Serialize gridOffset of RackScrollWidget in patch.

src/app/RackScrollWidget.cpp

@@ -39,18 +39,17 @@ RackScrollWidget::~RackScrollWidget() {
 
 
 void RackScrollWidget::reset() {
-	offset = RACK_OFFSET.mult(zoomWidget->zoom);
-	offset = offset.minus(math::Vec(30, 30));
+	offset = RACK_OFFSET * zoomWidget->getZoom() - math::Vec(30, 30);
 }
 
 
 math::Vec RackScrollWidget::getGridOffset() {
-	return offset.minus(RACK_OFFSET).div(RACK_GRID_SIZE);
+	return (offset / zoomWidget->getZoom() - RACK_OFFSET) / RACK_GRID_SIZE;
 }
 
 
 void RackScrollWidget::setGridOffset(math::Vec gridOffset) {
-	offset = gridOffset.mult(RACK_GRID_SIZE).plus(RACK_OFFSET);
+	offset = (gridOffset * RACK_GRID_SIZE + RACK_OFFSET) * zoomWidget->getZoom();
 }
 
 
@@ -67,7 +66,7 @@ void RackScrollWidget::setZoom(float zoom) {
 void RackScrollWidget::setZoom(float zoom, math::Vec pivot) {
 	zoom = math::clamp(zoom, std::pow(2.f, -2), std::pow(2.f, 2));
 
-	offset = offset.plus(pivot).mult(zoom / zoomWidget->getZoom()).minus(pivot);
+	offset = (offset + pivot) * (zoom / zoomWidget->getZoom()) - pivot;
 	zoomWidget->setZoom(zoom);
 }
 

src/patch.cpp

@@ -416,10 +416,15 @@ json_t* Manager::toJson() {
 	if (!APP->history->isSaved())
 		json_object_set_new(rootJ, "unsaved", json_boolean(true));
 
-	// zoom
 	if (APP->scene) {
+		// zoom
 		float zoom = APP->scene->rackScroll->getZoom();
 		json_object_set_new(rootJ, "zoom", json_real(zoom));
+
+		// gridOffset
+		math::Vec gridOffset = APP->scene->rackScroll->getGridOffset();
+		json_t* gridOffsetJ = json_pack("[f, f]", gridOffset.x, gridOffset.y);
+		json_object_set_new(rootJ, "gridOffset", gridOffsetJ);
 	}
 
 	// Merge with Engine JSON
@@ -460,11 +465,19 @@ void Manager::fromJson(json_t* rootJ) {
 	if (!unsavedJ)
 		APP->history->setSaved();
 
-	// zoom
 	if (APP->scene) {
+		// zoom
 		json_t* zoomJ = json_object_get(rootJ, "zoom");
 		if (zoomJ)
 			APP->scene->rackScroll->setZoom(json_number_value(zoomJ));
+
+		// gridOffset
+		json_t* gridOffsetJ = json_object_get(rootJ, "gridOffset");
+		if (gridOffsetJ) {
+			double x, y;
+			json_unpack(gridOffsetJ, "[F, F]", &x, &y);
+			APP->scene->rackScroll->setGridOffset(math::Vec(x, y));
+		}
 	}
 
 	// Pass JSON to Engine and RackWidget