3D View: x-ray support for depth picking

Selection loop would draw the selection ignoring xray.
Now draw in a separate pass after clearing the depth buffer,
as with regular drawing.

Also disable depth sorting,
caller can sort the hit-list by depth if needed.

4 files changed, 136 insertions, 75 deletions

diff --git a/source/blender/editors/space_view3d/drawobject.c b/source/blender/editors/space_view3d/drawobject.c
index 90d33dc5995..898f155cc92 100644
--- a/source/blender/editors/space_view3d/drawobject.c
+++ b/source/blender/editors/space_view3d/drawobject.c
@@ -8174,6 +8174,50 @@ void draw_object(Scene *scene, ARegion *ar, View3D *v3d, Base *base, const short
 	ED_view3d_clear_mats_rv3d(rv3d);
 }
 
+
+/**
+ * Drawing for selection picking,
+ * caller must have called 'GPU_select_load_id(base->selcode)' first.
+ */
+void draw_object_select(Scene *scene, ARegion *ar, View3D *v3d, Base *base, const short dflag)
+{
+	BLI_assert(dflag & DRAW_PICKING && dflag & DRAW_CONSTCOLOR);
+	draw_object(scene, ar, v3d, base, dflag);
+
+	/* we draw duplicators for selection too */
+	if ((base->object->transflag & OB_DUPLI)) {
+		ListBase *lb;
+		DupliObject *dob;
+		Base tbase;
+
+		tbase.flag = OB_FROMDUPLI;
+		lb = object_duplilist(G.main->eval_ctx, scene, base->object);
+
+		for (dob = lb->first; dob; dob = dob->next) {
+			float omat[4][4];
+			char dt;
+			short dtx;
+
+			tbase.object = dob->ob;
+			copy_m4_m4(omat, dob->ob->obmat);
+			copy_m4_m4(dob->ob->obmat, dob->mat);
+
+			/* extra service: draw the duplicator in drawtype of parent */
+			/* MIN2 for the drawtype to allow bounding box objects in groups for lods */
+			dt = tbase.object->dt;   tbase.object->dt = MIN2(tbase.object->dt, base->object->dt);
+			dtx = tbase.object->dtx; tbase.object->dtx = base->object->dtx;
+
+			draw_object(scene, ar, v3d, &tbase, dflag);
+
+			tbase.object->dt = dt;
+			tbase.object->dtx = dtx;
+
+			copy_m4_m4(dob->ob->obmat, omat);
+		}
+		free_object_duplilist(lb);
+	}
+}
+
 /* ***************** BACKBUF SEL (BBS) ********* */
 
 static void bbs_obmode_mesh_verts__mapFunc(void *userData, int index, const float co[3],
diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index 0c5cf1bd936..3fb2761d40e 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -100,6 +100,7 @@
 #include "GPU_material.h"
 #include "GPU_compositing.h"
 #include "GPU_extensions.h"
+#include "GPU_select.h"
 
 #include "view3d_intern.h"  /* own include */
 
@@ -2023,6 +2024,35 @@ static void view3d_draw_xraytransp(Scene *scene, ARegion *ar, View3D *v3d, const
 	glDepthMask(GL_TRUE);
 }
 
+/* clears zbuffer and draws it over,
+ * note that in the select version we don't care about transparent flag as with regular drawing */
+static void view3d_draw_xray_select(Scene *scene, ARegion *ar, View3D *v3d, bool *clear)
+{
+	/* Not ideal, but we need to read from the previous depths before clearing
+	 * otherwise we could have a function to load the depths after drawing.
+	 *
+	 * Clearing the depth buffer isn't all that common between drawing objects so accept this for now.
+	 */
+	if (U.gpu_select_pick_deph) {
+		GPU_select_load_id(-1);
+	}
+
+	View3DAfter *v3da;
+	if (*clear && v3d->zbuf) {
+		glClear(GL_DEPTH_BUFFER_BIT);
+		*clear = false;
+	}
+
+	v3d->xray = true;
+	while ((v3da = BLI_pophead(&v3d->afterdraw_xray))) {
+		if (GPU_select_load_id(v3da->base->selcol)) {
+			draw_object_select(scene, ar, v3d, v3da->base, v3da->dflag);
+		}
+		MEM_freeN(v3da);
+	}
+	v3d->xray = false;
+}
+
 /* *********************** */
 
 /*
@@ -2487,6 +2517,58 @@ void ED_view3d_draw_depth(Scene *scene, ARegion *ar, View3D *v3d, bool alphaover
 	U.obcenter_dia = obcenter_dia;
 }
 
+void ED_view3d_draw_select_loop(
+        ViewContext *vc, Scene *scene, View3D *v3d, ARegion *ar,
+        bool use_obedit_skip, bool use_nearest)
+{
+	short code = 1;
+	const short dflag = DRAW_PICKING | DRAW_CONSTCOLOR;
+
+	if (vc->obedit && vc->obedit->type == OB_MBALL) {
+		draw_object(scene, ar, v3d, BASACT, dflag);
+	}
+	else if ((vc->obedit && vc->obedit->type == OB_ARMATURE)) {
+		/* if not drawing sketch, draw bones */
+		if (!BDR_drawSketchNames(vc)) {
+			draw_object(scene, ar, v3d, BASACT, dflag);
+		}
+	}
+	else {
+		Base *base;
+
+		for (base = scene->base.first; base; base = base->next) {
+			if (base->lay & v3d->lay) {
+
+				if ((base->object->restrictflag & OB_RESTRICT_SELECT) ||
+				    (use_obedit_skip && (scene->obedit->data == base->object->data)))
+				{
+					base->selcol = 0;
+				}
+				else {
+					base->selcol = code;
+
+					if (use_nearest && (base->object->dtx & OB_DRAWXRAY)) {
+						ED_view3d_after_add(&v3d->afterdraw_xray, base, dflag);
+					}
+					else {
+						if (GPU_select_load_id(code)) {
+							draw_object_select(scene, ar, v3d, base, dflag);
+						}
+					}
+					code++;
+				}
+			}
+		}
+
+		if (use_nearest) {
+			bool xrayclear = true;
+			if (v3d->afterdraw_xray.first) {
+				view3d_draw_xray_select(scene, ar, v3d, &xrayclear);
+			}
+		}
+	}
+}
+
 typedef struct View3DShadow {
 	struct View3DShadow *next, *prev;
 	GPULamp *lamp;
diff --git a/source/blender/editors/space_view3d/view3d_intern.h b/source/blender/editors/space_view3d/view3d_intern.h
index 87b3d95cd4e..c2b8d1f8bda 100644
--- a/source/blender/editors/space_view3d/view3d_intern.h
+++ b/source/blender/editors/space_view3d/view3d_intern.h
@@ -143,6 +143,8 @@ void draw_motion_paths_cleanup(View3D *v3d);
 
 /* drawobject.c */
 void draw_object(Scene *scene, struct ARegion *ar, View3D *v3d, Base *base, const short dflag);
+void draw_object_select(Scene *scene, ARegion *ar, View3D *v3d, Base *base, const short dflag);
+
 bool draw_glsl_material(Scene *scene, struct Object *ob, View3D *v3d, const char dt);
 void draw_object_instance(Scene *scene, View3D *v3d, RegionView3D *rv3d, struct Object *ob, const char dt, int outline);
 void draw_object_backbufsel(Scene *scene, View3D *v3d, RegionView3D *rv3d, struct Object *ob);
@@ -195,7 +197,11 @@ void draw_sim_debug_data(Scene *scene, View3D *v3d, ARegion *ar);
 void view3d_main_region_draw(const struct bContext *C, struct ARegion *ar);
 void ED_view3d_draw_depth(Scene *scene, struct ARegion *ar, View3D *v3d, bool alphaoverride);
 void ED_view3d_draw_depth_gpencil(Scene *scene, ARegion *ar, View3D *v3d);
-void ED_view3d_after_add(ListBase *lb, Base *base, const short dflag);
+void ED_view3d_draw_select_loop(
+        ViewContext *vc, Scene *scene, View3D *v3d, ARegion *ar,
+        bool use_obedit_skip, bool use_nearest);
+
+void ED_view3d_after_add(ListBase *lb, Base *base, const short dflag);\
 
 void circf(float x, float y, float rad);
 void circ(float x, float y, float rad);
diff --git a/source/blender/editors/space_view3d/view3d_view.c b/source/blender/editors/space_view3d/view3d_view.c
index e8deaabec7a..8230a0de6b9 100644
--- a/source/blender/editors/space_view3d/view3d_view.c
+++ b/source/blender/editors/space_view3d/view3d_view.c
@@ -1091,78 +1091,6 @@ void view3d_viewmatrix_set(Scene *scene, const View3D *v3d, RegionView3D *rv3d)
 	}
 }
 
-static void view3d_select_loop(ViewContext *vc, Scene *scene, View3D *v3d, ARegion *ar, bool use_obedit_skip)
-{
-	short code = 1;
-	char dt;
-	short dtx;
-
-	if (vc->obedit && vc->obedit->type == OB_MBALL) {
-		draw_object(scene, ar, v3d, BASACT, DRAW_PICKING | DRAW_CONSTCOLOR);
-	}
-	else if ((vc->obedit && vc->obedit->type == OB_ARMATURE)) {
-		/* if not drawing sketch, draw bones */
-		if (!BDR_drawSketchNames(vc)) {
-			draw_object(scene, ar, v3d, BASACT, DRAW_PICKING | DRAW_CONSTCOLOR);
-		}
-	}
-	else {
-		Base *base;
-
-		v3d->xray = true;  /* otherwise it postpones drawing */
-		for (base = scene->base.first; base; base = base->next) {
-			if (base->lay & v3d->lay) {
-
-				if ((base->object->restrictflag & OB_RESTRICT_SELECT) ||
-				    (use_obedit_skip && (scene->obedit->data == base->object->data)))
-				{
-					base->selcol = 0;
-				}
-				else {
-					base->selcol = code;
-
-					if (GPU_select_load_id(code)) {
-						draw_object(scene, ar, v3d, base, DRAW_PICKING | DRAW_CONSTCOLOR);
-
-						/* we draw duplicators for selection too */
-						if ((base->object->transflag & OB_DUPLI)) {
-							ListBase *lb;
-							DupliObject *dob;
-							Base tbase;
-
-							tbase.flag = OB_FROMDUPLI;
-							lb = object_duplilist(G.main->eval_ctx, scene, base->object);
-
-							for (dob = lb->first; dob; dob = dob->next) {
-								float omat[4][4];
-
-								tbase.object = dob->ob;
-								copy_m4_m4(omat, dob->ob->obmat);
-								copy_m4_m4(dob->ob->obmat, dob->mat);
-
-								/* extra service: draw the duplicator in drawtype of parent */
-								/* MIN2 for the drawtype to allow bounding box objects in groups for lods */
-								dt = tbase.object->dt;   tbase.object->dt = MIN2(tbase.object->dt, base->object->dt);
-								dtx = tbase.object->dtx; tbase.object->dtx = base->object->dtx;
-
-								draw_object(scene, ar, v3d, &tbase, DRAW_PICKING | DRAW_CONSTCOLOR);
-
-								tbase.object->dt = dt;
-								tbase.object->dtx = dtx;
-
-								copy_m4_m4(dob->ob->obmat, omat);
-							}
-							free_object_duplilist(lb);
-						}
-					}
-					code++;
-				}
-			}
-		}
-		v3d->xray = false;  /* restore */
-	}
-}
-
 /**
  * Optionally cache data for multiple calls to #view3d_opengl_select
  *
@@ -1200,6 +1128,7 @@ int view3d_opengl_select(
 	        (is_pick_select == false) &&
 	        (select_mode == VIEW3D_SELECT_PICK_NEAREST) &&
 	        GPU_select_query_check_active());
+	const bool use_nearest = (is_pick_select && select_mode == VIEW3D_SELECT_PICK_NEAREST);
 
 	char gpu_select_mode;
 
@@ -1256,7 +1185,7 @@ int view3d_opengl_select(
 	
 	GPU_select_begin(buffer, bufsize, &rect, gpu_select_mode, 0);
 
-	view3d_select_loop(vc, scene, v3d, ar, use_obedit_skip);
+	ED_view3d_draw_select_loop(vc, scene, v3d, ar, use_obedit_skip, use_nearest);
 
 	hits = GPU_select_end();
 	
@@ -1264,7 +1193,7 @@ int view3d_opengl_select(
 	if (do_passes) {
 		GPU_select_begin(buffer, bufsize, &rect, GPU_SELECT_NEAREST_SECOND_PASS, hits);
 
-		view3d_select_loop(vc, scene, v3d, ar, use_obedit_skip);
+		ED_view3d_draw_select_loop(vc, scene, v3d, ar, use_obedit_skip, use_nearest);
 
 		GPU_select_end();
 	}