>From ec018be621989234e3c570213084fe8705786e4c Mon Sep 17 00:00:00 2001
From: AwesomeAdam54321 <adam.f...@disroot.org>
Date: Sun, 16 Feb 2025 12:47:18 +0800
Subject: [PATCH] src: (math trigonometry): Add it.
* src/math/trigonometry.scm: New file.
* doc/guile-library.scm: Document it in the manual.
* unit-tests/math.trigonometry.scm: New unit test.
* src/Makefile.am: Register module.
* unit-tests/Makefile.am: Register unit test.
---
doc/guile-library.scm | 2 ++
src/Makefile.am | 1 +
src/math/trigonometry.scm | 61 ++++++++++++++++++++++++++++++++
unit-tests/Makefile.am | 1 +
unit-tests/math.trigonometry.scm | 44 +++++++++++++++++++++++
5 files changed, 109 insertions(+)
create mode 100644 src/math/trigonometry.scm
create mode 100644 unit-tests/math.trigonometry.scm
diff --git a/doc/guile-library.scm b/doc/guile-library.scm
index 496c283..d9593b7 100644
--- a/doc/guile-library.scm
+++ b/doc/guile-library.scm
@@ -102,6 +102,8 @@ License\".")
"A golden-section minimum finder")
((math primes)
"Functions related to prime numbers and factorization")
+ ((math trigonometry)
+ "Functions related to motion trigonometry")
((os process)
"Spawning processes and capturing their output")
((scheme documentation)
diff --git a/src/Makefile.am b/src/Makefile.am
index 889a575..507bbab 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -86,6 +86,7 @@ SOURCES = \
logging/rotating-log.scm \
math/minima.scm \
math/primes.scm \
+ math/trigonometry.scm \
match-bind.scm \
md5.scm \
os/process.scm \
diff --git a/src/math/trigonometry.scm b/src/math/trigonometry.scm
new file mode 100644
index 0000000..0afc047
--- /dev/null
+++ b/src/math/trigonometry.scm
@@ -0,0 +1,61 @@
+;; (math trigonometry) -- More exact trigonometry for motion
+;; Copyright (C) 2025 Adam Faiz <adam.f...@disroot.org>
+
+;; 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 3 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, see <http://www.gnu.org/licenses/>.
+
+
+;;; Commentary:
+;;
+;; @cindex normalise angle
+;; @cindex sine
+;; @cindex cosine
+;; @cindex angle, normalised
+;; @cindex angle, sine of
+;; @cindex angle, cosine of
+;; This module defines functions for computing the sine and cosine of an angle,
+;; as more robust versions of the built-in sin and cos functions in Guile.
+;; They return exact values for angles representing up, down, left and right,
+;; regardless of whether they're negative or how many rotations occurred.
+;;
+;;; Code:
+
+(define-module (math trigonometry)
+ #:use-module (scheme documentation)
+ #:export (normalise-angle
+ sine
+ cosine))
+
+(define (normalise-angle angle)
+ "Return a normalised angle where 0 <= angle < 360."
+ (define angle-from-north (remainder angle 360))
+ (+ angle-from-north
+ (if (< angle-from-north 0) 360 0)))
+
+(define (sine angle)
+ "Calculate the sine of an angle,
+with full precision for 90 degree increments."
+ (define normalised-angle (normalise-angle angle))
+ (cond ((or (= normalised-angle 0) (= normalised-angle 180)) 0)
+ ((= normalised-angle 90) 1)
+ ((= normalised-angle 270) -1)
+ (else (sin normalised-angle))))
+
+(define (cosine angle)
+ "Calculate the cosine of an angle,
+with full precision for 90 degree increments."
+ (define normalised-angle (normalise-angle angle))
+ (cond ((= normalised-angle 0) 1)
+ ((or (= normalised-angle 90) (= normalised-angle 270)) 0)
+ ((= normalised-angle 180) -1)
+ (else (cos normalised-angle))))
diff --git a/unit-tests/Makefile.am b/unit-tests/Makefile.am
index 00530ca..0a7ab37 100644
--- a/unit-tests/Makefile.am
+++ b/unit-tests/Makefile.am
@@ -58,6 +58,7 @@ TESTS= \
match-bind.scm \
math.minima.scm \
math.primes.scm \
+ math.trigonometry.scm \
md5.scm \
os.process.scm \
search.basic.scm \
diff --git a/unit-tests/math.trigonometry.scm b/unit-tests/math.trigonometry.scm
new file mode 100644
index 0000000..8c2a21e
--- /dev/null
+++ b/unit-tests/math.trigonometry.scm
@@ -0,0 +1,44 @@
+;;; ----------------------------------------------------------------------
+;;; unit test
+;;; Copyright (C) 2025 Adam Faiz <adam.f...@disroot.org>
+;;;
+;;; 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 3 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, see <http://www.gnu.org/licenses/>.
+;;; ----------------------------------------------------------------------
+
+(use-modules (math trigonometry)
+ (unit-test)
+ (oop goops))
+
+;; **********************************************************************
+;; Test of trigonometry
+;; **********************************************************************
+(define-class <test-trigonometry> (<test-case>)
+ (angles #:accessor test-angles))
+
+(define-method (set-up-test (self <test-trigonometry>))
+ (set! (test-angles self)
+ (list -720 -360 -270 -180 -90 -0
+ 0 90 180 270 360 720)))
+
+(define-method (test-sine (self <test-trigonometry>))
+ (assert-equal (map sine (test-angles self))
+ (list 0 0 1 0 -1 0
+ 0 1 0 -1 0 0)))
+
+(define-method (test-cosine (self <test-trigonometry>))
+ (assert-equal (map cosine (test-angles self))
+ (list 1 1 0 -1 0 1
+ 1 0 -1 0 1 1)))
+
+(exit-with-summary (run-all-defined-test-cases))
--
2.46.0
