The _MEMGET statement reads a portion of a memory block at an OFFSET position into a variable, array or user defined type.
- _MEMGET memoryBlock, bytePosition, destinationVariable
- memoryBlock is a _MEM variable type memory block name created by _MEMNEW or the _MEM function.
- bytePosition is the memoryBlock.OFFSET memory start position plus any bytes to move into the block.
- destinationVariable is the variable assigned to hold the data. The number of bytes read is determined by the variable type used.
- The _MEMGET statement is similar to the GET statement used in files, but the position is required.
- The memory block name.OFFSET returns the starting byte position of the block. Add bytes to move into the block.
- The variable type held in the memory block can determine the next bytePosition to read.
- LEN can be used to determine the byte size of numerical or user defined variable types regardless of the value held.
- STRING values should be of a defined length. Variable length strings can actually move around in memory and not be found.
Example: Shows how to read the PSET color values from a program's SCREEN memory to an array.
SCREEN 13 PSET (0, 0), 123 PSET (1, 0), 222 'create screen image 'here is an array DIM screen_array(319, 199) AS _UNSIGNED _BYTE 'use screen dimensions from 0 'here's how we can copy the screen to our array DIM m AS _MEM m = _MEMIMAGE '0 or no handle necessary when accessing the current program screen _MEMGET m, m.OFFSET, screen_array() 'here's the proof PRINT screen_array(0, 0) 'print 123 PRINT screen_array(1, 0) 'print 222 END