trapq: Add code to calculate definitive integral

Support calculating the definitive integral of a cartesian axis
position over a time range of the movement queue.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 7 insertions, 1 deletions

diff --git a/klippy/chelper/trapq.h b/klippy/chelper/trapq.h
index 4572ef1a..fa55faaf 100644
--- a/klippy/chelper/trapq.h
+++ b/klippy/chelper/trapq.h
@@ -4,7 +4,12 @@
 #include "list.h" // list_node
 
 struct coord {
-    double x, y, z;
+    union {
+        struct {
+            double x, y, z;
+        };
+        double axis[3];
+    };
 };
 
 struct move {
@@ -27,6 +32,7 @@ void trapq_append(struct trapq *tq, double print_time
                   , double start_v, double cruise_v, double accel);
 double move_get_distance(struct move *m, double move_time);
 struct coord move_get_coord(struct move *m, double move_time);
+double trapq_integrate(struct move *m, int axis, double start, double end);
 struct trapq *trapq_alloc(void);
 void trapq_free(struct trapq *tq);
 void trapq_check_sentinels(struct trapq *tq);