223303..6dfd6f73ae8 100644
--- a/source/blender/gpu/GPU_compute.h
+++ b/source/blender/gpu/GPU_compute.h
@@ -9,6 +9,7 @@
 #include "BLI_sys_types.h"
 
 #include "GPU_shader.h"
+#include "GPU_storage_buffer.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -19,6 +20,8 @@ void GPU_compute_dispatch(GPUShader *shader,
                           uint groups_y_len,
                           uint groups_z_len);
 
+void GPU_compute_dispatch_indirect(GPUShader *shader, GPUStorageBuf *indirect_buf);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/gpu/intern/gpu_backend.hh b/source/blender/gpu/intern/gpu_backend.hh
index 56d7c3b4e46..ad906c74980 100644
--- a/source/blender/gpu/intern/gpu_backend.hh
+++ b/source/blender/gpu/intern/gpu_backend.hh
@@ -35,6 +35,7 @@ class GPUBackend {
 
   virtual void samplers_update() = 0;
   virtual void compute_dispatch(int groups_x_len, int groups_y_len, int groups_z_len) = 0;
+  virtual void compute_dispatch_indirect(StorageBuf *indirect_buf) = 0;
 
   virtual Context *context_alloc(void *ghost_window) = 0;
 
diff --git a/source/blender/gpu/intern/gpu_compute.cc b/source/blender/gpu/intern/gpu_compute.cc
index e99455b756a..b45cf8211cb 100644
--- a/source/blender/gpu/intern/gpu_compute.cc
+++ b/source/blender/gpu/intern/gpu_compute.cc
@@ -7,10 +7,7 @@
 #include "GPU_compute.h"
 
 #include "gpu_backend.hh"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
+#include "gpu_storage_buffer_private.hh"
 
 void GPU_compute_dispatch(GPUShader *shader,
                           uint groups_x_len,
@@ -22,6 +19,12 @@ void GPU_compute_dispatch(GPUShader *shader,
   gpu_backend.compute_dispatch(groups_x_len, groups_y_len, groups_z_len);
 }
 
-#ifdef __cplusplus
+void GPU_compute_dispatch_indirect(GPUShader *shader, GPUStorageBuf *indirect_buf_)
+{
+  blender::gpu::GPUBackend &gpu_backend = *blender::gpu::GPUBackend::get();
+  blender::gpu::StorageBuf *indirect_buf = reinterpret_cast<blender::gpu::StorageBuf *>(
+      indirect_buf_);
+
+  GPU_shader_bind(shader);
+  gpu_backend.compute_dispatch_indirect(indirect_buf);
 }
-#endif
diff --git a/source/blender/gpu/opengl/gl_backend.hh b/source/blender/gpu/opengl/gl_backend.hh
index d7edd162f33..e72726d9c7b 100644
--- a/source/blender/gpu/opengl/gl_backend.hh
+++ b/source/blender/gpu/opengl/gl_backend.hh
@@ -123,6 +123,19 @@ class GLBackend : public GPUBackend {
     GLCompute::dispatch(groups_x_len, groups_y_len, groups_z_len);
   }
 
+  void compute_dispatch_indirect(StorageBuf *indirect_buf) override
+  {
+    GLContext::get()->state_manager_active_get()->apply_state();
+
+    dynamic_cast<GLStorageBuf *>(indirect_buf)->bind_as(GL_DISPATCH_INDIRECT_BUFFER);
+    /* This barrier needs to be here as it only work on the currently bound indirect buffer. */
+    glMemoryBarrier(GL_DRAW_INDIRECT_BUFFER);
+
+    glDispatchComputeIndirect((GLintptr)0);
+    /* Unbind. */
+    glBindBuffer(GL_DRAW_INDIRECT_BUFFER, 0);
+  }
+
  private:
   static void platform_init();
   static void platform_exit();
diff --git a/source/blender/gpu/opengl/gl_compute.cc b/source/blender/gpu/opengl/gl_compute.cc
index 1913174eaef..2fbf23c227d 100644
--- a/source/blender/gpu/opengl/gl_compute.cc
+++ b/source/blender/gpu/opengl/gl_compute.cc
@@ -16,8 +16,6 @@ void GLCompute::dispatch(int group_x_len, int group_y_len, int group_z_len)
 {
   GL_CHECK_RESOURCES("Compute");
 
-  GLContext::get()->state_manager->apply_state();
-
   glDispatchCompute(group_x_len, group_y_len, group_z_len);
 }
 
diff --git a/source/blender/gpu/opengl/gl_storage_buffer.cc b/source/blender/gpu/opengl/gl_storage_buffer.cc
index 9cdde0b5734..a461d834790 100644
--- a/source/blender/gpu/opengl/gl_storage_buffer.cc
+++ b/source/blender/gpu/opengl/gl_storage_buffer.cc
@@ -100,6 +100,13 @@ void GLStorageBuf::bind(int slot)
 #endif
 }
 
+void GLStorageBuf::bind_as(GLenum target)
+{
+  BLI_assert_msg(ssbo_id_ != 0,
+                 "Trying to use storage buf as indirect buffer but buffer was never filled.");
+  glBindBuffer(target, ssbo_id_);
+}
+
 void GLStorageBuf::unbind()
 {
 #ifdef DEBUG
diff --git a/source/blender/gpu/opengl/gl_storage_buffer.hh b/source/blender/gpu/opengl/gl_storage_buffer.hh
index d657a4de09c..c808a0bdda1 100644
--- a/source/blender/gpu/opengl/gl_storage_buffer.hh
+++ b/source/blender/gpu/opengl/gl_storage_buffer.hh
@@ -37,6 +37,9 @@ class GLStorageBuf : public StorageBuf {
   void unbind() override;
   void clear(eGPUTextureFormat internal_format, eGPUDataFormat data_format, void *data) override;
 
+  /* Special internal function to bind SSBOs to indirect argument targets. */
+  void bind_as(GLenum target);
+
  private:
   void init();