From ae33cb7fa2f31996a00b25d5cfafc723df3c8e96 Mon Sep 17 00:00:00 2001
From: Michael Moon <triffid.hunter@gmail.com>
Date: Sat, 9 Apr 2011 09:16:05 +1000
Subject: [PATCH] start implementing absolute E support

---
 gcode_parse.c   | 9 +++++++--
 gcode_process.c | 9 +++++++--
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/gcode_parse.c b/gcode_parse.c
index c0829c6..e6f811d 100644
--- a/gcode_parse.c
+++ b/gcode_parse.c
@@ -385,9 +385,14 @@ void gcode_parse_char(uint8_t c) {
 
 		if (next_target.option_relative) {
 			next_target.target.X = next_target.target.Y = next_target.target.Z = 0;
+			#ifdef	E_ABSOLUTE
+				next_target.target.E = 0;
+			#endif
 		}
-		// E always relative
-		next_target.target.E = 0;
+		#ifndef	E_ABSOLUTE
+			// E always relative
+			next_target.target.E = 0;
+		#endif
 	}
 }
 
diff --git a/gcode_process.c b/gcode_process.c
index 5edee49..b67b95b 100644
--- a/gcode_process.c
+++ b/gcode_process.c
@@ -88,6 +88,9 @@ void process_gcode_command() {
 		next_target.target.X += startpoint.X;
 		next_target.target.Y += startpoint.Y;
 		next_target.target.Z += startpoint.Z;
+		#ifdef	E_ABSOLUTE
+			next_target.target.E += startpoint.E;
+		#endif
 	}
 	// E ALWAYS relative, otherwise we overflow our registers after only a few layers
 	// 	next_target.target.E += startpoint.E;
@@ -193,7 +196,7 @@ void process_gcode_command() {
 					zero_z();
 					axisSelected = 1;
 				}
-				// there's no point in moving E, as E is always relative
+				// there's no point in moving E, as E has no endstops
 
 				if (!axisSelected) {
 					zero_x();
@@ -231,7 +234,9 @@ void process_gcode_command() {
 						axisSelected = 1;
 					}
 					if (next_target.seen_E) {
-						// there's no point in setting E, as E is always relative
+						#ifdef	E_ABSOLUTE
+							startpoint.E = current_position.E = next_target.target.E;
+						#endif
 						axisSelected = 1;
 					}