GPU/GL: Add StorageBuf implementation

Almost 1:1 identical to UniformBuf implementation.

9 files changed, 455 insertions, 0 deletions

diff --git a/source/blender/gpu/CMakeLists.txt b/source/blender/gpu/CMakeLists.txt
index 2e802844f71..13522f049e8 100644
--- a/source/blender/gpu/CMakeLists.txt
+++ b/source/blender/gpu/CMakeLists.txt
@@ -87,6 +87,7 @@ set(SRC
   intern/gpu_shader_interface.cc
   intern/gpu_shader_log.cc
   intern/gpu_state.cc
+  intern/gpu_storage_buffer.cc
   intern/gpu_texture.cc
   intern/gpu_uniform_buffer.cc
   intern/gpu_vertex_buffer.cc
@@ -108,6 +109,7 @@ set(SRC
   opengl/gl_shader_interface.cc
   opengl/gl_shader_log.cc
   opengl/gl_state.cc
+  opengl/gl_storage_buffer.cc
   opengl/gl_texture.cc
   opengl/gl_uniform_buffer.cc
   opengl/gl_vertex_array.cc
diff --git a/source/blender/gpu/GPU_storage_buffer.h b/source/blender/gpu/GPU_storage_buffer.h
new file mode 100644
index 00000000000..f768181e826
--- /dev/null
+++ b/source/blender/gpu/GPU_storage_buffer.h
@@ -0,0 +1,61 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2005 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ *
+ * Storage buffers API. Used to handle many way bigger buffers than Uniform buffers update at once.
+ * Make sure that the data structure is compatible with what the implementation expect.
+ * (see "7.8 Shader Buffer Variables and Shader Storage Blocks" from the OpenGL spec for more info
+ * about std430 layout)
+ * Rule of thumb: Padding to 16bytes, don't use vec3.
+ */
+
+#pragma once
+
+#include "GPU_vertex_buffer.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct ListBase;
+
+/** Opaque type hiding blender::gpu::StorageBuf. */
+typedef struct GPUStorageBuf GPUStorageBuf;
+
+GPUStorageBuf *GPU_storagebuf_create_ex(size_t size,
+                                        const void *data,
+                                        GPUUsageType usage,
+                                        const char *name);
+
+#define GPU_storagebuf_create(size) \
+  GPU_storagebuf_create_ex(size, NULL, GPU_USAGE_DYNAMIC, __func__);
+
+void GPU_storagebuf_free(GPUStorageBuf *ubo);
+
+void GPU_storagebuf_update(GPUStorageBuf *ubo, const void *data);
+
+void GPU_storagebuf_bind(GPUStorageBuf *ubo, int slot);
+void GPU_storagebuf_unbind(GPUStorageBuf *ubo);
+void GPU_storagebuf_unbind_all(void);
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/gpu/intern/gpu_storage_buffer.cc b/source/blender/gpu/intern/gpu_storage_buffer.cc
new file mode 100644
index 00000000000..adbc71319b3
--- /dev/null
+++ b/source/blender/gpu/intern/gpu_storage_buffer.cc
@@ -0,0 +1,108 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ */
+
+#include "MEM_guardedalloc.h"
+#include <cstring>
+
+#include "BLI_blenlib.h"
+#include "BLI_math_base.h"
+
+#include "gpu_backend.hh"
+#include "gpu_node_graph.h"
+
+#include "GPU_material.h"
+#include "GPU_vertex_buffer.h" /* For GPUUsageType. */
+
+#include "GPU_storage_buffer.h"
+#include "gpu_storage_buffer_private.hh"
+
+/* -------------------------------------------------------------------- */
+/** \name Creation & Deletion
+ * \{ */
+
+namespace blender::gpu {
+
+StorageBuf::StorageBuf(size_t size, const char *name)
+{
+  /* Make sure that UBO is padded to size of vec4 */
+  BLI_assert((size % 16) == 0);
+
+  size_in_bytes_ = size;
+
+  BLI_strncpy(name_, name, sizeof(name_));
+}
+
+StorageBuf::~StorageBuf()
+{
+  MEM_SAFE_FREE(data_);
+}
+
+}  // namespace blender::gpu
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name C-API
+ * \{ */
+
+using namespace blender::gpu;
+
+GPUStorageBuf *GPU_storagebuf_create_ex(size_t size,
+                                        const void *data,
+                                        GPUUsageType usage,
+                                        const char *name)
+{
+  StorageBuf *ubo = GPUBackend::get()->storagebuf_alloc(size, usage, name);
+  /* Direct init. */
+  if (data != nullptr) {
+    ubo->update(data);
+  }
+  return wrap(ubo);
+}
+
+void GPU_storagebuf_free(GPUStorageBuf *ubo)
+{
+  delete unwrap(ubo);
+}
+
+void GPU_storagebuf_update(GPUStorageBuf *ubo, const void *data)
+{
+  unwrap(ubo)->update(data);
+}
+
+void GPU_storagebuf_bind(GPUStorageBuf *ubo, int slot)
+{
+  unwrap(ubo)->bind(slot);
+}
+
+void GPU_storagebuf_unbind(GPUStorageBuf *ubo)
+{
+  unwrap(ubo)->unbind();
+}
+
+void GPU_storagebuf_unbind_all()
+{
+  /* FIXME */
+}
+
+/** \} */
diff --git a/source/blender/gpu/intern/gpu_storage_buffer_private.hh b/source/blender/gpu/intern/gpu_storage_buffer_private.hh
new file mode 100644
index 00000000000..46b7b2e9555
--- /dev/null
+++ b/source/blender/gpu/intern/gpu_storage_buffer_private.hh
@@ -0,0 +1,77 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright 2020, Blender Foundation.
+ */
+
+/** \file
+ * \ingroup gpu
+ */
+
+#pragma once
+
+#include "BLI_sys_types.h"
+
+struct GPUStorageBuf;
+
+namespace blender {
+namespace gpu {
+
+#ifdef DEBUG
+#  define DEBUG_NAME_LEN 64
+#else
+#  define DEBUG_NAME_LEN 8
+#endif
+
+/**
+ * Implementation of Storage Buffers.
+ * Base class which is then specialized for each implementation (GL, VK, ...).
+ */
+class StorageBuf {
+ protected:
+  /** Data size in bytes. */
+  size_t size_in_bytes_;
+  /** Continuous memory block to copy to GPU. This data is owned by the StorageBuf. */
+  void *data_ = NULL;
+  /** Debugging name */
+  char name_[DEBUG_NAME_LEN];
+
+ public:
+  StorageBuf(size_t size, const char *name);
+  virtual ~StorageBuf();
+
+  virtual void update(const void *data) = 0;
+  virtual void bind(int slot) = 0;
+  virtual void unbind() = 0;
+};
+
+/* Syntactic sugar. */
+static inline GPUStorageBuf *wrap(StorageBuf *vert)
+{
+  return reinterpret_cast<GPUStorageBuf *>(vert);
+}
+static inline StorageBuf *unwrap(GPUStorageBuf *vert)
+{
+  return reinterpret_cast<StorageBuf *>(vert);
+}
+static inline const StorageBuf *unwrap(const GPUStorageBuf *vert)
+{
+  return reinterpret_cast<const StorageBuf *>(vert);
+}
+
+#undef DEBUG_NAME_LEN
+
+}  // namespace gpu
+}  // namespace blender
diff --git a/source/blender/gpu/opengl/gl_backend.cc b/source/blender/gpu/opengl/gl_backend.cc
index 2ee7c0503f4..2a921e8f6a2 100644
--- a/source/blender/gpu/opengl/gl_backend.cc
+++ b/source/blender/gpu/opengl/gl_backend.cc
@@ -436,6 +436,8 @@ GLint GLContext::max_cubemap_size = 0;
 GLint GLContext::max_texture_3d_size = 0;
 GLint GLContext::max_ubo_binds = 0;
 GLint GLContext::max_ubo_size = 0;
+GLint GLContext::max_ssbo_binds = 0;
+GLint GLContext::max_ssbo_size = 0;
 
 /** Extensions. */
 
@@ -500,7 +502,9 @@ void GLBackend::capabilities_init()
   glGetIntegerv(GL_MAX_3D_TEXTURE_SIZE, &GLContext::max_texture_3d_size);
   glGetIntegerv(GL_MAX_CUBE_MAP_TEXTURE_SIZE, &GLContext::max_cubemap_size);
   glGetIntegerv(GL_MAX_FRAGMENT_UNIFORM_BLOCKS, &GLContext::max_ubo_binds);
+  glGetIntegerv(GL_MAX_FRAGMENT_SHADER_STORAGE_BLOCKS, &GLContext::max_ssbo_binds);
   glGetIntegerv(GL_MAX_UNIFORM_BLOCK_SIZE, &GLContext::max_ubo_size);
+  glGetIntegerv(GL_MAX_SHADER_STORAGE_BLOCK_SIZE, &GLContext::max_ssbo_size);
   GLContext::base_instance_support = GLEW_ARB_base_instance;
   GLContext::clear_texture_support = GLEW_ARB_clear_texture;
   GLContext::copy_image_support = GLEW_ARB_copy_image;
diff --git a/source/blender/gpu/opengl/gl_backend.hh b/source/blender/gpu/opengl/gl_backend.hh
index abac9174d4a..40580c369ad 100644
--- a/source/blender/gpu/opengl/gl_backend.hh
+++ b/source/blender/gpu/opengl/gl_backend.hh
@@ -35,6 +35,7 @@
 #include "gl_index_buffer.hh"
 #include "gl_query.hh"
 #include "gl_shader.hh"
+#include "gl_storage_buffer.hh"
 #include "gl_texture.hh"
 #include "gl_uniform_buffer.hh"
 #include "gl_vertex_buffer.hh"
@@ -117,6 +118,11 @@ class GLBackend : public GPUBackend {
     return new GLUniformBuf(size, name);
   };
 
+  StorageBuf *storagebuf_alloc(int size, GPUUsageType usage, const char *name) override
+  {
+    return new GLStorageBuf(size, usage, name);
+  };
+
   VertBuf *vertbuf_alloc() override
   {
     return new GLVertBuf();
diff --git a/source/blender/gpu/opengl/gl_context.hh b/source/blender/gpu/opengl/gl_context.hh
index b7a74863ac4..6b405b7e95b 100644
--- a/source/blender/gpu/opengl/gl_context.hh
+++ b/source/blender/gpu/opengl/gl_context.hh
@@ -61,6 +61,8 @@ class GLContext : public Context {
   static GLint max_texture_3d_size;
   static GLint max_ubo_size;
   static GLint max_ubo_binds;
+  static GLint max_ssbo_size;
+  static GLint max_ssbo_binds;
 
   /** Extensions. */
 
diff --git a/source/blender/gpu/opengl/gl_storage_buffer.cc b/source/blender/gpu/opengl/gl_storage_buffer.cc
new file mode 100644
index 00000000000..c24f9841a09
--- /dev/null
+++ b/source/blender/gpu/opengl/gl_storage_buffer.cc
@@ -0,0 +1,133 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ */
+
+#include "BKE_global.h"
+
+#include "BLI_string.h"
+
+#include "gpu_backend.hh"
+#include "gpu_context_private.hh"
+
+#include "gl_backend.hh"
+#include "gl_debug.hh"
+#include "gl_storage_buffer.hh"
+#include "gl_vertex_buffer.hh"
+
+namespace blender::gpu {
+
+/* -------------------------------------------------------------------- */
+/** \name Creation & Deletion
+ * \{ */
+
+GLStorageBuf::GLStorageBuf(size_t size, GPUUsageType usage, const char *name)
+    : StorageBuf(size, name)
+{
+  usage_ = usage;
+  /* Do not create ubo GL buffer here to allow allocation from any thread. */
+  BLI_assert(size <= GLContext::max_ssbo_size);
+}
+
+GLStorageBuf::~GLStorageBuf()
+{
+  GLContext::buf_free(ssbo_id_);
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Data upload / update
+ * \{ */
+
+void GLStorageBuf::init()
+{
+  BLI_assert(GLContext::get());
+
+  glGenBuffers(1, &ssbo_id_);
+  glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssbo_id_);
+  glBufferData(GL_SHADER_STORAGE_BUFFER, size_in_bytes_, nullptr, to_gl(this->usage_));
+
+  debug::object_label(GL_SHADER_STORAGE_BUFFER, ssbo_id_, name_);
+}
+
+void GLStorageBuf::update(const void *data)
+{
+  if (ssbo_id_ == 0) {
+    this->init();
+  }
+  glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssbo_id_);
+  glBufferSubData(GL_SHADER_STORAGE_BUFFER, 0, size_in_bytes_, data);
+  glBindBuffer(GL_SHADER_STORAGE_BUFFER, 0);
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Usage
+ * \{ */
+
+void GLStorageBuf::bind(int slot)
+{
+  if (slot >= GLContext::max_ssbo_binds) {
+    fprintf(
+        stderr,
+        "Error: Trying to bind \"%s\" ssbo to slot %d which is above the reported limit of %d.",
+        name_,
+        slot,
+        GLContext::max_ssbo_binds);
+    return;
+  }
+
+  if (ssbo_id_ == 0) {
+    this->init();
+  }
+
+  if (data_ != nullptr) {
+    this->update(data_);
+    MEM_SAFE_FREE(data_);
+  }
+
+  slot_ = slot;
+  glBindBufferBase(GL_SHADER_STORAGE_BUFFER, slot_, ssbo_id_);
+
+#ifdef DEBUG
+  BLI_assert(slot < 16);
+  /* TODO */
+  // GLContext::get()->bound_ssbo_slots |= 1 << slot;
+#endif
+}
+
+void GLStorageBuf::unbind()
+{
+#ifdef DEBUG
+  /* NOTE: This only unbinds the last bound slot. */
+  glBindBufferBase(GL_SHADER_STORAGE_BUFFER, slot_, 0);
+  /* Hope that the context did not change. */
+  /* TODO */
+  // GLContext::get()->bound_ssbo_slots &= ~(1 << slot_);
+#endif
+  slot_ = 0;
+}
+
+/** \} */
+
+}  // namespace blender::gpu
diff --git a/source/blender/gpu/opengl/gl_storage_buffer.hh b/source/blender/gpu/opengl/gl_storage_buffer.hh
new file mode 100644
index 00000000000..3280db4e521
--- /dev/null
+++ b/source/blender/gpu/opengl/gl_storage_buffer.hh
@@ -0,0 +1,62 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup gpu
+ */
+
+#pragma once
+
+#include "MEM_guardedalloc.h"
+
+#include "gpu_storage_buffer_private.hh"
+
+#include "glew-mx.h"
+
+namespace blender {
+namespace gpu {
+
+/**
+ * Implementation of Storage Buffers using OpenGL.
+ */
+class GLStorageBuf : public StorageBuf {
+ private:
+  /** Slot to which this UBO is currently bound. -1 if not bound. */
+  int slot_ = -1;
+  /** OpenGL Object handle. */
+  GLuint ssbo_id_ = 0;
+  /** Usage type. */
+  GPUUsageType usage_;
+
+ public:
+  GLStorageBuf(size_t size, GPUUsageType usage, const char *name);
+  ~GLStorageBuf();
+
+  void update(const void *data) override;
+  void bind(int slot) override;
+  void unbind() override;
+
+ private:
+  void init();
+
+  MEM_CXX_CLASS_ALLOC_FUNCS("GLStorageBuf");
+};
+
+}  // namespace gpu
+}  // namespace blender