- grease pencil mode for drawing onto geometry (using the z-buffer), access in the 3D view panel.

- account for parts of the line going off into infinity by making the stroke stretch between the last valid depth values (like an elastic band), if the endpoints are not over any geometry then use the closest valid depth.

2 files changed, 99 insertions, 19 deletions

diff --git a/source/blender/editors/gpencil/gpencil_buttons.c b/source/blender/editors/gpencil/gpencil_buttons.c
index 5deffbabb77..54dd43160a6 100644
--- a/source/blender/editors/gpencil/gpencil_buttons.c
+++ b/source/blender/editors/gpencil/gpencil_buttons.c
@@ -229,7 +229,7 @@ static void draw_gpencil_panel (bContext *C, uiLayout *layout, bGPdata *gpd, Poi
 {
 	PointerRNA gpd_ptr;
 	bGPDlayer *gpl;
-	uiLayout *col;
+	uiLayout *col, *row;
 	
 	/* make new PointerRNA for Grease Pencil block */
 	RNA_id_pointer_create((ID *)gpd, &gpd_ptr);
@@ -259,7 +259,11 @@ static void draw_gpencil_panel (bContext *C, uiLayout *layout, bGPdata *gpd, Poi
 		uiItemL(col, "Drawing Settings:", 0);
 		
 		/* 'stick to view' option */
-		uiItemR(col, NULL, 0, &gpd_ptr, "view_space_draw", 0);
+		//uiItemR(col, NULL, 0, &gpd_ptr, "draw_mode", 0);
+		row= uiLayoutRow(layout, 1);
+		uiItemEnumR_string(row, NULL, 0, &gpd_ptr, "draw_mode", "VIEW");
+		uiItemEnumR_string(row, NULL, 0, &gpd_ptr, "draw_mode", "CURSOR");
+		uiItemEnumR_string(row, NULL, 0, &gpd_ptr, "draw_mode", "DEPTH");
 }	
 
 
diff --git a/source/blender/editors/gpencil/gpencil_paint.c b/source/blender/editors/gpencil/gpencil_paint.c
index 3f9e3e04411..86ca69f6cf6 100644
--- a/source/blender/editors/gpencil/gpencil_paint.c
+++ b/source/blender/editors/gpencil/gpencil_paint.c
@@ -155,15 +155,7 @@ static int gpencil_draw_poll (bContext *C)
 static int gpencil_project_check (tGPsdata *p)
 {
 	bGPdata *gpd= p->gpd;
-	
-	if(	(gpd->sbuffer_sflag & GP_STROKE_3DSPACE) &&
-		(p->scene->toolsettings->snap_mode==SCE_SNAP_MODE_FACE) &&
-		(p->scene->toolsettings->snap_flag & SCE_SNAP_PROJECT) )
-	{
-		return 1;
-	}
-
-	return 0;
+	return ((gpd->sbuffer_sflag & GP_STROKE_3DSPACE) && (p->gpd->flag & GP_DATA_VIEWDEPTH)) ? 1:0;
 }
 
 /* ******************************************* */
@@ -220,13 +212,13 @@ static short gp_stroke_filtermval (tGPsdata *p, int mval[2], int pmval[2])
 
 /* convert screen-coordinates to buffer-coordinates */
 // XXX this method needs a total overhaul!
-static void gp_stroke_convertcoords (tGPsdata *p, short mval[], float out[])
+static void gp_stroke_convertcoords (tGPsdata *p, short mval[], float out[], float *depth)
 {
 	bGPdata *gpd= p->gpd;
 	
 	/* in 3d-space - pt->x/y/z are 3 side-by-side floats */
 	if (gpd->sbuffer_sflag & GP_STROKE_3DSPACE) {
-		if(gpencil_project_check(p) && (view_autodist_simple(p->ar, mval, out))) {
+		if(gpencil_project_check(p) && (view_autodist_simple(p->ar, mval, out, depth))) {
 			/* projecting onto 3D-Geometry
 			 *	- nothing more needs to be done here, since view_autodist_simple() has already done it
 			 */
@@ -501,7 +493,7 @@ static void gp_stroke_newfrombuffer (tGPsdata *p)
 			ptc= gpd->sbuffer;
 			
 			/* convert screen-coordinates to appropriate coordinates (and store them) */
-			gp_stroke_convertcoords(p, &ptc->x, &pt->x);
+			gp_stroke_convertcoords(p, &ptc->x, &pt->x, NULL);
 			
 			/* copy pressure */
 			pt->pressure= ptc->pressure;
@@ -514,23 +506,107 @@ static void gp_stroke_newfrombuffer (tGPsdata *p)
 			ptc= ((tGPspoint *)gpd->sbuffer) + (gpd->sbuffer_size - 1);
 			
 			/* convert screen-coordinates to appropriate coordinates (and store them) */
-			gp_stroke_convertcoords(p, &ptc->x, &pt->x);
+			gp_stroke_convertcoords(p, &ptc->x, &pt->x, NULL);
 			
 			/* copy pressure */
 			pt->pressure= ptc->pressure;
 		}
 	}
 	else {
+		float *depth_arr= NULL;
+
+		/* get an array of depths, far depths are blended */
+		if(gpencil_project_check(p)) {
+			short mval[2];
+			int interp_depth = 0;
+			int found_depth = 0;
+
+			depth_arr= MEM_mallocN(sizeof(float) * gpd->sbuffer_size, "depth_points");
+
+			for (i=0, ptc=gpd->sbuffer; i < gpd->sbuffer_size; i++, ptc++, pt++) {
+				mval[0]= ptc->x; mval[1]= ptc->y;
+				if(view_autodist_depth(p->ar, mval, depth_arr+i) == 0)
+					interp_depth= TRUE;
+				else
+					found_depth= TRUE;
+			}
+
+			if(found_depth==FALSE) {
+				/* eeh... not much we can do.. :/, ignore depth in this case, use the 3D cursor */
+				for (i=gpd->sbuffer_size-1; i >= 0; i--)
+					depth_arr[i] = 0.9999f;
+			}
+			else if(interp_depth) {
+				/* found invalid depths, interpolate */
+				float valid_last= FLT_MAX;
+				int valid_ofs= 0;
+
+				float *depth_arr_up= MEM_callocN(sizeof(float) * gpd->sbuffer_size, "depth_points_up");
+				float *depth_arr_down= MEM_callocN(sizeof(float) * gpd->sbuffer_size, "depth_points_down");
+
+				int *depth_tot_up= MEM_callocN(sizeof(int) * gpd->sbuffer_size, "depth_tot_up");
+				int *depth_tot_down= MEM_callocN(sizeof(int) * gpd->sbuffer_size, "depth_tot_down");
+
+				for (i=0; i < gpd->sbuffer_size; i++) {
+					if(depth_arr[i] == FLT_MAX) {
+						depth_arr_up[i]= valid_last;
+						depth_tot_up[i]= ++valid_ofs;
+					}
+					else {
+						valid_last= depth_arr[i];
+						valid_ofs= 0;
+					}
+				}
+
+				valid_last= FLT_MAX;
+				valid_ofs= 0;
+
+				for (i=gpd->sbuffer_size-1; i >= 0; i--) {
+					if(depth_arr[i] == FLT_MAX) {
+						depth_arr_down[i]= valid_last;
+						depth_tot_down[i]= ++valid_ofs;
+					}
+					else {
+						valid_last= depth_arr[i];
+						valid_ofs= 0;
+					}
+				}
+
+				/* now blend */
+				for (i=0; i < gpd->sbuffer_size; i++) {
+					if(depth_arr[i] == FLT_MAX) {
+						if(depth_arr_up[i] != FLT_MAX && depth_arr_down[i] != FLT_MAX) {
+							depth_arr[i]= ((depth_arr_up[i] * depth_tot_down[i]) +  (depth_arr_down[i] * depth_tot_up[i])) / (float)(depth_tot_down[i] + depth_tot_up[i]);
+						} else if (depth_arr_up[i] != FLT_MAX) {
+							depth_arr[i]= depth_arr_up[i];
+						} else if (depth_arr_down[i] != FLT_MAX) {
+							depth_arr[i]= depth_arr_down[i];
+						}
+					}
+				}
+
+				MEM_freeN(depth_arr_up);
+				MEM_freeN(depth_arr_down);
+
+				MEM_freeN(depth_tot_up);
+				MEM_freeN(depth_tot_down);
+			}
+		}
+
+
+		pt= gps->points;
+
 		/* convert all points (normal behaviour) */
-		for (i=0, ptc=gpd->sbuffer; i < gpd->sbuffer_size && ptc; i++, ptc++) {
+		for (i=0, ptc=gpd->sbuffer; i < gpd->sbuffer_size && ptc; i++, ptc++, pt++) {
 			/* convert screen-coordinates to appropriate coordinates (and store them) */
-			gp_stroke_convertcoords(p, &ptc->x, &pt->x);
+			gp_stroke_convertcoords(p, &ptc->x, &pt->x, depth_arr ? depth_arr+i:NULL);
 			
 			/* copy pressure */
 			pt->pressure= ptc->pressure;
-			
-			pt++;
 		}
+
+		if(depth_arr)
+			MEM_freeN(depth_arr);
 	}
 	
 	/* add stroke to frame */