EEVEE-Next: Add Film and RenderBuffers module

This modules handles renderpasses allocation and filling. Also handles
blitting to viewport framebuffer and render result reading.

Changes against the old implementation:
- the filling of the renderpasses happens all at once requiring
  only 1 geometry pass.
- The filtering is optimized with weights precomputed on CPU and
  reuse of neighboor pixels.
- Only one accumulation buffer for renderpasses (no ping-pong).
- Accumulation happens in one pass for every passes using a single
  dispatch or fullscreen triangle pass.

TAA and history reprojection is not yet implemented.
AOVs support is present but with a 16 AOV limit for now.
Cryptomatte is not yet implemented.

1 files changed, 57 insertions, 0 deletions

diff --git a/source/blender/draw/engines/eevee_next/eevee_renderbuffers.hh b/source/blender/draw/engines/eevee_next/eevee_renderbuffers.hh
new file mode 100644
index 00000000000..8c91fed2f0f
--- /dev/null
+++ b/source/blender/draw/engines/eevee_next/eevee_renderbuffers.hh
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2022 Blender Foundation.
+ */
+
+/** \file
+ * \ingroup eevee
+ *
+ * Render buffers are textures that are filled during a view rendering.
+ * Their content is then added to the accumulation buffers of the film class.
+ * They are short lived and can be reused when doing multi view rendering.
+ */
+
+#pragma once
+
+#include "DRW_render.h"
+
+#include "eevee_shader_shared.hh"
+
+namespace blender::eevee {
+
+class Instance;
+
+class RenderBuffers {
+ public:
+  TextureFromPool depth_tx;
+  TextureFromPool combined_tx;
+
+  // TextureFromPool mist_tx; /* Derived from depth_tx during accumulation. */
+  TextureFromPool normal_tx;
+  TextureFromPool vector_tx;
+  TextureFromPool diffuse_light_tx;
+  TextureFromPool diffuse_color_tx;
+  TextureFromPool specular_light_tx;
+  TextureFromPool specular_color_tx;
+  TextureFromPool volume_light_tx;
+  TextureFromPool emission_tx;
+  TextureFromPool environment_tx;
+  TextureFromPool shadow_tx;
+  TextureFromPool ambient_occlusion_tx;
+  // TextureFromPool cryptomatte_tx; /* TODO */
+  /* TODO(fclem): Use texture from pool once they support texture array. */
+  Texture aov_color_tx;
+  Texture aov_value_tx;
+
+ private:
+  Instance &inst_;
+
+ public:
+  RenderBuffers(Instance &inst) : inst_(inst){};
+
+  void sync();
+  /* Acquires (also ensures) the render buffer before rendering to them. */
+  void acquire(int2 extent, void *owner);
+  void release();
+};
+
+}  // namespace blender::eevee