+static void crop_calculate( mlt_transition self, mlt_properties properties, struct geometry_s *result, double position )
+{
+ // Initialize panning info
+ result->x_src = 0;
+ result->y_src = 0;
+ if ( mlt_properties_get( properties, "crop" ) )
+ {
+ mlt_geometry crop = mlt_properties_get_data( properties, "crop_geometry", NULL );
+ if ( !crop )
+ {
+ crop = mlt_geometry_init();
+ mlt_position length = mlt_transition_get_length( self );
+ double cycle = mlt_properties_get_double( properties, "cycle" );
+
+ // Allow a geometry repeat cycle
+ if ( cycle >= 1 )
+ length = cycle;
+ else if ( cycle > 0 )
+ length *= cycle;
+ mlt_geometry_parse( crop, mlt_properties_get( properties, "crop" ), length, result->sw, result->sh );
+ mlt_properties_set_data( properties, "crop_geometry", crop, 0, (mlt_destructor)mlt_geometry_close, NULL );
+ }
+
+ // Repeat processing
+ int length = mlt_geometry_get_length( crop );
+ int mirror_off = mlt_properties_get_int( properties, "mirror_off" );
+ int repeat_off = mlt_properties_get_int( properties, "repeat_off" );
+ if ( !repeat_off && position >= length && length != 0 )
+ {
+ int section = position / length;
+ position -= section * length;
+ if ( !mirror_off && section % 2 == 1 )
+ position = length - position;
+ }
+
+ // Compute the pan
+ struct mlt_geometry_item_s crop_item;
+ mlt_geometry_fetch( crop, &crop_item, position );
+ result->x_src = rint( crop_item.x );
+ result->y_src = rint( crop_item.y );
+ }
+}