Occlusion Query based selection.

This patch creates an interface for selection mechanisms in opengl. This
makes it possible to switch between occlusion query based or select
rendermode based selection transparently.

This is really useful on graphics drivers that do not accelerate the
select rendermode path (some ATI cards are notorious for this, and the
new path is used by default there), since occlusion queries are always
hardware accelerated due to their use in games.

The option can be found under system - selection. Auto just enables
occlusion queries for ATI users while the rest of the options enforce
one of the two methods always.

There is just one known change, previous code enforced nearest bone to
always get selected, even when mouse selecting near the same position, I
couldn't replicate the behaviour though.

patch by me with edits and review by Campbell.

Thanks!

1 files changed, 96 insertions, 76 deletions

diff --git a/source/blender/editors/space_view3d/view3d_view.c b/source/blender/editors/space_view3d/view3d_view.c
index 716f4b10fae..e51cf371a64 100644
--- a/source/blender/editors/space_view3d/view3d_view.c
+++ b/source/blender/editors/space_view3d/view3d_view.c
@@ -56,6 +56,7 @@
 #include "BIF_glutil.h"
 
 #include "GPU_draw.h"
+#include "GPU_select.h"
 
 #include "WM_api.h"
 #include "WM_types.h"
@@ -955,6 +956,78 @@ void view3d_viewmatrix_set(Scene *scene, 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 */
+	}
+}
+
 /**
  * \warning be sure to account for a negative return value
  * This is an error, "Too many objects in select buffer"
@@ -962,17 +1035,16 @@ void view3d_viewmatrix_set(Scene *scene, View3D *v3d, RegionView3D *rv3d)
  *
  * \note (vc->obedit == NULL) can be set to explicitly skip edit-object selection.
  */
-short view3d_opengl_select(ViewContext *vc, unsigned int *buffer, unsigned int bufsize, const rcti *input)
+short view3d_opengl_select(ViewContext *vc, unsigned int *buffer, unsigned int bufsize, const rcti *input, bool do_nearest)
 {
 	Scene *scene = vc->scene;
 	View3D *v3d = vc->v3d;
 	ARegion *ar = vc->ar;
-	rctf rect;
-	short code, hits;
-	char dt;
-	short dtx;
+	rctf rect, selrect;
+	short hits;
 	const bool use_obedit_skip = (scene->obedit != NULL) && (vc->obedit == NULL);
-	
+	const bool do_passes = do_nearest && GPU_select_query_check_active();
+
 	G.f |= G_PICKSEL;
 	
 	/* case not a border select */
@@ -985,6 +1057,8 @@ short view3d_opengl_select(ViewContext *vc, unsigned int *buffer, unsigned int b
 	else {
 		BLI_rctf_rcti_copy(&rect, input);
 	}
+
+	selrect = rect;
 	
 	view3d_winmatrix_set(ar, v3d, &rect);
 	mul_m4_m4m4(vc->rv3d->persmat, vc->rv3d->winmat, vc->rv3d->viewmat);
@@ -997,78 +1071,24 @@ short view3d_opengl_select(ViewContext *vc, unsigned int *buffer, unsigned int b
 	if (vc->rv3d->rflag & RV3D_CLIPPING)
 		ED_view3d_clipping_set(vc->rv3d);
 	
-	glSelectBuffer(bufsize, (GLuint *)buffer);
-	glRenderMode(GL_SELECT);
-	glInitNames();  /* these two calls whatfor? It doesnt work otherwise */
-	glPushName(-1);
-	code = 1;
+	if (do_passes)
+		GPU_select_begin(buffer, bufsize, &selrect, GPU_SELECT_NEAREST_FIRST_PASS, 0);
+	else
+		GPU_select_begin(buffer, bufsize, &selrect, GPU_SELECT_ALL, 0);
+
+	view3d_select_loop(vc, scene, v3d, ar, use_obedit_skip);
+
+	hits = GPU_select_end();
 	
-	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;
-					glLoadName(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 */
+	/* second pass, to get the closest object to camera */
+	if (do_passes) {
+		GPU_select_begin(buffer, bufsize, &selrect, GPU_SELECT_NEAREST_SECOND_PASS, hits);
+
+		view3d_select_loop(vc, scene, v3d, ar, use_obedit_skip);
+
+		GPU_select_end();
 	}
-	
-	glPopName();    /* see above (pushname) */
-	hits = glRenderMode(GL_RENDER);
-	
+
 	G.f &= ~G_PICKSEL;
 	view3d_winmatrix_set(ar, v3d, NULL);
 	mul_m4_m4m4(vc->rv3d->persmat, vc->rv3d->winmat, vc->rv3d->viewmat);