1 files changed, 102 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..e2022d74093
--- /dev/null
+++ b/source/blender/draw/engines/eevee_next/eevee_hizbuffer.cc
@@ -0,0 +1,102 @@
+/* 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_ = DRW_pass_create("HizUpdate", DRW_STATE_NO_DRAW);
+    GPUShader *sh = inst_.shaders.static_shader_get(HIZ_UPDATE);
+    DRWShadingGroup *grp = DRW_shgroup_create(sh, hiz_update_ps_);
+    DRW_shgroup_storage_block(grp, "finished_tile_counter", atomic_tile_counter_);
+    DRW_shgroup_uniform_texture_ref_ex(grp, "depth_tx", &render_buffers.depth_tx, with_filter);
+    DRW_shgroup_uniform_image(grp, "out_mip_0", hiz_tx_.mip_view(0));
+    DRW_shgroup_uniform_image(grp, "out_mip_1", hiz_tx_.mip_view(1));
+    DRW_shgroup_uniform_image(grp, "out_mip_2", hiz_tx_.mip_view(2));
+    DRW_shgroup_uniform_image(grp, "out_mip_3", hiz_tx_.mip_view(3));
+    DRW_shgroup_uniform_image(grp, "out_mip_4", hiz_tx_.mip_view(4));
+    DRW_shgroup_uniform_image(grp, "out_mip_5", hiz_tx_.mip_view(5));
+    DRW_shgroup_uniform_image(grp, "out_mip_6", hiz_tx_.mip_view(6));
+    DRW_shgroup_uniform_image(grp, "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. */
+    DRW_shgroup_uniform_bool_copy(grp, "update_mip_0", true);
+    DRW_shgroup_call_compute(grp, UNPACK2(dispatch_size), 1);
+    DRW_shgroup_barrier(grp, GPU_BARRIER_TEXTURE_FETCH);
+  }
+
+  if (inst_.debug_mode == eDebugMode::DEBUG_HIZ_VALIDATION) {
+    DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_CUSTOM;
+    debug_draw_ps_ = DRW_pass_create("HizUpdate.Debug", state);
+    GPUShader *sh = inst_.shaders.static_shader_get(HIZ_DEBUG);
+    DRWShadingGroup *grp = DRW_shgroup_create(sh, debug_draw_ps_);
+    this->bind_resources(grp);
+    DRW_shgroup_call_procedural_triangles(grp, nullptr, 1);
+  }
+  else {
+    debug_draw_ps_ = nullptr;
+  }
+}
+
+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();
+  }
+
+  DRW_draw_pass(hiz_update_ps_);
+
+  if (G.debug & G_DEBUG_GPU) {
+    GPU_framebuffer_bind(fb);
+  }
+}
+
+void HiZBuffer::debug_draw(GPUFrameBuffer *view_fb)
+{
+  if (debug_draw_ps_ == nullptr) {
+    return;
+  }
+  inst_.info = "Debug Mode: HiZ Validation";
+  inst_.hiz_buffer.update();
+  GPU_framebuffer_bind(view_fb);
+  DRW_draw_pass(debug_draw_ps_);
+}
+
+/** \} */
+
+}  // namespace blender::eevee