From f3d340fb0ce72b9db59b8c701153bc82b595f75e Mon Sep 17 00:00:00 2001
From: Eugene Sandulenko
Date: Mon, 12 Apr 2004 21:40:49 +0000
Subject: WIP for SAGA engine.

 o text formatting is not consistent with rules, just indent utility is too
   dumb for that
 o it does not use OSystem, i.e. it runs on direct SDL calls
 o it may not even compile on your box
 o if you enable it, expect zillions of warnings
 o no sound

Now it runs ITE intro as reinherit did

svn-id: r13564
---
 saga/sthread.cpp | 1120 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1120 insertions(+)
 create mode 100644 saga/sthread.cpp

(limited to 'saga/sthread.cpp')

diff --git a/saga/sthread.cpp b/saga/sthread.cpp
new file mode 100644
index 0000000000..04407a1eec
--- /dev/null
+++ b/saga/sthread.cpp
@@ -0,0 +1,1120 @@
+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2004 The ScummVM project
+ *
+ * The ReInherit Engine is (C)2000-2003 by Daniel Balsom.
+ *
+ * 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.
+ *
+ * $Header$
+ *
+ */
+/*
+
+ Description:   
+ 
+    Scripting module thread management component
+
+ Notes: 
+*/
+
+#include "reinherit.h"
+
+#include "yslib.h"
+
+#include <limits.h>
+
+/*
+ * Uses the following modules:
+\*--------------------------------------------------------------------------*/
+#include "actor_mod.h"
+#include "console_mod.h"
+#include "text_mod.h"
+
+/*
+ * Begin module component
+\*--------------------------------------------------------------------------*/
+#include "script.h"
+#include "script_mod.h"
+
+#include "sdata.h"
+#include "sstack.h"
+#include "sthread.h"
+#include "sfuncs.h"
+
+namespace Saga {
+
+R_SCRIPT_THREAD *STHREAD_Create(void)
+{
+	YS_DL_NODE *new_node;
+	R_SCRIPT_THREAD *new_thread;
+
+	int result;
+
+	if (!ScriptModule.initialized) {
+
+		return NULL;
+	}
+
+	new_thread = (R_SCRIPT_THREAD *)calloc(1, sizeof *new_thread);
+	if (new_thread == NULL) {
+		return NULL;
+	}
+
+	result = SSTACK_Create(&(new_thread->stack),
+	    R_DEF_THREAD_STACKSIZE, STACK_GROW);
+
+	if (result != STACK_SUCCESS) {
+		return NULL;
+	}
+
+	new_node = ys_dll_add_head(ScriptModule.thread_list,
+	    new_thread, sizeof *new_thread);
+
+	free(new_thread);
+
+	return (R_SCRIPT_THREAD *)ys_dll_get_data(new_node);
+
+}
+
+int STHREAD_Destroy(R_SCRIPT_THREAD * thread)
+{
+	if (thread == NULL) {
+		return R_FAILURE;
+	}
+
+	SSTACK_Destroy(thread->stack);
+
+	return R_SUCCESS;
+}
+
+int STHREAD_ExecThreads(int msec)
+{
+	YS_DL_NODE *walk_p;
+	R_SCRIPT_THREAD *thread;
+
+	if (!ScriptModule.initialized) {
+
+		return R_FAILURE;
+	}
+
+	for (walk_p = ys_dll_head(ScriptModule.thread_list);
+	    walk_p != NULL; walk_p = ys_dll_next(walk_p)) {
+
+		thread = (R_SCRIPT_THREAD *)ys_dll_get_data(walk_p);
+
+		if (thread->executing) {
+
+			STHREAD_Run(thread, STHREAD_DEF_INSTR_COUNT, msec);
+		}
+	}
+
+	return R_SUCCESS;
+}
+
+int STHREAD_SetEntrypoint(R_SCRIPT_THREAD * thread, int ep_num)
+{
+
+	R_SCRIPT_BYTECODE *bytecode;
+	int max_entrypoint;
+
+	assert(ScriptModule.initialized);
+
+	bytecode = ScriptModule.current_script->bytecode;
+	max_entrypoint = bytecode->n_entrypoints;
+
+	if ((ep_num < 0) || (ep_num >= max_entrypoint)) {
+		return R_FAILURE;
+	}
+
+	thread->ep_num = ep_num;
+	thread->ep_offset = bytecode->entrypoints[ep_num].offset;
+
+	return R_SUCCESS;
+}
+
+int STHREAD_Execute(R_SCRIPT_THREAD * thread, int ep_num)
+{
+
+	assert(ScriptModule.initialized);
+
+	if ((ScriptModule.current_script == NULL) ||
+	    (!ScriptModule.current_script->loaded)) {
+
+		return R_FAILURE;
+	}
+
+	STHREAD_SetEntrypoint(thread, ep_num);
+
+	thread->i_offset = thread->ep_offset;
+	thread->executing = 1;
+
+	return R_SUCCESS;
+}
+
+unsigned char *GetReadPtr(R_SCRIPT_THREAD * thread)
+{
+
+	return ScriptModule.current_script->bytecode->bytecode_p +
+	    thread->i_offset;
+}
+
+unsigned long GetReadOffset(const uchar * read_p)
+{
+
+	return (unsigned long)(read_p - (unsigned char *)
+	    ScriptModule.current_script->bytecode->bytecode_p);
+}
+
+int STHREAD_HoldSem(R_SEMAPHORE * sem)
+{
+	if (sem == NULL) {
+		return R_FAILURE;
+	}
+
+	sem->hold_count++;
+
+	return R_SUCCESS;
+}
+
+int STHREAD_ReleaseSem(R_SEMAPHORE * sem)
+{
+	if (sem == NULL) {
+		return R_FAILURE;
+	}
+
+	sem->hold_count--;
+	if (sem->hold_count < 0) {
+		sem->hold_count = 0;
+	}
+
+	return R_SUCCESS;
+}
+
+int STHREAD_DebugStep(void)
+{
+
+	if (ScriptModule.dbg_singlestep) {
+		ScriptModule.dbg_dostep = 1;
+	}
+
+	return R_SUCCESS;
+}
+
+int STHREAD_Run(R_SCRIPT_THREAD * thread, int instr_limit, int msec)
+{
+
+	int instr_count;
+
+	const uchar *read_p;
+	ulong saved_offset;
+
+	SDataWord_T param1;
+	SDataWord_T param2;
+
+	long iparam1;
+	long iparam2;
+	long iresult;
+
+	SDataWord_T data;
+
+	int debug_print = 0;
+	int n_buf;
+	int bitstate;
+
+	int result;
+	int in_char;
+	int i;
+
+	int unhandled = 0;
+
+	/* Handle debug single-stepping */
+	if ((thread == ScriptModule.dbg_thread) && ScriptModule.dbg_singlestep) {
+
+		if (ScriptModule.dbg_dostep) {
+
+			debug_print = 1;
+
+			thread->sleep_time = 0;
+			instr_limit = 1;
+			ScriptModule.dbg_dostep = 0;
+		} else {
+
+			return R_SUCCESS;
+		}
+	}
+
+	for (instr_count = 0; instr_count < instr_limit; instr_count++) {
+
+		if ((!thread->executing) || (thread->sem.hold_count)) {
+			break;
+		}
+
+		thread->sleep_time -= msec;
+		if (thread->sleep_time < 0) {
+			thread->sleep_time = 0;
+		}
+
+		if (thread->sleep_time) {
+			break;
+		}
+
+		saved_offset = thread->i_offset;
+#if 0
+		R_printf(R_STDOUT, "Executing thread offset: %lu",
+		    thread->i_offset);
+#endif
+		read_p = GetReadPtr(thread);
+
+		in_char = ys_read_u8(read_p, &read_p);
+
+		switch (in_char) {
+
+			/* Align (ALGN) */
+		case 0x01:
+			break;
+
+	    /*-------------------------------------------------------------*\
+             * STACK INSTRUCTIONS     
+            \*-------------------------------------------------------------*/
+
+			/* Push nothing (PSHN) */
+		case 0x02:
+
+			SSTACK_PushNull(thread->stack);
+
+			break;
+
+			/* Pop nothing (POPN) */
+		case 0x03:
+
+			SSTACK_Pop(thread->stack, NULL);
+
+			break;
+
+			/* Push false (PSHF) */
+		case 0x04:
+
+			SSTACK_Push(thread->stack, 0);
+
+			break;
+
+			/* Push true (PSHT) */
+		case 0x05:
+
+			SSTACK_Push(thread->stack, 1);
+
+			break;
+
+			/* Push word (PUSH) */
+		case 0x06:
+
+			param1 = (SDataWord_T) ys_read_u16_le(read_p, &read_p);
+			SSTACK_Push(thread->stack, param1);
+
+			break;
+
+			/* Push word (PSHD) (dialogue string index) */
+		case 0x08:
+
+			param1 = (SDataWord_T) ys_read_u16_le(read_p, &read_p);
+			SSTACK_Push(thread->stack, param1);
+
+			break;
+
+	    /*-------------------------------------------------------------*\
+             * DATA INSTRUCTIONS  
+            \*-------------------------------------------------------------*/
+
+			/* Test flag (TSTF) */
+		case 0x0B:
+
+			n_buf = *read_p++;
+			param1 = (SDataWord_T) ys_read_u16_le(read_p, &read_p);
+
+			SDATA_GetBit(n_buf, param1, &bitstate);
+			SSTACK_Push(thread->stack, bitstate);
+
+			break;
+
+			/* Get word (GETW) */
+		case 0x0C:
+
+			n_buf = *read_p++;
+			param1 = ys_read_u16_le(read_p, &read_p);
+
+			SDATA_GetWord(n_buf, param1, &data);
+			SSTACK_Push(thread->stack, data);
+
+			break;
+
+			/* Modify flag (MODF) */
+		case 0x0F:
+
+			n_buf = *read_p++;
+			param1 = (SDataWord_T) ys_read_u16_le(read_p, &read_p);
+
+			bitstate = SDATA_ReadWordU(param1);
+
+			SSTACK_Top(thread->stack, &data);
+
+			if (bitstate) {
+				SDATA_SetBit(n_buf, data, 1);
+			} else {
+				SDATA_SetBit(n_buf, data, 0);
+			}
+
+			break;
+
+			/* Put word (PUTW) */
+		case 0x10:
+
+			n_buf = *read_p++;
+			param1 = (SDataWord_T) ys_read_u16_le(read_p, &read_p);
+
+			SSTACK_Top(thread->stack, &data);
+			SDATA_PutWord(n_buf, param1, data);
+
+			break;
+
+			/* Modify flag and pop (MDFP) */
+		case 0x13:
+
+			n_buf = *read_p++;
+			param1 = (SDataWord_T) ys_read_u16_le(read_p, &read_p);
+
+			SSTACK_Pop(thread->stack, &param1);
+
+			bitstate = SDATA_ReadWordU(param1);
+
+			if (bitstate) {
+				SDATA_SetBit(n_buf, param1, 1);
+			} else {
+				SDATA_SetBit(n_buf, param1, 0);
+			}
+
+			break;
+
+			/* Put word and pop (PTWP) */
+		case 0x14:
+
+			n_buf = *read_p++;
+			param1 = (SDataWord_T) ys_read_u16_le(read_p, &read_p);
+
+			SSTACK_Top(thread->stack, &data);
+			SDATA_PutWord(n_buf, param1, data);
+
+			break;
+
+	    /*-------------------------------------------------------------*\
+             * CONTROL INSTRUCTIONS    
+            \*-------------------------------------------------------------*/
+
+			/* (GOSB): Call subscript ? */
+		case 0x17:
+			{
+
+				int temp;
+				int temp2;
+
+				temp = *read_p++;
+				temp2 = *read_p++;
+
+				param1 =
+				    (SDataWord_T) ys_read_u16_le(read_p,
+				    &read_p);
+				data = GetReadOffset(read_p);
+
+				/*SSTACK_Push( thread->stack, (SDataWord_T)temp ); */
+				SSTACK_Push(thread->stack, data);
+
+				thread->i_offset = (unsigned long)param1;
+			}
+			break;
+
+			/* (CALL): Call function */
+		case 0x19:
+		case 0x18:
+			{
+				int n_args;
+				uint func_num;
+				int result;
+
+				SFunc_T sfunc;
+
+				n_args = ys_read_u8(read_p, &read_p);
+				func_num = ys_read_u16_le(read_p, &read_p);
+
+				if (func_num >= R_SFUNC_NUM) {
+
+					CON_Print(S_ERROR_PREFIX
+					    "Invalid script function number: (%X)\n",
+					    func_num);
+
+					thread->executing = 0;
+					break;
+				}
+
+				sfunc = SFuncList[func_num].sfunc_fp;
+
+				if (sfunc == NULL) {
+
+					CON_Print(S_WARN_PREFIX
+					    "%X: Undefined script function number: (%X)\n",
+					    thread->i_offset, func_num);
+
+					CON_Print(S_WARN_PREFIX
+					    "Removing %d operand(s) from stack.\n",
+					    n_args);
+
+					for (i = 0; i < n_args; i++) {
+
+						SSTACK_Pop(thread->stack,
+						    NULL);
+					}
+				} else {
+
+					result = sfunc(thread);
+
+					if (result != R_SUCCESS) {
+						CON_Print(S_WARN_PREFIX
+						    "%X: Script function %d failed.\n",
+						    thread->i_offset,
+						    func_num);
+					}
+				}
+
+			}
+			break;
+
+			/* (ENTR) Enter the dragon */
+		case 0x1A:
+
+			param1 = ys_read_u16_le(read_p, &read_p);
+
+			break;
+
+			/* (?) Unknown */
+		case 0x1B:
+
+			unhandled = 1;
+			break;
+
+			/* (EXIT) End subscript */
+		case 0x1C:
+
+			result = SSTACK_Pop(thread->stack, &data);
+
+			if (result != STACK_SUCCESS) {
+
+				CON_Print("Script execution complete.");
+				thread->executing = 0;
+			} else {
+
+				thread->i_offset = data;
+			}
+			break;
+
+	    /*-------------------------------------------------------------*\
+             * BRANCH INSTRUCTIONS    
+            \*-------------------------------------------------------------*/
+
+			/* (JMP): Unconditional jump */
+		case 0x1D:
+
+			param1 = ys_read_u16_le(read_p, &read_p);
+			thread->i_offset = (unsigned long)param1;
+
+			break;
+
+			/* (JNZP): Jump if nonzero + POP */
+		case 0x1E:
+
+			param1 = ys_read_u16_le(read_p, &read_p);
+
+			SSTACK_Pop(thread->stack, &data);
+			if (data) {
+				thread->i_offset = (unsigned long)param1;
+			}
+
+			break;
+
+			/* (JZP): Jump if zero + POP */
+		case 0x1F:
+
+			param1 = ys_read_u16_le(read_p, &read_p);
+
+			SSTACK_Pop(thread->stack, &data);
+			if (!data) {
+				thread->i_offset = (unsigned long)param1;
+			}
+
+			break;
+
+			/* (JNZ): Jump if nonzero */
+		case 0x20:
+
+			param1 = ys_read_u16_le(read_p, &read_p);
+
+			SSTACK_Top(thread->stack, &data);
+			if (data) {
+				thread->i_offset = (unsigned long)param1;
+			}
+
+			break;
+
+			/* (JZ): Jump if zero */
+		case 0x21:
+
+			param1 = ys_read_u16_le(read_p, &read_p);
+
+			SSTACK_Top(thread->stack, &data);
+			if (!data) {
+				thread->i_offset = (unsigned long)param1;
+			}
+
+			break;
+
+			/* (JMPR): Relative jump */
+		case 0x57:
+
+			/* ignored? */
+			ys_read_u16_le(read_p, &read_p);
+			ys_read_u16_le(read_p, &read_p);
+
+			iparam1 = (long)*read_p++;
+
+			thread->i_offset += iparam1;
+			break;
+
+			/* (SWCH): Switch */
+		case 0x22:
+			{
+
+				int n_switch;
+				unsigned int switch_num;
+				unsigned int switch_jmp;
+				unsigned int default_jmp;
+				int case_found = 0;
+
+				SSTACK_Pop(thread->stack, &data);
+
+				n_switch = ys_read_u16_le(read_p, &read_p);
+
+				for (i = 0; i < n_switch; i++) {
+
+					switch_num =
+					    ys_read_u16_le(read_p, &read_p);
+					switch_jmp =
+					    ys_read_u16_le(read_p, &read_p);
+
+					/* Found the specified case */
+					if (data == (SDataWord_T) switch_num) {
+
+						thread->i_offset = switch_jmp;
+						case_found = 1;
+						break;
+					}
+				}
+
+				/* Jump to default case */
+				if (!case_found) {
+
+					default_jmp =
+					    ys_read_u16_le(read_p, &read_p);
+					thread->i_offset = default_jmp;
+				}
+
+			}
+			break;
+
+			/* (RJMP): Random branch */
+		case 0x24:
+			{
+				int n_branch;
+				unsigned int branch_wt;
+				unsigned int branch_jmp;
+
+				int rand_sel = 0;
+				int branch_found = 0;
+
+				/* Ignored? */
+				ys_read_u16_le(read_p, &read_p);
+
+				n_branch = ys_read_u16_le(read_p, &read_p);
+
+				for (i = 0; i < n_branch; i++) {
+
+					branch_wt =
+					    ys_read_u16_le(read_p, &read_p);
+					branch_jmp =
+					    ys_read_u16_le(read_p, &read_p);
+
+					if (rand_sel == i) {
+
+						thread->i_offset = branch_jmp;
+						branch_found = 1;
+						break;
+					}
+				}
+
+				if (!branch_found) {
+					CON_Print(S_ERROR_PREFIX
+					    "%X: Random jump target out of "
+					    "bounds.", thread->i_offset);
+				}
+
+			}
+			break;
+
+	    /*-------------------------------------------------------------*\
+             * MISC. INSTRUCTIONS
+            \*-------------------------------------------------------------*/
+
+			/* (NEG) Negate stack by 2's complement */
+		case 0x25:
+
+			SSTACK_Pop(thread->stack, &data);
+			data = ~data;
+			data++;
+			SSTACK_Push(thread->stack, data);
+
+			break;
+
+			/* (TSTZ) Test for zero */
+		case 0x26:
+
+			SSTACK_Pop(thread->stack, &data);
+			data = data ? 0 : 1;
+			SSTACK_Push(thread->stack, data);
+
+			break;
+
+			/* (NOT) Binary not */
+		case 0x27:
+
+			SSTACK_Pop(thread->stack, &data);
+			data = ~data;
+			SSTACK_Push(thread->stack, data);
+
+			break;
+
+			/* (?) */
+		case 0x28:
+			unhandled = 1;
+			printf("??? ");
+			read_p++;
+			ys_read_u16_le(read_p, &read_p);
+			break;
+
+			/* (?) */
+		case 0x29:
+			unhandled = 1;
+			printf("??? ");
+			read_p++;
+			ys_read_u16_le(read_p, &read_p);
+			break;
+
+			/* (?) */
+		case 0x2A:
+			unhandled = 1;
+			printf("??? ");
+			read_p++;
+			ys_read_u16_le(read_p, &read_p);
+			break;
+
+			/* (?) */
+		case 0x2B:
+			unhandled = 1;
+			printf("??? ");
+			read_p++;
+			ys_read_u16_le(read_p, &read_p);
+			break;
+
+	    /*-------------------------------------------------------------*\
+             * ARITHMETIC INSTRUCTIONS    
+            \*-------------------------------------------------------------*/
+
+			/* (ADD): Addition */
+		case 0x2C:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			iresult = iparam1 + iparam2;
+
+			SSTACK_Push(thread->stack, (SDataWord_T) iresult);
+			break;
+
+			/* (SUB): Subtraction */
+		case 0x2D:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			iresult = iparam1 - iparam2;
+
+			SSTACK_Push(thread->stack, (SDataWord_T) iresult);
+			break;
+
+			/* (MULT): Integer multiplication */
+		case 0x2E:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			iresult = iparam1 * iparam2;
+
+			SSTACK_Push(thread->stack, (SDataWord_T) iresult);
+			break;
+
+			/* (DIB): Integer division */
+		case 0x2F:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			iresult = iparam1 / iparam2;
+
+			SSTACK_Push(thread->stack, (SDataWord_T) iresult);
+			break;
+
+			/* (MOD) Modulus */
+		case 0x30:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			iresult = iparam1 % iparam2;
+
+			SSTACK_Push(thread->stack, (SDataWord_T) iresult);
+			break;
+
+			/* (EQU) Test equality */
+		case 0x33:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			data = (iparam1 == iparam2) ? 1 : 0;
+
+			SSTACK_Push(thread->stack, data);
+			break;
+
+			/* (NEQU) Test inequality */
+		case 0x34:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			data = (iparam1 != iparam2) ? 1 : 0;
+
+			SSTACK_Push(thread->stack, data);
+			break;
+
+			/* (GRT) Test Greater-than */
+		case 0x35:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			data = (iparam1 > iparam2) ? 1 : 0;
+
+			SSTACK_Push(thread->stack, data);
+			break;
+
+			/* (LST) Test Less-than */
+		case 0x36:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			data = (iparam1 < iparam2) ? 1 : 0;
+
+			SSTACK_Push(thread->stack, data);
+			break;
+
+			/* (GRTE) Test Greater-than or Equal to */
+		case 0x37:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			data = (iparam1 >= iparam2) ? 1 : 0;
+
+			SSTACK_Push(thread->stack, data);
+			break;
+
+			/* (LSTE) Test Less-than or Equal to */
+		case 0x38:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+			iparam2 = (long)param2;
+			iparam1 = (long)param1;
+
+			data = (iparam1 <= iparam2) ? 1 : 0;
+
+			SSTACK_Push(thread->stack, data);
+			break;
+
+			/* (SHR): Arithmetic binary shift right */
+		case 0x3F:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+
+			iparam2 = (long)param2;
+
+			/* Preserve most significant bit */
+			data =
+			    (0x01 << ((sizeof param1 * CHAR_BIT) -
+				1)) & param1;
+
+			for (i = 0; i < (int)iparam2; i++) {
+				param1 >>= 1;
+				param1 |= data;
+			}
+
+			SSTACK_Push(thread->stack, param1);
+			break;
+
+	    /*-------------------------------------------------------------*\
+             * BITWISE INSTRUCTIONS   
+            \*-------------------------------------------------------------*/
+
+			/* (SHL) Binary shift left */
+		case 0x40:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+
+			param1 <<= param2;
+
+			SSTACK_Push(thread->stack, param1);
+			break;
+
+			/* (AND) Binary AND */
+		case 0x41:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+
+			param1 &= param2;
+
+			SSTACK_Push(thread->stack, param1);
+			break;
+
+			/* (OR) Binary OR */
+		case 0x42:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+
+			param1 |= param2;
+
+			SSTACK_Push(thread->stack, param1);
+			break;
+
+			/* (XOR) Binary XOR */
+		case 0x43:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+
+			param1 ^= param2;
+
+			SSTACK_Push(thread->stack, param1);
+			break;
+
+	    /*-------------------------------------------------------------*\
+             * BOOLEAN LOGIC INSTRUCTIONS     
+            \*-------------------------------------------------------------*/
+
+			/* (LAND): Logical AND */
+		case 0x44:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+
+			data = (param1 && param2) ? 1 : 0;
+
+			SSTACK_Push(thread->stack, data);
+			break;
+
+			/* (LOR): Logical OR */
+		case 0x45:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+
+			data = (param1 || param2) ? 1 : 0;
+
+			SSTACK_Push(thread->stack, data);
+			break;
+
+			/* (LXOR): Logical XOR */
+		case 0x46:
+
+			SSTACK_Pop(thread->stack, &param2);
+			SSTACK_Pop(thread->stack, &param1);
+
+			data = ((param1) ? !(param2) : !!(param2));
+
+			SSTACK_Push(thread->stack, data);
+			break;
+
+	    /*-------------------------------------------------------------*\
+             * GAME INSTRUCTIONS  
+            \*-------------------------------------------------------------*/
+
+			/* (DLGP): Play Character Dialogue */
+		case 0x53:
+			{
+				int n_voices;
+				int a_index;
+				int voice_rn;
+
+				n_voices = *read_p++;
+				param1 =
+				    (SDataWord_T) ys_read_u16_le(read_p,
+				    &read_p);
+
+				/* ignored ? */
+				*read_p++;
+				ys_read_u16_le(read_p, &read_p);
+
+				a_index = ACTOR_GetActorIndex(param1);
+
+				if (a_index < 0) {
+					CON_Print(S_WARN_PREFIX
+					    "%X: DLGP Actor id not found.",
+					    thread->i_offset);
+				}
+
+				for (i = 0; i < n_voices; i++) {
+
+					SSTACK_Pop(thread->stack, &data);
+
+					if (a_index < 0)
+						continue;
+
+					if (!ScriptModule.voice_lut_present) {
+						voice_rn = -1;
+					} else {
+						voice_rn =
+						    ScriptModule.
+						    current_script->voice->
+						    voices[data];
+					}
+
+					ACTOR_Speak(a_index,
+					    ScriptModule.current_script->diag->
+					    str[data], voice_rn, &thread->sem);
+
+				}
+
+			}
+			break;
+
+			/* (DLGS): Initialize dialogue interface */
+		case 0x54:
+			break;
+
+			/* (DLGX): Run dialogue interface */
+		case 0x55:
+			break;
+
+			/* (DLGO): Add a dialogue option to interface */
+		case 0x56:
+			{
+				int param1;
+				int param2;
+				int param3;
+
+				printf("DLGO | ");
+				param1 = *read_p++;
+				param2 = *read_p++;
+
+				printf("%02X %02X ", param1, param2);
+
+				if (param2 > 0) {
+					param3 =
+					    ys_read_u16_le(read_p, &read_p);
+
+					printf("%04X", param3);
+				}
+			}
+			break;
+
+	    /*-------------------------------------------------------------*\
+             * End instruction list
+            \*-------------------------------------------------------------*/
+
+		default:
+
+			CON_Print(S_ERROR_PREFIX
+			    "%X: Invalid opcode encountered: " "(%X).\n",
+			    thread->i_offset, in_char);
+			thread->executing = 0;
+
+			break;
+
+		}		/* end switch( in_char ) */
+
+		/* Set instruction offset only if a previous instruction didn't 
+		 * branch */
+		if (saved_offset == thread->i_offset) {
+
+			thread->i_offset = GetReadOffset(read_p);
+		}
+
+		if (unhandled) {
+
+			CON_Print(S_ERROR_PREFIX "%X: Unhandled opcode.\n",
+			    thread->i_offset);
+			thread->executing = 0;
+		}
+
+		if (thread->executing && debug_print) {
+			SDEBUG_PrintInstr(thread);
+		}
+
+	}
+
+	return R_SUCCESS;
+}
+
+} // End of namespace Saga
+
-- 
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