Fix T65837: "Zoom Axis" is not working on the node editor

We would not take into account the user "Zoom Axis" setting in certain
2D space viewports.  In addition to this, the "Scale Zoom" didn't work
consistently in these spaces either.

Reviewed By: Brecht

Differential Revision: http://developer.blender.org/D5132

1 files changed, 42 insertions, 13 deletions

diff --git a/source/blender/editors/interface/view2d_ops.c b/source/blender/editors/interface/view2d_ops.c
index 7d9b722fcc0..b57d100127e 100644
--- a/source/blender/editors/interface/view2d_ops.c
+++ b/source/blender/editors/interface/view2d_ops.c
@@ -31,6 +31,7 @@
 #include "BLI_blenlib.h"
 #include "BLI_utildefines.h"
 #include "BLI_math_base.h"
+#include "BLI_math_vector.h"
 
 #include "BKE_context.h"
 
@@ -1146,33 +1147,49 @@ static int view_zoomdrag_modal(bContext *C, wmOperator *op, const wmEvent *event
   }
   else if (event->type == MOUSEMOVE) {
     float dx, dy;
+    float zoomfac = 0.01f;
+
+    /* some view2d's (graph) don't have min/max zoom, or extreme ones */
+    if (v2d->maxzoom > 0.0f) {
+      zoomfac = clamp_f(0.001f * v2d->maxzoom, 0.001f, 0.01f);
+    }
 
     /* calculate new delta transform, based on zooming mode */
     if (U.viewzoom == USER_ZOOM_SCALE) {
       /* 'scale' zooming */
       float dist;
+      float len_old[2];
+      float len_new[2];
 
       /* x-axis transform */
       dist = BLI_rcti_size_x(&v2d->mask) / 2.0f;
-      dx = 1.0f - (fabsf(vzd->lastx - vzd->ar->winrct.xmin - dist) + 2.0f) /
-                      (fabsf(event->mval[0] - dist) + 2.0f);
-      dx *= 0.5f * BLI_rctf_size_x(&v2d->cur);
+      len_old[0] = fabsf(vzd->lastx - vzd->ar->winrct.xmin - dist);
+      len_new[0] = fabsf(event->x - vzd->ar->winrct.xmin - dist);
+
+      len_old[0] *= zoomfac * BLI_rctf_size_x(&v2d->cur);
+      len_new[0] *= zoomfac * BLI_rctf_size_x(&v2d->cur);
 
       /* y-axis transform */
       dist = BLI_rcti_size_y(&v2d->mask) / 2.0f;
-      dy = 1.0f - (fabsf(vzd->lasty - vzd->ar->winrct.ymin - dist) + 2.0f) /
-                      (fabsf(event->mval[1] - dist) + 2.0f);
-      dy *= 0.5f * BLI_rctf_size_y(&v2d->cur);
+      len_old[1] = fabsf(vzd->lasty - vzd->ar->winrct.ymin - dist);
+      len_new[1] = fabsf(event->y - vzd->ar->winrct.ymin - dist);
+
+      len_old[1] *= zoomfac * BLI_rctf_size_y(&v2d->cur);
+      len_new[1] *= zoomfac * BLI_rctf_size_y(&v2d->cur);
+
+      /* Calculate distance */
+      if (v2d->keepzoom & V2D_KEEPASPECT) {
+        dist = len_v2(len_new) - len_v2(len_old);
+        dx = dy = dist;
+      }
+      else {
+        dx = len_new[0] - len_old[0];
+        dy = len_new[1] - len_old[1];
+      }
     }
     else {
       /* 'continuous' or 'dolly' */
-      float fac, zoomfac = 0.01f;
-
-      /* some view2d's (graph) don't have min/max zoom, or extreme ones */
-      if (v2d->maxzoom > 0.0f) {
-        zoomfac = clamp_f(0.001f * v2d->maxzoom, 0.001f, 0.01f);
-      }
-
+      float fac;
       /* x-axis transform */
       fac = zoomfac * (event->x - vzd->lastx);
       dx = fac * BLI_rctf_size_x(&v2d->cur);
@@ -1180,6 +1197,18 @@ static int view_zoomdrag_modal(bContext *C, wmOperator *op, const wmEvent *event
       /* y-axis transform */
       fac = zoomfac * (event->y - vzd->lasty);
       dy = fac * BLI_rctf_size_y(&v2d->cur);
+
+      /* Only respect user setting zoom axis if the view does not have any zoom restrictions
+       * any will be scaled uniformly */
+      if ((v2d->keepzoom & V2D_LOCKZOOM_X) == 0 && (v2d->keepzoom & V2D_LOCKZOOM_Y) == 0 &&
+          (v2d->keepzoom & V2D_KEEPASPECT)) {
+        if (U.uiflag & USER_ZOOM_HORIZ) {
+          dy = 0;
+        }
+        else {
+          dx = 0;
+        }
+      }
     }
 
     /* support zoom to always zoom entirely - the v2d code uses portrait or