1 files changed, 99 insertions, 0 deletions
diff --git a/source/blender/draw/engines/eevee_next/eevee_hizbuffer.cc b/source/blender/draw/engines/eevee_next/eevee_hizbuffer.cc
new file mode 100644
index 00000000000..cf9049da514
--- /dev/null
+++ b/source/blender/draw/engines/eevee_next/eevee_hizbuffer.cc
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2022 Blender Foundation.
+ */
+
+#include "BKE_global.h"
+
+#include "eevee_instance.hh"
+
+#include "eevee_hizbuffer.hh"
+
+namespace blender::eevee {
+
+/* -------------------------------------------------------------------- */
+/** \name Hierarchical-Z buffer
+ *
+ * \{ */
+
+void HiZBuffer::sync()
+{
+  RenderBuffers &render_buffers = inst_.render_buffers;
+
+  int2 render_extent = inst_.film.render_extent_get();
+  /* Padding to avoid complexity during down-sampling and screen tracing. */
+  int2 hiz_extent = math::ceil_to_multiple(render_extent, int2(1u << (HIZ_MIP_COUNT - 1)));
+  int2 dispatch_size = math::divide_ceil(hiz_extent, int2(HIZ_GROUP_SIZE));
+
+  hiz_tx_.ensure_2d(GPU_R32F, hiz_extent, nullptr, HIZ_MIP_COUNT);
+  hiz_tx_.ensure_mip_views();
+  GPU_texture_mipmap_mode(hiz_tx_, true, false);
+
+  data_.uv_scale = float2(render_extent) / float2(hiz_extent);
+  data_.push_update();
+
+  {
+    hiz_update_ps_.init();
+    hiz_update_ps_.shader_set(inst_.shaders.static_shader_get(HIZ_UPDATE));
+    hiz_update_ps_.bind_ssbo("finished_tile_counter", atomic_tile_counter_);
+    hiz_update_ps_.bind_texture("depth_tx", &render_buffers.depth_tx, with_filter);
+    hiz_update_ps_.bind_image("out_mip_0", hiz_tx_.mip_view(0));
+    hiz_update_ps_.bind_image("out_mip_1", hiz_tx_.mip_view(1));
+    hiz_update_ps_.bind_image("out_mip_2", hiz_tx_.mip_view(2));
+    hiz_update_ps_.bind_image("out_mip_3", hiz_tx_.mip_view(3));
+    hiz_update_ps_.bind_image("out_mip_4", hiz_tx_.mip_view(4));
+    hiz_update_ps_.bind_image("out_mip_5", hiz_tx_.mip_view(5));
+    hiz_update_ps_.bind_image("out_mip_6", hiz_tx_.mip_view(6));
+    hiz_update_ps_.bind_image("out_mip_7", hiz_tx_.mip_view(7));
+    /* TODO(@fclem): There might be occasions where we might not want to
+     * copy mip 0 for performance reasons if there is no need for it. */
+    hiz_update_ps_.push_constant("update_mip_0", true);
+    hiz_update_ps_.dispatch(int3(dispatch_size, 1));
+    hiz_update_ps_.barrier(GPU_BARRIER_TEXTURE_FETCH);
+  }
+
+  if (inst_.debug_mode == eDebugMode::DEBUG_HIZ_VALIDATION) {
+    debug_draw_ps_.init();
+    debug_draw_ps_.state_set(DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_CUSTOM);
+    debug_draw_ps_.shader_set(inst_.shaders.static_shader_get(HIZ_DEBUG));
+    this->bind_resources(&debug_draw_ps_);
+    debug_draw_ps_.draw_procedural(GPU_PRIM_TRIS, 1, 3);
+  }
+}
+
+void HiZBuffer::update()
+{
+  if (!is_dirty_) {
+    return;
+  }
+
+  /* Bind another framebuffer in order to avoid triggering the feedback loop check.
+   * This is safe because we only use compute shaders in this section of the code.
+   * Ideally the check should be smarter. */
+  GPUFrameBuffer *fb = GPU_framebuffer_active_get();
+  if (G.debug & G_DEBUG_GPU) {
+    GPU_framebuffer_restore();
+  }
+
+  inst_.manager->submit(hiz_update_ps_);
+
+  if (G.debug & G_DEBUG_GPU) {
+    GPU_framebuffer_bind(fb);
+  }
+}
+
+void HiZBuffer::debug_draw(View &view, GPUFrameBuffer *view_fb)
+{
+  if (inst_.debug_mode == eDebugMode::DEBUG_HIZ_VALIDATION) {
+    inst_.info =
+        "Debug Mode: HiZ Validation\n"
+        " - Red: pixel in front of HiZ tile value.\n"
+        " - Blue: No error.";
+    inst_.hiz_buffer.update();
+    GPU_framebuffer_bind(view_fb);
+    inst_.manager->submit(debug_draw_ps_, view);
+  }
+}
+
+/** \} */
+
+}  // namespace blender::eevee