2009-11-14 Colin D Bennet <colin@gibibit.com>

Trigonometry support.

	* include/grub/trig.h: New file.
	* lib/trig.c: Likewise.
	* maintainance/gentrigtables.py: Likewise.
	* conf/common.rmk (pkglib_MODULES): Add trig.mod.
	(trig_mod_SOURCES): New variable.
	(trig_mod_CFLAGS): Likewise.
	(trig_mod_LDFLAGS): Likewise.

conf/common.rmk

@@ -638,6 +638,12 @@ xnu_uuid_mod_SOURCES = commands/xnu_uuid.c
 xnu_uuid_mod_CFLAGS = $(COMMON_CFLAGS)
 xnu_uuid_mod_LDFLAGS = $(COMMON_LDFLAGS)
 
+# For trig.mod.
+pkglib_MODULES += trig.mod
+trig_mod_SOURCES = lib/trig.c
+trig_mod_CFLAGS = $(COMMON_CFLAGS)
+trig_mod_LDFLAGS = $(COMMON_LDFLAGS)
+
 pkglib_MODULES += setjmp.mod
 setjmp_mod_SOURCES = lib/$(target_cpu)/setjmp.S
 setjmp_mod_ASFLAGS = $(COMMON_ASFLAGS)

include/grub/trig.h

@@ -0,0 +1,44 @@
+/* trig.h - Trigonometric function support.  */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2008  Free Software Foundation, Inc.
+ *
+ *  GRUB 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.
+ *
+ *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GRUB_TRIG_HEADER
+#define GRUB_TRIG_HEADER 1
+
+#define GRUB_TRIG_ANGLE_MAX 256
+#define GRUB_TRIG_ANGLE_MASK 255
+#define GRUB_TRIG_FRACTION_SCALE 16384
+
+extern short grub_trig_sintab[];
+extern short grub_trig_costab[];
+
+static __inline int
+grub_sin (int x)
+{
+  x &= GRUB_TRIG_ANGLE_MASK;
+  return grub_trig_sintab[x];
+}
+
+static __inline int
+grub_cos (int x)
+{
+  x &= GRUB_TRIG_ANGLE_MASK;
+  return grub_trig_costab[x];
+}
+
+#endif /* ! GRUB_TRIG_HEADER */

lib/trig.c

@@ -0,0 +1,83 @@
+/* trig.c - Trigonometric table definitions.  */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2008  Free Software Foundation, Inc.
+ *
+ *  GRUB 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.
+ *
+ *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/trig.h>
+
+/* These tables were generated with `gentrigtables.py'.  */
+
+short grub_trig_sintab[] =
+{
+  0,402,804,1205,1606,2006,2404,2801,3196,3590,
+  3981,4370,4756,5139,5520,5897,6270,6639,7005,7366,
+  7723,8076,8423,8765,9102,9434,9760,10080,10394,10702,
+  11003,11297,11585,11866,12140,12406,12665,12916,13160,13395,
+  13623,13842,14053,14256,14449,14635,14811,14978,15137,15286,
+  15426,15557,15679,15791,15893,15986,16069,16143,16207,16261,
+  16305,16340,16364,16379,16384,16379,16364,16340,16305,16261,
+  16207,16143,16069,15986,15893,15791,15679,15557,15426,15286,
+  15137,14978,14811,14635,14449,14256,14053,13842,13623,13395,
+  13160,12916,12665,12406,12140,11866,11585,11297,11003,10702,
+  10394,10080,9760,9434,9102,8765,8423,8076,7723,7366,
+  7005,6639,6270,5897,5520,5139,4756,4370,3981,3590,
+  3196,2801,2404,2006,1606,1205,804,402,0,-402,
+  -804,-1205,-1606,-2006,-2404,-2801,-3196,-3590,-3981,-4370,
+  -4756,-5139,-5520,-5897,-6270,-6639,-7005,-7366,-7723,-8076,
+  -8423,-8765,-9102,-9434,-9760,-10080,-10394,-10702,-11003,-11297,
+  -11585,-11866,-12140,-12406,-12665,-12916,-13160,-13395,-13623,-13842,
+  -14053,-14256,-14449,-14635,-14811,-14978,-15137,-15286,-15426,-15557,
+  -15679,-15791,-15893,-15986,-16069,-16143,-16207,-16261,-16305,-16340,
+  -16364,-16379,-16384,-16379,-16364,-16340,-16305,-16261,-16207,-16143,
+  -16069,-15986,-15893,-15791,-15679,-15557,-15426,-15286,-15137,-14978,
+  -14811,-14635,-14449,-14256,-14053,-13842,-13623,-13395,-13160,-12916,
+  -12665,-12406,-12140,-11866,-11585,-11297,-11003,-10702,-10394,-10080,
+  -9760,-9434,-9102,-8765,-8423,-8076,-7723,-7366,-7005,-6639,
+  -6270,-5897,-5520,-5139,-4756,-4370,-3981,-3590,-3196,-2801,
+  -2404,-2006,-1606,-1205,-804,-402
+};
+
+short grub_trig_costab[] =
+{
+  16384,16379,16364,16340,16305,16261,16207,16143,16069,15986,
+  15893,15791,15679,15557,15426,15286,15137,14978,14811,14635,
+  14449,14256,14053,13842,13623,13395,13160,12916,12665,12406,
+  12140,11866,11585,11297,11003,10702,10394,10080,9760,9434,
+  9102,8765,8423,8076,7723,7366,7005,6639,6270,5897,
+  5520,5139,4756,4370,3981,3590,3196,2801,2404,2006,
+  1606,1205,804,402,0,-402,-804,-1205,-1606,-2006,
+  -2404,-2801,-3196,-3590,-3981,-4370,-4756,-5139,-5520,-5897,
+  -6270,-6639,-7005,-7366,-7723,-8076,-8423,-8765,-9102,-9434,
+  -9760,-10080,-10394,-10702,-11003,-11297,-11585,-11866,-12140,-12406,
+  -12665,-12916,-13160,-13395,-13623,-13842,-14053,-14256,-14449,-14635,
+  -14811,-14978,-15137,-15286,-15426,-15557,-15679,-15791,-15893,-15986,
+  -16069,-16143,-16207,-16261,-16305,-16340,-16364,-16379,-16384,-16379,
+  -16364,-16340,-16305,-16261,-16207,-16143,-16069,-15986,-15893,-15791,
+  -15679,-15557,-15426,-15286,-15137,-14978,-14811,-14635,-14449,-14256,
+  -14053,-13842,-13623,-13395,-13160,-12916,-12665,-12406,-12140,-11866,
+  -11585,-11297,-11003,-10702,-10394,-10080,-9760,-9434,-9102,-8765,
+  -8423,-8076,-7723,-7366,-7005,-6639,-6270,-5897,-5520,-5139,
+  -4756,-4370,-3981,-3590,-3196,-2801,-2404,-2006,-1606,-1205,
+  -804,-402,0,402,804,1205,1606,2006,2404,2801,
+  3196,3590,3981,4370,4756,5139,5520,5897,6270,6639,
+  7005,7366,7723,8076,8423,8765,9102,9434,9760,10080,
+  10394,10702,11003,11297,11585,11866,12140,12406,12665,12916,
+  13160,13395,13623,13842,14053,14256,14449,14635,14811,14978,
+  15137,15286,15426,15557,15679,15791,15893,15986,16069,16143,
+  16207,16261,16305,16340,16364,16379
+};
+

maintainance/gentrigtables.py

@@ -0,0 +1,58 @@
+#!/usr/bin/python
+# Script to generate trigonometric function tables.
+#
+#  GRUB  --  GRand Unified Bootloader
+#  Copyright (C) 2008  Free Software Foundation, Inc.
+#
+#  GRUB 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.
+#
+#  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
+
+from math import *
+from sys import stdout
+
+def write(x):
+    stdout.write(x)
+
+def writeTable(arr, name):
+    indent = ' ' * 4
+    write("short ")
+    write(name)
+    write("[] =\n{\n")
+    write(indent)
+    for i in range(len(arr)):
+        if i != 0:
+            write(",")
+            if i % 10 == 0:
+                write("\n")
+                write(indent)
+        write("%d" % arr[i])
+    write("\n};\n")
+
+def main():
+    sintab = []
+    costab = []
+    for i in range(256):
+        # Convert to an angle in 1/256 of a circle.
+        x = i * 2 * pi / 256
+        sintab.append(int(round(sin(x) * 16384)))
+        costab.append(int(round(cos(x) * 16384)))
+
+    write("#define TRIG_ANGLE_MAX 256\n")
+    write("#define TRIG_FRACTION_SCALE 16384\n")
+    writeTable(sintab, "sintab")
+    writeTable(costab, "costab")
+
+if __name__ == "__main__":
+    main()
+
+# vim:ai et sw=4 ts=4