Merged changes in the trunk up to revision 55357.

Resolved conflicts:
release/datafiles/startup.blend
source/blender/editors/space_nla/nla_buttons.c

Also updated source/blender/blenkernel/intern/linestyle.c as a follow-up of
recent changes for the use of bool.

15 files changed, 1264 insertions, 229 deletions

diff --git a/source/blender/editors/space_view3d/CMakeLists.txt b/source/blender/editors/space_view3d/CMakeLists.txt
index 462619a7e8b..a04371a5ed9 100644
--- a/source/blender/editors/space_view3d/CMakeLists.txt
+++ b/source/blender/editors/space_view3d/CMakeLists.txt
@@ -54,6 +54,7 @@ set(SRC
 	view3d_iterators.c
 	view3d_ops.c
 	view3d_project.c
+	view3d_ruler.c
 	view3d_select.c
 	view3d_snap.c
 	view3d_toolbar.c
diff --git a/source/blender/editors/space_view3d/drawmesh.c b/source/blender/editors/space_view3d/drawmesh.c
index 2cef10e1981..9000ccbf324 100644
--- a/source/blender/editors/space_view3d/drawmesh.c
+++ b/source/blender/editors/space_view3d/drawmesh.c
@@ -428,7 +428,9 @@ static DMDrawOption draw_tface__set_draw_legacy(MTFace *tface, int has_mcol, int
 		return DM_DRAW_OPTION_NO_MCOL; /* Don't set color */
 	}
 	else if (!has_mcol) {
-		if (tface) glColor3f(1.0, 1.0, 1.0);
+		if (tface) {
+			glColor3f(1.0, 1.0, 1.0);
+		}
 		else {
 			if (ma) {
 				float col[3];
@@ -437,7 +439,9 @@ static DMDrawOption draw_tface__set_draw_legacy(MTFace *tface, int has_mcol, int
 				
 				glColor3fv(col);
 			}
-			else glColor3f(1.0, 1.0, 1.0);
+			else {
+				glColor3f(1.0, 1.0, 1.0);
+			}
 		}
 		return DM_DRAW_OPTION_NO_MCOL; /* Don't set color */
 	}
diff --git a/source/blender/editors/space_view3d/drawobject.c b/source/blender/editors/space_view3d/drawobject.c
index 158b75c494a..743b53ce16c 100644
--- a/source/blender/editors/space_view3d/drawobject.c
+++ b/source/blender/editors/space_view3d/drawobject.c
@@ -615,7 +615,7 @@ static void draw_empty_image(Object *ob, const short dflag, const unsigned char
 		glColor4fv(ob->col);
 
 		/* Draw the Image on the screen */
-		glaDrawPixelsTex(ofs_x, ofs_y, ima_x, ima_y, GL_UNSIGNED_BYTE, ibuf->rect);
+		glaDrawPixelsTex(ofs_x, ofs_y, ima_x, ima_y, GL_UNSIGNED_BYTE, GL_LINEAR, ibuf->rect);
 		glPixelTransferf(GL_ALPHA_SCALE, 1.0f);
 
 		glDisable(GL_BLEND);
@@ -812,17 +812,6 @@ void view3d_cached_text_draw_end(View3D *v3d, ARegion *ar, int depth_write, floa
 		}
 		
 		for (vos = strings->first; vos; vos = vos->next) {
-			/* too slow, reading opengl info while drawing is very bad,
-			 * better to see if we can use the zbuffer while in pixel space - campbell */
-#if 0
-			if (v3d->zbuf && (vos->flag & V3D_CACHE_TEXT_ZBUF)) {
-				gluProject(vos->vec[0], vos->vec[1], vos->vec[2], mats.modelview, mats.projection, (GLint *)mats.viewport, &ux, &uy, &uz);
-				glReadPixels(ar->winrct.xmin + vos->mval[0] + vos->xoffs, ar->winrct.ymin + vos->mval[1], 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &depth);
-
-				if (uz > depth)
-					continue;
-			}
-#endif
 			if (vos->sco[0] != IS_CLIPPED) {
 				const char *str = (char *)(vos + 1);
 
@@ -3862,7 +3851,7 @@ static int drawDispList(Scene *scene, View3D *v3d, RegionView3D *rv3d, Base *bas
 	if (v3d->flag2 & V3D_BACKFACE_CULLING) {
 		/* not all displists use same in/out normal direction convention */
 		glEnable(GL_CULL_FACE);
-		glCullFace((base->object->type == OB_MBALL) ? GL_BACK : GL_FRONT);
+		glCullFace((base->object->type == OB_MBALL || base->object->derivedFinal) ? GL_BACK : GL_FRONT);
 	}
 
 	retval = drawDispList_nobackface(scene, v3d, rv3d, base, dt, dflag, ob_wire_col);
@@ -3968,7 +3957,9 @@ static void draw_particle(ParticleKey *state, int draw_as, short draw, float pix
 			if (draw_as == PART_DRAW_AXIS) {
 				copy_v3_v3(vec2, state->co);
 			}
-			else sub_v3_v3v3(vec2, state->co, vec);
+			else {
+				sub_v3_v3v3(vec2, state->co, vec);
+			}
 
 			add_v3_v3(vec, state->co);
 			copy_v3_v3(pdd->vd, vec); pdd->vd += 3;
@@ -3980,7 +3971,9 @@ static void draw_particle(ParticleKey *state, int draw_as, short draw, float pix
 			if (draw_as == PART_DRAW_AXIS) {
 				copy_v3_v3(vec2, state->co);
 			}
-			else sub_v3_v3v3(vec2, state->co, vec);
+			else {
+				sub_v3_v3v3(vec2, state->co, vec);
+			}
 
 			add_v3_v3(vec, state->co);
 
@@ -6055,8 +6048,10 @@ static void drawtexspace(Object *ob)
 		copy_v3_v3(size, mb->size);
 		copy_v3_v3(loc, mb->loc);
 	}
-	else return;
-	
+	else {
+		return;
+	}
+
 	vec[0][0] = vec[1][0] = vec[2][0] = vec[3][0] = loc[0] - size[0];
 	vec[4][0] = vec[5][0] = vec[6][0] = vec[7][0] = loc[0] + size[0];
 	
diff --git a/source/blender/editors/space_view3d/space_view3d.c b/source/blender/editors/space_view3d/space_view3d.c
index 57755231240..d332fb9f8b3 100644
--- a/source/blender/editors/space_view3d/space_view3d.c
+++ b/source/blender/editors/space_view3d/space_view3d.c
@@ -48,10 +48,12 @@
 #include "BKE_object.h"
 #include "BKE_screen.h"
 
+#include "ED_render.h"
 #include "ED_space_api.h"
 #include "ED_screen.h"
 #include "ED_object.h"
 
+#include "GPU_extensions.h"
 #include "GPU_material.h"
 
 #include "BIF_gl.h"
@@ -350,7 +352,7 @@ static void view3d_free(SpaceLink *sl)
 
 
 /* spacetype; init callback */
-static void view3d_init(struct wmWindowManager *UNUSED(wm), ScrArea *UNUSED(sa))
+static void view3d_init(wmWindowManager *UNUSED(wm), ScrArea *UNUSED(sa))
 {
 
 }
@@ -469,7 +471,22 @@ static void view3d_main_area_init(wmWindowManager *wm, ARegion *ar)
 	
 }
 
-static int view3d_ob_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UNUSED(event))
+static void view3d_main_area_exit(wmWindowManager *UNUSED(wm), ARegion *ar)
+{
+	RegionView3D *rv3d = ar->regiondata;
+
+	if (rv3d->render_engine) {
+		RE_engine_free(rv3d->render_engine);
+		rv3d->render_engine = NULL;
+	}
+
+	if (rv3d->gpuoffscreen) {
+		GPU_offscreen_free(rv3d->gpuoffscreen);
+		rv3d->gpuoffscreen = NULL;
+	}
+}
+
+static int view3d_ob_drop_poll(bContext *UNUSED(C), wmDrag *drag, const wmEvent *UNUSED(event))
 {
 	if (drag->type == WM_DRAG_ID) {
 		ID *id = (ID *)drag->poin;
@@ -479,7 +496,7 @@ static int view3d_ob_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UNUSE
 	return 0;
 }
 
-static int view3d_group_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UNUSED(event))
+static int view3d_group_drop_poll(bContext *UNUSED(C), wmDrag *drag, const wmEvent *UNUSED(event))
 {
 	if (drag->type == WM_DRAG_ID) {
 		ID *id = (ID *)drag->poin;
@@ -489,7 +506,7 @@ static int view3d_group_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UN
 	return 0;
 }
 
-static int view3d_mat_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UNUSED(event))
+static int view3d_mat_drop_poll(bContext *UNUSED(C), wmDrag *drag, const wmEvent *UNUSED(event))
 {
 	if (drag->type == WM_DRAG_ID) {
 		ID *id = (ID *)drag->poin;
@@ -499,7 +516,7 @@ static int view3d_mat_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UNUS
 	return 0;
 }
 
-static int view3d_ima_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UNUSED(event))
+static int view3d_ima_drop_poll(bContext *UNUSED(C), wmDrag *drag, const wmEvent *UNUSED(event))
 {
 	if (drag->type == WM_DRAG_ID) {
 		ID *id = (ID *)drag->poin;
@@ -513,7 +530,7 @@ static int view3d_ima_drop_poll(bContext *UNUSED(C), wmDrag *drag, wmEvent *UNUS
 	return 0;
 }
 
-static int view3d_ima_bg_drop_poll(bContext *C, wmDrag *drag, wmEvent *event)
+static int view3d_ima_bg_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 {
 	if (event->ctrl)
 		return false;
@@ -524,7 +541,7 @@ static int view3d_ima_bg_drop_poll(bContext *C, wmDrag *drag, wmEvent *event)
 	return 0;
 }
 
-static int view3d_ima_empty_drop_poll(bContext *C, wmDrag *drag, wmEvent *event)
+static int view3d_ima_empty_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 {
 	Base *base = ED_view3d_give_base_under_cursor(C, event->mval);
 
@@ -535,7 +552,7 @@ static int view3d_ima_empty_drop_poll(bContext *C, wmDrag *drag, wmEvent *event)
 	return 0;
 }
 
-static int view3d_ima_mesh_drop_poll(bContext *C, wmDrag *drag, wmEvent *event)
+static int view3d_ima_mesh_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
 {
 	Base *base = ED_view3d_give_base_under_cursor(C, event->mval);
 
@@ -615,6 +632,10 @@ static void view3d_main_area_free(ARegion *ar)
 		if (rv3d->sms) {
 			MEM_freeN(rv3d->sms);
 		}
+		if (rv3d->gpuoffscreen) {
+			GPU_offscreen_free(rv3d->gpuoffscreen);
+		}
+
 		MEM_freeN(rv3d);
 		ar->regiondata = NULL;
 	}
@@ -633,6 +654,7 @@ static void *view3d_main_area_duplicate(void *poin)
 			new->clipbb = MEM_dupallocN(rv3d->clipbb);
 		
 		new->depths = NULL;
+		new->gpuoffscreen = NULL;
 		new->ri = NULL;
 		new->render_engine = NULL;
 		new->gpd = NULL;
@@ -1216,6 +1238,7 @@ void ED_spacetype_view3d(void)
 	art->keymapflag = ED_KEYMAP_GPENCIL;
 	art->draw = view3d_main_area_draw;
 	art->init = view3d_main_area_init;
+	art->exit = view3d_main_area_exit;
 	art->free = view3d_main_area_free;
 	art->duplicate = view3d_main_area_duplicate;
 	art->listener = view3d_main_area_listener;
diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index 4aaa3332252..8fdc9416513 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -219,15 +219,12 @@ void ED_view3d_clipping_enable(void)
 	}
 }
 
-static int view3d_clipping_test(const float vec[3], float clip[6][4])
+static int view3d_clipping_test(const float co[3], float clip[6][4])
 {
-	float view[3];
-	copy_v3_v3(view, vec);
-
-	if (0.0f < clip[0][3] + dot_v3v3(view, clip[0]))
-		if (0.0f < clip[1][3] + dot_v3v3(view, clip[1]))
-			if (0.0f < clip[2][3] + dot_v3v3(view, clip[2]))
-				if (0.0f < clip[3][3] + dot_v3v3(view, clip[3]))
+	if (0.0f < clip[0][3] + dot_v3v3(co, clip[0]))
+		if (0.0f < clip[1][3] + dot_v3v3(co, clip[1]))
+			if (0.0f < clip[2][3] + dot_v3v3(co, clip[2]))
+				if (0.0f < clip[3][3] + dot_v3v3(co, clip[3]))
 					return 0;
 
 	return 1;
@@ -235,9 +232,9 @@ static int view3d_clipping_test(const float vec[3], float clip[6][4])
 
 /* for 'local' ED_view3d_clipping_local must run first
  * then all comparisons can be done in localspace */
-int ED_view3d_clipping_test(RegionView3D *rv3d, const float vec[3], const int is_local)
+int ED_view3d_clipping_test(RegionView3D *rv3d, const float co[3], const bool is_local)
 {
-	return view3d_clipping_test(vec, is_local ? rv3d->clip_local : rv3d->clip);
+	return view3d_clipping_test(co, is_local ? rv3d->clip_local : rv3d->clip);
 }
 
 /* ********* end custom clipping *********** */
@@ -971,7 +968,7 @@ static void draw_selected_name(Scene *scene, Object *ob, rcti *rect)
 }
 
 static void view3d_camera_border(Scene *scene, ARegion *ar, View3D *v3d, RegionView3D *rv3d,
-                                 rctf *viewborder_r, short no_shift, short no_zoom)
+                                 rctf *r_viewborder, const bool no_shift, const bool no_zoom)
 {
 	CameraParams params;
 	rctf rect_view, rect_camera;
@@ -995,25 +992,25 @@ static void view3d_camera_border(Scene *scene, ARegion *ar, View3D *v3d, RegionV
 	rect_camera = params.viewplane;
 
 	/* get camera border within viewport */
-	viewborder_r->xmin = ((rect_camera.xmin - rect_view.xmin) / BLI_rctf_size_x(&rect_view)) * ar->winx;
-	viewborder_r->xmax = ((rect_camera.xmax - rect_view.xmin) / BLI_rctf_size_x(&rect_view)) * ar->winx;
-	viewborder_r->ymin = ((rect_camera.ymin - rect_view.ymin) / BLI_rctf_size_y(&rect_view)) * ar->winy;
-	viewborder_r->ymax = ((rect_camera.ymax - rect_view.ymin) / BLI_rctf_size_y(&rect_view)) * ar->winy;
+	r_viewborder->xmin = ((rect_camera.xmin - rect_view.xmin) / BLI_rctf_size_x(&rect_view)) * ar->winx;
+	r_viewborder->xmax = ((rect_camera.xmax - rect_view.xmin) / BLI_rctf_size_x(&rect_view)) * ar->winx;
+	r_viewborder->ymin = ((rect_camera.ymin - rect_view.ymin) / BLI_rctf_size_y(&rect_view)) * ar->winy;
+	r_viewborder->ymax = ((rect_camera.ymax - rect_view.ymin) / BLI_rctf_size_y(&rect_view)) * ar->winy;
 }
 
-void ED_view3d_calc_camera_border_size(Scene *scene, ARegion *ar, View3D *v3d, RegionView3D *rv3d, float size_r[2])
+void ED_view3d_calc_camera_border_size(Scene *scene, ARegion *ar, View3D *v3d, RegionView3D *rv3d, float r_size[2])
 {
 	rctf viewborder;
 
 	view3d_camera_border(scene, ar, v3d, rv3d, &viewborder, TRUE, TRUE);
-	size_r[0] = BLI_rctf_size_x(&viewborder);
-	size_r[1] = BLI_rctf_size_y(&viewborder);
+	r_size[0] = BLI_rctf_size_x(&viewborder);
+	r_size[1] = BLI_rctf_size_y(&viewborder);
 }
 
 void ED_view3d_calc_camera_border(Scene *scene, ARegion *ar, View3D *v3d, RegionView3D *rv3d,
-                                  rctf *viewborder_r, short no_shift)
+                                  rctf *viewborder_r, const bool no_shift)
 {
-	view3d_camera_border(scene, ar, v3d, rv3d, viewborder_r, no_shift, FALSE);
+	view3d_camera_border(scene, ar, v3d, rv3d, viewborder_r, no_shift, false);
 }
 
 static void drawviewborder_grid3(float x1, float x2, float y1, float y2, float fac)
@@ -1316,11 +1313,6 @@ static void backdrawview3d(Scene *scene, ARegion *ar, View3D *v3d)
 	{
 		/* do nothing */
 	}
-	else if ((base && (base->object->mode & OB_MODE_TEXTURE_PAINT)) &&
-	         scene->toolsettings && (scene->toolsettings->imapaint.flag & IMAGEPAINT_PROJECT_DISABLE))
-	{
-		/* do nothing */
-	}
 	else if ((base && (base->object->mode & OB_MODE_PARTICLE_EDIT)) &&
 	         v3d->drawtype > OB_WIRE && (v3d->flag & V3D_ZBUF_SELECT))
 	{
@@ -1356,7 +1348,35 @@ static void backdrawview3d(Scene *scene, ARegion *ar, View3D *v3d)
 	if (multisample_enabled)
 		glDisable(GL_MULTISAMPLE_ARB);
 
-	glScissor(ar->winrct.xmin, ar->winrct.ymin, BLI_rcti_size_x(&ar->winrct), BLI_rcti_size_y(&ar->winrct));
+	if (U.ogl_multisamples != USER_MULTISAMPLE_NONE) {
+		/* for multisample we use an offscreen FBO. multisample drawing can fail
+		 * with color coded selection drawing, and reading back depths from such
+		 * a buffer can also cause a few seconds freeze on OS X / NVidia. */
+		int w = BLI_rcti_size_x(&ar->winrct);
+		int h = BLI_rcti_size_y(&ar->winrct);
+		char error[256];
+
+		if (rv3d->gpuoffscreen) {
+			if (GPU_offscreen_width(rv3d->gpuoffscreen)  != w ||
+			    GPU_offscreen_height(rv3d->gpuoffscreen) != h)
+			{
+				GPU_offscreen_free(rv3d->gpuoffscreen);
+				rv3d->gpuoffscreen = NULL;
+			}
+		}
+
+		if (!rv3d->gpuoffscreen) {
+			rv3d->gpuoffscreen = GPU_offscreen_create(w, h, error);
+
+			if (!rv3d->gpuoffscreen)
+				fprintf(stderr, "Failed to create offscreen selection buffer for multisample: %s\n", error);
+		}
+	}
+
+	if (rv3d->gpuoffscreen)
+		GPU_offscreen_bind(rv3d->gpuoffscreen);
+	else
+		glScissor(ar->winrct.xmin, ar->winrct.ymin, BLI_rcti_size_x(&ar->winrct), BLI_rcti_size_y(&ar->winrct));
 
 	glClearColor(0.0, 0.0, 0.0, 0.0); 
 	if (v3d->zbuf) {
@@ -1375,9 +1395,13 @@ static void backdrawview3d(Scene *scene, ARegion *ar, View3D *v3d)
 	
 	if (base && (base->lay & v3d->lay))
 		draw_object_backbufsel(scene, v3d, rv3d, base->object);
+	
+	if (rv3d->gpuoffscreen)
+		GPU_offscreen_unbind(rv3d->gpuoffscreen);
+	else
+		ar->swap = 0; /* mark invalid backbuf for wm draw */
 
 	v3d->flag &= ~V3D_INVALID_BACKBUF;
-	ar->swap = 0; /* mark invalid backbuf for wm draw */
 
 	G.f &= ~G_BACKBUFSEL;
 	v3d->zbuf = FALSE;
@@ -1394,6 +1418,21 @@ static void backdrawview3d(Scene *scene, ARegion *ar, View3D *v3d)
 
 }
 
+void view3d_opengl_read_pixels(ARegion *ar, int x, int y, int w, int h, int format, int type, void *data)
+{
+	RegionView3D *rv3d = ar->regiondata;
+
+	if (rv3d->gpuoffscreen) {
+		GPU_offscreen_bind(rv3d->gpuoffscreen);
+		glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
+		glReadPixels(x, y, w, h, format, type, data);
+		GPU_offscreen_unbind(rv3d->gpuoffscreen);
+	}
+	else {
+		glReadPixels(ar->winrct.xmin + x, ar->winrct.ymin + y, w, h, format, type, data);
+	}
+}
+
 void view3d_validate_backbuf(ViewContext *vc)
 {
 	if (vc->v3d->flag & V3D_INVALID_BACKBUF)
@@ -1409,12 +1448,9 @@ unsigned int view3d_sample_backbuf(ViewContext *vc, int x, int y)
 		return 0;
 	}
 
-	x += vc->ar->winrct.xmin;
-	y += vc->ar->winrct.ymin;
-	
 	view3d_validate_backbuf(vc);
 
-	glReadPixels(x, y, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &col);
+	view3d_opengl_read_pixels(vc->ar, x, y, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &col);
 	glReadBuffer(GL_BACK);
 	
 	if (ENDIAN_ORDER == B_ENDIAN) {
@@ -1445,8 +1481,8 @@ ImBuf *view3d_read_backbuf(ViewContext *vc, short xmin, short ymin, short xmax,
 
 	view3d_validate_backbuf(vc);
 
-	glReadPixels(vc->ar->winrct.xmin + xminc,
-	             vc->ar->winrct.ymin + yminc,
+	view3d_opengl_read_pixels(vc->ar,
+	             xminc, yminc,
 	             (xmaxc - xminc + 1),
 	             (ymaxc - yminc + 1),
 	             GL_RGBA, GL_UNSIGNED_BYTE, ibuf->rect);
@@ -1573,7 +1609,7 @@ static void view3d_draw_bgpic(Scene *scene, ARegion *ar, View3D *v3d,
 			float fac, asp, zoomx, zoomy;
 			float x1, y1, x2, y2;
 
-			ImBuf *ibuf = NULL, *freeibuf;
+			ImBuf *ibuf = NULL, *freeibuf, *releaseibuf;
 
 			Image *ima;
 			MovieClip *clip;
@@ -1583,6 +1619,7 @@ static void view3d_draw_bgpic(Scene *scene, ARegion *ar, View3D *v3d,
 				continue;
 
 			freeibuf = NULL;
+			releaseibuf = NULL;
 			if (bgpic->source == V3D_BGPIC_IMAGE) {
 				ima = bgpic->ima;
 				if (ima == NULL)
@@ -1593,7 +1630,7 @@ static void view3d_draw_bgpic(Scene *scene, ARegion *ar, View3D *v3d,
 				}
 				else {
 					ibuf = BKE_image_acquire_ibuf(ima, &bgpic->iuser, NULL);
-					freeibuf = ibuf;
+					releaseibuf = ibuf;
 				}
 
 				image_aspect[0] = ima->aspx;
@@ -1608,7 +1645,9 @@ static void view3d_draw_bgpic(Scene *scene, ARegion *ar, View3D *v3d,
 					if (scene->camera)
 						clip = BKE_object_movieclip_get(scene, scene->camera, 1);
 				}
-				else clip = bgpic->clip;
+				else {
+					clip = bgpic->clip;
+				}
 
 				if (clip == NULL)
 					continue;
@@ -1636,6 +1675,8 @@ static void view3d_draw_bgpic(Scene *scene, ARegion *ar, View3D *v3d,
 			if ((ibuf->rect == NULL && ibuf->rect_float == NULL) || ibuf->channels != 4) { /* invalid image format */
 				if (freeibuf)
 					IMB_freeImBuf(freeibuf);
+				if (releaseibuf)
+					BKE_image_release_ibuf(ima, releaseibuf, NULL);
 
 				continue;
 			}
@@ -1708,10 +1749,12 @@ static void view3d_draw_bgpic(Scene *scene, ARegion *ar, View3D *v3d,
 				float tvec[3];
 				float sco[2];
 				const float mval_f[2] = {1.0f, 0.0f};
+				const float co_zero[3] = {0};
+				float zfac;
 
 				/* calc window coord */
-				initgrabz(rv3d, 0.0, 0.0, 0.0);
-				ED_view3d_win_to_delta(ar, mval_f, tvec);
+				zfac = ED_view3d_calc_zfac(rv3d, co_zero, NULL);
+				ED_view3d_win_to_delta(ar, mval_f, tvec, zfac);
 				fac = max_ff(fabsf(tvec[0]), max_ff(fabsf(tvec[1]), fabsf(tvec[2]))); /* largest abs axis */
 				fac = 1.0f / fac;
 
@@ -1731,6 +1774,8 @@ static void view3d_draw_bgpic(Scene *scene, ARegion *ar, View3D *v3d,
 			if (x2 < 0 || y2 < 0 || x1 > ar->winx || y1 > ar->winy) {
 				if (freeibuf)
 					IMB_freeImBuf(freeibuf);
+				if (releaseibuf)
+					BKE_image_release_ibuf(ima, releaseibuf, NULL);
 
 				continue;
 			}
@@ -1774,7 +1819,7 @@ static void view3d_draw_bgpic(Scene *scene, ARegion *ar, View3D *v3d,
 
 			glPixelZoom(zoomx, zoomy);
 			glColor4f(1.0f, 1.0f, 1.0f, 1.0f - bgpic->blend);
-			glaDrawPixelsTex(x1, y1, ibuf->x, ibuf->y, GL_UNSIGNED_BYTE, ibuf->rect);
+			glaDrawPixelsAuto(x1, y1, ibuf->x, ibuf->y, GL_UNSIGNED_BYTE, GL_LINEAR, ibuf->rect);
 
 			glPixelZoom(1.0, 1.0);
 			glPixelTransferf(GL_ALPHA_SCALE, 1.0f);
@@ -1789,9 +1834,10 @@ static void view3d_draw_bgpic(Scene *scene, ARegion *ar, View3D *v3d,
 			glDepthMask(1);
 			if (v3d->zbuf) glEnable(GL_DEPTH_TEST);
 
-			if (freeibuf) {
+			if (freeibuf)
 				IMB_freeImBuf(freeibuf);
-			}
+			if (releaseibuf)
+				BKE_image_release_ibuf(ima, releaseibuf, NULL);
 		}
 	}
 }
@@ -2102,7 +2148,7 @@ void view3d_update_depths_rect(ARegion *ar, ViewDepths *d, rcti *rect)
 	}
 
 	if (d->damaged) {
-		glReadPixels(ar->winrct.xmin + d->x, ar->winrct.ymin + d->y, d->w, d->h, GL_DEPTH_COMPONENT, GL_FLOAT, d->depths);
+		view3d_opengl_read_pixels(ar, d->x, d->y, d->w, d->h, GL_DEPTH_COMPONENT, GL_FLOAT, d->depths);
 		glGetDoublev(GL_DEPTH_RANGE, d->depth_range);
 		d->damaged = FALSE;
 	}
@@ -2130,9 +2176,7 @@ void ED_view3d_depth_update(ARegion *ar)
 		}
 		
 		if (d->damaged) {
-			glReadPixels(ar->winrct.xmin, ar->winrct.ymin, d->w, d->h,
-			             GL_DEPTH_COMPONENT, GL_FLOAT, d->depths);
-			
+			view3d_opengl_read_pixels(ar, 0, 0, d->w, d->h, GL_DEPTH_COMPONENT, GL_FLOAT, d->depths);
 			glGetDoublev(GL_DEPTH_RANGE, d->depth_range);
 			
 			d->damaged = 0;
@@ -2999,7 +3043,7 @@ static void view3d_main_area_clear(Scene *scene, View3D *v3d, ARegion *ar)
 #define VIEWGRAD_RES_Y 16
 
 			GLubyte grid_col[VIEWGRAD_RES_X][VIEWGRAD_RES_Y][4];
-			static float   grid_pos[VIEWGRAD_RES_X][VIEWGRAD_RES_Y][2];
+			static float   grid_pos[VIEWGRAD_RES_X][VIEWGRAD_RES_Y][3];
 			static GLushort indices[VIEWGRAD_RES_X - 1][VIEWGRAD_RES_X - 1][4];
 			static char buf_calculated = FALSE;
 
@@ -3008,8 +3052,6 @@ static void view3d_main_area_clear(Scene *scene, View3D *v3d, ARegion *ar)
 			IMB_colormanagement_pixel_to_display_space_v3(col_zen, &scene->world->zenr, &scene->view_settings,
 			                                              &scene->display_settings);
 
-			glClear(GL_DEPTH_BUFFER_BIT);
-
 			glMatrixMode(GL_PROJECTION);
 			glPushMatrix();
 			glLoadIdentity();
@@ -3029,6 +3071,7 @@ static void view3d_main_area_clear(Scene *scene, View3D *v3d, ARegion *ar)
 						/* -1..1 range */
 						grid_pos[x][y][0] = (xf - 0.5f) * 2.0f;
 						grid_pos[x][y][1] = (yf - 0.5f) * 2.0f;
+						grid_pos[x][y][2] = 1.0;
 					}
 				}
 
@@ -3082,15 +3125,22 @@ static void view3d_main_area_clear(Scene *scene, View3D *v3d, ARegion *ar)
 				}
 			}
 
+			glEnable(GL_DEPTH_TEST);
+			glDepthFunc(GL_ALWAYS);
+
 			glEnableClientState(GL_VERTEX_ARRAY);
 			glEnableClientState(GL_COLOR_ARRAY);
-			glVertexPointer(2, GL_FLOAT, 0, grid_pos);
+			glVertexPointer(3, GL_FLOAT, 0, grid_pos);
 			glColorPointer(4, GL_UNSIGNED_BYTE, 0, grid_col);
 
 			glDrawElements(GL_QUADS, (VIEWGRAD_RES_X - 1) * (VIEWGRAD_RES_Y - 1) * 4, GL_UNSIGNED_SHORT, indices);
+
 			glDisableClientState(GL_VERTEX_ARRAY);
 			glDisableClientState(GL_COLOR_ARRAY);
 
+			glDepthFunc(GL_LEQUAL);
+			glDisable(GL_DEPTH_TEST);
+
 			glMatrixMode(GL_PROJECTION);
 			glPopMatrix();
 			glMatrixMode(GL_MODELVIEW);
@@ -3112,9 +3162,6 @@ static void view3d_main_area_clear(Scene *scene, View3D *v3d, ARegion *ar)
 	}
 	else {
 		if (UI_GetThemeValue(TH_SHOW_BACK_GRAD)) {
-			/* only clear depth buffer here */
-			glClear(GL_DEPTH_BUFFER_BIT);
-
 			glMatrixMode(GL_PROJECTION);
 			glPushMatrix();
 			glLoadIdentity();
@@ -3122,17 +3169,22 @@ static void view3d_main_area_clear(Scene *scene, View3D *v3d, ARegion *ar)
 			glPushMatrix();
 			glLoadIdentity();
 
+			glEnable(GL_DEPTH_TEST);
+			glDepthFunc(GL_ALWAYS);
 			glShadeModel(GL_SMOOTH);
 			glBegin(GL_QUADS);
 			UI_ThemeColor(TH_LOW_GRAD);
-			glVertex2f(-1.0, -1.0);
-			glVertex2f(1.0, -1.0);
+			glVertex3f(-1.0, -1.0, 1.0);
+			glVertex3f(1.0, -1.0, 1.0);
 			UI_ThemeColor(TH_HIGH_GRAD);
-			glVertex2f(1.0, 1.0);
-			glVertex2f(-1.0, 1.0);
+			glVertex3f(1.0, 1.0, 1.0);
+			glVertex3f(-1.0, 1.0, 1.0);
 			glEnd();
 			glShadeModel(GL_FLAT);
 
+			glDepthFunc(GL_LEQUAL);
+			glDisable(GL_DEPTH_TEST);
+
 			glMatrixMode(GL_PROJECTION);
 			glPopMatrix();
 
diff --git a/source/blender/editors/space_view3d/view3d_edit.c b/source/blender/editors/space_view3d/view3d_edit.c
index 5f54f0dcfc8..8c8332075a2 100644
--- a/source/blender/editors/space_view3d/view3d_edit.c
+++ b/source/blender/editors/space_view3d/view3d_edit.c
@@ -368,6 +368,7 @@ typedef struct ViewOpsData {
 	float reverse, dist0, camzoom0;
 	float grid, far;
 	short axis_snap; /* view rotate only */
+	float zfac;
 
 	/* use for orbit selection and auto-dist */
 	float ofs[3], dyn_ofs[3];
@@ -407,7 +408,7 @@ static void calctrackballvec(const rcti *rect, int mx, int my, float vec[3])
 }
 
 
-static void viewops_data_create(bContext *C, wmOperator *op, wmEvent *event)
+static void viewops_data_create(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	static float lastofs[3] = {0, 0, 0};
 	RegionView3D *rv3d;
@@ -504,7 +505,11 @@ static void viewops_data_create(bContext *C, wmOperator *op, wmEvent *event)
 
 	calctrackballvec(&vod->ar->winrct, event->x, event->y, vod->trackvec);
 
-	initgrabz(rv3d, -rv3d->ofs[0], -rv3d->ofs[1], -rv3d->ofs[2]);
+	{
+		float tvec[3];
+		negate_v3_v3(tvec, rv3d->ofs);
+		vod->zfac = ED_view3d_calc_zfac(rv3d, tvec, NULL);
+	}
 
 	vod->reverse = 1.0f;
 	if (rv3d->persmat[2][1] < 0.0f)
@@ -836,7 +841,7 @@ static void viewrotate_apply(ViewOpsData *vod, int x, int y)
 	ED_region_tag_redraw(vod->ar);
 }
 
-static int viewrotate_modal(bContext *C, wmOperator *op, wmEvent *event)
+static int viewrotate_modal(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	ViewOpsData *vod = op->customdata;
 	short event_code = VIEW_PASS;
@@ -885,7 +890,7 @@ static int viewrotate_modal(bContext *C, wmOperator *op, wmEvent *event)
 	return OPERATOR_RUNNING_MODAL;
 }
 
-static int viewrotate_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int viewrotate_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	ViewOpsData *vod;
 	RegionView3D *rv3d;
@@ -1092,7 +1097,7 @@ static void view3d_ndof_orbit(const struct wmNDOFMotionData *ndof, RegionView3D
  * -- zooming
  * -- panning in rotationally-locked views
  */
-static int ndof_orbit_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int ndof_orbit_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	
 	if (event->type != NDOF_MOTION)
@@ -1174,7 +1179,7 @@ void VIEW3D_OT_ndof_orbit(struct wmOperatorType *ot)
 }
 
 
-static int ndof_orbit_zoom_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int ndof_orbit_zoom_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	
 	if (event->type != NDOF_MOTION)
@@ -1272,7 +1277,7 @@ void VIEW3D_OT_ndof_orbit_zoom(struct wmOperatorType *ot)
 /* -- "pan" navigation
  * -- zoom or dolly?
  */
-static int ndof_pan_invoke(bContext *C, wmOperator *UNUSED(op), wmEvent *event)
+static int ndof_pan_invoke(bContext *C, wmOperator *UNUSED(op), const wmEvent *event)
 {
 	if (event->type != NDOF_MOTION)
 		return OPERATOR_CANCELLED;
@@ -1366,7 +1371,7 @@ void VIEW3D_OT_ndof_pan(struct wmOperatorType *ot)
 /*
  * this is basically just the pan only code + the rotate only code crammed into one function that does both
  */
-static int ndof_all_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int ndof_all_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	if (event->type != NDOF_MOTION) {
 		return OPERATOR_CANCELLED;
@@ -1508,7 +1513,7 @@ static void viewmove_apply(ViewOpsData *vod, int x, int y)
 
 		mval_f[0] = x - vod->oldx;
 		mval_f[1] = y - vod->oldy;
-		ED_view3d_win_to_delta(vod->ar, mval_f, dvec);
+		ED_view3d_win_to_delta(vod->ar, mval_f, dvec, vod->zfac);
 
 		add_v3_v3(vod->rv3d->ofs, dvec);
 
@@ -1525,7 +1530,7 @@ static void viewmove_apply(ViewOpsData *vod, int x, int y)
 }
 
 
-static int viewmove_modal(bContext *C, wmOperator *op, wmEvent *event)
+static int viewmove_modal(bContext *C, wmOperator *op, const wmEvent *event)
 {
 
 	ViewOpsData *vod = op->customdata;
@@ -1568,7 +1573,7 @@ static int viewmove_modal(bContext *C, wmOperator *op, wmEvent *event)
 	return OPERATOR_RUNNING_MODAL;
 }
 
-static int viewmove_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int viewmove_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	ViewOpsData *vod;
 
@@ -1665,15 +1670,16 @@ static void view_zoom_mouseloc(ARegion *ar, float dfac, int mx, int my)
 		float tpos[3];
 		float mval_f[2];
 		float new_dist;
+		float zfac;
 
 		negate_v3_v3(tpos, rv3d->ofs);
 
-		/* Project cursor position into 3D space */
-		initgrabz(rv3d, tpos[0], tpos[1], tpos[2]);
-
 		mval_f[0] = (float)(((mx - ar->winrct.xmin) * 2) - ar->winx) / 2.0f;
 		mval_f[1] = (float)(((my - ar->winrct.ymin) * 2) - ar->winy) / 2.0f;
-		ED_view3d_win_to_delta(ar, mval_f, dvec);
+
+		/* Project cursor position into 3D space */
+		zfac = ED_view3d_calc_zfac(rv3d, tpos, NULL);
+		ED_view3d_win_to_delta(ar, mval_f, dvec, zfac);
 
 		/* Calculate view target position for dolly */
 		add_v3_v3v3(tvec, tpos, dvec);
@@ -1788,7 +1794,7 @@ static void viewzoom_apply(ViewOpsData *vod, const int x, const int y, const sho
 }
 
 
-static int viewzoom_modal(bContext *C, wmOperator *op, wmEvent *event)
+static int viewzoom_modal(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	ViewOpsData *vod = op->customdata;
 	short event_code = VIEW_PASS;
@@ -1933,7 +1939,7 @@ void viewdolly_modal_keymap(wmKeyConfig *keyconf)
 }
 
 /* viewdolly_invoke() copied this function, changes here may apply there */
-static int viewzoom_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int viewzoom_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	ViewOpsData *vod;
 
@@ -2053,7 +2059,7 @@ static void viewdolly_apply(ViewOpsData *vod, int x, int y, const short zoom_inv
 }
 
 
-static int viewdolly_modal(bContext *C, wmOperator *op, wmEvent *event)
+static int viewdolly_modal(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	ViewOpsData *vod = op->customdata;
 	short event_code = VIEW_PASS;
@@ -2145,7 +2151,7 @@ static int viewdolly_exec(bContext *C, wmOperator *op)
 }
 
 /* copied from viewzoom_invoke(), changes here may apply there */
-static int viewdolly_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int viewdolly_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	ViewOpsData *vod;
 
@@ -2957,14 +2963,20 @@ static int view3d_zoom_border_exec(bContext *C, wmOperator *op)
 		}
 		else {
 			float mval_f[2];
+			float zfac;
+
 			/* We cant use the depth, fallback to the old way that dosnt set the center depth */
 			copy_v3_v3(new_ofs, rv3d->ofs);
 
-			initgrabz(rv3d, -new_ofs[0], -new_ofs[1], -new_ofs[2]);
+			{
+				float tvec[3];
+				negate_v3_v3(tvec, new_ofs);
+				zfac = ED_view3d_calc_zfac(rv3d, tvec, NULL);
+			}
 
 			mval_f[0] = (rect.xmin + rect.xmax - vb[0]) / 2.0f;
 			mval_f[1] = (rect.ymin + rect.ymax - vb[1]) / 2.0f;
-			ED_view3d_win_to_delta(ar, mval_f, dvec);
+			ED_view3d_win_to_delta(ar, mval_f, dvec, zfac);
 			/* center the view to the center of the rectangle */
 			sub_v3_v3(new_ofs, dvec);
 		}
@@ -2997,7 +3009,7 @@ static int view3d_zoom_border_exec(bContext *C, wmOperator *op)
 	return OPERATOR_FINISHED;
 }
 
-static int view3d_zoom_border_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int view3d_zoom_border_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	View3D *v3d = CTX_wm_view3d(C);
 	RegionView3D *rv3d = CTX_wm_region_view3d(C);
@@ -3415,16 +3427,19 @@ static int viewpan_exec(bContext *C, wmOperator *op)
 	ARegion *ar = CTX_wm_region(C);
 	RegionView3D *rv3d = CTX_wm_region_view3d(C);
 	float vec[3];
+	const float co_zero[3] = {0.0f};
 	float mval_f[2] = {0.0f, 0.0f};
+	float zfac;
 	int pandir;
 
 	pandir = RNA_enum_get(op->ptr, "type");
 
-	initgrabz(rv3d, 0.0, 0.0, 0.0);
-	if      (pandir == V3D_VIEW_PANRIGHT)  { mval_f[0] = -32.0f; ED_view3d_win_to_delta(ar, mval_f, vec); }
-	else if (pandir == V3D_VIEW_PANLEFT)   { mval_f[0] =  32.0f; ED_view3d_win_to_delta(ar, mval_f, vec); }
-	else if (pandir == V3D_VIEW_PANUP)     { mval_f[1] = -25.0f; ED_view3d_win_to_delta(ar, mval_f, vec); }
-	else if (pandir == V3D_VIEW_PANDOWN)   { mval_f[1] =  25.0f; ED_view3d_win_to_delta(ar, mval_f, vec); }
+	zfac = ED_view3d_calc_zfac(rv3d, co_zero, NULL);
+	if      (pandir == V3D_VIEW_PANRIGHT)  { mval_f[0] = -32.0f; }
+	else if (pandir == V3D_VIEW_PANLEFT)   { mval_f[0] =  32.0f; }
+	else if (pandir == V3D_VIEW_PANUP)     { mval_f[1] = -25.0f; }
+	else if (pandir == V3D_VIEW_PANDOWN)   { mval_f[1] =  25.0f; }
+	ED_view3d_win_to_delta(ar, mval_f, vec, zfac);
 	add_v3_v3(rv3d->ofs, vec);
 
 	if (rv3d->viewlock & RV3D_BOXVIEW)
@@ -3506,7 +3521,7 @@ static int background_image_add_exec(bContext *C, wmOperator *UNUSED(op))
 	return OPERATOR_FINISHED;
 }
 
-static int background_image_add_invoke(bContext *C, wmOperator *op, wmEvent *UNUSED(event))
+static int background_image_add_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
 	View3D *v3d = CTX_wm_view3d(C);
 	Image *ima = NULL;
@@ -3661,7 +3676,7 @@ static int view3d_clipping_exec(bContext *C, wmOperator *op)
 	return OPERATOR_FINISHED;
 }
 
-static int view3d_clipping_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int view3d_clipping_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	RegionView3D *rv3d = CTX_wm_region_view3d(C);
 	ARegion *ar = CTX_wm_region(C);
@@ -3713,15 +3728,16 @@ void ED_view3d_cursor3d_position(bContext *C, float fp[3], const int mval[2])
 	View3D *v3d = CTX_wm_view3d(C);
 	RegionView3D *rv3d = CTX_wm_region_view3d(C);
 	float mval_fl[2];
-	int flip;
+	float zfac;
+	bool flip;
 	
-	flip = initgrabz(rv3d, fp[0], fp[1], fp[2]);
+	zfac = ED_view3d_calc_zfac(rv3d, fp, &flip);
 	
 	/* reset the depth based on the view offset (we _know_ the offset is infront of us) */
 	if (flip) {
 		negate_v3_v3(fp, rv3d->ofs);
 		/* re initialize, no need to check flip again */
-		/* flip = */ initgrabz(rv3d, fp[0], fp[1], fp[2]);
+		zfac = ED_view3d_calc_zfac(rv3d, fp, NULL /* &flip */ );
 	}
 
 	if (ED_view3d_project_float_global(ar, fp, mval_fl, V3D_PROJ_TEST_NOP) == V3D_PROJ_RET_OK) {
@@ -3736,17 +3752,17 @@ void ED_view3d_cursor3d_position(bContext *C, float fp[3], const int mval[2])
 		if (depth_used == FALSE) {
 			float dvec[3];
 			VECSUB2D(mval_fl, mval_fl, mval);
-			ED_view3d_win_to_delta(ar, mval_fl, dvec);
+			ED_view3d_win_to_delta(ar, mval_fl, dvec, zfac);
 			sub_v3_v3(fp, dvec);
 		}
 	}
 	else {
-		const float dx = ((float)(mval[0] - (ar->winx / 2))) * rv3d->zfac / (ar->winx / 2);
-		const float dy = ((float)(mval[1] - (ar->winy / 2))) * rv3d->zfac / (ar->winy / 2);
+		const float dx = ((float)(mval[0] - (ar->winx / 2))) * zfac / (ar->winx / 2);
+		const float dy = ((float)(mval[1] - (ar->winy / 2))) * zfac / (ar->winy / 2);
 		const float fz = (rv3d->persmat[0][3] * fp[0] +
 		                  rv3d->persmat[1][3] * fp[1] +
 		                  rv3d->persmat[2][3] * fp[2] +
-		                  rv3d->persmat[3][3]) / rv3d->zfac;
+		                  rv3d->persmat[3][3]) / zfac;
 
 		fp[0] = (rv3d->persinv[0][0] * dx + rv3d->persinv[1][0] * dy + rv3d->persinv[2][0] * fz) - rv3d->ofs[0];
 		fp[1] = (rv3d->persinv[0][1] * dx + rv3d->persinv[1][1] * dy + rv3d->persinv[2][1] * fz) - rv3d->ofs[1];
@@ -3755,7 +3771,7 @@ void ED_view3d_cursor3d_position(bContext *C, float fp[3], const int mval[2])
 
 }
 
-static int view3d_cursor3d_invoke(bContext *C, wmOperator *UNUSED(op), wmEvent *event)
+static int view3d_cursor3d_invoke(bContext *C, wmOperator *UNUSED(op), const wmEvent *event)
 {
 	Scene *scene = CTX_data_scene(C);
 	View3D *v3d = CTX_wm_view3d(C);
@@ -3794,7 +3810,7 @@ void VIEW3D_OT_cursor3d(wmOperatorType *ot)
 /* ***************** manipulator op ******************* */
 
 
-static int manipulator_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int manipulator_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	View3D *v3d = CTX_wm_view3d(C);
 
@@ -3830,7 +3846,7 @@ void VIEW3D_OT_manipulator(wmOperatorType *ot)
 	Transform_Properties(ot, P_CONSTRAINT);
 }
 
-static int enable_manipulator_invoke(bContext *C, wmOperator *op, wmEvent *UNUSED(event))
+static int enable_manipulator_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
 	View3D *v3d = CTX_wm_view3d(C);
 
diff --git a/source/blender/editors/space_view3d/view3d_fly.c b/source/blender/editors/space_view3d/view3d_fly.c
index c2e75a1c5d9..700027d62a2 100644
--- a/source/blender/editors/space_view3d/view3d_fly.c
+++ b/source/blender/editors/space_view3d/view3d_fly.c
@@ -272,7 +272,7 @@ static void drawFlyPixel(const struct bContext *UNUSED(C), ARegion *UNUSED(ar),
 #define FLY_CANCEL      1
 #define FLY_CONFIRM     2
 
-static int initFlyInfo(bContext *C, FlyInfo *fly, wmOperator *op, wmEvent *event)
+static int initFlyInfo(bContext *C, FlyInfo *fly, wmOperator *op, const wmEvent *event)
 {
 	wmWindow *win = CTX_wm_window(C);
 	float upvec[3]; /* tmp */
@@ -486,7 +486,7 @@ static int flyEnd(bContext *C, FlyInfo *fly)
 	return OPERATOR_CANCELLED;
 }
 
-static void flyEvent(FlyInfo *fly, wmEvent *event)
+static void flyEvent(FlyInfo *fly, const wmEvent *event)
 {
 	if (event->type == TIMER && event->customdata == fly->timer) {
 		fly->redraw = 1;
@@ -1179,7 +1179,7 @@ static int flyApply_ndof(bContext *C, FlyInfo *fly)
 	return OPERATOR_FINISHED;
 }
 
-static int fly_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int fly_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	RegionView3D *rv3d = CTX_wm_region_view3d(C);
 	FlyInfo *fly;
@@ -1214,7 +1214,7 @@ static int fly_cancel(bContext *C, wmOperator *op)
 	return OPERATOR_CANCELLED;
 }
 
-static int fly_modal(bContext *C, wmOperator *op, wmEvent *event)
+static int fly_modal(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	int exit_code;
 	short do_draw = FALSE;
diff --git a/source/blender/editors/space_view3d/view3d_header.c b/source/blender/editors/space_view3d/view3d_header.c
index e078fa8eda1..430ed8698d7 100644
--- a/source/blender/editors/space_view3d/view3d_header.c
+++ b/source/blender/editors/space_view3d/view3d_header.c
@@ -28,7 +28,6 @@
  *  \ingroup spview3d
  */
 
-
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -37,8 +36,6 @@
 #include "DNA_object_types.h"
 #include "DNA_mesh_types.h"
 
-#include "RNA_access.h"
-
 #include "MEM_guardedalloc.h"
 
 #include "BLI_math.h"
@@ -57,18 +54,19 @@
 #include "BKE_screen.h"
 #include "BKE_tessmesh.h"
 
+#include "RNA_access.h"
+#include "RNA_define.h"
+#include "RNA_enum_types.h"
+
+#include "WM_api.h"
+#include "WM_types.h"
+
 #include "ED_mesh.h"
 #include "ED_util.h"
 #include "ED_screen.h"
 #include "ED_transform.h"
 #include "ED_types.h"
 
-#include "WM_api.h"
-#include "WM_types.h"
-
-#include "RNA_define.h"
-#include "RNA_enum_types.h"
-
 #include "UI_interface.h"
 #include "UI_resources.h"
 
@@ -209,7 +207,7 @@ static int view3d_layers_exec(bContext *C, wmOperator *op)
 
 /* applies shift and alt, lazy coding or ok? :) */
 /* the local per-keymap-entry keymap will solve it */
-static int view3d_layers_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int view3d_layers_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	if (event->ctrl || event->oskey)
 		return OPERATOR_PASS_THROUGH;
diff --git a/source/blender/editors/space_view3d/view3d_intern.h b/source/blender/editors/space_view3d/view3d_intern.h
index d4cfa9076a6..26ed8e1885c 100644
--- a/source/blender/editors/space_view3d/view3d_intern.h
+++ b/source/blender/editors/space_view3d/view3d_intern.h
@@ -108,6 +108,9 @@ float ndof_to_axis_angle(const struct wmNDOFMotionData *ndof, float axis[3]);
 void view3d_keymap(struct wmKeyConfig *keyconf);
 void VIEW3D_OT_fly(struct wmOperatorType *ot);
 
+/* view3d_ruler.c */
+void VIEW3D_OT_ruler(struct wmOperatorType *ot);
+
 /* drawanim.c */
 void draw_motion_paths_init(View3D *v3d, struct ARegion *ar);
 void draw_motion_path_instance(Scene *scene,
diff --git a/source/blender/editors/space_view3d/view3d_ops.c b/source/blender/editors/space_view3d/view3d_ops.c
index bf1c5404c0e..e567ebda4b7 100644
--- a/source/blender/editors/space_view3d/view3d_ops.c
+++ b/source/blender/editors/space_view3d/view3d_ops.c
@@ -166,6 +166,7 @@ void view3d_operatortypes(void)
 	WM_operatortype_append(VIEW3D_OT_localview);
 	WM_operatortype_append(VIEW3D_OT_game_start);
 	WM_operatortype_append(VIEW3D_OT_fly);
+	WM_operatortype_append(VIEW3D_OT_ruler);
 	WM_operatortype_append(VIEW3D_OT_layers);
 	WM_operatortype_append(VIEW3D_OT_copybuffer);
 	WM_operatortype_append(VIEW3D_OT_pastebuffer);
diff --git a/source/blender/editors/space_view3d/view3d_project.c b/source/blender/editors/space_view3d/view3d_project.c
index bc1656ff7c6..30a100283cc 100644
--- a/source/blender/editors/space_view3d/view3d_project.c
+++ b/source/blender/editors/space_view3d/view3d_project.c
@@ -73,7 +73,7 @@ void ED_view3d_project_float_v2_m4(const ARegion *ar, const float co[3], float r
 /**
  * \note use #ED_view3d_ob_project_mat_get to get projecting mat
  */
-void ED_view3d_project_float_v3_m4(ARegion *ar, const float vec[3], float r_co[3], float mat[4][4])
+void ED_view3d_project_float_v3_m4(const ARegion *ar, const float vec[3], float r_co[3], float mat[4][4])
 {
 	float vec4[4];
 	
@@ -97,7 +97,7 @@ void ED_view3d_project_float_v3_m4(ARegion *ar, const float vec[3], float r_co[3
 /* Clipping Projection Functions
  * ***************************** */
 
-eV3DProjStatus ED_view3d_project_base(struct ARegion *ar, struct Base *base)
+eV3DProjStatus ED_view3d_project_base(const struct ARegion *ar, struct Base *base)
 {
 	eV3DProjStatus ret = ED_view3d_project_short_global(ar, base->object->obmat[3], &base->sx, V3D_PROJ_TEST_CLIP_DEFAULT);
 
@@ -113,8 +113,8 @@ eV3DProjStatus ED_view3d_project_base(struct ARegion *ar, struct Base *base)
  * - 'rv3d->perspmat',   is_local == FALSE
  * - 'rv3d->persmatob', is_local == TRUE
  */
-static eV3DProjStatus ed_view3d_project__internal(ARegion *ar,
-                                                  float perspmat[4][4], const int is_local,  /* normally hidden */
+static eV3DProjStatus ed_view3d_project__internal(const ARegion *ar,
+                                                  float perspmat[4][4], const bool is_local,  /* normally hidden */
                                                   const float co[3], float r_co[2], const eV3DProjTest flag)
 {
 	float vec4[4];
@@ -171,7 +171,7 @@ static eV3DProjStatus ed_view3d_project__internal(ARegion *ar,
 	return V3D_PROJ_RET_OK;
 }
 
-eV3DProjStatus ED_view3d_project_short_ex(ARegion *ar, float perspmat[4][4], const int is_local,
+eV3DProjStatus ED_view3d_project_short_ex(const ARegion *ar, float perspmat[4][4], const bool is_local,
                                           const float co[3], short r_co[2], const eV3DProjTest flag)
 {
 	float tvec[2];
@@ -190,7 +190,7 @@ eV3DProjStatus ED_view3d_project_short_ex(ARegion *ar, float perspmat[4][4], con
 	return ret;
 }
 
-eV3DProjStatus ED_view3d_project_int_ex(ARegion *ar, float perspmat[4][4], const int is_local,
+eV3DProjStatus ED_view3d_project_int_ex(const ARegion *ar, float perspmat[4][4], const bool is_local,
                                         const float co[3], int r_co[2], const eV3DProjTest flag)
 {
 	float tvec[2];
@@ -209,7 +209,7 @@ eV3DProjStatus ED_view3d_project_int_ex(ARegion *ar, float perspmat[4][4], const
 	return ret;
 }
 
-eV3DProjStatus ED_view3d_project_float_ex(ARegion *ar, float perspmat[4][4], const int is_local,
+eV3DProjStatus ED_view3d_project_float_ex(const ARegion *ar, float perspmat[4][4], const bool is_local,
                                         const float co[3], float r_co[2], const eV3DProjTest flag)
 {
 	float tvec[2];
@@ -228,39 +228,39 @@ eV3DProjStatus ED_view3d_project_float_ex(ARegion *ar, float perspmat[4][4], con
 }
 
 /* --- short --- */
-eV3DProjStatus ED_view3d_project_short_global(ARegion *ar, const float co[3], short r_co[2], const eV3DProjTest flag)
+eV3DProjStatus ED_view3d_project_short_global(const ARegion *ar, const float co[3], short r_co[2], const eV3DProjTest flag)
 {
 	RegionView3D *rv3d = ar->regiondata;
 	return ED_view3d_project_short_ex(ar, rv3d->persmat, FALSE, co, r_co, flag);
 }
 /* object space, use ED_view3d_init_mats_rv3d before calling */
-eV3DProjStatus ED_view3d_project_short_object(ARegion *ar, const float co[3], short r_co[2], const eV3DProjTest flag)
+eV3DProjStatus ED_view3d_project_short_object(const ARegion *ar, const float co[3], short r_co[2], const eV3DProjTest flag)
 {
 	RegionView3D *rv3d = ar->regiondata;
 	return ED_view3d_project_short_ex(ar, rv3d->persmatob, TRUE, co, r_co, flag);
 }
 
 /* --- int --- */
-eV3DProjStatus ED_view3d_project_int_global(ARegion *ar, const float co[3], int r_co[2], const eV3DProjTest flag)
+eV3DProjStatus ED_view3d_project_int_global(const ARegion *ar, const float co[3], int r_co[2], const eV3DProjTest flag)
 {
 	RegionView3D *rv3d = ar->regiondata;
 	return ED_view3d_project_int_ex(ar, rv3d->persmat, FALSE, co, r_co, flag);
 }
 /* object space, use ED_view3d_init_mats_rv3d before calling */
-eV3DProjStatus ED_view3d_project_int_object(ARegion *ar, const float co[3], int r_co[2], const eV3DProjTest flag)
+eV3DProjStatus ED_view3d_project_int_object(const ARegion *ar, const float co[3], int r_co[2], const eV3DProjTest flag)
 {
 	RegionView3D *rv3d = ar->regiondata;
 	return ED_view3d_project_int_ex(ar, rv3d->persmatob, TRUE, co, r_co, flag);
 }
 
 /* --- float --- */
-eV3DProjStatus ED_view3d_project_float_global(ARegion *ar, const float co[3], float r_co[2], const eV3DProjTest flag)
+eV3DProjStatus ED_view3d_project_float_global(const ARegion *ar, const float co[3], float r_co[2], const eV3DProjTest flag)
 {
 	RegionView3D *rv3d = ar->regiondata;
 	return ED_view3d_project_float_ex(ar, rv3d->persmat, FALSE, co, r_co, flag);
 }
 /* object space, use ED_view3d_init_mats_rv3d before calling */
-eV3DProjStatus ED_view3d_project_float_object(ARegion *ar, const float co[3], float r_co[2], const eV3DProjTest flag)
+eV3DProjStatus ED_view3d_project_float_object(const ARegion *ar, const float co[3], float r_co[2], const eV3DProjTest flag)
 {
 	RegionView3D *rv3d = ar->regiondata;
 	return ED_view3d_project_float_ex(ar, rv3d->persmatob, TRUE, co, r_co, flag);
@@ -271,28 +271,30 @@ eV3DProjStatus ED_view3d_project_float_object(ARegion *ar, const float co[3], fl
 /* More Generic Window/Ray/Vector projection functions
  * *************************************************** */
 
-/* odd function, need to document better */
-int initgrabz(RegionView3D *rv3d, float x, float y, float z)
+/**
+ * Caculate a depth value from \a co, use with #ED_view3d_win_to_delta
+ */
+float ED_view3d_calc_zfac(const RegionView3D *rv3d, const float co[3], bool *r_flip)
 {
-	int flip = FALSE;
-	if (rv3d == NULL) return flip;
-	rv3d->zfac = rv3d->persmat[0][3] * x + rv3d->persmat[1][3] * y + rv3d->persmat[2][3] * z + rv3d->persmat[3][3];
-	if (rv3d->zfac < 0.0f)
-		flip = TRUE;
+	float zfac = mul_project_m4_v3_zfac((float (*)[4])rv3d->persmat, co);
+
+	if (r_flip) {
+		*r_flip = (zfac < 0.0f);
+	}
+
 	/* if x,y,z is exactly the viewport offset, zfac is 0 and we don't want that
-	 * (accounting for near zero values)
-	 */
-	if (rv3d->zfac < 1.e-6f && rv3d->zfac > -1.e-6f) rv3d->zfac = 1.0f;
+	 * (accounting for near zero values) */
+	if (zfac < 1.e-6f && zfac > -1.e-6f) {
+		zfac = 1.0f;
+	}
 
 	/* Negative zfac means x, y, z was behind the camera (in perspective).
-	 * This gives flipped directions, so revert back to ok default case.
-	 */
-	/* NOTE: I've changed this to flip zfac to be positive again for now so that GPencil draws ok
-	 * Aligorith, 2009Aug31 */
-	//if (rv3d->zfac < 0.0f) rv3d->zfac = 1.0f;
-	if (rv3d->zfac < 0.0f) rv3d->zfac = -rv3d->zfac;
-
-	return flip;
+	 * This gives flipped directions, so revert back to ok default case. */
+	if (zfac < 0.0f) {
+		zfac = -zfac;
+	}
+
+	return zfac;
 }
 
 /**
@@ -306,7 +308,7 @@ int initgrabz(RegionView3D *rv3d, float x, float y, float z)
  * \param ray_start The world-space starting point of the segment.
  * \param ray_normal The normalized world-space direction of towards mval.
  */
-void ED_view3d_win_to_ray(ARegion *ar, View3D *v3d, const float mval[2], float ray_start[3], float ray_normal[3])
+void ED_view3d_win_to_ray(const ARegion *ar, View3D *v3d, const float mval[2], float ray_start[3], float ray_normal[3])
 {
 	float ray_end[3];
 	
@@ -322,7 +324,7 @@ void ED_view3d_win_to_ray(ARegion *ar, View3D *v3d, const float mval[2], float r
  * \param coord The world-space location.
  * \param vec The resulting normalized vector.
  */
-void ED_view3d_global_to_vector(RegionView3D *rv3d, const float coord[3], float vec[3])
+void ED_view3d_global_to_vector(const RegionView3D *rv3d, const float coord[3], float vec[3])
 {
 	if (rv3d->is_persp) {
 		float p1[4], p2[4];
@@ -331,11 +333,11 @@ void ED_view3d_global_to_vector(RegionView3D *rv3d, const float coord[3], float
 		p1[3] = 1.0f;
 		copy_v3_v3(p2, p1);
 		p2[3] = 1.0f;
-		mul_m4_v4(rv3d->viewmat, p2);
+		mul_m4_v4((float (*)[4])rv3d->viewmat, p2);
 
 		mul_v3_fl(p2, 2.0f);
 
-		mul_m4_v4(rv3d->viewinv, p2);
+		mul_m4_v4((float (*)[4])rv3d->viewinv, p2);
 
 		sub_v3_v3v3(vec, p1, p2);
 	}
@@ -352,7 +354,7 @@ void ED_view3d_global_to_vector(RegionView3D *rv3d, const float coord[3], float
  * \param mval The area relative location (such as event->mval converted to floats).
  * \param out The resulting world-space location.
  */
-void ED_view3d_win_to_3d(ARegion *ar, const float depth_pt[3], const float mval[2], float out[3])
+void ED_view3d_win_to_3d(const ARegion *ar, const float depth_pt[3], const float mval[2], float out[3])
 {
 	RegionView3D *rv3d = ar->regiondata;
 	
@@ -384,19 +386,19 @@ void ED_view3d_win_to_3d(ARegion *ar, const float depth_pt[3], const float mval[
 
 /**
  * Calculate a 3d difference vector from 2d window offset.
- * note that initgrabz() must be called first to determine
+ * note that ED_view3d_calc_zfac() must be called first to determine
  * the depth used to calculate the delta.
  * \param ar The region (used for the window width and height).
  * \param mval The area relative 2d difference (such as event->mval[0] - other_x).
  * \param out The resulting world-space delta.
  */
-void ED_view3d_win_to_delta(ARegion *ar, const float mval[2], float out[3])
+void ED_view3d_win_to_delta(const ARegion *ar, const float mval[2], float out[3], const float zfac)
 {
 	RegionView3D *rv3d = ar->regiondata;
 	float dx, dy;
 	
-	dx = 2.0f * mval[0] * rv3d->zfac / ar->winx;
-	dy = 2.0f * mval[1] * rv3d->zfac / ar->winy;
+	dx = 2.0f * mval[0] * zfac / ar->winx;
+	dy = 2.0f * mval[1] * zfac / ar->winy;
 	
 	out[0] = (rv3d->persinv[0][0] * dx + rv3d->persinv[1][0] * dy);
 	out[1] = (rv3d->persinv[0][1] * dx + rv3d->persinv[1][1] * dy);
@@ -408,7 +410,7 @@ void ED_view3d_win_to_delta(ARegion *ar, const float mval[2], float out[3])
  * This direction vector starts and the view in the direction of the 2d window coordinates.
  * In orthographic view all window coordinates yield the same vector.
  *
- * \note doesn't rely on initgrabz
+ * \note doesn't rely on ED_view3d_calc_zfac
  * for perspective view, get the vector direction to
  * the mouse cursor as a normalized vector.
  *
@@ -416,7 +418,7 @@ void ED_view3d_win_to_delta(ARegion *ar, const float mval[2], float out[3])
  * \param mval The area relative 2d location (such as event->mval converted to floats).
  * \param out The resulting normalized world-space direction vector.
  */
-void ED_view3d_win_to_vector(ARegion *ar, const float mval[2], float out[3])
+void ED_view3d_win_to_vector(const ARegion *ar, const float mval[2], float out[3])
 {
 	RegionView3D *rv3d = ar->regiondata;
 
@@ -433,7 +435,7 @@ void ED_view3d_win_to_vector(ARegion *ar, const float mval[2], float out[3])
 	normalize_v3(out);
 }
 
-void ED_view3d_win_to_segment(ARegion *ar, View3D *v3d, const float mval[2], float ray_start[3], float ray_end[3])
+void ED_view3d_win_to_segment(const ARegion *ar, View3D *v3d, const float mval[2], float ray_start[3], float ray_end[3])
 {
 	RegionView3D *rv3d = ar->regiondata;
 
@@ -472,7 +474,7 @@ void ED_view3d_win_to_segment(ARegion *ar, View3D *v3d, const float mval[2], flo
  * \param ray_end The world-space end point of the segment.
  * \return success, FALSE if the segment is totally clipped.
  */
-int ED_view3d_win_to_segment_clip(ARegion *ar, View3D *v3d, const float mval[2], float ray_start[3], float ray_end[3])
+int ED_view3d_win_to_segment_clip(const ARegion *ar, View3D *v3d, const float mval[2], float ray_start[3], float ray_end[3])
 {
 	RegionView3D *rv3d = ar->regiondata;
 	ED_view3d_win_to_segment(ar, v3d, mval, ray_start, ray_end);
@@ -503,12 +505,12 @@ int ED_view3d_win_to_segment_clip(ARegion *ar, View3D *v3d, const float mval[2],
 /* Utility functions for projection
  * ******************************** */
 
-void ED_view3d_ob_project_mat_get(RegionView3D *rv3d, Object *ob, float pmat[4][4])
+void ED_view3d_ob_project_mat_get(const RegionView3D *rv3d, Object *ob, float pmat[4][4])
 {
 	float vmat[4][4];
 
-	mult_m4_m4m4(vmat, rv3d->viewmat, ob->obmat);
-	mult_m4_m4m4(pmat, rv3d->winmat, vmat);
+	mult_m4_m4m4(vmat, (float (*)[4])rv3d->viewmat, ob->obmat);
+	mult_m4_m4m4(pmat, (float (*)[4])rv3d->winmat, vmat);
 }
 
 /**
diff --git a/source/blender/editors/space_view3d/view3d_ruler.c b/source/blender/editors/space_view3d/view3d_ruler.c
new file mode 100644
index 00000000000..410d20a1dc0
--- /dev/null
+++ b/source/blender/editors/space_view3d/view3d_ruler.c
@@ -0,0 +1,939 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Contributor(s): Campbell Barton
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/editors/space_view3d/view3d_ruler.c
+ *  \ingroup spview3d
+ */
+
+/* defines VIEW3D_OT_ruler modal operator */
+
+#include "DNA_scene_types.h"
+#include "DNA_gpencil_types.h"
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_math.h"
+#include "BLI_blenlib.h"
+
+#include "BKE_context.h"
+#include "BKE_unit.h"
+#include "BKE_gpencil.h"
+
+#include "BIF_gl.h"
+
+#include "WM_api.h"
+#include "WM_types.h"
+
+#include "ED_screen.h"
+#include "ED_space_api.h"
+
+#include "BLF_api.h"
+#include "BIF_glutil.h"
+
+#include "UI_resources.h"
+#include "UI_interface.h"
+
+#include "view3d_intern.h"  /* own include */
+
+
+/* -------------------------------------------------------------------- */
+/* Snapping (could be own function) */
+/* NOTE - this is not very nice use of transform snapping */
+#include "ED_transform.h"
+#include "../transform/transform.h"
+
+static bool ED_view3d_snap_co(bContext *C, float r_co[3], const float co_ss[2],
+                              bool use_vert, bool use_edge, bool use_face)
+{
+	TransInfo t = {0};
+	int dist = 12;  /* snap dist */
+	float r_no_dummy[3];
+	bool ret = false;
+	char  backup_snap_mode;
+	Base *backup_baseact;
+
+	t.scene  = CTX_data_scene(C);
+	t.view   = CTX_wm_view3d(C);
+	t.ar     = CTX_wm_region(C);
+	t.obedit = CTX_data_edit_object(C);
+
+	backup_snap_mode = t.scene->toolsettings->snap_mode;
+	backup_baseact = t.scene->basact;
+	t.scene->basact = NULL;
+
+	/* try snap edge, then face if it fails */
+	if (use_vert) {
+		t.scene->toolsettings->snap_mode = SCE_SNAP_MODE_VERTEX;
+		ret = snapObjectsTransform(&t, co_ss, &dist, r_co, r_no_dummy, SNAP_ALL);
+	}
+	if (use_edge && (ret == false)) {
+		t.scene->toolsettings->snap_mode = SCE_SNAP_MODE_EDGE;
+		ret = snapObjectsTransform(&t, co_ss, &dist, r_co, r_no_dummy, SNAP_ALL);
+	}
+	if (use_face && (ret == false)) {
+		t.scene->toolsettings->snap_mode = SCE_SNAP_MODE_FACE;
+		ret = snapObjectsTransform(&t, co_ss, &dist, r_co, r_no_dummy, SNAP_ALL);
+	}
+
+	t.scene->toolsettings->snap_mode = backup_snap_mode;
+	t.scene->basact = backup_baseact;
+
+	return ret;
+}
+/* done snapping */
+
+
+/* -------------------------------------------------------------------- */
+/* Ruler Item (we can have many) */
+enum {
+	RULERITEM_USE_ANGLE = (1 << 0),  /* use protractor */
+	RULERITEM_USE_RAYCAST = (1 << 1)
+};
+
+enum {
+	RULERITEM_DIRECTION_IN = 0,
+	RULERITEM_DIRECTION_OUT
+};
+
+#define RULER_PICK_DIST 75.0f
+#define RULER_PICK_DIST_SQ (RULER_PICK_DIST * RULER_PICK_DIST)
+
+typedef struct RulerItem {
+	struct RulerItem *next, *prev;
+
+	/* worldspace coords, middle being optional */
+	float co[3][3];
+
+	/* selected coord */
+	char  co_index; /* 0 -> 2*/
+
+	int   flag;
+	int   raycast_dir;  /* RULER_DIRECTION_* */
+} RulerItem;
+
+enum {
+	RULER_STATE_NORMAL = 0,
+	RULER_STATE_DRAG
+};
+
+
+/* -------------------------------------------------------------------- */
+/* Ruler Info (one per session) */
+
+typedef struct RulerInfo {
+	ListBase items;
+	int      item_active;
+	int flag;
+	int snap_flag;
+	int state;
+
+	/* --- */
+	ARegion *ar;
+	void *draw_handle_pixel;
+} RulerInfo;
+
+/* -------------------------------------------------------------------- */
+/* local functions */
+static RulerItem *ruler_item_add(RulerInfo *ruler_info)
+{
+	RulerItem *ruler_item = MEM_callocN(sizeof(RulerItem), "RulerItem");
+	BLI_addtail(&ruler_info->items, ruler_item);
+	return ruler_item;
+}
+
+static void ruler_item_remove(RulerInfo *ruler_info, RulerItem *ruler_item)
+{
+	BLI_remlink(&ruler_info->items, ruler_item);
+	MEM_freeN(ruler_item);
+}
+
+static RulerItem *ruler_item_active_get(RulerInfo *ruler_info)
+{
+	return BLI_findlink(&ruler_info->items, ruler_info->item_active);
+}
+
+static void ruler_item_active_set(RulerInfo *ruler_info, RulerItem *ruler_item)
+{
+	ruler_info->item_active = BLI_findindex(&ruler_info->items, ruler_item);
+}
+
+static void ruler_item_as_string(RulerItem *ruler_item, UnitSettings *unit,
+                                 char *numstr, size_t numstr_size, int prec)
+{
+	const int do_split = unit->flag & USER_UNIT_OPT_SPLIT;
+
+	if (ruler_item->flag & RULERITEM_USE_ANGLE) {
+		const float ruler_angle = angle_v3v3v3(ruler_item->co[0],
+		                                       ruler_item->co[1],
+		                                       ruler_item->co[2]);
+
+		if (unit->system == USER_UNIT_NONE) {
+			BLI_snprintf(numstr, numstr_size, "%.*f°", prec, RAD2DEGF(ruler_angle));
+		}
+		else {
+			bUnit_AsString(numstr, numstr_size,
+			               (double)ruler_angle,
+			               prec, unit->system, B_UNIT_ROTATION, do_split, false);
+		}
+	}
+	else {
+		const float ruler_len = len_v3v3(ruler_item->co[0],
+		                                 ruler_item->co[2]);
+
+		if (unit->system == USER_UNIT_NONE) {
+			BLI_snprintf(numstr, numstr_size, "%.*f", prec, ruler_len);
+		}
+		else {
+			bUnit_AsString(numstr, numstr_size,
+			               (double)(ruler_len * unit->scale_length),
+			               prec, unit->system, B_UNIT_LENGTH, do_split, false);
+		}
+	}
+
+}
+
+static bool view3d_ruler_pick(RulerInfo *ruler_info, const float mval[2],
+                              RulerItem **r_ruler_item, int *r_co_index)
+{
+	ARegion *ar = ruler_info->ar;
+	RulerItem *ruler_item;
+
+	float dist_best = RULER_PICK_DIST_SQ;
+	RulerItem *ruler_item_best = NULL;
+	int co_index_best = -1;
+
+	for (ruler_item = ruler_info->items.first; ruler_item; ruler_item = ruler_item->next) {
+		float co_ss[3][2];
+		float dist;
+		int j;
+
+		/* should these be checked? - ok for now not to */
+		for (j = 0; j < 3; j++) {
+			ED_view3d_project_float_global(ar, ruler_item->co[j], co_ss[j], V3D_PROJ_TEST_NOP);
+		}
+
+		if (ruler_item->flag & RULERITEM_USE_ANGLE) {
+			dist = min_ff(dist_squared_to_line_segment_v2(mval, co_ss[0], co_ss[1]),
+			              dist_squared_to_line_segment_v2(mval, co_ss[1], co_ss[2]));
+			if (dist < dist_best) {
+				dist_best = dist;
+				ruler_item_best = ruler_item;
+
+				{
+					float dist_points[3] = {len_squared_v2v2(co_ss[0], mval),
+					                        len_squared_v2v2(co_ss[1], mval),
+					                        len_squared_v2v2(co_ss[2], mval)};
+					if (min_fff(UNPACK3(dist_points)) < RULER_PICK_DIST_SQ) {
+						co_index_best = min_axis_v3(dist_points);
+					}
+					else {
+						co_index_best = -1;
+					}
+				}
+			}
+		}
+		else {
+			dist = dist_squared_to_line_segment_v2(mval, co_ss[0], co_ss[2]);
+			if (dist < dist_best) {
+				dist_best = dist;
+				ruler_item_best = ruler_item;
+
+				{
+					float dist_points[2] = {len_squared_v2v2(co_ss[0], mval),
+					                        len_squared_v2v2(co_ss[2], mval)};
+					if (min_ff(UNPACK2(dist_points)) < RULER_PICK_DIST_SQ) {
+						co_index_best = (dist_points[0] < dist_points[1]) ? 0 : 2;
+					}
+					else {
+						co_index_best = -1;
+					}
+				}
+			}
+		}
+	}
+
+	if (ruler_item_best) {
+		*r_ruler_item = ruler_item_best;
+		*r_co_index = co_index_best;
+		return true;
+	}
+	else {
+		*r_ruler_item = NULL;
+		*r_co_index = -1;
+		return false;
+	}
+}
+
+#define RULER_ID "RulerData3D"
+static bool view3d_ruler_to_gpencil(bContext *C, RulerInfo *ruler_info)
+{
+	Scene *scene = CTX_data_scene(C);
+	bGPDlayer *gpl;
+	bGPDframe *gpf;
+	bGPDstroke *gps;
+	RulerItem *ruler_item;
+	const char *ruler_name = RULER_ID;
+	bool change = false;
+
+	if (scene->gpd == NULL) {
+		scene->gpd = gpencil_data_addnew("GPencil");
+	}
+
+	gpl = BLI_findstring(&scene->gpd->layers, ruler_name, offsetof(bGPDlayer, info));
+	if (gpl == NULL) {
+		gpl = gpencil_layer_addnew(scene->gpd, ruler_name, false);
+		gpl->thickness = 1;
+		gpl->flag |= GP_LAYER_HIDE;
+	}
+
+	gpf = gpencil_layer_getframe(gpl, CFRA, true);
+	free_gpencil_strokes(gpf);
+
+	for (ruler_item = ruler_info->items.first; ruler_item; ruler_item = ruler_item->next) {
+		bGPDspoint *pt;
+		int j;
+
+		/* allocate memory for a new stroke */
+		gps = MEM_callocN(sizeof(bGPDstroke), "gp_stroke");
+		if (ruler_item->flag & RULERITEM_USE_ANGLE) {
+			gps->totpoints = 3;
+			pt = gps->points = MEM_callocN(sizeof(bGPDspoint) * gps->totpoints, "gp_stroke_points");
+			for (j = 0; j < 3; j++) {
+				copy_v3_v3(&pt->x, ruler_item->co[j]);
+				pt->pressure = 1.0f;
+				pt++;
+			}
+		}
+		else {
+			gps->totpoints = 2;
+			pt = gps->points = MEM_callocN(sizeof(bGPDspoint) * gps->totpoints, "gp_stroke_points");
+			for (j = 0; j < 3; j += 2) {
+				copy_v3_v3(&pt->x, ruler_item->co[j]);
+				pt->pressure = 1.0f;
+				pt++;
+			}
+		}
+		gps->flag = GP_STROKE_3DSPACE;
+		BLI_addtail(&gpf->strokes, gps);
+		change = true;
+	}
+
+	return change;
+}
+
+static bool view3d_ruler_from_gpencil(bContext *C, RulerInfo *ruler_info)
+{
+	Scene *scene = CTX_data_scene(C);
+	bool change = false;
+
+	if (scene->gpd) {
+		bGPDlayer *gpl;
+		const char *ruler_name = RULER_ID;
+		gpl = BLI_findstring(&scene->gpd->layers, ruler_name, offsetof(bGPDlayer, info));
+		if (gpl) {
+			bGPDframe *gpf;
+			gpf = gpencil_layer_getframe(gpl, CFRA, false);
+			if (gpf) {
+				bGPDstroke *gps;
+				for (gps = gpf->strokes.first; gps; gps = gps->next) {
+					bGPDspoint *pt = gps->points;
+					int j;
+					if (gps->totpoints == 3) {
+						RulerItem *ruler_item = ruler_item_add(ruler_info);
+						for (j = 0; j < 3; j++) {
+							copy_v3_v3(ruler_item->co[j], &pt->x);
+							pt++;
+						}
+						ruler_item->flag |= RULERITEM_USE_ANGLE;
+						change = true;
+					}
+					else if (gps->totpoints == 2) {
+						RulerItem *ruler_item = ruler_item_add(ruler_info);
+						for (j = 0; j < 3; j += 2) {
+							copy_v3_v3(ruler_item->co[j], &pt->x);
+							pt++;
+						}
+						change = true;
+					}
+				}
+			}
+		}
+	}
+
+	return change;
+}
+
+/* -------------------------------------------------------------------- */
+/* local callbacks */
+
+static void ruler_info_draw_pixel(const struct bContext *C, ARegion *ar, void *arg)
+{
+	Scene *scene = CTX_data_scene(C);
+	UnitSettings *unit = &scene->unit;
+	RulerItem *ruler_item;
+	RulerInfo *ruler_info = arg;
+	RegionView3D *rv3d = ruler_info->ar->regiondata;
+//	ARegion *ar = ruler_info->ar;
+	const float cap_size = 4.0f;
+	const float bg_margin = 4.0f * U.pixelsize;
+	const float bg_radius = 4.0f * U.pixelsize;
+	const float arc_size = 64.0f * U.pixelsize;
+#define ARC_STEPS 24
+	const int arc_steps = ARC_STEPS;
+	int i;
+	//unsigned int color_act = 0x666600;
+	unsigned int color_act = 0xffffff;
+	unsigned int color_base = 0x0;
+	unsigned char color_back[4] = {0xff, 0xff, 0xff, 0x80};
+	unsigned char color_text[3];
+	unsigned char color_wire[3];
+
+	/* anti-aliased lines for more consistent appearance */
+	glEnable(GL_LINE_SMOOTH);
+
+	BLF_enable(blf_mono_font, BLF_ROTATION);
+	BLF_size(blf_mono_font, 14 * U.pixelsize, U.dpi);
+	BLF_rotation(blf_mono_font, 0.0f);
+
+	UI_GetThemeColor3ubv(TH_TEXT, color_text);
+	UI_GetThemeColor3ubv(TH_WIRE, color_wire);
+
+	for (ruler_item = ruler_info->items.first, i = 0; ruler_item; ruler_item = ruler_item->next, i++) {
+		const bool is_act = (i == ruler_info->item_active);
+		float dir_ruler[2];
+		float co_ss[3][2];
+		int j;
+
+		/* should these be checked? - ok for now not to */
+		for (j = 0; j < 3; j++) {
+			ED_view3d_project_float_global(ar, ruler_item->co[j], co_ss[j], V3D_PROJ_TEST_NOP);
+		}
+
+		glEnable(GL_BLEND);
+
+		cpack(is_act ? color_act : color_base);
+
+		if (ruler_item->flag & RULERITEM_USE_ANGLE) {
+			glBegin(GL_LINE_STRIP);
+			for (j = 0; j < 3; j++) {
+				glVertex2fv(co_ss[j]);
+			}
+			glEnd();
+			cpack(0xaaaaaa);
+			setlinestyle(3);
+			glBegin(GL_LINE_STRIP);
+			for (j = 0; j < 3; j++) {
+				glVertex2fv(co_ss[j]);
+			}
+			glEnd();
+			setlinestyle(0);
+
+			/* arc */
+			{
+				float dir_tmp[3];
+				float co_tmp[3];
+				float arc_ss_coords[ARC_STEPS + 1][2];
+
+				float dir_a[3];
+				float dir_b[3];
+				float quat[4];
+				float axis[3];
+				float angle;
+				const float px_scale = (ED_view3d_pixel_size(rv3d, ruler_item->co[1]) *
+				                        min_fff(arc_size,
+				                                len_v2v2(co_ss[0], co_ss[1]) / 2.0f,
+				                                len_v2v2(co_ss[2], co_ss[1]) / 2.0f));
+
+				sub_v3_v3v3(dir_a, ruler_item->co[0], ruler_item->co[1]);
+				sub_v3_v3v3(dir_b, ruler_item->co[2], ruler_item->co[1]);
+				normalize_v3(dir_a);
+				normalize_v3(dir_b);
+
+				cross_v3_v3v3(axis, dir_a, dir_b);
+				angle = angle_normalized_v3v3(dir_a, dir_b);
+
+				axis_angle_to_quat(quat, axis, angle / arc_steps);
+
+				copy_v3_v3(dir_tmp, dir_a);
+
+				glColor3ubv(color_wire);
+
+				for (j = 0; j <= arc_steps; j++) {
+					madd_v3_v3v3fl(co_tmp, ruler_item->co[1], dir_tmp, px_scale);
+					ED_view3d_project_float_global(ar, co_tmp, arc_ss_coords[j], V3D_PROJ_TEST_NOP);
+					mul_qt_v3(quat, dir_tmp);
+				}
+
+				glEnableClientState(GL_VERTEX_ARRAY);
+				glVertexPointer(2, GL_FLOAT, 0, arc_ss_coords);
+				glDrawArrays(GL_LINE_STRIP, 0, arc_steps + 1);
+				glDisableClientState(GL_VERTEX_ARRAY);
+			}
+
+			/* text */
+			{
+				char numstr[256];
+				float numstr_size[2];
+				float pos[2];
+				const int prec = 2;  /* XXX, todo, make optional */
+
+				ruler_item_as_string(ruler_item, unit, numstr, sizeof(numstr), prec);
+
+				BLF_width_and_height(blf_mono_font, numstr, &numstr_size[0], &numstr_size[1]);
+
+				pos[0] = co_ss[1][0] + (cap_size * 2.0f);
+				pos[1] = co_ss[1][1] - (numstr_size[1] / 2.0f);
+
+				/* draw text (bg) */
+				glColor4ubv(color_back);
+				uiSetRoundBox(UI_CNR_ALL);
+				uiRoundBox(pos[0] - bg_margin,                  pos[1] - bg_margin,
+				           pos[0] + bg_margin + numstr_size[0], pos[1] + bg_margin + numstr_size[1],
+				           bg_radius);
+				/* draw text */
+				glColor3ubv(color_text);
+				BLF_position(blf_mono_font, pos[0], pos[1], 0.0f);
+				BLF_rotation(blf_mono_font, 0.0f);
+				BLF_draw(blf_mono_font, numstr, sizeof(numstr));
+			}
+
+			/* capping */
+			{
+				float rot_90_vec_a[2];
+				float rot_90_vec_b[2];
+				float cap[2];
+
+				sub_v2_v2v2(dir_ruler, co_ss[0], co_ss[1]);
+				rot_90_vec_a[0] = -dir_ruler[1];
+				rot_90_vec_a[1] =  dir_ruler[0];
+				normalize_v2(rot_90_vec_a);
+
+				sub_v2_v2v2(dir_ruler, co_ss[1], co_ss[2]);
+				rot_90_vec_b[0] = -dir_ruler[1];
+				rot_90_vec_b[1] =  dir_ruler[0];
+				normalize_v2(rot_90_vec_b);
+
+				glEnable(GL_BLEND);
+
+				glColor3ubv(color_wire);
+
+				glBegin(GL_LINES);
+
+				madd_v2_v2v2fl(cap, co_ss[0], rot_90_vec_a, cap_size);
+				glVertex2fv(cap);
+				madd_v2_v2v2fl(cap, co_ss[0], rot_90_vec_a, -cap_size);
+				glVertex2fv(cap);
+
+				madd_v2_v2v2fl(cap, co_ss[2], rot_90_vec_b, cap_size);
+				glVertex2fv(cap);
+				madd_v2_v2v2fl(cap, co_ss[2], rot_90_vec_b, -cap_size);
+				glVertex2fv(cap);
+
+				/* angle vertex */
+				glVertex2f(co_ss[1][0] - cap_size, co_ss[1][1] - cap_size);
+				glVertex2f(co_ss[1][0] + cap_size, co_ss[1][1] + cap_size);
+				glVertex2f(co_ss[1][0] - cap_size, co_ss[1][1] + cap_size);
+				glVertex2f(co_ss[1][0] + cap_size, co_ss[1][1] - cap_size);
+				glEnd();
+
+				glDisable(GL_BLEND);
+			}
+		}
+		else {
+			glBegin(GL_LINE_STRIP);
+			for (j = 0; j < 3; j += 2) {
+				glVertex2fv(co_ss[j]);
+			}
+			glEnd();
+			cpack(0xaaaaaa);
+			setlinestyle(3);
+			glBegin(GL_LINE_STRIP);
+			for (j = 0; j < 3; j += 2) {
+				glVertex2fv(co_ss[j]);
+			}
+			glEnd();
+			setlinestyle(0);
+
+			sub_v2_v2v2(dir_ruler, co_ss[0], co_ss[2]);
+
+			/* text */
+			{
+				char numstr[256];
+				float numstr_size[2];
+				const int prec = 6;  /* XXX, todo, make optional */
+				float pos[2];
+
+				ruler_item_as_string(ruler_item, unit, numstr, sizeof(numstr), prec);
+
+				BLF_width_and_height(blf_mono_font, numstr, &numstr_size[0], &numstr_size[1]);
+
+				mid_v2_v2v2(pos, co_ss[0], co_ss[2]);
+
+				/* center text */
+				pos[0] -= numstr_size[0] / 2.0f;
+				pos[1] -= numstr_size[1] / 2.0f;
+
+				/* draw text (bg) */
+				glColor4ubv(color_back);
+				uiSetRoundBox(UI_CNR_ALL);
+				uiRoundBox(pos[0] - bg_margin,                  pos[1] - bg_margin,
+				           pos[0] + bg_margin + numstr_size[0], pos[1] + bg_margin + numstr_size[1],
+				           bg_radius);
+				/* draw text */
+				glColor3ubv(color_text);
+				BLF_position(blf_mono_font, pos[0], pos[1], 0.0f);
+				BLF_draw(blf_mono_font, numstr, sizeof(numstr));
+			}
+
+			/* capping */
+			{
+				float rot_90_vec[2] = {-dir_ruler[1], dir_ruler[0]};
+				float cap[2];
+
+				normalize_v2(rot_90_vec);
+
+				glEnable(GL_BLEND);
+				glColor3ubv(color_wire);
+
+				glBegin(GL_LINES);
+				madd_v2_v2v2fl(cap, co_ss[0], rot_90_vec, cap_size);
+				glVertex2fv(cap);
+				madd_v2_v2v2fl(cap, co_ss[0], rot_90_vec, -cap_size);
+				glVertex2fv(cap);
+
+				madd_v2_v2v2fl(cap, co_ss[2], rot_90_vec, cap_size);
+				glVertex2fv(cap);
+				madd_v2_v2v2fl(cap, co_ss[2], rot_90_vec, -cap_size);
+				glVertex2fv(cap);
+				glEnd();
+
+				glDisable(GL_BLEND);
+			}
+		}
+	}
+
+	glDisable(GL_LINE_SMOOTH);
+
+	BLF_disable(blf_mono_font, BLF_ROTATION);
+
+#undef ARC_STEPS
+}
+
+/* free, use for both cancel and finish */
+static void view3d_ruler_end(const struct bContext *UNUSED(C), RulerInfo *ruler_info)
+{
+	ED_region_draw_cb_exit(ruler_info->ar->type, ruler_info->draw_handle_pixel);
+}
+
+static void view3d_ruler_free(RulerInfo *ruler_info)
+{
+	BLI_freelistN(&ruler_info->items);
+	MEM_freeN(ruler_info);
+}
+
+static void view3d_ruler_item_project(RulerInfo *ruler_info, float r_co[3],
+                                      const int xy[2])
+{
+	view3d_get_view_aligned_coordinate(ruler_info->ar, r_co, xy, true);
+}
+
+/* use for mousemove events */
+static bool view3d_ruler_item_mousemove(bContext *C, RulerInfo *ruler_info, const int mval[2], const bool do_snap)
+{
+	RulerItem *ruler_item = ruler_item_active_get(ruler_info);
+
+	if (ruler_item) {
+		float *co = ruler_item->co[ruler_item->co_index];
+		view3d_ruler_item_project(ruler_info, co, mval);
+		if (do_snap) {
+			const float mval_fl[2] = {UNPACK2(mval)};
+			ED_view3d_snap_co(C, co, mval_fl, true, true, true);
+		}
+		return true;
+	}
+	else {
+		return false;
+	}
+}
+
+static void view3d_ruler_header_update(ScrArea *sa)
+{
+	const char *text = "Ctrl+LMB: Add, "
+	                   "Del: Remove, "
+	                   "Ctrl+Drag: Snap, "
+	                   "Ctrl+C: Copy Value, "
+	                   "Enter: Store,  "
+	                   "Esc: Cancel";
+
+	ED_area_headerprint(sa, text);
+}
+
+/* -------------------------------------------------------------------- */
+/* Operator callbacks */
+
+static int view3d_ruler_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
+{
+	wmWindow *win = CTX_wm_window(C);
+	ScrArea *sa = CTX_wm_area(C);
+	ARegion *ar = CTX_wm_region(C);
+	RulerInfo *ruler_info;
+
+	ruler_info = MEM_callocN(sizeof(RulerInfo), "RulerInfo");
+
+	if (view3d_ruler_from_gpencil(C, ruler_info)) {
+		WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL);
+	}
+
+	op->customdata = ruler_info;
+
+	ruler_info->ar = ar;
+	ruler_info->draw_handle_pixel = ED_region_draw_cb_activate(ar->type, ruler_info_draw_pixel,
+	                                                           ruler_info, REGION_DRAW_POST_PIXEL);
+
+	view3d_ruler_header_update(sa);
+
+	WM_cursor_modal(win, BC_CROSSCURSOR);
+	WM_event_add_modal_handler(C, op);
+
+	return OPERATOR_RUNNING_MODAL;
+}
+
+static int view3d_ruler_cancel(bContext *C, wmOperator *op)
+{
+	RulerInfo *ruler_info = op->customdata;
+
+	view3d_ruler_end(C, ruler_info);
+	view3d_ruler_free(ruler_info);
+	op->customdata = NULL;
+
+	return OPERATOR_CANCELLED;
+}
+
+static int view3d_ruler_modal(bContext *C, wmOperator *op, const wmEvent *event)
+{
+	bool do_draw = false;
+	int exit_code = OPERATOR_RUNNING_MODAL;
+	RulerInfo *ruler_info = op->customdata;
+	ARegion *ar = ruler_info->ar;
+	RegionView3D *rv3d = ar->regiondata;
+
+	(void)C;
+
+	switch (event->type) {
+		case LEFTMOUSE:
+			if (event->val == KM_RELEASE) {
+				if (ruler_info->state == RULER_STATE_DRAG) {
+					/* rubber-band angle removal */
+					RulerItem *ruler_item = ruler_item_active_get(ruler_info);
+					if (ruler_item && (ruler_item->co_index == 1) && (ruler_item->flag & RULERITEM_USE_ANGLE)) {
+						if (!BLI_rcti_isect_pt_v(&ar->winrct, &event->x)) {
+							ruler_item->flag &= ~RULERITEM_USE_ANGLE;
+							do_draw = true;
+						}
+					}
+					ruler_info->state = RULER_STATE_NORMAL;
+				}
+			}
+			else {
+				if (ruler_info->state == RULER_STATE_NORMAL) {
+
+					if (event->ctrl ||
+					    /* weak - but user friendly */
+					    (ruler_info->items.first == NULL))
+					{
+						/* Create new line */
+						RulerItem *ruler_item;
+						/* check if we want to drag an existing point or add a new one */
+						ruler_info->state = RULER_STATE_DRAG;
+
+						ruler_item = ruler_item_add(ruler_info);
+						ruler_item_active_set(ruler_info, ruler_item);
+
+						negate_v3_v3(ruler_item->co[0], rv3d->ofs);
+						view3d_ruler_item_project(ruler_info, ruler_item->co[0], event->mval);
+
+						/* snap the first point added, not essential but handy */
+						{
+							ruler_item->co_index = 0;
+							view3d_ruler_item_mousemove(C, ruler_info, event->mval, true);
+						}
+
+						copy_v3_v3(ruler_item->co[2], ruler_item->co[0]);
+						ruler_item->co_index = 2;
+
+						do_draw = true;
+					}
+					else {
+						float mval_fl[2] = {UNPACK2(event->mval)};
+						RulerItem *ruler_item_pick;
+						int co_index;
+
+						/* select and drag */
+						if (view3d_ruler_pick(ruler_info, mval_fl, &ruler_item_pick, &co_index)) {
+							if (co_index == -1) {
+								if ((ruler_item_pick->flag & RULERITEM_USE_ANGLE) == 0) {
+									/* Add Center Point */
+									ruler_item_active_set(ruler_info, ruler_item_pick);
+									ruler_item_pick->flag |= RULERITEM_USE_ANGLE;
+									ruler_item_pick->co_index = 1;
+									ruler_info->state = RULER_STATE_DRAG;
+
+									/* find the factor */
+									{
+										float co_ss[2][2];
+										float fac;
+
+										ED_view3d_project_float_global(ar, ruler_item_pick->co[0], co_ss[0], V3D_PROJ_TEST_NOP);
+										ED_view3d_project_float_global(ar, ruler_item_pick->co[2], co_ss[1], V3D_PROJ_TEST_NOP);
+
+										fac = line_point_factor_v2(mval_fl, co_ss[0], co_ss[1]);
+										CLAMP(fac, 0.0f, 1.0f);
+
+										interp_v3_v3v3(ruler_item_pick->co[1],
+										               ruler_item_pick->co[0],
+										               ruler_item_pick->co[2], fac);
+									}
+
+									/* update the new location */
+									view3d_ruler_item_mousemove(C, ruler_info, event->mval, event->ctrl != 0);
+									do_draw = true;
+								}
+							}
+							else {
+								ruler_item_active_set(ruler_info, ruler_item_pick);
+								ruler_item_pick->co_index = co_index;
+								ruler_info->state = RULER_STATE_DRAG;
+								do_draw = true;
+							}
+						}
+						else {
+							exit_code = OPERATOR_PASS_THROUGH;
+						}
+
+					}
+				}
+			}
+			break;
+		case CKEY:
+		{
+			if (event->ctrl) {
+				RulerItem *ruler_item = ruler_item_active_get(ruler_info);
+				if (ruler_item) {
+					const int prec = 8;
+					char numstr[256];
+					Scene *scene = CTX_data_scene(C);
+					UnitSettings *unit = &scene->unit;
+
+					ruler_item_as_string(ruler_item, unit, numstr, sizeof(numstr), prec);
+					WM_clipboard_text_set((void *) numstr, false);
+				}
+			}
+		}
+		case RIGHTCTRLKEY:
+		case LEFTCTRLKEY:
+		{
+			WM_event_add_mousemove(C);
+			break;
+		}
+		case MOUSEMOVE:
+		{
+			if (ruler_info->state == RULER_STATE_DRAG) {
+				if (view3d_ruler_item_mousemove(C, ruler_info, event->mval, event->ctrl != 0)) {
+					do_draw = true;
+				}
+			}
+			break;
+		}
+		case ESCKEY:
+		{
+			do_draw = true;
+			exit_code = OPERATOR_CANCELLED;
+			break;
+		}
+		case RETKEY:
+		{
+			view3d_ruler_to_gpencil(C, ruler_info);
+			do_draw = true;
+			exit_code = OPERATOR_FINISHED;
+			break;
+		}
+		case DELKEY:
+		{
+			if (event->val == KM_PRESS) {
+				if (ruler_info->state == RULER_STATE_NORMAL) {
+					RulerItem *ruler_item = ruler_item_active_get(ruler_info);
+					if (ruler_item) {
+						ruler_item_remove(ruler_info, ruler_item);
+						ruler_info->item_active = -1;
+						do_draw = true;
+					}
+				}
+			}
+			break;
+		}
+		default:
+			exit_code = OPERATOR_PASS_THROUGH;
+			break;
+
+	}
+
+	if (do_draw) {
+		ScrArea *sa = CTX_wm_area(C);
+
+		view3d_ruler_header_update(sa);
+
+		/* all 3d views draw rulers */
+		WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL);
+	}
+
+	if (ELEM(exit_code, OPERATOR_FINISHED, OPERATOR_CANCELLED)) {
+		wmWindow *win = CTX_wm_window(C);
+		ScrArea *sa = CTX_wm_area(C);
+
+		WM_cursor_restore(win);
+
+		view3d_ruler_end(C, ruler_info);
+		view3d_ruler_free(ruler_info);
+		op->customdata = NULL;
+
+		ED_area_headerprint(sa, NULL);
+	}
+
+	return exit_code;
+}
+
+void VIEW3D_OT_ruler(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "3D Ruler & Protractor";
+	ot->description = "Interactive ruler";
+	ot->idname = "VIEW3D_OT_ruler";
+
+	/* api callbacks */
+	ot->invoke = view3d_ruler_invoke;
+	ot->cancel = view3d_ruler_cancel;
+	ot->modal = view3d_ruler_modal;
+	ot->poll = ED_operator_view3d_active;
+
+	/* flags */
+	ot->flag = 0;
+}
diff --git a/source/blender/editors/space_view3d/view3d_select.c b/source/blender/editors/space_view3d/view3d_select.c
index 24260898066..b441e48f59d 100644
--- a/source/blender/editors/space_view3d/view3d_select.c
+++ b/source/blender/editors/space_view3d/view3d_select.c
@@ -108,23 +108,23 @@ void view3d_set_viewcontext(bContext *C, ViewContext *vc)
 	vc->obedit = CTX_data_edit_object(C);
 }
 
-int view3d_get_view_aligned_coordinate(ViewContext *vc, float fp[3], const int mval[2], const short do_fallback)
+/**
+ * Re-project \a fp so it stays on the same view-plane but is under \a mval (normally the cursor location).
+ */
+bool view3d_get_view_aligned_coordinate(ARegion *ar, float fp[3], const int mval[2], const bool do_fallback)
 {
+	RegionView3D *rv3d = ar->regiondata;
 	float dvec[3];
 	int mval_cpy[2];
 	eV3DProjStatus ret;
 
-	mval_cpy[0] = mval[0];
-	mval_cpy[1] = mval[1];
-
-	ret = ED_view3d_project_int_global(vc->ar, fp, mval_cpy, V3D_PROJ_TEST_NOP);
-
-	initgrabz(vc->rv3d, fp[0], fp[1], fp[2]);
+	ret = ED_view3d_project_int_global(ar, fp, mval_cpy, V3D_PROJ_TEST_NOP);
 
 	if (ret == V3D_PROJ_RET_OK) {
 		const float mval_f[2] = {(float)(mval_cpy[0] - mval[0]),
 		                         (float)(mval_cpy[1] - mval[1])};
-		ED_view3d_win_to_delta(vc->ar, mval_f, dvec);
+		const float zfac = ED_view3d_calc_zfac(rv3d, fp, NULL);
+		ED_view3d_win_to_delta(ar, mval_f, dvec, zfac);
 		sub_v3_v3(fp, dvec);
 
 		return TRUE;
@@ -132,11 +132,11 @@ int view3d_get_view_aligned_coordinate(ViewContext *vc, float fp[3], const int m
 	else {
 		/* fallback to the view center */
 		if (do_fallback) {
-			negate_v3_v3(fp, vc->rv3d->ofs);
-			return view3d_get_view_aligned_coordinate(vc, fp, mval, FALSE);
+			negate_v3_v3(fp, rv3d->ofs);
+			return view3d_get_view_aligned_coordinate(ar, fp, mval, false);
 		}
 		else {
-			return FALSE;
+			return false;
 		}
 	}
 }
@@ -177,10 +177,9 @@ static void edbm_backbuf_check_and_select_verts(BMEditMesh *em, int select)
 {
 	BMVert *eve;
 	BMIter iter;
-	int index = bm_wireoffs;
+	unsigned int index = bm_wireoffs;
 
-	eve = BM_iter_new(&iter, em->bm, BM_VERTS_OF_MESH, NULL);
-	for (; eve; eve = BM_iter_step(&iter), index++) {
+	for (eve = BM_iter_new(&iter, em->bm, BM_VERTS_OF_MESH, NULL); eve; eve = BM_iter_step(&iter), index++) {
 		if (!BM_elem_flag_test(eve, BM_ELEM_HIDDEN)) {
 			if (EDBM_backbuf_check(index)) {
 				BM_vert_select_set(em->bm, eve, select);
@@ -209,7 +208,7 @@ static void edbm_backbuf_check_and_select_faces(BMEditMesh *em, int select)
 {
 	BMFace *efa;
 	BMIter iter;
-	int index = 1;
+	unsigned int index = 1;
 
 	efa = BM_iter_new(&iter, em->bm, BM_FACES_OF_MESH, NULL);
 	for (; efa; efa = BM_iter_step(&iter), index++) {
@@ -226,11 +225,11 @@ static void edbm_backbuf_check_and_select_faces(BMEditMesh *em, int select)
 static void edbm_backbuf_check_and_select_verts_obmode(Mesh *me, int select)
 {
 	MVert *mv = me->mvert;
-	int a;
+	unsigned int index;
 
 	if (mv) {
-		for (a = 1; a <= me->totvert; a++, mv++) {
-			if (EDBM_backbuf_check(a)) {
+		for (index = 1; index <= me->totvert; index++, mv++) {
+			if (EDBM_backbuf_check(index)) {
 				if (!(mv->flag & ME_HIDE)) {
 					mv->flag = select ? (mv->flag | SELECT) : (mv->flag & ~SELECT);
 				}
@@ -243,11 +242,11 @@ static void edbm_backbuf_check_and_select_verts_obmode(Mesh *me, int select)
 static void edbm_backbuf_check_and_select_tfaces(Mesh *me, int select)
 {
 	MPoly *mpoly = me->mpoly;
-	int a;
+	unsigned int index;
 
 	if (mpoly) {
-		for (a = 1; a <= me->totpoly; a++, mpoly++) {
-			if (EDBM_backbuf_check(a)) {
+		for (index = 1; index <= me->totpoly; index++, mpoly++) {
+			if (EDBM_backbuf_check(index)) {
 				mpoly->flag = select ? (mpoly->flag | ME_FACE_SEL) : (mpoly->flag & ~ME_FACE_SEL);
 			}
 		}
@@ -733,7 +732,7 @@ static void do_lasso_select_meta(ViewContext *vc, const int mcords[][2], short m
 	MetaBall *mb = (MetaBall *)vc->obedit->data;
 
 	if (extend == 0 && select)
-		 BKE_mball_deselect_all(mb);
+		BKE_mball_deselect_all(mb);
 
 	BLI_lasso_boundbox(&rect, mcords, moves);
 
@@ -780,9 +779,6 @@ static void do_lasso_select_paintvert(ViewContext *vc, const int mcords[][2], sh
 	}
 	else {
 		LassoSelectUserData data;
-		rcti rect;
-
-		BLI_lasso_boundbox(&rect, mcords, moves);
 
 		view3d_userdata_lassoselect_init(&data, vc, &rect, mcords, moves, select);
 
@@ -1054,7 +1050,7 @@ static int object_select_menu_exec(bContext *C, wmOperator *op)
 	CTX_DATA_BEGIN (C, Base *, base, selectable_bases)
 	{
 		/* this is a bit dodjy, there should only be ONE object with this name, but library objects can mess this up */
-		if (strcmp(name, base->object->id.name + 2) == 0) {
+		if (STREQ(name, base->object->id.name + 2)) {
 			ED_base_object_activate(C, base);
 			ED_base_object_select(base, BA_SELECT);
 			changed = 1;
@@ -2230,7 +2226,7 @@ static int mouse_weight_paint_vertex_select(bContext *C, const int mval[2], shor
 /* ****** Mouse Select ****** */
 
 
-static int view3d_select_invoke(bContext *C, wmOperator *op, wmEvent *event)
+static int view3d_select_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	Object *obedit = CTX_data_edit_object(C);
 	Object *obact = CTX_data_active_object(C);
diff --git a/source/blender/editors/space_view3d/view3d_toolbar.c b/source/blender/editors/space_view3d/view3d_toolbar.c
index bb5b7aa6911..d3bf8a30792 100644
--- a/source/blender/editors/space_view3d/view3d_toolbar.c
+++ b/source/blender/editors/space_view3d/view3d_toolbar.c
@@ -156,7 +156,7 @@ static void operator_search_cb(const struct bContext *C, void *UNUSED(arg), cons
 {
 	GHashIterator *iter = WM_operatortype_iter();
 
-	for (; !BLI_ghashIterator_isDone(iter); BLI_ghashIterator_step(iter)) {
+	for (; BLI_ghashIterator_notDone(iter); BLI_ghashIterator_step(iter)) {
 		wmOperatorType *ot = BLI_ghashIterator_getValue(iter);
 
 		if (BLI_strcasestr(ot->name, str)) {
diff --git a/source/blender/editors/space_view3d/view3d_view.c b/source/blender/editors/space_view3d/view3d_view.c
index fba1ce328ba..b2e10fa8457 100644
--- a/source/blender/editors/space_view3d/view3d_view.c
+++ b/source/blender/editors/space_view3d/view3d_view.c
@@ -294,7 +294,7 @@ void view3d_smooth_view(bContext *C, View3D *v3d, ARegion *ar, Object *oldcamera
 }
 
 /* only meant for timer usage */
-static int view3d_smoothview_invoke(bContext *C, wmOperator *UNUSED(op), wmEvent *event)
+static int view3d_smoothview_invoke(bContext *C, wmOperator *UNUSED(op), const wmEvent *event)
 {
 	View3D *v3d = CTX_wm_view3d(C);
 	RegionView3D *rv3d = CTX_wm_region_view3d(C);
@@ -667,22 +667,29 @@ void ED_view3d_depth_tag_update(RegionView3D *rv3d)
 }
 
 /* copies logic of get_view3d_viewplane(), keep in sync */
-int ED_view3d_clip_range_get(View3D *v3d, RegionView3D *rv3d, float *clipsta, float *clipend)
+bool ED_view3d_clip_range_get(View3D *v3d, RegionView3D *rv3d, float *r_clipsta, float *r_clipend,
+                              const bool use_ortho_factor)
 {
 	CameraParams params;
 
 	BKE_camera_params_init(&params);
 	BKE_camera_params_from_view3d(&params, v3d, rv3d);
 
-	if (clipsta) *clipsta = params.clipsta;
-	if (clipend) *clipend = params.clipend;
+	if (use_ortho_factor && params.is_ortho) {
+		const float fac = 2.0f / (params.clipend - params.clipsta);
+		params.clipsta *= fac;
+		params.clipend *= fac;
+	}
+
+	if (r_clipsta) *r_clipsta = params.clipsta;
+	if (r_clipend) *r_clipend = params.clipend;
 
 	return params.is_ortho;
 }
 
 /* also exposed in previewrender.c */
-int ED_view3d_viewplane_get(View3D *v3d, RegionView3D *rv3d, int winx, int winy,
-                            rctf *viewplane, float *clipsta, float *clipend)
+bool ED_view3d_viewplane_get(View3D *v3d, RegionView3D *rv3d, int winx, int winy,
+                             rctf *r_viewplane, float *r_clipsta, float *r_clipend)
 {
 	CameraParams params;
 
@@ -690,9 +697,9 @@ int ED_view3d_viewplane_get(View3D *v3d, RegionView3D *rv3d, int winx, int winy,
 	BKE_camera_params_from_view3d(&params, v3d, rv3d);
 	BKE_camera_params_compute_viewplane(&params, winx, winy, 1.0f, 1.0f);
 
-	if (viewplane) *viewplane = params.viewplane;
-	if (clipsta) *clipsta = params.clipsta;
-	if (clipend) *clipend = params.clipend;
+	if (r_viewplane) *r_viewplane = params.viewplane;
+	if (r_clipsta) *r_clipsta = params.clipsta;
+	if (r_clipend) *r_clipend = params.clipend;
 	
 	return params.is_ortho;
 }
@@ -791,7 +798,7 @@ static void obmat_to_viewmat(View3D *v3d, RegionView3D *rv3d, Object *ob, short
 
 #define QUATSET(a, b, c, d, e) { a[0] = b; a[1] = c; a[2] = d; a[3] = e; } (void)0
 
-int ED_view3d_lock(RegionView3D *rv3d)
+bool ED_view3d_lock(RegionView3D *rv3d)
 {
 	switch (rv3d->view) {
 		case RV3D_VIEW_BOTTOM:
@@ -818,10 +825,10 @@ int ED_view3d_lock(RegionView3D *rv3d)
 			QUATSET(rv3d->viewquat, 0.5, -0.5, -0.5, -0.5);
 			break;
 		default:
-			return FALSE;
+			return false;
 	}
 
-	return TRUE;
+	return true;
 }
 
 /* don't set windows active in here, is used by renderwin too */
@@ -863,7 +870,9 @@ void setviewmatrixview3d(Scene *scene, View3D *v3d, RegionView3D *rv3d)
 			copy_v3_v3(vec, give_cursor(scene, v3d));
 			translate_m4(rv3d->viewmat, -vec[0], -vec[1], -vec[2]);
 		}
-		else translate_m4(rv3d->viewmat, rv3d->ofs[0], rv3d->ofs[1], rv3d->ofs[2]);
+		else {
+			translate_m4(rv3d->viewmat, rv3d->ofs[0], rv3d->ofs[1], rv3d->ofs[2]);
+		}
 	}
 }
 
@@ -1558,11 +1567,7 @@ static void UNUSED_FUNCTION(view3d_align_axis_to_vector)(View3D *v3d, RegionView
 
 float ED_view3d_pixel_size(RegionView3D *rv3d, const float co[3])
 {
-	return (rv3d->persmat[3][3] + (
-	            rv3d->persmat[0][3] * co[0] +
-	            rv3d->persmat[1][3] * co[1] +
-	            rv3d->persmat[2][3] * co[2])
-	        ) * rv3d->pixsize * U.pixelsize;
+	return mul_project_m4_v3_zfac(rv3d->persmat, co) * rv3d->pixsize * U.pixelsize;
 }
 
 float ED_view3d_radius_to_persp_dist(const float angle, const float radius)