Layer references

A REF string is a string that encodes enough information to find a particular data layer that can be interpreted as being relative to a particular base file that is not shown in the string.

The following example shows a reference to the third channel of the file /pci/demo/irvine.pix.

gdb:/pci/src/gen/irvine.pix/{IMG:3}

The following example shows a reference to the third channel of the current (base) file.

gdb:/{IMG:3}

The following example shows a reference to vector segment five (not necessarily the fifth vector segment) in the file irvine.pix, which is one directory above the current base file.

gdb:../irvine.pix/{VEC:5}

The following example shows a reference to LUT segment 6 in the current file.

gdb:/{LUT:6}

The following example shows a reference to the file /pci/demo/irvine.pix. Within the API, the layer type would be LAYER_FILE.

gdb:/pci/demo/irvine.pix

The following example shows a reference to the vector segment in the current file with a layer name of FIELDBND.

gdb:/{VEC:"FIELDBND"}

Generally, a GDB REF layer contains the following pieces:

• REF class: This is currently "gdb:"; however, it can be treated as optional to the input, so that the layer /pci/demo/irvine.pix is the same as gdb:/pci/demo/irvine.pix.
• File name: This is a file name in absolute or relative format. Either forward or backward slashes are considered acceptable as path component separators. This field is optional; if omitted, the file of operation is implicitly the current one. Relative paths are interpreted relative to the path of the current file.
• Layer Specifier: This takes the form /{layer_type:layer_id}. The entire layer specifier is omitted for LAYER_FILE REF strings. The layer type is either IMG or one of the three-letter segment type names. The layer_id is either a channel number, segment number, or layer name enclosed in double quotation marks.