- // determine new "coordinates"
- var CWidth = gCurrentImageData.C_max.r - gCurrentImageData.C_min.r;
- var CHeight = gCurrentImageData.C_max.i - gCurrentImageData.C_min.i;
- var newC_min = new complex(
- gCurrentImageData.C_min.r + zoomstart.x / gCurrentImageData.iWidth * CWidth,
- gCurrentImageData.C_min.i + zoomstart.y / gCurrentImageData.iHeight * CHeight);
- var newC_max = new complex(
- gCurrentImageData.C_min.r + zoomend.x / gCurrentImageData.iWidth * CWidth,
- gCurrentImageData.C_min.i + zoomend.y / gCurrentImageData.iHeight * CHeight);
+ if (gCurrentImageData) {
+ // determine new "coordinates"
+ var CWidth = gCurrentImageData.C_max.r - gCurrentImageData.C_min.r;
+ var CHeight = gCurrentImageData.C_max.i - gCurrentImageData.C_min.i;
+ var newC_min = new complex(
+ gCurrentImageData.C_min.r + zoomstart.x / gCurrentImageData.iWidth * CWidth,
+ gCurrentImageData.C_min.i + zoomstart.y / gCurrentImageData.iHeight * CHeight);
+ var newC_max = new complex(
+ gCurrentImageData.C_min.r + zoomend.x / gCurrentImageData.iWidth * CWidth,
+ gCurrentImageData.C_min.i + zoomend.y / gCurrentImageData.iHeight * CHeight);
+ }
+ else {
+ var newC_min = new complex(-2, -1.5);
+ var newC_max = new complex(1, 1.5);
+ }