Fix #138521: Overlay: Edit Mode Curves display in front of meshes

The lines were not drawn inside a depth aware framebuffer.

Splitting the display into 2 draw pass fixes the issue.

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

@@ -27,13 +27,17 @@ namespace blender::draw::overlay {
 class Curves : Overlay {
  private:
   PassSimple edit_curves_ps_ = {"Curve Edit"};
-  PassSimple::Sub *edit_curves_points_ = nullptr;
   PassSimple::Sub *edit_curves_lines_ = nullptr;
+
+  PassSimple edit_legacy_curve_handles_ps_ = {"Curve Edit Handles"};
+  PassSimple::Sub *edit_curves_points_ = nullptr;
   PassSimple::Sub *edit_curves_handles_ = nullptr;
 
   PassSimple edit_legacy_curve_ps_ = {"Legacy Curve Edit"};
   PassSimple::Sub *edit_legacy_curve_wires_ = nullptr;
   PassSimple::Sub *edit_legacy_curve_normals_ = nullptr;
+
+  PassSimple edit_curves_handles_ps_ = {"Legacy Curve Edit Handles"};
   PassSimple::Sub *edit_legacy_curve_points_ = nullptr;
   PassSimple::Sub *edit_legacy_curve_handles_ = nullptr;
 
@@ -76,6 +80,13 @@ class Curves : Overlay {
         sub.push_constant("use_grease_pencil", false);
         edit_curves_lines_ = ⊂
       }
+    }
+
+    {
+      auto &pass = edit_curves_handles_ps_;
+      pass.init();
+      pass.bind_ubo(OVERLAY_GLOBALS_SLOT, &res.globals_buf);
+      pass.bind_ubo(DRW_CLIPPING_UBO_SLOT, &res.clip_planes_buf);
       {
         auto &sub = pass.sub("Handles");
         sub.state_set(DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_ALPHA, state.clipping_plane_count);
@@ -127,6 +138,13 @@ class Curves : Overlay {
       else {
         edit_legacy_curve_normals_ = nullptr;
       }
+    }
+
+    {
+      auto &pass = edit_legacy_curve_handles_ps_;
+      pass.init();
+      pass.bind_ubo(OVERLAY_GLOBALS_SLOT, &res.globals_buf);
+      pass.bind_ubo(DRW_CLIPPING_UBO_SLOT, &res.clip_planes_buf);
       {
         auto &sub = pass.sub("Handles");
         sub.state_set(DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_ALPHA, state.clipping_plane_count);
@@ -247,6 +265,8 @@ class Curves : Overlay {
     view_edit_cage.sync(view.viewmat(), offset_data_.winmat_polygon_offset(view.winmat(), 0.5f));
 
     GPU_framebuffer_bind(framebuffer);
+    manager.submit(edit_legacy_curve_ps_, view);
+    manager.submit(edit_curves_ps_, view_edit_cage);
     manager.submit(edit_legacy_surface_handles_ps, view);
   }
 
@@ -259,8 +279,8 @@ class Curves : Overlay {
     view_edit_cage.sync(view.viewmat(), offset_data_.winmat_polygon_offset(view.winmat(), 0.5f));
 
     GPU_framebuffer_bind(framebuffer);
-    manager.submit(edit_legacy_curve_ps_, view);
+    manager.submit(edit_legacy_curve_handles_ps_, view);
-    manager.submit(edit_curves_ps_, view_edit_cage);
+    manager.submit(edit_curves_handles_ps_, view_edit_cage);
   }
 };
 

source/blender/draw/engines/overlay/shaders/infos/overlay_edit_mode_info.hh

@@ -512,7 +512,9 @@ VERTEX_IN(1, uint, data)
 VERTEX_OUT(overlay_edit_flat_color_iface)
 PUSH_CONSTANT(bool, show_curve_handles)
 PUSH_CONSTANT(int, curve_handle_display)
+DEFINE("LINE_OUTPUT")
 FRAGMENT_OUT(0, float4, frag_color)
+FRAGMENT_OUT(1, float4, line_output)
 VERTEX_SOURCE("overlay_edit_curve_point_vert.glsl")
 FRAGMENT_SOURCE("overlay_point_varying_color_frag.glsl")
 ADDITIONAL_INFO(draw_view)
@@ -530,7 +532,9 @@ VERTEX_IN(2, float3, tangent)
 VERTEX_IN(3, float, rad)
 PUSH_CONSTANT(float, normal_size)
 VERTEX_OUT(overlay_edit_flat_color_iface)
+DEFINE("LINE_OUTPUT")
 FRAGMENT_OUT(0, float4, frag_color)
+FRAGMENT_OUT(1, float4, line_output)
 VERTEX_SOURCE("overlay_edit_curve_wire_vert.glsl")
 FRAGMENT_SOURCE("overlay_varying_color.glsl")
 ADDITIONAL_INFO(draw_view)
@@ -553,7 +557,9 @@ PUSH_CONSTANT(int2, gpu_attr_3)
 PUSH_CONSTANT(float, normal_size)
 PUSH_CONSTANT(bool, use_hq_normals)
 VERTEX_OUT(overlay_edit_flat_color_iface)
+DEFINE("LINE_OUTPUT")
 FRAGMENT_OUT(0, float4, frag_color)
+FRAGMENT_OUT(1, float4, line_output)
 VERTEX_SOURCE("overlay_edit_curve_normals_vert.glsl")
 FRAGMENT_SOURCE("overlay_varying_color.glsl")
 ADDITIONAL_INFO(draw_view)