+ double zoomFactor = 2.0;
+/*
+We need to find the center of the screen, then figure out where the new corner
+will be in the zoomed in window.
+
+So we know in Qt coords, the center is found via:
+size.width() / 2 --> xCenter
+size.height() / 2 --> yCenter
+
+transform x/yCenter to Cartesian coordinates. So far, so good.
+
+when zooming in, new origin will be (xCenter - origin.x) / 2, (yCenter - origin.y) / 2
+(after subtracting from center, that is...)
+*/
+ QSize size = drawing->size();
+ Vector center(size.width() / 2.0, size.height() / 2.0);
+//printf("Zoom in... Center=%.2f,%.2f; ", center.x, center.y);
+ center = Painter::QtToCartesianCoords(center);
+//printf("(%.2f,%.2f); origin=%.2f,%.2f; ", center.x, center.y, Painter::origin.x, Painter::origin.y);
+ Vector newOrigin = center - ((center - Painter::origin) / zoomFactor);
+//printf("newOrigin=%.2f,%.2f;\n", newOrigin.x, newOrigin.y);
+ Painter::origin = newOrigin;
+