add script module: flat event scripts with menus, switches, variables

1 files changed, 134 insertions, 0 deletions

diff --git a/kon/konscript.h b/kon/konscript.h
new file mode 100644
index 0000000..8b5a024
--- /dev/null
+++ b/kon/konscript.h
@@ -0,0 +1,134 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * konscript.h
+ *
+ * Copyright (c) 2026 KonAki
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef KONSCRIPT_H
+#define KONSCRIPT_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/*** definition ***/
+
+/* a script is a flat list of commands and jumps go to a place in the list. no nesting, so a converter can write one
+(or write it as C) without a parser, and a person can write one by hand. the program does the talking and the
+showing: say, menus and anything else the script cannot know about are handed over and the script waits */
+
+typedef enum {
+	KON_OP_END,
+	KON_OP_SAY,	/* a: who (your own number, -1 for nobody), text */
+	KON_OP_MENU,	/* a: how many OPTION commands follow */
+	KON_OP_OPTION,	/* a: where to go, b: switch that must be on to show it (-1 always), text */
+	KON_OP_JUMP,	/* a: where */
+	KON_OP_SWITCH,	/* a: switch, b: 0 off, 1 on, 2 flip */
+	KON_OP_VAR,	/* a: variable, b: KON_SET.., c: number, or KON_VARIABLE + a variable */
+	KON_OP_IFSWITCH,	/* a: switch, b: wanted 0 or 1, c: where to go if it is not */
+	KON_OP_IFVAR,	/* a: variable, b: KON_IS.., c: number or KON_VARIABLE + a variable, d: where to go if not */
+	KON_OP_WAIT,	/* a: milliseconds */
+	KON_OP_HOST,	/* a: your own command number, b, c, d, text: yours to use */
+	KON_OP_CALL,	/* a: where, comes back at the RETURN */
+	KON_OP_RETURN
+} kon_op_t;
+
+enum { KON_SET, KON_ADD, KON_SUB, KON_MUL, KON_DIV, KON_MOD };
+enum { KON_IS_EQ, KON_IS_NE, KON_IS_GE, KON_IS_LE, KON_IS_GT, KON_IS_LT };
+
+/* add a variable number to this to use that variable where a command wants a number */
+#define KON_VARIABLE 0x40000000
+
+typedef struct kon_cmd {
+	int op, a, b, c, d;
+	const char *text;
+} kon_cmd_t;
+
+/* so a script written by hand or by a converter reads as a list */
+#define KON_END() {KON_OP_END, 0, 0, 0, 0, NULL}
+#define KON_SAY(who, text) {KON_OP_SAY, who, 0, 0, 0, text}
+#define KON_MENU(count) {KON_OP_MENU, count, 0, 0, 0, NULL}
+#define KON_OPTION(text, where, needs) {KON_OP_OPTION, where, needs, 0, 0, text}
+#define KON_JUMP(where) {KON_OP_JUMP, where, 0, 0, 0, NULL}
+#define KON_SWITCH(id, how) {KON_OP_SWITCH, id, how, 0, 0, NULL}
+#define KON_VAR(id, how, n) {KON_OP_VAR, id, how, n, 0, NULL}
+#define KON_IFSWITCH(id, want, elseWhere) {KON_OP_IFSWITCH, id, want, elseWhere, 0, NULL}
+#define KON_IFVAR(id, how, n, elseWhere) {KON_OP_IFVAR, id, how, n, elseWhere, NULL}
+#define KON_WAIT(ms) {KON_OP_WAIT, ms, 0, 0, 0, NULL}
+#define KON_HOST(id, b, c, d, text) {KON_OP_HOST, id, b, c, d, text}
+#define KON_CALL(where) {KON_OP_CALL, where, 0, 0, 0, NULL}
+#define KON_RETURN() {KON_OP_RETURN, 0, 0, 0, 0, NULL}
+
+typedef enum {
+	KON_SCRIPT_DONE,
+	KON_SCRIPT_RUNNING,	/* started, kon_scriptRun has not stopped it yet */
+	KON_SCRIPT_SAY,	/* show kon_scriptText, then kon_scriptResume */
+	KON_SCRIPT_MENU,	/* show the options, then kon_scriptChoose */
+	KON_SCRIPT_WAIT,	/* kon_scriptUpdate counts it down */
+	KON_SCRIPT_HOST,	/* the host function wanted to wait, kon_scriptResume when it is over */
+	KON_SCRIPT_ERROR	/* bad jump, calls too deep, or going round and round without stopping */
+} kon_scriptStatus_t;
+
+#define KON_SCRIPT_MAX_OPTIONS 16
+#define KON_SCRIPT_MAX_CALLS 8
+
+struct kon_script;
+typedef int (*kon_hostFn)(struct kon_script *vm, const kon_cmd_t *cmd, void *user);
+
+typedef struct kon_script {
+	const kon_cmd_t *cmds;
+	int count;
+	uint8_t *switches;
+	int switchCount;
+	int32_t *vars;
+	int varCount;
+	kon_hostFn host; /* returns nonzero to make the script wait for kon_scriptResume */
+	void *user;
+	kon_scriptStatus_t status;
+	int pc;
+	int cmd; /* the command that is being waited on */
+	float wait;
+	int stack[KON_SCRIPT_MAX_CALLS], depth;
+	int options[KON_SCRIPT_MAX_OPTIONS], optionCount;
+} kon_script_t;
+
+/*** script ***/
+
+/* the switches and variables are yours, they start however you left them, and a number past the end reads as 0 and is not written */
+void kon_scriptInit(kon_script_t *vm, const kon_cmd_t *cmds, int count, uint8_t *switches, int switchCount, int32_t *vars, int varCount);
+void kon_scriptStart(kon_script_t *vm, int where);
+
+/* goes until it has to wait for something and says what, call it each frame (it does nothing while waiting) */
+kon_scriptStatus_t kon_scriptRun(kon_script_t *vm);
+void kon_scriptUpdate(kon_script_t *vm, float dt);
+void kon_scriptResume(kon_script_t *vm);
+
+const kon_cmd_t *kon_scriptCurrent(const kon_script_t *vm);
+int kon_scriptOptionCount(const kon_script_t *vm);
+const char *kon_scriptOption(const kon_script_t *vm, int i);
+void kon_scriptChoose(kon_script_t *vm, int i);
+
+int kon_scriptSwitch(const kon_script_t *vm, int id);
+int32_t kon_scriptVar(const kon_script_t *vm, int id);
+void kon_scriptSetSwitch(kon_script_t *vm, int id, int on);
+void kon_scriptSetVar(kon_script_t *vm, int id, int32_t value);
+
+#endif /* KONSCRIPT_H */