1 files changed, 261 insertions, 0 deletions

diff --git a/apps/plugins/frotz/math.c b/apps/plugins/frotz/math.c
new file mode 100644
index 0000000000..5ff5163230
--- /dev/null
+++ b/apps/plugins/frotz/math.c
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+/* math.c - Arithmetic, compare and logical opcodes
+ *      Copyright (c) 1995-1997 Stefan Jokisch
+ *
+ * This file is part of Frotz.
+ *
+ * Frotz 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.
+ *
+ * Frotz 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
+ */
+
+#include "frotz.h"
+
+/*
+ * z_add, 16bit addition.
+ *
+ *      zargs[0] = first value
+ *      zargs[1] = second value
+ *
+ */
+
+void z_add (void)
+{
+
+    store ((zword) ((short) zargs[0] + (short) zargs[1]));
+
+}/* z_add */
+
+/*
+ * z_and, bitwise AND operation.
+ *
+ *      zargs[0] = first value
+ *      zargs[1] = second value
+ *
+ */
+
+void z_and (void)
+{
+
+    store ((zword) (zargs[0] & zargs[1]));
+
+}/* z_and */
+
+/*
+ * z_art_shift, arithmetic SHIFT operation.
+ *
+ *      zargs[0] = value
+ *      zargs[1] = #positions to shift left (positive) or right
+ *
+ */
+
+void z_art_shift (void)
+{
+
+    if ((short) zargs[1] > 0)
+        store ((zword) ((short) zargs[0] << (short) zargs[1]));
+    else
+        store ((zword) ((short) zargs[0] >> - (short) zargs[1]));
+
+}/* z_art_shift */
+
+/*
+ * z_div, signed 16bit division.
+ *
+ *      zargs[0] = first value
+ *      zargs[1] = second value
+ *
+ */
+
+void z_div (void)
+{
+
+    if (zargs[1] == 0)
+        runtime_error (ERR_DIV_ZERO);
+
+    store ((zword) ((short) zargs[0] / (short) zargs[1]));
+
+}/* z_div */
+
+/*
+ * z_je, branch if the first value equals any of the following.
+ *
+ *      zargs[0] = first value
+ *      zargs[1] = second value (optional)
+ *      ...
+ *      zargs[3] = fourth value (optional)
+ *
+ */
+
+void z_je (void)
+{
+
+    branch (
+        zargc > 1 && (zargs[0] == zargs[1] || (
+        zargc > 2 && (zargs[0] == zargs[2] || (
+        zargc > 3 && (zargs[0] == zargs[3]))))));
+
+}/* z_je */
+
+/*
+ * z_jg, branch if the first value is greater than the second.
+ *
+ *      zargs[0] = first value
+ *      zargs[1] = second value
+ *
+ */
+
+void z_jg (void)
+{
+
+    branch ((short) zargs[0] > (short) zargs[1]);
+
+}/* z_jg */
+
+/*
+ * z_jl, branch if the first value is less than the second.
+ *
+ *      zargs[0] = first value
+ *      zargs[1] = second value
+ *
+ */
+
+void z_jl (void)
+{
+
+    branch ((short) zargs[0] < (short) zargs[1]);
+
+}/* z_jl */
+
+/*
+ * z_jz, branch if value is zero.
+ *
+ *      zargs[0] = value
+ *
+ */
+
+void z_jz (void)
+{
+
+    branch ((short) zargs[0] == 0);
+
+}/* z_jz */
+
+/*
+ * z_log_shift, logical SHIFT operation.
+ *
+ *      zargs[0] = value
+ *      zargs[1] = #positions to shift left (positive) or right (negative)
+ *
+ */
+
+void z_log_shift (void)
+{
+
+    if ((short) zargs[1] > 0)
+        store ((zword) (zargs[0] << (short) zargs[1]));
+    else
+        store ((zword) (zargs[0] >> - (short) zargs[1]));
+
+}/* z_log_shift */
+
+/*
+ * z_mod, remainder after signed 16bit division.
+ *
+ *      zargs[0] = first value
+ *      zargs[1] = second value
+ *
+ */
+
+void z_mod (void)
+{
+
+    if (zargs[1] == 0)
+        runtime_error (ERR_DIV_ZERO);
+
+    store ((zword) ((short) zargs[0] % (short) zargs[1]));
+
+}/* z_mod */
+
+/*
+ * z_mul, 16bit multiplication.
+ *
+ *      zargs[0] = first value
+ *      zargs[1] = second value
+ *
+ */
+
+void z_mul (void)
+{
+
+    store ((zword) ((short) zargs[0] * (short) zargs[1]));
+
+}/* z_mul */
+
+/*
+ * z_not, bitwise NOT operation.
+ *
+ *      zargs[0] = value
+ *
+ */
+
+void z_not (void)
+{
+
+    store ((zword) ~zargs[0]);
+
+}/* z_not */
+
+/*
+ * z_or, bitwise OR operation.
+ *
+ *      zargs[0] = first value
+ *      zargs[1] = second value
+ *
+ */
+
+void z_or (void)
+{
+
+    store ((zword) (zargs[0] | zargs[1]));
+
+}/* z_or */
+
+/*
+ * z_sub, 16bit substraction.
+ *
+ *      zargs[0] = first value
+ *      zargs[1] = second value
+ *
+ */
+
+void z_sub (void)
+{
+
+    store ((zword) ((short) zargs[0] - (short) zargs[1]));
+
+}/* z_sub */
+
+/*
+ * z_test, branch if all the flags of a bit mask are set in a value.
+ *
+ *      zargs[0] = value to be examined
+ *      zargs[1] = bit mask
+ *
+ */
+
+void z_test (void)
+{
+
+    branch ((zargs[0] & zargs[1]) == zargs[1]);
+
+}/* z_test */