Make toggle and hold snap method cohabit nicely.

Shift-Tab toggles the global toolsetting snap settings (both in and out of transform).
Holding down Ctrl inverts the snap setting in transform (turns it on when global snap is off and vice versa).
Ctrl-Shift-Tab to select snap mode (only outside of transform for now).

For old (pre 2.5) behavior, just keep global snap off and use Ctrl.

NOTE: transform modal events for snap have change a bit, saved keymap might not work anymore.

1 files changed, 83 insertions, 72 deletions

diff --git a/source/blender/editors/transform/transform_snap.c b/source/blender/editors/transform/transform_snap.c
index ae28986017f..b8ea49110fc 100644
--- a/source/blender/editors/transform/transform_snap.c
+++ b/source/blender/editors/transform/transform_snap.c
@@ -90,7 +90,7 @@
 
 /********************* PROTOTYPES ***********************/
 
-void setSnappingCallback(TransInfo *t, short snap_target);
+void setSnappingCallback(TransInfo *t);
 
 void ApplySnapTranslation(TransInfo *t, float vec[3]);
 void ApplySnapRotation(TransInfo *t, float *vec);
@@ -123,15 +123,20 @@ int BIF_snappingSupported(Object *obedit)
 	return status;
 }
 
-int validSnap(TransInfo *t) {
+int validSnap(TransInfo *t)
+{
 	return (t->tsnap.status & (POINT_INIT|TARGET_INIT)) == (POINT_INIT|TARGET_INIT) ||
 			(t->tsnap.status & (MULTI_POINTS|TARGET_INIT)) == (MULTI_POINTS|TARGET_INIT);
 }
 
+int activeSnap(TransInfo *t)
+{
+	return (t->modifiers & (MOD_SNAP|MOD_SNAP_INVERT)) == MOD_SNAP || (t->modifiers & (MOD_SNAP|MOD_SNAP_INVERT)) == MOD_SNAP_INVERT;
+}
+
 void drawSnapping(const struct bContext *C, TransInfo *t)
 {
-	if (validSnap(t) &&
-		(t->modifiers & MOD_SNAP))
+	if (validSnap(t) && activeSnap(t))
 		{
 		
 		char col[4] = {1, 0, 1};
@@ -232,7 +237,7 @@ int  handleSnapping(TransInfo *t, wmEvent *event)
 void applyProject(TransInfo *t)
 {
 	/* XXX FLICKER IN OBJECT MODE */
-	if ((t->tsnap.project) && (t->modifiers & MOD_SNAP) && (t->modifiers & MOD_SNAP))
+	if ((t->tsnap.project) && activeSnap(t))
 	{
 		TransData *td = t->data;
 		float tvec[3];
@@ -268,7 +273,7 @@ void applyProject(TransInfo *t)
 			
 			project_float(t->ar, iloc, mval);
 			
-			if (snapObjectsTransform(t, mval, &dist, loc, no, t->tsnap.modeTarget))
+			if (snapObjectsTransform(t, mval, &dist, loc, no, t->tsnap.target))
 			{
 //				if(t->flag & (T_EDIT|T_POSE)) {
 //					mul_m4_v3(imat, loc);
@@ -298,8 +303,7 @@ void applySnapping(TransInfo *t, float *vec)
 	
 		t->tsnap.applySnap(t, vec);
 	}
-	else if ((t->tsnap.mode != SCE_SNAP_MODE_INCREMENT) &&
-		(t->modifiers & MOD_SNAP))
+	else if ((t->tsnap.mode != SCE_SNAP_MODE_INCREMENT) && activeSnap(t))
 	{
 		double current = PIL_check_seconds_timer();
 		
@@ -325,7 +329,7 @@ void resetSnapping(TransInfo *t)
 	t->tsnap.align = 0;
 	t->tsnap.mode = 0;
 	t->tsnap.modeSelect = 0;
-	t->tsnap.modeTarget = 0;
+	t->tsnap.target = 0;
 	t->tsnap.last = 0;
 	t->tsnap.applySnap = NULL;
 
@@ -352,11 +356,67 @@ int validSnappingNormal(TransInfo *t)
 	return 0;
 }
 
-void initSnapping(TransInfo *t, wmOperator *op)
+void initSnappingMode(TransInfo *t)
 {
 	ToolSettings *ts = t->settings;
 	Object *obedit = t->obedit;
 	Scene *scene = t->scene;
+
+	resetSnapping(t);
+
+	/* force project off when not supported */
+	if (ts->snap_mode != SCE_SNAP_MODE_FACE)
+	{
+		t->tsnap.project = 0;
+	}
+
+	t->tsnap.mode = ts->snap_mode;
+
+	if ((t->spacetype == SPACE_VIEW3D || t->spacetype == SPACE_IMAGE) && // Only 3D view or UV
+			(t->flag & T_CAMERA) == 0) { // Not with camera selected in camera view
+		setSnappingCallback(t);
+
+		/* Edit mode */
+		if (t->tsnap.applySnap != NULL && // A snapping function actually exist
+			(obedit != NULL && ELEM3(obedit->type, OB_MESH, OB_ARMATURE, OB_CURVE)) ) // Temporary limited to edit mode meshes, armature, curves
+		{
+			if (t->flag & T_PROP_EDIT)
+			{
+				t->tsnap.modeSelect = SNAP_NOT_OBEDIT;
+			}
+			else
+			{
+				t->tsnap.modeSelect = SNAP_ALL;
+			}
+		}
+		/* Particles edit mode*/
+		else if (t->tsnap.applySnap != NULL && // A snapping function actually exist
+			(obedit == NULL && BASACT && BASACT->object && BASACT->object->mode & OB_MODE_PARTICLE_EDIT ))
+		{
+			t->tsnap.modeSelect = SNAP_ALL;
+		}
+		/* Object mode */
+		else if (t->tsnap.applySnap != NULL && // A snapping function actually exist
+			(obedit == NULL) ) // Object Mode
+		{
+			t->tsnap.modeSelect = SNAP_NOT_SELECTED;
+		}
+		else
+		{
+			/* Grid if snap is not possible */
+			t->tsnap.mode = SCE_SNAP_MODE_INCREMENT;
+		}
+	}
+	else
+	{
+		/* Always grid outside of 3D view */
+		t->tsnap.mode = SCE_SNAP_MODE_INCREMENT;
+	}
+}
+
+void initSnapping(TransInfo *t, wmOperator *op)
+{
+	ToolSettings *ts = t->settings;
 	short snap_target = t->settings->snap_target;
 	
 	resetSnapping(t);
@@ -405,76 +465,27 @@ void initSnapping(TransInfo *t, wmOperator *op)
 		t->tsnap.peel = ((t->settings->snap_flag & SCE_SNAP_PROJECT) == SCE_SNAP_PROJECT);
 	}
 	
-	/* force project off when not supported */
-	if (ts->snap_mode != SCE_SNAP_MODE_FACE)
-	{
-		t->tsnap.project = 0;
-	}
-	
-	t->tsnap.mode = ts->snap_mode;
+	t->tsnap.target = snap_target;
 
-	if ((t->spacetype == SPACE_VIEW3D || t->spacetype == SPACE_IMAGE) && // Only 3D view or UV
-			(t->flag & T_CAMERA) == 0) { // Not with camera selected in camera view
-		setSnappingCallback(t, snap_target);
-
-		/* Edit mode */
-		if (t->tsnap.applySnap != NULL && // A snapping function actually exist
-			(obedit != NULL && ELEM3(obedit->type, OB_MESH, OB_ARMATURE, OB_CURVE)) ) // Temporary limited to edit mode meshes, armature, curves
-		{
-			if (t->flag & T_PROP_EDIT)
-			{
-				t->tsnap.modeSelect = SNAP_NOT_OBEDIT;
-			}
-			else
-			{
-				t->tsnap.modeSelect = SNAP_ALL;
-			}
-		}
-		/* Particles edit mode*/
-		else if (t->tsnap.applySnap != NULL && // A snapping function actually exist
-			(obedit == NULL && BASACT && BASACT->object && BASACT->object->mode & OB_MODE_PARTICLE_EDIT ))
-		{
-			t->tsnap.modeSelect = SNAP_ALL;
-		}
-		/* Object mode */
-		else if (t->tsnap.applySnap != NULL && // A snapping function actually exist
-			(obedit == NULL) ) // Object Mode
-		{
-			t->tsnap.modeSelect = SNAP_NOT_SELECTED;
-		}
-		else
-		{	
-			/* Grid if snap is not possible */
-			t->tsnap.mode = SCE_SNAP_MODE_INCREMENT;
-		}
-	}
-	else
-	{
-		/* Always grid outside of 3D view */
-		t->tsnap.mode = SCE_SNAP_MODE_INCREMENT;
-	}
+	initSnappingMode(t);
 }
 
-void setSnappingCallback(TransInfo *t, short snap_target)
+void setSnappingCallback(TransInfo *t)
 {
 	t->tsnap.calcSnap = CalcSnapGeometry;
 
-	switch(snap_target)
+	switch(t->tsnap.target)
 	{
 		case SCE_SNAP_TARGET_CLOSEST:
-			t->tsnap.modeTarget = SNAP_CLOSEST;
 			t->tsnap.targetSnap = TargetSnapClosest;
 			break;
 		case SCE_SNAP_TARGET_CENTER:
-			t->tsnap.modeTarget = SNAP_CENTER;
 			t->tsnap.targetSnap = TargetSnapCenter;
 			break;
 		case SCE_SNAP_TARGET_MEDIAN:
-			t->tsnap.modeTarget = SNAP_MEDIAN;
 			t->tsnap.targetSnap = TargetSnapMedian;
 			break;
 		case SCE_SNAP_TARGET_ACTIVE:
-			t->tsnap.modeTarget = SNAP_ACTIVE;
 			t->tsnap.targetSnap = TargetSnapActive;
 			break;
 
@@ -491,8 +502,8 @@ void setSnappingCallback(TransInfo *t, short snap_target)
 		t->tsnap.distance = RotationBetween;
 		
 		// Can't do TARGET_CENTER with rotation, use TARGET_MEDIAN instead
-		if (snap_target == SCE_SNAP_TARGET_CENTER) {
-			t->tsnap.modeTarget = SNAP_MEDIAN;
+		if (t->tsnap.target == SCE_SNAP_TARGET_CENTER) {
+			t->tsnap.target = SCE_SNAP_TARGET_MEDIAN;
 			t->tsnap.targetSnap = TargetSnapMedian;
 		}
 		break;
@@ -501,8 +512,8 @@ void setSnappingCallback(TransInfo *t, short snap_target)
 		t->tsnap.distance = ResizeBetween;
 		
 		// Can't do TARGET_CENTER with resize, use TARGET_MEDIAN instead
-		if (snap_target == SCE_SNAP_TARGET_CENTER) {
-			t->tsnap.modeTarget = SNAP_MEDIAN;
+		if (t->tsnap.target == SCE_SNAP_TARGET_CENTER) {
+			t->tsnap.target = SCE_SNAP_TARGET_MEDIAN;
 			t->tsnap.targetSnap = TargetSnapMedian;
 		}
 		break;
@@ -569,7 +580,7 @@ void ApplySnapTranslation(TransInfo *t, float vec[3])
 
 void ApplySnapRotation(TransInfo *t, float *vec)
 {
-	if (t->tsnap.modeTarget == SNAP_CLOSEST) {
+	if (t->tsnap.target == SCE_SNAP_TARGET_CLOSEST) {
 		*vec = t->tsnap.dist;
 	}
 	else {
@@ -581,7 +592,7 @@ void ApplySnapRotation(TransInfo *t, float *vec)
 
 void ApplySnapResize(TransInfo *t, float vec[3])
 {
-	if (t->tsnap.modeTarget == SNAP_CLOSEST) {
+	if (t->tsnap.target == SCE_SNAP_TARGET_CLOSEST) {
 		vec[0] = vec[1] = vec[2] = t->tsnap.dist;
 	}
 	else {
@@ -887,7 +898,7 @@ void TargetSnapActive(TransInfo *t)
 		/* No active, default to median */
 		else
 		{
-			t->tsnap.modeTarget = SNAP_MEDIAN;
+			t->tsnap.target = SCE_SNAP_TARGET_MEDIAN;
 			t->tsnap.targetSnap = TargetSnapMedian;
 			TargetSnapMedian(t);
 		}		
@@ -1907,10 +1918,10 @@ void snapGrid(TransInfo *t, float *val) {
 		invert = U.flag & USER_AUTOGRABGRID;
 
 	if(invert) {
-		action = (t->modifiers & MOD_SNAP) ? NO_GEARS: BIG_GEARS;
+		action = activeSnap(t) ? NO_GEARS: BIG_GEARS;
 	}
 	else {
-		action = (t->modifiers & MOD_SNAP) ? BIG_GEARS : NO_GEARS;
+		action = activeSnap(t) ? BIG_GEARS : NO_GEARS;
 	}
 
 	if (action == BIG_GEARS && (t->modifiers & MOD_PRECISION)) {