Xworld - Another World interpreter for Rockbox

Co-conspirators: Franklin Wei, Benjamin Brown

--------------------------------------------------------------------
This work is based on:
- Fabien Sanglard's "Fabother World" based on
- Piotr Padkowski's newRaw interpreter which was based on
- Gregory Montoir's reverse engineering of
- Eric Chahi's assembly code

--------------------------------------------------------------------
Progress:

* The plugin runs pretty nicely (with sound!) on most color targets
* Keymaps for color LCD targets are complete
* The manual entry is finished
* Grayscale/monochrome support is NOT PLANNED
  - the game looks horrible in grayscale! :p

--------------------------------------------------------------------
Notes:

* The original game strings were built-in to the executable, and
  were copyrighted and could not be used.
* This port ships with an alternate set of strings by default, but
  can load the "official" strings from a file at runtime.

--------------------------------------------------------------------
To be done (in descending order of importance):

* vertical stride compatibility                          <30% done>
* optimization                                           <10% done>

Change-Id: I3155b0d97c2ac470cb8a2040f40d4139ddcebfa5
Reviewed-on: http://gerrit.rockbox.org/1077
Reviewed-by: Michael Giacomelli <giac2000@hotmail.com>

1 files changed, 184 insertions, 0 deletions

diff --git a/apps/plugins/xworld/vm.h b/apps/plugins/xworld/vm.h
new file mode 100644
index 0000000..1409dd4
--- /dev/null
+++ b/apps/plugins/xworld/vm.h
@@ -0,0 +1,184 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2014 Franklin Wei, Benjamin Brown
+ * Copyright (C) 2004 Gregory Montoir
+ *
+ * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#ifndef __LOGIC_H__
+#define __LOGIC_H__
+
+
+
+#include "intern.h"
+
+#define VM_NUM_THREADS 64
+#define VM_NUM_VARIABLES 256
+#define VM_NO_SETVEC_REQUESTED 0xFFFF
+#define VM_INACTIVE_THREAD    0xFFFF
+
+
+#define    VM_VARIABLE_RANDOM_SEED          0x3C
+
+#define    VM_VARIABLE_LAST_KEYCHAR         0xDA
+
+#define    VM_VARIABLE_HERO_POS_UP_DOWN     0xE5
+#define    VM_VARIABLE_MUS_MARK             0xF4
+
+#define    VM_VARIABLE_SCROLL_Y             0xF9
+#define    VM_VARIABLE_HERO_ACTION          0xFA
+#define    VM_VARIABLE_HERO_POS_JUMP_DOWN   0xFB
+#define    VM_VARIABLE_HERO_POS_LEFT_RIGHT  0xFC
+#define    VM_VARIABLE_HERO_POS_MASK        0xFD
+#define    VM_VARIABLE_HERO_ACTION_POS_MASK 0xFE
+#define    VM_VARIABLE_PAUSE_SLICES         0xFF
+
+struct Mixer;
+struct Resource;
+struct Serializer;
+struct SfxPlayer;
+struct System;
+struct Video;
+
+//For threadsData navigation
+#define PC_OFFSET 0
+#define REQUESTED_PC_OFFSET 1
+#define NUM_DATA_FIELDS 2
+
+//For vmIsChannelActive navigation
+#define CURR_STATE 0
+#define REQUESTED_STATE 1
+#define NUM_THREAD_FIELDS 2
+
+struct VirtualMachine;
+
+void vm_create(struct VirtualMachine*, struct Mixer *mix, struct Resource *res, struct SfxPlayer *ply, struct Video *vid, struct System *stub);
+void vm_init(struct VirtualMachine*);
+
+void vm_op_movConst(struct VirtualMachine*);
+void vm_op_mov(struct VirtualMachine*);
+void vm_op_add(struct VirtualMachine*);
+void vm_op_addConst(struct VirtualMachine*);
+void vm_op_call(struct VirtualMachine*);
+void vm_op_ret(struct VirtualMachine*);
+void vm_op_pauseThread(struct VirtualMachine*);
+void vm_op_jmp(struct VirtualMachine*);
+void vm_op_setSetVect(struct VirtualMachine*);
+void vm_op_jnz(struct VirtualMachine*);
+void vm_op_condJmp(struct VirtualMachine*);
+void vm_op_setPalette(struct VirtualMachine*);
+void vm_op_resetThread(struct VirtualMachine*);
+void vm_op_selectVideoPage(struct VirtualMachine*);
+void vm_op_fillVideoPage(struct VirtualMachine*);
+void vm_op_copyVideoPage(struct VirtualMachine*);
+void vm_op_blitFramebuffer(struct VirtualMachine*);
+void vm_op_killThread(struct VirtualMachine*);
+void vm_op_drawString(struct VirtualMachine*);
+void vm_op_sub(struct VirtualMachine*);
+void vm_op_and(struct VirtualMachine*);
+void vm_op_or(struct VirtualMachine*);
+void vm_op_shl(struct VirtualMachine*);
+void vm_op_shr(struct VirtualMachine*);
+void vm_op_playSound(struct VirtualMachine*);
+void vm_op_updateMemList(struct VirtualMachine*);
+void vm_op_playMusic(struct VirtualMachine*);
+
+void vm_initForPart(struct VirtualMachine*, uint16_t partId);
+void vm_setupPart(struct VirtualMachine*, uint16_t partId);
+void vm_checkThreadRequests(struct VirtualMachine*);
+void vm_hostFrame(struct VirtualMachine*);
+void vm_executeThread(struct VirtualMachine*);
+
+void vm_inp_updatePlayer(struct VirtualMachine*);
+void vm_inp_handleSpecialKeys(struct VirtualMachine*);
+
+void vm_snd_playSound(struct VirtualMachine*, uint16_t resNum, uint8_t freq, uint8_t vol, uint8_t channel);
+void vm_snd_playMusic(struct VirtualMachine*, uint16_t resNum, uint16_t delay, uint8_t pos);
+
+void vm_saveOrLoad(struct VirtualMachine*, struct Serializer *ser);
+void vm_bypassProtection(struct VirtualMachine*);
+
+typedef void (*OpcodeStub)(struct VirtualMachine*);
+
+// The type of entries in opcodeTable. This allows "fast" branching
+static const OpcodeStub vm_opcodeTable[] = {
+    /* 0x00 */
+    &vm_op_movConst,
+    &vm_op_mov,
+    &vm_op_add,
+    &vm_op_addConst,
+    /* 0x04 */
+    &vm_op_call,
+    &vm_op_ret,
+    &vm_op_pauseThread,
+    &vm_op_jmp,
+    /* 0x08 */
+    &vm_op_setSetVect,
+    &vm_op_jnz,
+    &vm_op_condJmp,
+    &vm_op_setPalette,
+    /* 0x0C */
+    &vm_op_resetThread,
+    &vm_op_selectVideoPage,
+    &vm_op_fillVideoPage,
+    &vm_op_copyVideoPage,
+    /* 0x10 */
+    &vm_op_blitFramebuffer,
+    &vm_op_killThread,
+    &vm_op_drawString,
+    &vm_op_sub,
+    /* 0x14 */
+    &vm_op_and,
+    &vm_op_or,
+    &vm_op_shl,
+    &vm_op_shr,
+    /* 0x18 */
+    &vm_op_playSound,
+    &vm_op_updateMemList,
+    &vm_op_playMusic
+};
+
+struct VirtualMachine {
+    //This table is used to play a sound
+    //static const uint16_t frequenceTable[];
+    /* FW: moved from staticres.c to vm.c */
+
+    struct Mixer *mixer;
+    struct Resource *res;
+    struct SfxPlayer *player;
+    struct Video *video;
+    struct System *sys;
+
+    int16_t vmVariables[VM_NUM_VARIABLES];
+    uint16_t _scriptStackCalls[VM_NUM_THREADS];
+
+    uint16_t threadsData[NUM_DATA_FIELDS][VM_NUM_THREADS];
+    // This array is used:
+    //     0 to save the channel's instruction pointer
+    //     when the channel release control (this happens on a break).
+
+    //     1 When a setVec is requested for the next vm frame.
+
+    uint8_t vmIsChannelActive[NUM_THREAD_FIELDS][VM_NUM_THREADS];
+
+    struct Ptr _scriptPtr;
+    uint8_t _stackPtr;
+    bool gotoNextThread;
+    bool _fastMode;
+};
+#endif