// Add a new linear movement to the buffer. steps_x, _y and _z is the absolute position in
// mm. Microseconds specify how many microseconds the move should take to perform. To aid acceleration
// calculation the caller must also provide the physical length of the line in millimeters.
-void plan_buffer_line(float &x, float &y, float &z, float &e, float feed_rate, uint8_t &extruder)
+void plan_buffer_line(const float &x, const float &y, const float &z, const float &e, float feed_rate, const uint8_t &extruder)
{
// Calculate the buffer head after we push this byte
int next_buffer_head = next_block_index(block_buffer_head);
// Add a new linear movement to the buffer. x, y and z is the signed, absolute target position in
// millimaters. Feed rate specifies the speed of the motion.
-void plan_buffer_line(float &x, float &y, float &z, float &e, float feed_rate, uint8_t &extruder);
+void plan_buffer_line(const float &x, const float &y, const float &z, const float &e, float feed_rate, const uint8_t &extruder);
// Set position. Used for G92 instructions.
void plan_set_position(const float &x, const float &y, const float &z, const float &e);