Refactor|libcommon: Use an object-oriented model for ACScript system …

…components

Now uses a common, OO model for all ACScript system components, in
"acs" namespace. Functionality is separated into Interpreter, Script
and System components.

Also fixed a couple of bugs that crept in during the custom episodes
implementation, through misinterpretation of vanilla behavior due to
a logic error in vanilla (which, subtly masked various bugs in the
Hexen IWAD(s)...).

doomsday/api/doomsday.h

@@ -69,6 +69,7 @@
 #include "api_server.h"
 #include "api_sound.h"
 #include "api_svg.h"
+#include "api_uri.h"
 
 #include <de/memoryzone.h>
 #include <de/point.h>

doomsday/plugins/common/common.pri

@@ -9,6 +9,9 @@ INCLUDEPATH += \
     $$DENG_LZSS_DIR/portable/include
 
 HEADERS += \
+    $$common_inc/acs/interpreter.h \
+    $$common_inc/acs/script.h \
+    $$common_inc/acs/system.h \
     $$common_inc/am_map.h \
     $$common_inc/animdefs.h \
     $$common_inc/common.h \
@@ -93,6 +96,9 @@ HEADERS += \
     $$common_inc/menu/widgets/widget.h
 
 SOURCES += \
+    $$common_src/acs/interpreter.cpp \
+    $$common_src/acs/script.cpp \
+    $$common_src/acs/system.cpp \
     $$common_src/am_map.c \
     $$common_src/animdefs.cpp \
     $$common_src/common.c \
@@ -132,7 +138,7 @@ SOURCES += \
     $$common_src/p_iterlist.c \
     $$common_src/p_map.cpp \
     $$common_src/p_mapsetup.cpp \
-    $$common_src/p_mapspec.c \
+    $$common_src/p_mapspec.cpp \
     $$common_src/p_plat.cpp \
     $$common_src/p_saveg.cpp \
     $$common_src/p_saveio.cpp \

doomsday/plugins/common/include/acs/interpreter.h

@@ -0,0 +1,112 @@
+/** @file interpreter.h  Action Code Script (ACS) interpreter.
+ *
+ * @authors Copyright © 2003-2013 Jaakko Keränen <jaakko.keranen@iki.fi>
+ * @authors Copyright © 2005-2015 Daniel Swanson <danij@dengine.net>
+ * @authors Copyright © 1999 Activision
+ *
+ * @par License
+ * GPL: http://www.gnu.org/licenses/gpl.html
+ *
+ * <small>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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA</small>
+ */
+
+#ifndef LIBCOMMON_ACS_INTERPRETER_H
+#define LIBCOMMON_ACS_INTERPRETER_H
+
+#if __cplusplus
+#  include "acs/script.h"
+#  include "mapstatereader.h"
+#  include "mapstatewriter.h"
+#endif
+
+#define ACS_INTERPRETER_MAX_SCRIPT_ARGS     10
+#define ACS_INTERPRETER_SCRIPT_STACK_DEPTH  32
+
+#ifdef __cplusplus
+
+namespace acs {
+
+class System;
+
+/**
+ * Action Code Script (ACS) interpreter (thinker).
+ *
+ * @ingroup playsim
+ */
+struct Interpreter
+{
+    thinker_t thinker;
+    struct mobj_s *activator;
+    Line *line;
+    int side;
+    void *_script;
+    int delayCount;
+    struct Stack { // Local value stack.
+        int values[ACS_INTERPRETER_SCRIPT_STACK_DEPTH];
+        int height;
+
+        void push(int value);
+        int pop();
+        int top() const;
+        void drop();
+    } locals;
+    int args[ACS_INTERPRETER_MAX_SCRIPT_ARGS];
+    int const *pcodePtr;
+
+    acs::System &scriptSys() const;
+
+    /**
+     * Returns the Script data for the thinker.
+     */
+    acs::Script &script() const;
+
+    void think();
+
+    /**
+     * Deserialize the thinker from the currently open save file.
+     */
+    int read(MapStateReader *msr);
+
+    /**
+     * Serialize the thinker to the currently open save file.
+     */
+    void write(MapStateWriter *msw) const;
+
+    /**
+     * @param script      Logical ACS script-state instance.
+     * @param scriptArgs  Args passed to the script.
+     * @param delayCount  Delay in tics to wait before interpretation begins.
+     */
+    static thinker_s *newThinker(acs::Script &script, acs::Script::Args const &scriptArgs,
+                                 struct mobj_s *activator = nullptr, Line *line = nullptr,
+                                 int side = 0, int delayCount = 0);
+};
+
+}  // namespace acs
+#endif  // __cplusplus
+
+// C wrapper API ---------------------------------------------------------------
+
+// Opaque type for interpreter instances.
+struct acs_Interpreter;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void acs_Interpreter_Think(acs_Interpreter *interp);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // LIBCOMMON_ACS_INTERPRETER_H

doomsday/plugins/common/include/acs/script.h

@@ -0,0 +1,174 @@
+/** @file script.h  Action Code Script (ACS), script model.
+ *
+ * @authors Copyright © 2003-2013 Jaakko Keränen <jaakko.keranen@iki.fi>
+ * @authors Copyright © 2005-2015 Daniel Swanson <danij@dengine.net>
+ * @authors Copyright © 1999 Activision
+ *
+ * @par License
+ * GPL: http://www.gnu.org/licenses/gpl.html
+ *
+ * <small>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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA</small>
+ */
+
+#ifndef LIBCOMMON_ACS_SCRIPT_H
+#define LIBCOMMON_ACS_SCRIPT_H
+
+#include "common.h"
+#include <array>
+#include <de/reader.h>
+#include <de/writer.h>
+#include <de/String>
+
+namespace acs {
+
+class System;
+
+/**
+ * Models the high-level state of an Action Code Script (ACS).
+ *
+ * @ingroup playsim
+ */
+class Script
+{
+public:
+    /**
+     * Stores information about an ACS byte/p-code entry point.
+     */
+    struct EntryPoint
+    {
+        int const *pcodePtr     = nullptr;
+        bool startWhenMapBegins = false;
+        int scriptNumber        = 0;
+        int scriptArgCount      = 0;
+    };
+
+    /**
+     * Script arguments.
+     */
+    class Args : public std::array<de::dbyte, 4>
+    {
+    public:
+        Args();
+        Args(de::dbyte const *cArr, de::dint length);
+    };
+
+    /**
+     * Logical script states.
+     */
+    enum State {
+        Inactive,
+        Running,
+        Suspended,
+
+        WaitingForSector,
+        WaitingForPolyobj,
+        WaitingForScript,
+
+        Terminating
+    };
+    static de::String stateAsText(State state);
+
+public:
+    Script();
+    Script(EntryPoint const &ep);
+
+    /**
+     * Composes the human-friendly, styled, textual name of the object.
+     */
+    de::String describe() const;
+
+    /**
+     * Composes a human-friendly, styled, textual description of the script.
+     */
+    de::String description() const;
+
+    /**
+     * Start/resume script interpretation if inactive/suspended.
+     *
+     * If currently suspended the script is instructed to resume (deferred).
+     *
+     * Otherwise instantiate a new script Interpreter and add it to the list of
+     * thinkers for the @em current map.
+     *
+     * @param args       Script argument values.
+     * @param activator  Mobj activator, if any (can be @c nullptr).
+     * @param line       Line activator, if any (can be @c nullptr).
+     * @param side       Line side number.
+     * @param delayTics  Number of tics to wait before interpretation begins.
+     *                   (Can be used to delay processing during map startup).
+     *
+     * @return  @c true if started/resumed.
+     */
+    bool start(Args const &args, mobj_t *activator = nullptr,
+               Line *line = nullptr, int side = 0, int delayTics = 0);
+
+    /**
+     * Instruct the script to self-suspend if running (deferred).
+     *
+     * @return  @c true if marked for suspension.
+     */
+    bool suspend();
+
+    /**
+     * Instruct the script to self-terminate if running (deferred).
+     *
+     * @return  @c true if marked for termination.
+     */
+    bool terminate();
+
+    /**
+     * Returns the current logical state of the script (FYI).
+     */
+    State state() const;
+
+    bool isRunning()   const;
+    bool isSuspended() const;
+    bool isWaiting()   const;
+
+    void waitForPolyobj(int tag);
+    void waitForScript (int number);
+    void waitForSector (int tag);
+
+    void polyobjFinished(int tag);
+    void sectorFinished (int tag);
+
+    /**
+     * Returns the entry point info for the script.
+     */
+    EntryPoint const &entryPoint() const;
+
+    /**
+     * Reconfigure the entry point info for the script.
+     */
+    void applyEntryPoint(EntryPoint const &epToCopy);
+
+    void read(Reader *reader);
+    void write(Writer *writer) const;
+
+public:  /// @todo make private:
+
+    /**
+     * Resume @em this script if it is waiting on @a other (which has just terminated).
+     *
+     * @param other  Script to be considered.
+     */
+    void resumeIfWaitingForScript(Script const &other);
+
+    void setState(State newState);
+
+private:
+    DENG2_PRIVATE(d)
+};
+
+} // namespace acs
+
+#endif  // LIBCOMMON_ACS_SCRIPT_H