kin_cartesian: Remove stepcompress_push_const()

All the kinematic code now uses the iterative solver to generate
steps.  Remove the old stepcompress_push_const() mechanism.

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

klippy/chelper/__init__.py

@@ -55,10 +55,6 @@ defs_itersolve = """
 """
 
 defs_kin_cartesian = """
-    int32_t stepcompress_push(struct stepcompress *sc, double step_clock
-        , int32_t sdir);
-    int32_t stepcompress_push_const(struct stepcompress *sc, double clock_offset
-        , double step_offset, double steps, double start_sv, double accel);
     struct stepper_kinematics *cartesian_stepper_alloc(char axis);
 """
 

klippy/chelper/kin_cartesian.c

@@ -1,129 +1,14 @@
 // Cartesian kinematics stepper pulse time generation
 //
-// Copyright (C) 2016-2018  Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2018  Kevin O'Connor <kevin@koconnor.net>
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
-#include <math.h> // sqrt
 #include <stdlib.h> // malloc
 #include <string.h> // memset
-#include "compiler.h" // likely
+#include "compiler.h" // __visible
 #include "itersolve.h" // move_get_coord
 #include "pyhelper.h" // errorf
-#include "stepcompress.h" // queue_append
-
-
-/****************************************************************
- * Direct step generation
- ****************************************************************/
-
-// Common suffixes: _sd is step distance (a unit length the same
-// distance the stepper moves on each step), _sv is step velocity (in
-// units of step distance per time), _sd2 is step distance squared, _r
-// is ratio (scalar usually between 0.0 and 1.0).  Times are in
-// seconds and acceleration is in units of step distance per second
-// squared.
-
-// Wrapper around sqrt() to handle small negative numbers
-static double
-_safe_sqrt(double v)
-{
-    // Due to floating point truncation, it's possible to get a small
-    // negative number - treat it as zero.
-    if (v < -0.001)
-        errorf("safe_sqrt of %.9f", v);
-    return 0.;
-}
-inline double safe_sqrt(double v) {
-    return likely(v >= 0.) ? sqrt(v) : _safe_sqrt(v);
-}
-
-// Schedule a step event at the specified step_clock time
-int32_t __visible
-stepcompress_push(struct stepcompress *sc, double print_time, int32_t sdir)
-{
-    int ret = set_next_step_dir(sc, !!sdir);
-    if (ret)
-        return ret;
-    struct queue_append qa = queue_append_start(sc, print_time, 0.5);
-    ret = queue_append(&qa, 0.);
-    if (ret)
-        return ret;
-    queue_append_finish(qa);
-    return sdir ? 1 : -1;
-}
-
-// Schedule 'steps' number of steps at constant acceleration. If
-// acceleration is zero (ie, constant velocity) it uses the formula:
-//  step_time = print_time + step_num/start_sv
-// Otherwise it uses the formula:
-//  step_time = (print_time + sqrt(2*step_num/accel + (start_sv/accel)**2)
-//               - start_sv/accel)
-int32_t __visible
-stepcompress_push_const(
-    struct stepcompress *sc, double print_time
-    , double step_offset, double steps, double start_sv, double accel)
-{
-    // Calculate number of steps to take
-    int sdir = 1;
-    if (steps < 0) {
-        sdir = 0;
-        steps = -steps;
-        step_offset = -step_offset;
-    }
-    int count = steps + .5 - step_offset;
-    if (count <= 0 || count > 10000000) {
-        if (count && steps) {
-            errorf("push_const invalid count %d %f %f %f %f %f"
-                   , stepcompress_get_oid(sc), print_time, step_offset, steps
-                   , start_sv, accel);
-            return ERROR_RET;
-        }
-        return 0;
-    }
-    int ret = set_next_step_dir(sc, sdir);
-    if (ret)
-        return ret;
-    int res = sdir ? count : -count;
-
-    // Calculate each step time
-    if (!accel) {
-        // Move at constant velocity (zero acceleration)
-        struct queue_append qa = queue_append_start(sc, print_time, .5);
-        double inv_cruise_sv = stepcompress_get_mcu_freq(sc) / start_sv;
-        double pos = (step_offset + .5) * inv_cruise_sv;
-        while (count--) {
-            ret = queue_append(&qa, pos);
-            if (ret)
-                return ret;
-            pos += inv_cruise_sv;
-        }
-        queue_append_finish(qa);
-    } else {
-        // Move with constant acceleration
-        double inv_accel = 1. / accel;
-        double mcu_freq = stepcompress_get_mcu_freq(sc);
-        double accel_time = start_sv * inv_accel * mcu_freq;
-        struct queue_append qa = queue_append_start(
-            sc, print_time, 0.5 - accel_time);
-        double accel_multiplier = 2. * inv_accel * mcu_freq * mcu_freq;
-        double pos = (step_offset + .5)*accel_multiplier + accel_time*accel_time;
-        while (count--) {
-            double v = safe_sqrt(pos);
-            int ret = queue_append(&qa, accel_multiplier >= 0. ? v : -v);
-            if (ret)
-                return ret;
-            pos += accel_multiplier;
-        }
-        queue_append_finish(qa);
-    }
-    return res;
-}
-
-
-/****************************************************************
- * Iterative solver
- ****************************************************************/
 
 static double
 cart_stepper_x_calc_position(struct stepper_kinematics *sk, struct move *m

klippy/chelper/stepcompress.c

@@ -313,7 +313,7 @@ stepcompress_flush_far(struct stepcompress *sc, uint64_t abs_step_clock)
 }
 
 // Send the set_next_step_dir command
-int
+static int
 set_next_step_dir(struct stepcompress *sc, int sdir)
 {
     if (sc->sdir == sdir)

klippy/chelper/stepcompress.h

@@ -10,7 +10,6 @@ void stepcompress_fill(struct stepcompress *sc, uint32_t max_error
                        , uint32_t invert_sdir, uint32_t queue_step_msgid
                        , uint32_t set_next_step_dir_msgid);
 void stepcompress_free(struct stepcompress *sc);
-int set_next_step_dir(struct stepcompress *sc, int sdir);
 int stepcompress_reset(struct stepcompress *sc, uint64_t last_step_clock);
 int stepcompress_set_homing(struct stepcompress *sc, uint64_t homing_clock);
 int stepcompress_queue_msg(struct stepcompress *sc, uint32_t *data, int len);
@@ -38,6 +37,4 @@ void steppersync_set_time(struct steppersync *ss, double time_offset
                           , double mcu_freq);
 int steppersync_flush(struct steppersync *ss, uint64_t move_clock);
 
-double safe_sqrt(double v);
-
 #endif // stepcompress.h

klippy/mcu.py

@@ -26,8 +26,7 @@ class MCU_stepper:
         self._stepqueue = ffi_main.gc(self._ffi_lib.stepcompress_alloc(oid),
                                       self._ffi_lib.stepcompress_free)
         self._mcu.register_stepqueue(self._stepqueue)
-        self._stepcompress_push_const = self._itersolve_gen_steps = None
+        self._stepper_kinematics = self._itersolve_gen_steps = None
-        self._stepper_kinematics = None
         self.set_ignore_move(False)
     def get_mcu(self):
         return self._mcu
@@ -88,13 +87,11 @@ class MCU_stepper:
             return int(mcu_pos + 0.5)
         return int(mcu_pos - 0.5)
     def set_ignore_move(self, ignore_move):
-        was_ignore = (self._stepcompress_push_const
+        was_ignore = (self._itersolve_gen_steps
-                      is not self._ffi_lib.stepcompress_push_const)
+                      is not self._ffi_lib.itersolve_gen_steps)
         if ignore_move:
-            self._stepcompress_push_const = (lambda *args: 0)
             self._itersolve_gen_steps = (lambda *args: 0)
         else:
-            self._stepcompress_push_const = self._ffi_lib.stepcompress_push_const
             self._itersolve_gen_steps = self._ffi_lib.itersolve_gen_steps
         return was_ignore
     def note_homing_start(self, homing_clock):
@@ -122,21 +119,6 @@ class MCU_stepper:
         if self._invert_dir:
             pos = -pos
         self._commanded_pos = pos - self._mcu_position_offset
-    def step(self, print_time, sdir):
-        count = self._ffi_lib.stepcompress_push(
-            self._stepqueue, print_time, sdir)
-        if count == STEPCOMPRESS_ERROR_RET:
-            raise error("Internal error in stepcompress")
-        self._commanded_pos += count
-    def step_const(self, print_time, start_pos, dist, start_v, accel):
-        inv_step_dist = self._inv_step_dist
-        step_offset = self._commanded_pos - start_pos * inv_step_dist
-        count = self._stepcompress_push_const(
-            self._stepqueue, print_time, step_offset, dist * inv_step_dist,
-            start_v * inv_step_dist, accel * inv_step_dist)
-        if count == STEPCOMPRESS_ERROR_RET:
-            raise error("Internal error in stepcompress")
-        self._commanded_pos += count
     def step_itersolve(self, cmove):
         count = self._itersolve_gen_steps(self._stepper_kinematics, cmove)
         if count == STEPCOMPRESS_ERROR_RET:

klippy/stepper.py

@@ -47,8 +47,6 @@ class PrinterStepper:
         self.mcu_stepper.setup_dir_pin(dir_pin_params)
         self.step_dist = config.getfloat('step_distance', above=0.)
         self.mcu_stepper.setup_step_distance(self.step_dist)
-        self.step = self.mcu_stepper.step
-        self.step_const = self.mcu_stepper.step_const
         self.step_itersolve = self.mcu_stepper.step_itersolve
         self.setup_itersolve = self.mcu_stepper.setup_itersolve
         self.enable = lookup_enable_pin(ppins, config.get('enable_pin', None))
@@ -185,7 +183,6 @@ class PrinterMultiStepper(PrinterHomingStepper):
         PrinterHomingStepper.__init__(self, printer, config)
         self.endstops = PrinterHomingStepper.get_endstops(self)
         self.extras = []
-        self.all_step_const = [self.step_const]
         self.all_step_itersolve = [self.step_itersolve]
         for i in range(1, 99):
             if not config.has_section(config.get_name() + str(i)):
@@ -193,7 +190,6 @@ class PrinterMultiStepper(PrinterHomingStepper):
             extraconfig = config.getsection(config.get_name() + str(i))
             extra = PrinterStepper(printer, extraconfig)
             self.extras.append(extra)
-            self.all_step_const.append(extra.step_const)
             self.all_step_itersolve.append(extra.step_itersolve)
             extraendstop = extraconfig.get('endstop_pin', None)
             if extraendstop is not None:
@@ -203,11 +199,7 @@ class PrinterMultiStepper(PrinterHomingStepper):
                 self.endstops.append((mcu_endstop, extra.name))
             else:
                 self.mcu_endstop.add_stepper(extra.mcu_stepper)
-        self.step_const = self.step_multi_const
         self.step_itersolve = self.step_multi_itersolve
-    def step_multi_const(self, print_time, start_pos, dist, start_v, accel):
-        for step_const in self.all_step_const:
-            step_const(print_time, start_pos, dist, start_v, accel)
     def step_multi_itersolve(self, cmove):
         for step_itersolve in self.all_step_itersolve:
             step_itersolve(cmove)