fix own regression in 2.65 [#33643] Rotation does not work at certain zoom level

caused by not projecting points behind the perspective view,
even though this worked in 2.64 the values were flipped (rotating direction was reversed and the center point was flipped).

added V3D_PROJ_TEST_CLIP_NEAR, when omitted ED_view3d_project_*** will project points from behind a perspective view plane.

3 files changed, 18 insertions, 12 deletions

diff --git a/source/blender/editors/space_view3d/drawobject.c b/source/blender/editors/space_view3d/drawobject.c
index d444612cfc5..1ec0e52292c 100644
--- a/source/blender/editors/space_view3d/drawobject.c
+++ b/source/blender/editors/space_view3d/drawobject.c
@@ -755,7 +755,7 @@ void view3d_cached_text_draw_end(View3D *v3d, ARegion *ar, int depth_write, floa
 		                               (vos->flag & V3D_CACHE_TEXT_GLOBALSPACE) ? rv3d->persmat : rv3d->persmatob,
 		                               (vos->flag & V3D_CACHE_TEXT_LOCALCLIP) != 0,
 		                               vos->vec, vos->sco,
-		                               V3D_PROJ_TEST_CLIP_BB | V3D_PROJ_TEST_CLIP_WIN) == V3D_PROJ_RET_OK)
+		                               V3D_PROJ_TEST_CLIP_BB | V3D_PROJ_TEST_CLIP_WIN | V3D_PROJ_TEST_CLIP_NEAR) == V3D_PROJ_RET_OK)
 		{
 			tot++;
 		}
diff --git a/source/blender/editors/space_view3d/view3d_project.c b/source/blender/editors/space_view3d/view3d_project.c
index 6227a55a890..153d7a61cf7 100644
--- a/source/blender/editors/space_view3d/view3d_project.c
+++ b/source/blender/editors/space_view3d/view3d_project.c
@@ -134,13 +134,19 @@ static eV3DProjStatus ed_view3d_project__internal(ARegion *ar,
 	vec4[3] = 1.0;
 	mul_m4_v4(perspmat, vec4);
 
-	if (vec4[3] > (float)BL_NEAR_CLIP) {
-		const float fx = ((float)ar->winx / 2.0f) * (1.0f + vec4[0] / vec4[3]);
-		if (((flag & V3D_PROJ_TEST_CLIP_WIN) == 0) || (fx > 0 && fx < ar->winx)) {
-			const float fy = ((float)ar->winy / 2.0f) * (1.0f + vec4[1] / vec4[3]);
+	if (((flag & V3D_PROJ_TEST_CLIP_NEAR) == 0)  || (vec4[3] > (float)BL_NEAR_CLIP)) {
+		const float scalar = (vec4[3] != 0.0f) ? (1.0f / vec4[3]): 0.0f;
+		const float fx = ((float)ar->winx / 2.0f) * (1.0f + (vec4[0] * scalar));
+		if (((flag & V3D_PROJ_TEST_CLIP_WIN) == 0) || (fx > 0.0f && fx < (float)ar->winx)) {
+			const float fy = ((float)ar->winy / 2.0f) * (1.0f + (vec4[1] * scalar));
 			if (((flag & V3D_PROJ_TEST_CLIP_WIN) == 0) || (fy > 0.0f && fy < (float)ar->winy)) {
 				r_co[0] = floorf(fx);
 				r_co[1] = floorf(fy);
+
+				/* check if the point is behind the view, we need to flip in this case */
+				if (UNLIKELY((flag & V3D_PROJ_TEST_CLIP_NEAR) == 0) && (vec4[3] < 0.0f)) {
+					negate_v2(r_co);
+				}
 			}
 			else {
 				return V3D_PROJ_RET_CLIP_WIN;
diff --git a/source/blender/editors/space_view3d/view3d_select.c b/source/blender/editors/space_view3d/view3d_select.c
index cffa53b5dfb..d37042fa2ec 100644
--- a/source/blender/editors/space_view3d/view3d_select.c
+++ b/source/blender/editors/space_view3d/view3d_select.c
@@ -541,11 +541,11 @@ static void do_lasso_select_mesh(ViewContext *vc, const int mcords[][2], short m
 	if (ts->selectmode & SCE_SELECT_EDGE) {
 		/* Does both bbsel and non-bbsel versions (need screen cos for both) */
 		data.pass = 0;
-		mesh_foreachScreenEdge(vc, do_lasso_select_mesh__doSelectEdge, &data, V3D_PROJ_TEST_NOP);
+		mesh_foreachScreenEdge(vc, do_lasso_select_mesh__doSelectEdge, &data, V3D_PROJ_TEST_CLIP_NEAR);
 
 		if (data.is_done == 0) {
 			data.pass = 1;
-			mesh_foreachScreenEdge(vc, do_lasso_select_mesh__doSelectEdge, &data, V3D_PROJ_TEST_NOP);
+			mesh_foreachScreenEdge(vc, do_lasso_select_mesh__doSelectEdge, &data, V3D_PROJ_TEST_CLIP_NEAR);
 		}
 	}
 	
@@ -1448,7 +1448,7 @@ static int mouse_select(bContext *C, const int mval[2], short extend, short dese
 				if (BASE_SELECTABLE(v3d, base)) {
 					float screen_co[2];
 					if (ED_view3d_project_float_global(ar, base->object->obmat[3], screen_co,
-					                                   V3D_PROJ_TEST_CLIP_BB | V3D_PROJ_TEST_CLIP_WIN) == V3D_PROJ_RET_OK)
+					                                   V3D_PROJ_TEST_CLIP_BB | V3D_PROJ_TEST_CLIP_WIN | V3D_PROJ_TEST_CLIP_NEAR) == V3D_PROJ_RET_OK)
 					{
 						float dist_temp = len_manhattan_v2v2(mval_fl, screen_co);
 						if (base == BASACT) dist_temp += 10.0f;
@@ -1803,11 +1803,11 @@ static int do_mesh_box_select(ViewContext *vc, rcti *rect, int select, int exten
 		/* Does both bbsel and non-bbsel versions (need screen cos for both) */
 
 		data.pass = 0;
-		mesh_foreachScreenEdge(vc, do_mesh_box_select__doSelectEdge, &data, V3D_PROJ_TEST_NOP);
+		mesh_foreachScreenEdge(vc, do_mesh_box_select__doSelectEdge, &data, V3D_PROJ_TEST_CLIP_NEAR);
 
 		if (data.is_done == 0) {
 			data.pass = 1;
-			mesh_foreachScreenEdge(vc, do_mesh_box_select__doSelectEdge, &data, V3D_PROJ_TEST_NOP);
+			mesh_foreachScreenEdge(vc, do_mesh_box_select__doSelectEdge, &data, V3D_PROJ_TEST_CLIP_NEAR);
 		}
 	}
 	
@@ -2333,7 +2333,7 @@ static void mesh_circle_select(ViewContext *vc, int select, const int mval[2], f
 			edbm_backbuf_check_and_select_edges(vc->em, select == LEFTMOUSE);
 		}
 		else {
-			mesh_foreachScreenEdge(vc, mesh_circle_doSelectEdge, &data, V3D_PROJ_TEST_NOP);
+			mesh_foreachScreenEdge(vc, mesh_circle_doSelectEdge, &data, V3D_PROJ_TEST_CLIP_NEAR);
 		}
 	}
 	
@@ -2670,7 +2670,7 @@ static int object_circle_select(ViewContext *vc, int select, const int mval[2],
 		if (BASE_SELECTABLE(vc->v3d, base) && ((base->flag & SELECT) != select_flag)) {
 			float screen_co[2];
 			if (ED_view3d_project_float_global(vc->ar, base->object->obmat[3], screen_co,
-			                                   V3D_PROJ_TEST_CLIP_BB | V3D_PROJ_TEST_CLIP_WIN) == V3D_PROJ_RET_OK)
+			                                   V3D_PROJ_TEST_CLIP_BB | V3D_PROJ_TEST_CLIP_WIN | V3D_PROJ_TEST_CLIP_NEAR) == V3D_PROJ_RET_OK)
 			{
 				if (len_squared_v2v2(mval_fl, screen_co) <= radius_squared) {
 					ED_base_object_select(base, select);