| Linden scripting Language Guide ÖÐÓ¢ÎĶÔÕÕ(2) |
| ×÷Õß:ÃÎÏè¶ù ÈÕÆÚ:2007-6-27 23:40:00 |
Linden sc<x>ripting Language GuideÁֵǽű¾±à¼ÓïÑÔÖ¸ÄÏ£¨ÖÐÓ¢ÎĶÔÕհ棩
2. Getting Started ÈëÃÅÐëÖª
Chapter 2. Getting Started You¡¯re probably wondering what you can do with LSL, and how quickly you can do it. We¡¯ll start with some simple examples, dissect them, and introduce you the sc<x>ript development process while we¡¯re at it. Äã¿ÉÄÜÔÚÏëÒª¶à¾Ã²Å»áÓÃÕâ¸öLSL,ÎÒÃÇ´Ó×î¼òµ¥Àý×Ó¿ªÊ¼°É,·Ö½âËüÃÇ,´Ó¶ø½éÉÜÈçºÎ±à³Ì. 2.1. Hello Avatar ÖÂÐéÄ⹫Ãñ Continuing a long tradition of getting started by looking at a sc<x>ript that says "Hello", we¡¯ll do just that. Though obviously not a particularly useful example on it¡¯s own, this example will introduce us to: ? Creating a basic sc<x>ript ? sc<x>ript states ? Calling functions ? sc<x>ript events ? Applying a sc<x>ript to an ob<x>ject ÎÒÃǶ¼ÖªµÀÈκγÌÐòÓïÑÔ¿ªÊ¼¶¼ÊÇ¡±hello¡±.ÎÒÃÇÕâÀïÒ²ÊÇÈç´Ë.ËäÈ»Õâ¸ö¡±Hello¡±µÄС³ÌÐò²»ÊÇÌØ±ðÓÐÓÃ,µ«ÊÇÎÒÃÇ¿ÉÒÔÖªµÀ: ´´½¨Ò»ÌõÖ¸Áî Ö¸Áî״̬ µ÷Óú¯Êý Ö¸Áîʼþ °ÑÖ¸ÁîÓ¦Óõ½¶ÔÏóÉÏ ________________________________________ 2.1.1. Creating the sc<x>ript´´½¨Ò»ÌõÖ¸Áî Start by opening your inventory and selecting ¡®Create|New sc<x>ript¡¯ from the inventory pull down menu. This will create an empty sc<x>ript called ¡®New sc<x>ript¡¯ in your ¡¯sc<x>ripts¡¯ folder. Double click on the text or icon of the sc<x>ript to open the sc<x>ript in the built in editor. When you open the sc<x>ript, the viewer will automatically insert a basic skeleton for lsl. It should look like: ÔÚ¡± inventory¡±ÏÂÀ²Ëµ¥ÖÐ,Ñ¡Ôñ¡± ¡®Create|New sc<x>ript¡¯¡±,ÕâÑùÎÒÃǾÍÒѾ´´½¨ÁËÒ»ÌõеĿÕÖ¸Áî: ¡®New sc<x>ript¡¯ÔÚÎÒÃǵġ± ¡¯sc<x>ripts¡±¡ª³ÌÐòÎļþ¼ÐÀï. ÔÚ±à¼Æ÷ÖÐ, Ë«»÷Îı¾,»òÕßÊÇÖ¸Áî°´Å¥,ÒÔ´ò¿ª³ÌÐò,ÊÓͼÆ÷¾Í»á×Ô¶¯²åÈëÒ»¸ö»ù±¾µÄ¿ò¼ÜÈçÏÂ: default { state_entry() { llSay(0, "Hello, Avatar!"); } touch_start(integer total_number) { llSay(0, "Touched."); } } A casual inspection of this sc<x>ript reveals that this sc<x>ript probably says ¡®Hello, Avatar!¡¯ when it enters some state, and it says ¡®Touched.¡¯ when it is touched. But since this is also probably the first time you have seen a sc<x>ript we¡¯ll dissect this short listing, explaining each segment individually. Õâ¸öС³ÌÐòµÄ¼¶Áª¸ñʽ»áÔÚijÖÖ״̬ÏÂ,ÔÚÆÁÄ»ÏÔʾ¡¯Hello, Avatar!¡¯,µ±´¥ÃþËüµÄʱºò,ÆÁÄ»ÏÔʾ¡¯Touched.¡¯.ÒòΪÕâÒ²ÐíÊÇÄãµÚÒ»´Î¿´µ½Ò»¸ö³ÌÐòÖ¸Áî,ÎÒÃÇÀ´·Ö½âÕâ¶ÎСָÁî,Ò»¸öС¶ÎÒ»¸öС¶ÎµÄ½âÊÍ. ________________________________________ 2.1.2. Default State default { ¡ } All LSL sc<x>ripts have a simple implicit state machine with one or more states. All sc<x>ripts must have a default state, so if there is only one state, it will be the ¡®default¡¯ state. When a sc<x>ript is first started or reset, it will start out in the default state.ÿ¶ÎLSLÖ¸Áî¶¼ÊÇÒ»¸ö´øÓÐÒ»µ½¶àÖÖ״̬µÄ¼òµ¥ÒþÐÍ״̬»ú.ÿһ¸ö³ÌÐò¶¼ÓÐĬÈÏ״̬,Èç¹ûÖ»ÓÐÒ»ÖÖ״̬µÄ»°,ÄǾÍÒ»¶¨ÊÇĬÈÏ״̬. µ±Ò»¸ö³ÌÐòµÚÒ»´Î´ò¿ª»òÕßresetºó,Ëü¶¼»áÊÇĬÈÏ״̬. The default state is declared by placing the default at the root level of the document, and marking the beginning with an open brace ¡®{¡¯ and ending with a close brace ¡®}¡¯. Because of it¡¯s privileged status, you do not declare that it is fact a state like you normally would with other states.ÕâÖÖĬÈÏ״̬ȡ´ú¸úĿ¼ÎļþϵÄ״̬,²¢ÇÒÔÚ³ÌÐò¶Î¿ªÊ¼ÒÔ { ¡ } ÐÎʽ±êÃ÷.ÕâºÍÆäËü״̬ϱØÐëÌØ±ðÖ¸Ã÷. Every time you enter a state, the sc<x>ript engine will automatically call the state_entry() event and execute the code found there. On state exit, the sc<x>ript engine will automatically call the state_exit() event before calling the next state¡¯s state_entry handler. In our example, we call the llSay() function in state_entry() and do not bother to define a state_exit() handler. the state entry and exit handlers are a convenient place to initialize state data and clean up state specific data such as listen event callback.ÿ´ÎÊäÈëÒ»ÖÖ״̬,³ÌÐòÒýÇæ»á×Ô¶¯µ÷ÓÃ״̬ÊäÈ뺯Êýstate_entry()²¢Ö´ÐÐÖ¸Áî. Ò»¸ö״̬´æÔÚ, ,³ÌÐòÒýÇæ»áÔÚµ÷ÓÃÒ»ÏÂÒ»¸ö״̬ÊäÈ뺯Êýstate_entry֮ǰ,×Ô¶¯µ÷ÓÃ״̬´æÔÚ´¦Àíº¯Êýstate_exit(). ÔÚÀý×ÓÖÐ,ÎÒÃÇÔÚ״̬ÊäÈ뺯Êýstate_entry()Öе÷Óú¯ÊýllSay(), ¶ø²»»áÈ¥¶¨Òå״̬´æÔÚ´¦Àíº¯Êýstate_exit(). ״̬ÊäÈëÆ÷ºÍ´æÔÚ´¦Àíº¯Êý¿ÉÒԷdz£·½±ã³õʼ»¯×´Ì¬ÒÔ¼°Çå³ý¾ßÌåµÄ״̬Êý¾Ý,±ÈÈçʼþ¡±Ìý¡±µÄ³·»Ø. You can read more about the default state, and how to create and utilize other states in the states chapter. ÔÚ¡±×´Ì¬¡±Ò»ÕÂÖÐ,Äã¿ÉÒÔÁ˽â¸ü¶à×Ô¶¯×´Ì¬ÒÔ¼°´´½¨ºÍÓ¦ÓÃÆäËü״̬. ________________________________________ 2.1.3. Functions º¯Êý The language comes with well over 200 built in functionswhich allow sc<x>ripts and ob<x>jects to interact with their environment. All of the built in functions start with ¡®ll¡¯. LSLÓïÑÔÓÐ200ÖÐÄÚÖú¯Êý,ÔÊÐíÖ¸ÁîºÍ¶ÔÏóÔÚ»·¾³Öл¥ÏàÓ°Ïì. ËùÓÐÕâЩÄÚÖú¯Êý¶¼ÒÔ¡¯ll¡¯¿ªÊ¼.±ÈÈçµ÷Óú¯ÊýllSay()Á½´Î,¾Í¿ÉÒÔÔÚÌØ¶¨µÄÐŵÀÖÐ,µ÷³öÎı¾. The example calls the llSay() function twice, which is used to emit text on the specified channel. Ö¸ÁîÈçÏÂ: llSay( integer channel string text ); Say text on channel. Channel 0 is the public chat channel that all avatars see as chat text. Channels 1 to 2,147,483,648 are private channels that aren¡¯t sent to avatars but other sc<x>ripts can listen for. ÒÔÎı¾ÐŵÀΪÀý.ÐŵÀ0Ê**«ÃñÁÄÌìµÄÎı¾¿ò,ÐŵÀ1,2.147,483µ½648ÊÇ˽ÈËÐŵÀ,²»¶Ô¹«Ãñ¿ª·Å,µ«ÊÇÆäËü³ÌÐò¶Î¿ÉÒÔÌýÈ¡. You can define your own functions as long as the name does not conflict with a reserved word, built in constant, or built in function.Äã¿ÉÒÔ¶¨ÒåÄ㺯Êý³¤¶È,Ö»ÒªÃû×Ö²»ÊÇLSLÓïÑÔÖÐרÓú¯ÊýÓïÑÔÒÔ¼°ÄÚÖó£Á¿,ǶÈ뺯Êý ________________________________________ 2.1.4. Touch Event ´¥Ãþʼþ touch_start(integer total_number) { llSay(0, "Touched."); } There are many eventsthat can be detected in your sc<x>ripts by declaring a handler. The touch_start() event is raised when a user touches the ob<x>ject through the user interface.Ðí¶àʼþ¿ÉÒÔͨ¹ýÄãµÄ³ÌÐòÐû²¼Ò»¸ö´¦ÀíÆ÷À´¼à²â.ÔÚͨ¹ýÓû§½çÃæ´¥Ãþµ½¶ÔÏóµÄʱºò, º¯Êýtouch_start()»áÖ´ÐÐ. ________________________________________ 2.1.5. Try it Out ²âÊÔ Now that we have seen the default sc<x>ript, and examined it in some detail, it is time to see the sc<x>ript in action. Save the sc<x>ript by clicking on Save. During the save process, the editor will save the text of the sc<x>ript and compile the sc<x>ript into bytecode and then save that. When you see message ¡®Compile successful!¡¯ in the preview window, you know the compile and save is done. ÎÒÃÇÒѾ֪µÀĬÈϳÌÐòÖ¸Áî.ÏÖÔÚÈÃÎÒÃÇ¿´¿´Ö¸ÁîÔËÐÐ.µã»÷¡±save¡±±£´æ³ÌÐò.ÔÚ±£´æ¹ý³ÌÖÐ,±à¼Æ÷»á±£´æ³ÌÐòÎı¾²¢±àÒë³ÌÐòÖ¸Áîµ½Ö´ÐÐÖ¸ÁîÖб£´æ.µ±ÄãÔÚÔ¤ÀÀ´°¿Ú,¿´µ½¡± Compile successful!¡±,±àÒëºÍ±£´æ To test the sc<x>ript you will have to apply it to an ob<x>ject in the world. Create a new ob<x>ject in the world by context clickingin the main world view and selecting Create. When the wand appears, you can create a simple primitive by clickingin the world. Once the ob<x>ject appears, you can drag your newly created sc<x>ript onto the ob<x>ject to start the sc<x>ript.Òª²âÊÔ³ÌÐò,ÄãÐèÒªÔÚ°ÑËüÓ¦Óõ½Ò»¸ö¶ÔÏóÖÐ . ÔÚworldÀï,ÔÚÖ÷ÊÓ´°Àï,µã»÷¡±create¡±. µ±ÄǸöС°ô°ô¡±wand¡±³öÏÖʱ,¿ÉÒÔµã»÷world,¶ø´´½¨Ò»¸öСµÄÔʼÊÀ½ç.ÔÚÕâ¸öеÄÔʼÊÀ½çÀï,Ò»¸ö¶ÔÏó³öÏÖʱ,Äã¿ÉÒÔÍϵ½Äãд´½¨µÄ³ÌÐòµ½Õâ¸ö¶ÔÏóÉíÉÏ,ÕâÑùÎÒÃÇ´´½¨µÄ³ÌÐò¾Í¿ÉÒÔÔËÐÐÁË. Soon after dragging the sc<x>ript onto the ob<x>ject, you will see the message ob<x>ject: Hello Avatar! µ±Äã°Ñ³ÌÐòÍϵ½¶ÔÏóÉíÉÏ,Äã¿ÉÒÔ¿´µ½¶ÔÏó˵: Hello Avatar! Make sure the touch event is working by clickingon the ob<x>ject. You should see the message Touched printed into the chat history.µ±ÔÚµã»÷¶ÔÏóʱºò,ÔÚÁÄÌìÀúÊ·¼Ç¼ÐŵÀÀï,»á³öÏÖ¡± Touched¡± 2.2. Using The Built-In Editor ʹÓÃÄÚÖÃ±à¼Æ÷ The built in editor comes with most of the typical features you would expect from a basic text editor. Highlight text with the mouse, or by holding down the shift key while using the arrow keys. You can cut, copy, paste, and delete your selection using the ¡®Edit¡¯ pull down menu or by pressing the usual shortcut key.ÔÚÄÚÖÃ±à¼Æ÷ÖÐ,ÓÐÒ»¸ö»ù±¾µÄÎı¾±à¼Æ÷ÓµÓеĴ󲿷ֹ¦ÄÜ.ÓÃÊó±êÑ¡ÖÐÎı¾,»òÕßÔÚÀûÓ÷½Ïò¼ü+¡±shift¡±À´Ñ¡ÖÐÎı¾,È»ºó Ctrl+X, Ctrl+C,Ctrl+V,ÓÃÆäËüµÄͨ³£¿ì½Ý¼ü,»òÕßÔÚ¡¯Edit¡¯ÏÂÀ²Ëµ¥ÖÐ, Äã¿ÉÒÔ¼ôÇÐ.¿½±´.Õ³ÌùºÍɾ³ýÄãËùÑ¡µÄÎı¾.________________________________________ 2.3. Using Alternative Editors ʹÓÿÉÑ¡Îı¾ Since the built-in editor supports pasting text from the clipboard, you can employ a different editor to edit your sc<x>ripts, copying them into Second Life when you¡¯re ready to save them. ÄÚÖÃ±à¼Æ÷Ö§³Ö´ÓÕ³Ìù°åÕ³ÌùÎı¾¹¦ÄÜ,ÎÒÃǾͿÉÒÔÀûÓÃÆäËü±à¼Æ÷(ÈçofficeϵÁÐword excelÖ®Àà)À´±à¼Ö¸Áî,È»ºó°ÑËûÃÇ¿½±´µ½secondlife worldÀï |
