# Canvas To use respackopts in your shader, you can `#include respackopts:config_supplier` This will import sanitized entries for all packs. You may access them as `_` or `__` Entries will be expressed as follows: | Type | Type in shader | --|-- | Boolean | Will either be `#define`d or not, use `#ifdef` | | Numeric | Will be defined as a number you can use directly | | Enum | First, a number entry will be `#define`d. You may check if a specific value is selected via `__` which will be handled like booleans | If respackopts is not present, the `#include` will not break the code, though you may want to define default values yourself. You can check whether the config supplier is properly imported through `#ifdef respackopts_loaded` ## V1 enums In respackopts v1 shaders, enums values are expressed by their ints and need to be compared to the value of the main entry.