Transform manipulator: Allow first clicking Shift before selecting axis

Avoids possible jumps when one is trying to do some really preciese tweak.

Quite striaghtforward change for mouse input initialization: take Shift
state into account. However, this will interfere with the axis exclusion
which is currently also uses Shift (the feature to move something in a
plane which doesn't have selected axis). This is probably not so commonly
used feature (nobody in the studio even knew of it) and the only downside
now would be that such a constrainted movement will become accurate by
default. That's easy to deal from user side by just unholding Shift key.

Reviewers: brecht, mont29, Severin

Differential Revision: https://developer.blender.org/D2418

3 files changed, 5 insertions, 5 deletions

diff --git a/source/blender/editors/transform/transform.c b/source/blender/editors/transform/transform.c
index 20c62e91d01..31ffa019e4e 100644
--- a/source/blender/editors/transform/transform.c
+++ b/source/blender/editors/transform/transform.c
@@ -2176,7 +2176,7 @@ bool initTransform(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
 	calculateCenter(t);
 
 	if (event) {
-		initMouseInput(t, &t->mouse, t->center2d, event->mval);
+		initMouseInput(t, &t->mouse, t->center2d, event->mval, event->shift);
 	}
 
 	switch (mode) {
@@ -8495,7 +8495,7 @@ static void initTimeScale(TransInfo *t)
 	center[1] = t->mouse.imval[1];
 
 	/* force a reinit with the center2d used here */
-	initMouseInput(t, &t->mouse, center, t->mouse.imval);
+	initMouseInput(t, &t->mouse, center, t->mouse.imval, false);
 
 	initMouseInputMode(t, &t->mouse, INPUT_SPRING_FLIP);
 
diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index a59f9dc43dd..7ea4448a44e 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -728,7 +728,7 @@ typedef enum {
 	INPUT_CUSTOM_RATIO_FLIP,
 } MouseInputMode;
 
-void initMouseInput(TransInfo *t, MouseInput *mi, const float center[2], const int mval[2]);
+void initMouseInput(TransInfo *t, MouseInput *mi, const float center[2], const int mval[2], const bool precision);
 void initMouseInputMode(TransInfo *t, MouseInput *mi, MouseInputMode mode);
 eRedrawFlag handleMouseInput(struct TransInfo *t, struct MouseInput *mi, const struct wmEvent *event);
 void applyMouseInput(struct TransInfo *t, struct MouseInput *mi, const int mval[2], float output[3]);
diff --git a/source/blender/editors/transform/transform_input.c b/source/blender/editors/transform/transform_input.c
index 9b7d19eacd5..42cc918ec8c 100644
--- a/source/blender/editors/transform/transform_input.c
+++ b/source/blender/editors/transform/transform_input.c
@@ -234,10 +234,10 @@ static void InputAngleSpring(TransInfo *t, MouseInput *mi, const double mval[2],
 	output[1] = toutput[0];
 }
 
-void initMouseInput(TransInfo *UNUSED(t), MouseInput *mi, const float center[2], const int mval[2])
+void initMouseInput(TransInfo *UNUSED(t), MouseInput *mi, const float center[2], const int mval[2], const bool precision)
 {
 	mi->factor = 0;
-	mi->precision = 0;
+	mi->precision = precision;
 
 	mi->center[0] = center[0];
 	mi->center[1] = center[1];