Overlay-Next: Xray Fade

Straight-forward port.

Rel #102179

Pull Request: https://projects.blender.org/blender/blender/pulls/126967

source/blender/draw/CMakeLists.txt

@@ -312,6 +312,7 @@ set(SRC
   engines/overlay/overlay_next_relation.hh
   engines/overlay/overlay_next_speaker.hh
   engines/overlay/overlay_next_wireframe.hh
+  engines/overlay/overlay_next_xray_fade.hh
   engines/overlay/overlay_private.hh
   engines/select/select_defines.hh
   engines/select/select_engine.hh

source/blender/draw/engines/overlay/overlay_next_instance.cc

@@ -113,6 +113,7 @@ void Instance::begin_sync()
   grid.begin_sync(resources, state, view);
 
   anti_aliasing.begin_sync(resources);
+  xray_fade.begin_sync(resources, state);
 }
 
 void Instance::object_sync(ObjectRef &ob_ref, Manager &manager)
@@ -261,7 +262,7 @@ void Instance::draw(Manager &manager)
 
   if (state.xray_enabled) {
     /* For X-ray we render the scene to a separate depth buffer. */
-    resources.xray_depth_tx.acquire(render_size, GPU_DEPTH_COMPONENT24);
+    resources.xray_depth_tx.acquire(render_size, GPU_DEPTH24_STENCIL8);
     resources.depth_target_tx.wrap(resources.xray_depth_tx);
   }
   else {
@@ -270,7 +271,7 @@ void Instance::draw(Manager &manager)
 
   /* TODO(fclem): Remove mandatory allocation. */
   if (!resources.depth_in_front_tx.is_valid()) {
-    resources.depth_in_front_alloc_tx.acquire(render_size, GPU_DEPTH_COMPONENT24);
+    resources.depth_in_front_alloc_tx.acquire(render_size, GPU_DEPTH24_STENCIL8);
     resources.depth_in_front_tx.wrap(resources.depth_in_front_alloc_tx);
   }
 
@@ -356,6 +357,8 @@ void Instance::draw(Manager &manager)
 
   draw_layer(regular, resources.overlay_line_fb);
 
+  xray_fade.draw(manager);
+
   auto draw_layer_color_only = [&](OverlayLayer &layer, Framebuffer &framebuffer) {
     layer.light_probes.draw_color_only(framebuffer, manager, view);
     layer.meshes.draw_color_only(framebuffer, manager, view);

source/blender/draw/engines/overlay/overlay_next_instance.hh

@@ -31,6 +31,7 @@
 #include "overlay_next_relation.hh"
 #include "overlay_next_speaker.hh"
 #include "overlay_next_wireframe.hh"
+#include "overlay_next_xray_fade.hh"
 
 namespace blender::draw::overlay {
 
@@ -80,6 +81,7 @@ class Instance {
   Grid grid;
 
   AntiAliasing anti_aliasing;
+  XrayFade xray_fade;
 
   Instance(const SelectionType selection_type) : selection_type_(selection_type){};
 

source/blender/draw/engines/overlay/overlay_next_private.hh

@@ -194,6 +194,7 @@ class ShaderModule {
   ShaderPtr outline_prepass_pointcloud;
   ShaderPtr outline_prepass_gpencil;
   ShaderPtr outline_detect = shader("overlay_outline_detect");
+  ShaderPtr xray_fade = shader("overlay_xray_fade");
 
   /** Selectable Shaders */
   ShaderPtr armature_sphere_outline;

source/blender/draw/engines/overlay/overlay_next_xray_fade.hh

@@ -0,0 +1,62 @@
+/* SPDX-FileCopyrightText: 2019 Blender Authors
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup draw_engine
+ *
+ * Overlay Xray Fade:
+ *
+ * Full-screen pass that dim overlays that are behind scene geometry.
+ * This allows to have a nice transition between opaque (or 100% xray) and wire-frame only mode.
+ * This is only available if Xray mode is enabled or in wire-frame mode.
+ */
+
+#pragma once
+
+#include "overlay_next_private.hh"
+
+namespace blender::draw::overlay {
+
+class XrayFade {
+ private:
+  PassSimple xray_fade_ps_ = {"XrayFade"};
+
+  bool enabled_ = false;
+
+ public:
+  void begin_sync(Resources &res, State &state)
+  {
+    enabled_ = state.xray_enabled && (state.xray_opacity > 0.0f) &&
+               (res.selection_type == SelectionType::DISABLED);
+
+    if (!enabled_) {
+      return;
+    }
+
+    {
+      PassSimple &pass = xray_fade_ps_;
+      pass.init();
+      pass.state_set(DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_MUL);
+      pass.framebuffer_set(&res.overlay_color_only_fb);
+      pass.shader_set(res.shaders.xray_fade.get());
+      /* TODO(fclem): Confusing. The meaning of xray depth texture changed between legacy engine
+       * and overlay next. To be renamed after shaders are not shared anymore. */
+      pass.bind_texture("depthTex", &res.xray_depth_tx);
+      pass.bind_texture("xrayDepthTex", &res.depth_tx);
+      pass.push_constant("opacity", 1.0f - state.xray_opacity);
+      pass.draw_procedural(GPU_PRIM_TRIS, 1, 3);
+    }
+  }
+
+  void draw(Manager &manager)
+  {
+    if (!enabled_) {
+      return;
+    }
+
+    manager.submit(xray_fade_ps_);
+  }
+};
+
+}  // namespace blender::draw::overlay