ScriptGlue.cpp

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/* Copyright (C) 2013 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. 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.
 *
 * 0 A.D. 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 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

// This module defines the table of all functions callable from JS.
// it's required by the interpreter; we make use of the opportunity to
// document them all in one spot. we thus obviate having to dig through
// all the other headers. most of the functions are implemented here;
// as for the rest, we only link to their docs (duplication is bad).

#include "precompiled.h"

#include "ScriptGlue.h"
#include "JSConversions.h"

#include "graphics/GameView.h"
#include "graphics/LightEnv.h"
#include "graphics/MapWriter.h"
#include "graphics/Unit.h"
#include "graphics/UnitManager.h"
#include "gui/GUIManager.h"
#include "gui/IGUIObject.h"
#include "lib/frequency_filter.h"
#include "lib/svn_revision.h"
#include "lib/timer.h"
#include "lib/sysdep/sysdep.h"  // sys_OpenFile
#include "maths/scripting/JSInterface_Vector3D.h"
#include "network/NetServer.h"
#include "ps/CConsole.h"
#include "ps/CLogger.h"
#include "ps/CStr.h"
#include "ps/Game.h"
#include "ps/Globals.h" // g_frequencyFilter
#include "ps/GameSetup/GameSetup.h"
#include "ps/Hotkey.h"
#include "ps/ProfileViewer.h"
#include "ps/World.h"
#include "ps/scripting/JSInterface_Console.h"
#include "ps/scripting/JSInterface_VFS.h"
#include "renderer/Renderer.h"
#include "scriptinterface/ScriptInterface.h"
#include "simulation2/Simulation2.h"
#include "soundmanager/ISoundManager.h"

// rationale: the function table is now at the end of the source file to
// avoid the need for forward declarations for every function.

// all normal function wrappers have the following signature:
//   JSBool func(JSContext* cx, JSObject* globalObject, uintN argc, jsval* argv, jsval* rval);
// all property accessors have the following signature:
//   JSBool accessor(JSContext* cx, JSObject* globalObject, jsval id, jsval* vp);


//-----------------------------------------------------------------------------
// Timer
//-----------------------------------------------------------------------------


// Script profiling functions: Begin timing a piece of code with StartJsTimer(num)
// and stop timing with StopJsTimer(num). The results will be printed to stdout
// when the game exits.

static const size_t MAX_JS_TIMERS = 20;
static TimerUnit js_start_times[MAX_JS_TIMERS];
static TimerUnit js_timer_overhead;
static TimerClient js_timer_clients[MAX_JS_TIMERS];
static wchar_t js_timer_descriptions_buf[MAX_JS_TIMERS * 12];   // depends on MAX_JS_TIMERS and format string below

static void InitJsTimers()
{
    wchar_t* pos = js_timer_descriptions_buf;
    for(size_t i = 0; i < MAX_JS_TIMERS; i++)
    {
        const wchar_t* description = pos;
        pos += swprintf_s(pos, 12, L"js_timer %d", (int)i)+1;
        timer_AddClient(&js_timer_clients[i], description);
    }

    // call several times to get a good approximation of 'hot' performance.
    // note: don't use a separate timer slot to warm up and then judge
    // overhead from another: that causes worse results (probably some
    // caching effects inside JS, but I don't entirely understand why).
    static const char* calibration_script =
        "startXTimer(0);\n"
        "stopXTimer (0);\n"
        "\n";
    g_ScriptingHost.RunMemScript(calibration_script, strlen(calibration_script));
    // slight hack: call RunMemScript twice because we can't average several
    // TimerUnit values because there's no operator/. this way is better anyway
    // because it hopefully avoids the one-time JS init overhead.
    g_ScriptingHost.RunMemScript(calibration_script, strlen(calibration_script));
    js_timer_overhead = js_timer_clients[0].sum;
    js_timer_clients[0].sum.SetToZero();
}

JSBool StartJsTimer(JSContext* cx, uintN argc, jsval* vp)
{
    ONCE(InitJsTimers());

    JSU_REQUIRE_PARAMS(1);
    size_t slot = ToPrimitive<size_t>(JS_ARGV(cx, vp)[0]);
    if (slot >= MAX_JS_TIMERS)
        return JS_FALSE;

    js_start_times[slot].SetFromTimer();

    JS_SET_RVAL(cx, vp, JSVAL_VOID);
    return JS_TRUE;
}


JSBool StopJsTimer(JSContext* cx, uintN argc, jsval* vp)
{
    JSU_REQUIRE_PARAMS(1);
    size_t slot = ToPrimitive<size_t>(JS_ARGV(cx, vp)[0]);
    if (slot >= MAX_JS_TIMERS)
        return JS_FALSE;

    TimerUnit now;
    now.SetFromTimer();
    now.Subtract(js_timer_overhead);
    BillingPolicy_Default()(&js_timer_clients[slot], js_start_times[slot], now);
    js_start_times[slot].SetToZero();

    JS_SET_RVAL(cx, vp, JSVAL_VOID);
    return JS_TRUE;
}


//-----------------------------------------------------------------------------
// Game Setup
//-----------------------------------------------------------------------------

// Immediately ends the current game (if any).
// params:
// returns:
JSBool EndGame(JSContext* cx, uintN argc, jsval* vp)
{
    JSU_REQUIRE_NO_PARAMS();

    EndGame();

    JS_SET_RVAL(cx, vp, JSVAL_VOID);
    return JS_TRUE;
}

//-----------------------------------------------------------------------------
// Misc. Engine Interface
//-----------------------------------------------------------------------------

// Return the global frames-per-second value.
// params:
// returns: FPS [int]
// notes:
// - This value is recalculated once a frame. We take special care to
//   filter it, so it is both accurate and free of jitter.
JSBool GetFps(JSContext* cx, uintN argc, jsval* vp)
{
    JSU_REQUIRE_NO_PARAMS();
    int freq = 0;
    if (g_frequencyFilter)
        freq = g_frequencyFilter->StableFrequency();
    JS_SET_RVAL(cx, vp, INT_TO_JSVAL(freq));
    return JS_TRUE;
}


// Cause the game to exit gracefully.
// params:
// returns:
// notes:
// - Exit happens after the current main loop iteration ends
//   (since this only sets a flag telling it to end)
JSBool ExitProgram(JSContext* cx, uintN argc, jsval* vp)
{
    JSU_REQUIRE_NO_PARAMS();

    kill_mainloop();

    JS_SET_RVAL(cx, vp, JSVAL_VOID);
    return JS_TRUE;
}


// Change the mouse cursor.
// params: cursor name [string] (i.e. basename of definition file and texture)
// returns:
// notes:
// - Cursors are stored in "art\textures\cursors"
JSBool SetCursor(JSContext* cx, uintN argc, jsval* vp)
{
    JSU_REQUIRE_PARAMS(1);
    g_CursorName = g_ScriptingHost.ValueToUCString(JS_ARGV(cx, vp)[0]);

    JS_SET_RVAL(cx, vp, JSVAL_VOID);
    return JS_TRUE;
}

JSBool GetGUIObjectByName(JSContext* cx, uintN argc, jsval* vp)
{
    JSU_REQUIRE_PARAMS(1);

    try
    {
        CStr name = ToPrimitive<CStr>(cx, JS_ARGV(cx, vp)[0]);
        IGUIObject* guiObj = g_GUI->FindObjectByName(name);
        if (guiObj)
            JS_SET_RVAL(cx, vp, OBJECT_TO_JSVAL(guiObj->GetJSObject()));
        else
            JS_SET_RVAL(cx, vp, JSVAL_NULL);
        return JS_TRUE;
    }
    catch (PSERROR_Scripting&)
    {
        return JS_FALSE;
    }
}

//-----------------------------------------------------------------------------
// Miscellany
//-----------------------------------------------------------------------------

// Return the date/time at which the current executable was compiled.
// params: none (-> "date time (svn revision)") OR an integer specifying
//   what to display: 0 for date, 1 for time, 2 for svn revision
// returns: string with the requested timestamp info
// notes:
// - Displayed on main menu screen; tells non-programmers which auto-build
//   they are running. Could also be determined via .EXE file properties,
//   but that's a bit more trouble.
// - To be exact, the date/time returned is when scriptglue.cpp was
//   last compiled, but the auto-build does full rebuilds.
// - svn revision is generated by calling svnversion and cached in
//   lib/svn_revision.cpp. it is useful to know when attempting to
//   reproduce bugs (the main EXE and PDB should be temporarily reverted to
//   that revision so that they match user-submitted crashdumps).
JSBool GetBuildTimestamp(JSContext* cx, uintN argc, jsval* vp)
{
    JSU_REQUIRE_MAX_PARAMS(1);

    char buf[200];

    // see function documentation
    const int mode = argc? JSVAL_TO_INT(JS_ARGV(cx, vp)[0]) : -1;
    switch(mode)
    {
    case -1:
        sprintf_s(buf, ARRAY_SIZE(buf), "%s %s (%ls)", __DATE__, __TIME__, svn_revision);
        break;
    case 0:
        sprintf_s(buf, ARRAY_SIZE(buf), "%s", __DATE__);
        break;
    case 1:
        sprintf_s(buf, ARRAY_SIZE(buf), "%s", __TIME__);
        break;
    case 2:
        sprintf_s(buf, ARRAY_SIZE(buf), "%ls", svn_revision);
        break;
    }

    JS_SET_RVAL(cx, vp, STRING_TO_JSVAL(JS_NewStringCopyZ(cx, buf)));
    return JS_TRUE;
}

#if MOZJS_DEBUG_ABI
void DumpHeap(const char* basename, int idx, JSContext* cx)
{
    char filename[64];
    sprintf_s(filename, ARRAY_SIZE(filename), "%s.%03d.txt", basename, idx);
    OsPath pathname = psLogDir() / filename;
    FILE* f = sys_OpenFile(pathname, "w");
    ENSURE(f);
    JS_DumpHeap(cx, f, NULL, 0, NULL, (size_t)-1, NULL);
    fclose(f);
}
#endif

JSBool DumpHeaps(JSContext* cx, uintN argc, jsval* vp)
{
    UNUSED2(cx);
    UNUSED2(argc);

#if MOZJS_DEBUG_ABI
    static int i = 0;

    if (ScriptingHost::IsInitialised())
        DumpHeap("gui", i, g_ScriptingHost.GetContext());
    if (g_Game)
        DumpHeap("sim", i, g_Game->GetSimulation2()->GetScriptInterface().GetContext());

    ++i;
#else
    debug_warn(L"DumpHeaps only available in DEBUG mode");
#endif

    JS_SET_RVAL(cx, vp, JSVAL_VOID);
    return JS_TRUE;
}

//-----------------------------------------------------------------------------

// Is the game paused?
JSBool IsPaused(JSContext* cx, uintN argc, jsval* vp)
{
    JSU_REQUIRE_NO_PARAMS();

    if (!g_Game)
    {
        JS_ReportError(cx, "Game is not started");
        return JS_FALSE;
    }

    JS_SET_RVAL(cx, vp, g_Game->m_Paused ? JSVAL_TRUE : JSVAL_FALSE);
    return JS_TRUE;
}

// Pause/unpause the game
JSBool SetPaused(JSContext* cx, uintN argc, jsval* vp)
{
    JSU_REQUIRE_PARAMS( 1 );

    if (!g_Game)
    {
        JS_ReportError(cx, "Game is not started");
        return JS_FALSE;
    }

    try
    {
        g_Game->m_Paused = ToPrimitive<bool> (JS_ARGV(cx, vp)[0]);

        if ( g_SoundManager )
            g_SoundManager->Pause(g_Game->m_Paused);
    }
    catch (PSERROR_Scripting_ConversionFailed&)
    {
        JS_ReportError(cx, "Invalid parameter to SetPaused");
    }

    JS_SET_RVAL(cx, vp, JSVAL_VOID);
    return JS_TRUE;
}


//-----------------------------------------------------------------------------
// function table
//-----------------------------------------------------------------------------

// the JS interpreter expects the table to contain 5-tuples as follows:
// - name the function will be called as from script;
// - function which will be called;
// - number of arguments this function expects
// - Flags (deprecated, always zero)
// - Extra (reserved for future use, always zero)
//
// we simplify this a bit with a macro:
#define JS_FUNC(script_name, cpp_function, min_params) { script_name, cpp_function, min_params, 0 },

JSFunctionSpec ScriptFunctionTable[] =
{
    // Profiling
    JS_FUNC("startXTimer", StartJsTimer, 1)
    JS_FUNC("stopXTimer", StopJsTimer, 1)

    // Game Setup
    JS_FUNC("endGame", EndGame, 0)

    // VFS (external)
    JS_FUNC("buildDirEntList", JSI_VFS::BuildDirEntList, 1)
    JS_FUNC("getFileMTime", JSI_VFS::GetFileMTime, 1)
    JS_FUNC("getFileSize", JSI_VFS::GetFileSize, 1)
    JS_FUNC("readFile", JSI_VFS::ReadFile, 1)
    JS_FUNC("readFileLines", JSI_VFS::ReadFileLines, 1)
    JS_FUNC("archiveBuilderCancel", JSI_VFS::ArchiveBuilderCancel, 1)

    // Misc. Engine Interface
    JS_FUNC("exit", ExitProgram, 0)
    JS_FUNC("isPaused", IsPaused, 0)
    JS_FUNC("setPaused", SetPaused, 1)
    JS_FUNC("setCursor", SetCursor, 1)
    JS_FUNC("getFPS", GetFps, 0)
    JS_FUNC("getGUIObjectByName", GetGUIObjectByName, 1)

    // Miscellany
    JS_FUNC("buildTime", GetBuildTimestamp, 0)
    JS_FUNC("dumpHeaps", DumpHeaps, 0)

    // end of table marker
    {0}
};
#undef JS_FUNC