summaryrefslogtreecommitdiff
path: root/backend/genesys/motor.h
diff options
context:
space:
mode:
authorJörg Frings-Fürst <debian@jff-webhosting.net>2020-03-30 21:30:45 +0200
committerJörg Frings-Fürst <debian@jff-webhosting.net>2020-03-30 21:30:45 +0200
commitee770c2346eb37e0dcb8b6cf3eaacf3d8efd6bbc (patch)
tree58f05092be1a17a939e861f8cadcda1b6ca2ecef /backend/genesys/motor.h
parent0da9e21872802cfc6e975b1ebaf9efb9e5934d84 (diff)
parentfef76e17ed4c607ea73b81279f9ef1d7121be900 (diff)
Merge branch 'release/experimental/1.0.29-1_experimental1'experimental/1.0.29-1_experimental1
Diffstat (limited to 'backend/genesys/motor.h')
-rw-r--r--backend/genesys/motor.h177
1 files changed, 177 insertions, 0 deletions
diff --git a/backend/genesys/motor.h b/backend/genesys/motor.h
new file mode 100644
index 0000000..d80da6d
--- /dev/null
+++ b/backend/genesys/motor.h
@@ -0,0 +1,177 @@
+/* sane - Scanner Access Now Easy.
+
+ Copyright (C) 2019 Povilas Kanapickas <povilas@radix.lt>
+
+ This file is part of the SANE package.
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ MA 02111-1307, USA.
+
+ As a special exception, the authors of SANE give permission for
+ additional uses of the libraries contained in this release of SANE.
+
+ The exception is that, if you link a SANE library with other files
+ to produce an executable, this does not by itself cause the
+ resulting executable to be covered by the GNU General Public
+ License. Your use of that executable is in no way restricted on
+ account of linking the SANE library code into it.
+
+ This exception does not, however, invalidate any other reasons why
+ the executable file might be covered by the GNU General Public
+ License.
+
+ If you submit changes to SANE to the maintainers to be included in
+ a subsequent release, you agree by submitting the changes that
+ those changes may be distributed with this exception intact.
+
+ If you write modifications of your own for SANE, it is your choice
+ whether to permit this exception to apply to your modifications.
+ If you do not wish that, delete this exception notice.
+*/
+
+#ifndef BACKEND_GENESYS_MOTOR_H
+#define BACKEND_GENESYS_MOTOR_H
+
+#include <cstdint>
+#include <vector>
+#include "enums.h"
+
+namespace genesys {
+
+/* Describes a motor acceleration curve.
+
+ Definitions:
+ v - speed in steps per pixeltime
+ w - speed in pixel times per step. w = 1 / v
+ a - acceleration in steps per pixeltime squared
+ s - distance travelled in steps
+ t - time in pixeltime
+
+ The physical mode defines the curve in physical quantities. We asssume that the scanner head
+ accelerates from standstill to the target speed uniformly. Then:
+
+ v(t) = v(0) + a * t (2)
+
+ Where `a` is acceleration, `t` is time. Also we can calculate the travelled distance `s`:
+
+ s(t) = v(0) * t + a * t^2 / 2 (3)
+
+ The actual motor slope is defined as the duration of each motor step. That means we need to
+ define speed in terms of travelled distance.
+
+ Solving (3) for `t` gives:
+
+ sqrt( v(0)^2 + 2 * a * s ) - v(0)
+ t(s) = --------------------------------- (4)
+ a
+
+ Combining (4) and (2) will yield:
+
+ v(s) = sqrt( v(0)^2 + 2 * a * s ) (5)
+
+ The data in the slope struct MotorSlope corresponds to the above in the following way:
+
+ maximum_start_speed is `w(0) = 1/v(0)`
+
+ maximum_speed is defines maximum speed which should not be exceeded
+
+ minimum_steps is not used
+
+ g is `a`
+
+ Given the start and target speeds on a known motor curve, `a` can be computed as follows:
+
+ v(t1)^2 - v(t0)^2
+ a = ----------------- (6)
+ 2 * s
+
+ Here `v(t0)` and `v(t1)` are the start and target speeds and `s` is the number of step required
+ to reach the target speeds.
+*/
+struct MotorSlope
+{
+ // initial speed in pixeltime per step
+ unsigned initial_speed_w = 0;
+
+ // max speed in pixeltime per step
+ unsigned max_speed_w = 0;
+
+ // maximum number of steps in the table
+ unsigned max_step_count;
+
+ // acceleration in steps per pixeltime squared.
+ float acceleration = 0;
+
+ unsigned get_table_step_shifted(unsigned step, StepType step_type) const;
+
+ static MotorSlope create_from_steps(unsigned initial_w, unsigned max_w,
+ unsigned steps);
+};
+
+struct MotorSlopeTable
+{
+ std::vector<std::uint16_t> table;
+ unsigned steps_count = 0;
+ unsigned pixeltime_sum = 0;
+
+ void slice_steps(unsigned count);
+};
+
+unsigned get_slope_table_max_size(AsicType asic_type);
+
+MotorSlopeTable create_slope_table(const MotorSlope& slope, unsigned target_speed_w,
+ StepType step_type, unsigned steps_alignment,
+ unsigned min_size, unsigned max_size);
+
+std::ostream& operator<<(std::ostream& out, const MotorSlope& slope);
+
+
+struct Genesys_Motor
+{
+ Genesys_Motor() = default;
+
+ // id of the motor description
+ MotorId id = MotorId::UNKNOWN;
+ // motor base steps. Unit: 1/inch
+ int base_ydpi = 0;
+ // maximum resolution in y-direction. Unit: 1/inch
+ int optical_ydpi = 0;
+ // slopes to derive individual slopes from
+ std::vector<MotorSlope> slopes;
+
+ MotorSlope& get_slope(StepType step_type)
+ {
+ return slopes[static_cast<unsigned>(step_type)];
+ }
+
+ const MotorSlope& get_slope(StepType step_type) const
+ {
+ return slopes[static_cast<unsigned>(step_type)];
+ }
+
+ StepType max_step_type() const
+ {
+ if (slopes.empty()) {
+ throw std::runtime_error("Slopes table is empty");
+ }
+ return static_cast<StepType>(slopes.size() - 1);
+ }
+};
+
+std::ostream& operator<<(std::ostream& out, const Genesys_Motor& motor);
+
+} // namespace genesys
+
+#endif // BACKEND_GENESYS_MOTOR_H