RASTER_minPossibleValue()

Datum RASTER_minPossibleValue

(

PG_FUNCTION_ARGS

)

Definition at line 97 of file rtpg_utility.c.

{
        text *pixeltypetext = NULL;
        char *pixeltypechar = NULL;
        rt_pixtype pixtype = PT_END;
        double pixsize = 0;
 
        if (PG_ARGISNULL(0))
                PG_RETURN_NULL();
 
        pixeltypetext = PG_GETARG_TEXT_P(0);
        pixeltypechar = text_to_cstring(pixeltypetext);
 
        pixtype = rt_pixtype_index_from_name(pixeltypechar);
        if (pixtype == PT_END) {
                elog(ERROR, "RASTER_minPossibleValue: Invalid pixel type: %s", pixeltypechar);
                PG_RETURN_NULL();
        }
 
        pixsize = rt_pixtype_get_min_value(pixtype);
 
        /*
                correct pixsize of unsigned pixel types
                example: for PT_8BUI, the value is CHAR_MIN but if char is signed,
                        the value returned is -127 instead of 0.
        */
        switch (pixtype) {
                case PT_1BB:
                case PT_2BUI:
                case PT_4BUI:
                case PT_8BUI:
                case PT_16BUI:
                case PT_32BUI:
                        pixsize = 0;
                        break;
                default:
                        break;
        }
 
        PG_RETURN_FLOAT8(pixsize);
}

References PT_16BUI, PT_1BB, PT_2BUI, PT_32BUI, PT_4BUI, PT_8BUI, PT_END, rt_pixtype_get_min_value(), rt_pixtype_index_from_name(), and text_to_cstring().

Here is the call graph for this function: