Angelscript/samples/tutorial/source/main.cpp

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2021-04-12 18:25:02 +00:00
#include <iostream> // cout
#include <assert.h> // assert()
#include <string.h> // strstr()
#ifdef _LINUX_
#include <sys/time.h>
#include <stdio.h>
#include <termios.h>
#include <unistd.h>
#else
#include <conio.h> // kbhit(), getch()
#include <windows.h> // timeGetTime()
#endif
#include <angelscript.h>
#include "../../../add_on/scriptstdstring/scriptstdstring.h"
using namespace std;
#ifdef _LINUX_
#define UINT unsigned int
typedef unsigned int DWORD;
// Linux doesn't have timeGetTime(), this essentially does the same
// thing, except this is milliseconds since Epoch (Jan 1st 1970) instead
// of system start. It will work the same though...
DWORD timeGetTime()
{
timeval time;
gettimeofday(&time, NULL);
return time.tv_sec*1000 + time.tv_usec/1000;
}
// Linux does have a getch() function in the curses library, but it doesn't
// work like it does on DOS. So this does the same thing, with out the need
// of the curses library.
int getch()
{
struct termios oldt, newt;
int ch;
tcgetattr(STDIN_FILENO, &oldt);
newt = oldt;
newt.c_lflag &= ~( ICANON | ECHO );
tcsetattr( STDIN_FILENO, TCSANOW, &newt );
ch = getchar();
tcsetattr( STDIN_FILENO, TCSANOW, &oldt );
return ch;
}
#endif
// Function prototypes
int RunApplication();
void ConfigureEngine(asIScriptEngine *engine);
int CompileScript(asIScriptEngine *engine);
void PrintString(string &str);
void PrintString_Generic(asIScriptGeneric *gen);
void timeGetTime_Generic(asIScriptGeneric *gen);
void LineCallback(asIScriptContext *ctx, DWORD *timeOut);
int main(int argc, char **argv)
{
RunApplication();
// Wait until the user presses a key
cout << endl << "Press any key to quit." << endl;
while(!getch());
return 0;
}
void MessageCallback(const asSMessageInfo *msg, void *param)
{
const char *type = "ERR ";
if( msg->type == asMSGTYPE_WARNING )
type = "WARN";
else if( msg->type == asMSGTYPE_INFORMATION )
type = "INFO";
printf("%s (%d, %d) : %s : %s\n", msg->section, msg->row, msg->col, type, msg->message);
}
int RunApplication()
{
int r;
// Create the script engine
asIScriptEngine *engine = asCreateScriptEngine();
if( engine == 0 )
{
cout << "Failed to create script engine." << endl;
return -1;
}
// The script compiler will write any compiler messages to the callback.
engine->SetMessageCallback(asFUNCTION(MessageCallback), 0, asCALL_CDECL);
// Configure the script engine with all the functions,
// and variables that the script should be able to use.
ConfigureEngine(engine);
// Compile the script code
r = CompileScript(engine);
if( r < 0 )
{
engine->Release();
return -1;
}
// Create a context that will execute the script.
asIScriptContext *ctx = engine->CreateContext();
if( ctx == 0 )
{
cout << "Failed to create the context." << endl;
engine->Release();
return -1;
}
// We don't want to allow the script to hang the application, e.g. with an
// infinite loop, so we'll use the line callback function to set a timeout
// that will abort the script after a certain time. Before executing the
// script the timeOut variable will be set to the time when the script must
// stop executing.
DWORD timeOut;
r = ctx->SetLineCallback(asFUNCTION(LineCallback), &timeOut, asCALL_CDECL);
if( r < 0 )
{
cout << "Failed to set the line callback function." << endl;
ctx->Release();
engine->Release();
return -1;
}
// Find the function for the function we want to execute.
asIScriptFunction *func = engine->GetModule(0)->GetFunctionByDecl("float calc(float, float)");
if( func == 0 )
{
cout << "The function 'float calc(float, float)' was not found." << endl;
ctx->Release();
engine->Release();
return -1;
}
// Prepare the script context with the function we wish to execute. Prepare()
// must be called on the context before each new script function that will be
// executed. Note, that if you intend to execute the same function several
// times, it might be a good idea to store the function returned by
// GetFunctionByDecl(), so that this relatively slow call can be skipped.
r = ctx->Prepare(func);
if( r < 0 )
{
cout << "Failed to prepare the context." << endl;
ctx->Release();
engine->Release();
return -1;
}
// Now we need to pass the parameters to the script function.
ctx->SetArgFloat(0, 3.14159265359f);
ctx->SetArgFloat(1, 2.71828182846f);
// Set the timeout before executing the function. Give the function 1 sec
// to return before we'll abort it.
timeOut = timeGetTime() + 1000;
// Execute the function
cout << "Executing the script." << endl;
cout << "---" << endl;
r = ctx->Execute();
cout << "---" << endl;
if( r != asEXECUTION_FINISHED )
{
// The execution didn't finish as we had planned. Determine why.
if( r == asEXECUTION_ABORTED )
cout << "The script was aborted before it could finish. Probably it timed out." << endl;
else if( r == asEXECUTION_EXCEPTION )
{
cout << "The script ended with an exception." << endl;
// Write some information about the script exception
asIScriptFunction *func = ctx->GetExceptionFunction();
cout << "func: " << func->GetDeclaration() << endl;
cout << "modl: " << func->GetModuleName() << endl;
cout << "sect: " << func->GetScriptSectionName() << endl;
cout << "line: " << ctx->GetExceptionLineNumber() << endl;
cout << "desc: " << ctx->GetExceptionString() << endl;
}
else
cout << "The script ended for some unforeseen reason (" << r << ")." << endl;
}
else
{
// Retrieve the return value from the context
float returnValue = ctx->GetReturnFloat();
cout << "The script function returned: " << returnValue << endl;
}
// We must release the contexts when no longer using them
ctx->Release();
// Shut down the engine
engine->ShutDownAndRelease();
return 0;
}
void ConfigureEngine(asIScriptEngine *engine)
{
int r;
// Register the script string type
// Look at the implementation for this function for more information
// on how to register a custom string type, and other object types.
RegisterStdString(engine);
if( !strstr(asGetLibraryOptions(), "AS_MAX_PORTABILITY") )
{
// Register the functions that the scripts will be allowed to use.
// Note how the return code is validated with an assert(). This helps
// us discover where a problem occurs, and doesn't pollute the code
// with a lot of if's. If an error occurs in release mode it will
// be caught when a script is being built, so it is not necessary
// to do the verification here as well.
r = engine->RegisterGlobalFunction("void Print(string &in)", asFUNCTION(PrintString), asCALL_CDECL); assert( r >= 0 );
r = engine->RegisterGlobalFunction("uint GetSystemTime()", asFUNCTION(timeGetTime), asCALL_STDCALL); assert( r >= 0 );
}
else
{
// Notice how the registration is almost identical to the above.
r = engine->RegisterGlobalFunction("void Print(string &in)", asFUNCTION(PrintString_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterGlobalFunction("uint GetSystemTime()", asFUNCTION(timeGetTime_Generic), asCALL_GENERIC); assert( r >= 0 );
}
// It is possible to register the functions, properties, and types in
// configuration groups as well. When compiling the scripts it then
// be defined which configuration groups should be available for that
// script. If necessary a configuration group can also be removed from
// the engine, so that the engine configuration could be changed
// without having to recompile all the scripts.
}
int CompileScript(asIScriptEngine *engine)
{
int r;
// We will load the script from a file on the disk.
FILE *f = fopen("script.as", "rb");
if( f == 0 )
{
cout << "Failed to open the script file 'script.as'." << endl;
return -1;
}
// Determine the size of the file
fseek(f, 0, SEEK_END);
int len = ftell(f);
fseek(f, 0, SEEK_SET);
// On Win32 it is possible to do the following instead
// int len = _filelength(_fileno(f));
// Read the entire file
string script;
script.resize(len);
size_t c = fread(&script[0], len, 1, f);
fclose(f);
if( c == 0 )
{
cout << "Failed to load script file." << endl;
return -1;
}
// Add the script sections that will be compiled into executable code.
// If we want to combine more than one file into the same script, then
// we can call AddScriptSection() several times for the same module and
// the script engine will treat them all as if they were one. The script
// section name, will allow us to localize any errors in the script code.
asIScriptModule *mod = engine->GetModule(0, asGM_ALWAYS_CREATE);
r = mod->AddScriptSection("script", &script[0], len);
if( r < 0 )
{
cout << "AddScriptSection() failed" << endl;
return -1;
}
// Compile the script. If there are any compiler messages they will
// be written to the message stream that we set right after creating the
// script engine. If there are no errors, and no warnings, nothing will
// be written to the stream.
r = mod->Build();
if( r < 0 )
{
cout << "Build() failed" << endl;
return -1;
}
// The engine doesn't keep a copy of the script sections after Build() has
// returned. So if the script needs to be recompiled, then all the script
// sections must be added again.
// If we want to have several scripts executing at different times but
// that have no direct relation with each other, then we can compile them
// into separate script modules. Each module use their own namespace and
// scope, so function names, and global variables will not conflict with
// each other.
return 0;
}
void LineCallback(asIScriptContext *ctx, DWORD *timeOut)
{
// If the time out is reached we abort the script
if( *timeOut < timeGetTime() )
ctx->Abort();
// It would also be possible to only suspend the script,
// instead of aborting it. That would allow the application
// to resume the execution where it left of at a later
// time, by simply calling Execute() again.
}
// Function implementation with native calling convention
void PrintString(string &str)
{
cout << str;
}
// Function implementation with generic script interface
void PrintString_Generic(asIScriptGeneric *gen)
{
string *str = (string*)gen->GetArgAddress(0);
cout << *str;
}
// Function wrapper is needed when native calling conventions are not supported
void timeGetTime_Generic(asIScriptGeneric *gen)
{
gen->SetReturnDWord(timeGetTime());
}