Armature: Add a special Pass for bone axes.

In object mode, the axes are drawn like any other wire objects with
depth test and depth write. Thus enabling MSAA to work but not their xray
behaviour.

In edit armature/pose mode, draw smooth line without depth testing. This
produces wrong draw ordering problem but still gives the desired xray
behaviour. We do it outside of the MSAA pass since the xray behaviour is not
compatible with it. But we are drawing smoothed lines so no need for MSAA.
The lines are 2px thick and improve readability.

1 files changed, 10 insertions, 0 deletions

diff --git a/source/blender/draw/modes/pose_mode.c b/source/blender/draw/modes/pose_mode.c
index d1b4dd77246..10d6bffcbe1 100644
--- a/source/blender/draw/modes/pose_mode.c
+++ b/source/blender/draw/modes/pose_mode.c
@@ -47,6 +47,7 @@ typedef struct POSE_PassList {
 	struct DRWPass *bone_outline;
 	struct DRWPass *bone_wire;
 	struct DRWPass *bone_envelope;
+	struct DRWPass *bone_axes;
 	struct DRWPass *relationship;
 } POSE_PassList;
 
@@ -107,6 +108,11 @@ static void POSE_cache_init(void *vedata)
 	}
 
 	{
+		DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_WIRE_SMOOTH | DRW_STATE_BLEND;
+		psl->bone_axes = DRW_pass_create("Bone Axes Pass", state);
+	}
+
+	{
 		/* Non Meshes Pass (Camera, empties, lamps ...) */
 		DRWState state =
 		        DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS |
@@ -136,6 +142,7 @@ static void POSE_cache_populate(void *vedata, Object *ob)
 			    .bone_outline = psl->bone_outline,
 			    .bone_wire = psl->bone_wire,
 			    .bone_envelope = psl->bone_envelope,
+			    .bone_axes = psl->bone_axes,
 			};
 			DRW_shgroup_armature_pose(ob, passes, stl->g_data->relationship_lines);
 		}
@@ -183,6 +190,9 @@ static void POSE_draw_scene(void *vedata)
 	DRW_draw_pass(psl->relationship);
 
 	MULTISAMPLE_SYNC_DISABLE(dfbl, dtxl)
+
+	/* Draw axes with linesmooth and outside of multisample buffer. */
+	DRW_draw_pass(psl->bone_axes);
 }
 
 /* Create collection settings here.