游戏脚本管理 (一)
前言:
在自己制作了单机泡泡堂的游戏之后,感觉应该加入游戏脚本的支持,通过一段时间学习,我将学的一些步骤和经验包括代码写了下来.
一、实现以指令为基础的游戏脚本语言
现在说的是理论方法,你马上可以实现一种以指令为基础的语言。首先设计一组简单的指令,用于显示文本,并加入简单的循环。最终用MessageBox对话框显示出来。
设计语言第一个步骤,建立自己的指令,为了更直观我建立一个指令表,列表如下:
文本控制指令表 |
命令 |
参数 |
描述 |
PrintString |
string |
输出字符串 |
PrintStringLoop |
string,count |
根据count指定输出次数 |
NewLine |
None |
增加一个空行 |
WaitForKeyPress |
None |
等待按键 |
二、编写一个脚本
首先确认你认为所需要的功能,目前它就是上表列的4条指令。它最好为一个标准的文本文件。
PrintString "这是一种以指令为基础的语言" PrintString "也是一个简单的脚本代码" Newline PrintString "但它相当的简单" Newline PrintStringLoop "将被输出4次" 4 Newline PrintString "等下将执行等待按键操作" WaitForKeyPress
三、编写TScript类
这段代码相当简单,主要体现于分解字符串的操作,根据不同的指令来执行不同的代码。
unit uScripting;
interface
uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms;
const
//四个指令的常量定义 COMMAND_PRINTSTRING = 'PrintString'; COMMAND_NEWLINE = 'Newline'; COMMAND_PRINTSTRINGLOOP = 'PrintStringLoop'; COMMAND_WAITFORKEYPRESS = 'WaitForKeyPress';
type TScript = class private FCommandList: TStrings; //保存脚本 procedure GetCommand(Index: integer; var strCommand: string); //获取一个命令 procedure GetStrParam(Index: integer; var strParam: string); //获取一个字符串参数 procedure GetIntParam(Index: integer; var intParam: integer); //获取一个整形参数 public constructor Create; destructor Destroy; override; procedure LoadScript(AFile: string); //装入脚本 procedure UnLoadScript; //清空脚本 procedure RunScript(); //运行脚本 end;
implementation
{ TScript }
constructor TScript.Create; begin FCommandList := TStringList.Create; end;
destructor TScript.Destroy; begin FCommandList.Clear; FCommandList.Free; inherited Destroy; end;
procedure TScript.GetCommand(Index: integer; var strCommand: string); begin if Pos(#32, Trim(FCommandList.Strings[Index])) <> 0 then strCommand := Trim(Copy(Trim(FCommandList.Strings[Index]), 1, Pos(#32, Trim(FCommandList.Strings[Index])))) else strCommand := Trim(FCommandList.Strings[Index]); end;
procedure TScript.GetIntParam(Index: integer; var intParam: integer); var cCurrChar : string; g_iCurrScriptLineChar: Integer; begin
g_iCurrScriptLineChar := Pos('"', FCommandList.Strings[Index]) + 1; g_iCurrScriptLineChar := Pos('"', Copy(FCommandList.Strings[Index], g_iCurrScriptLineChar + 1, length(FCommandList.Strings[Index]))) + g_iCurrScriptLineChar + 1; intParam := 0;
while (g_iCurrScriptLineChar <= Length(FCommandList.Strings[Index])) do begin cCurrChar := copy(FCommandList.Strings[Index], g_iCurrScriptLineChar, 1); if (cCurrChar = '#') or (cCurrChar = #13) or (cCurrChar = #10) then break; if (cCurrChar[1] in ['0'..'9']) then intParam := StrToInt(IntToStr(intParam) + cCurrChar); inc(g_iCurrScriptLineChar, 1); end;
end;
procedure TScript.GetStrParam(Index: integer; var strParam: string); var cCurrChar : string; g_iCurrScriptLineChar: Integer; begin
g_iCurrScriptLineChar := Pos('"', FCommandList.Strings[Index]) + 1; strParam := '';
while (g_iCurrScriptLineChar < Length(FCommandList.Strings[Index])) do begin cCurrChar := copy(FCommandList.Strings[Index], g_iCurrScriptLineChar, 1); if (cCurrChar = '"') or (cCurrChar = #13) or (cCurrChar = #10) then break; strParam := strParam + cCurrChar; inc(g_iCurrScriptLineChar, 1); end;
end;
procedure TScript.LoadScript(AFile: string); begin if FileExists(AFile) then FCommandList.LoadFromFile(AFile) else raise Exception.Create('无效的脚本文件'); end;
procedure TScript.RunScript; var strCommand : string; strParam : string; intParam : integer; i : Integer; iCurr : integer; sResult : string; begin if FCommandList.Count < 0 then Exit; sResult := '';
for i := 0 to FCommandList.Count - 1 do begin GetCommand(i, strCommand); if Uppercase(strCommand) = Uppercase(COMMAND_PRINTSTRING) then //检查指令是否匹配 begin GetStrParam(i, strParam); //获取字符串参数 sResult := sResult + strParam + #13#10; //保存结果 end else if UpperCase(strCommand) = UpperCase(COMMAND_PRINTSTRINGLOOP) then begin GetStrParam(i, strParam); GetIntParam(i, intParam); //获取整形参数
for iCurr := 0 to intParam - 1 do begin sResult := sResult + strParam + #13#10; //循环输出次数 end; end else if UpperCase(strCommand) = UpperCase(COMMAND_NEWLINE) then begin sResult := sResult + #13#10; end else if UpperCase(strCommand) = UpperCase(COMMAND_WAITFORKEYPRESS) then begin Application.Title := '等待按键'; while true do begin Application.ProcessMessages; if GetInputState() then break; end; Application.Title := '按键完成'; end else begin sResult := sResult + '无效指令!' + #13#10; end;
end;
Application.MessageBox(PAnsiChar(sResult), '运行结果', 0);
end;
procedure TScript.UnLoadScript; begin FCommandList.Clear; end;
end.
这里是测试代码。
procedure TGameMain.Button1Click(Sender: TObject); //请在form中放入一个button 后粘贴代码到单击事件中 var FScript : TScript; begin FScript := TScript.Create; FScript.LoadScript('E:\projects\GameEngine\Scripts\Test.src'); //修改为你保存脚本的路径 (Sender as TButton).Enabled := FALSE; FScript.RunScript; //等待按键时只需要单击一下form即可继续运行。 (Sender as TButton).Enabled := TRUE; FScript.Free; end;
这里是关于上面代码的图解说明:
阅读完上述的内容后,下一回将讲解如何解释向这样的脚本指令:
DrawBitmap "gfx/copyright.bmp" PlaySound "sound/ambient.wav" Pause 3000 PlaySound "sound/wipe.wav" FoldCloseEffectY DrawBitmap "gfx/ynh_presents.bmp" PlaySound "sound/ambient.wav" Pause 3000 PlaySound "sound/wipe.wav" FoldCloseEffectX DrawBitmap "gfx/title.bmp" PlaySound "sound/title.wav" WaitForKeyPress PlaySound "sound/wipe.wav" FoldCloseEffectY Exit
再见!2004年11月

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