Limitations of AGI Priority Bands - Revision history

Andrew Branscom at 22:35, 14 April 2019

2019-04-14T22:35:00Z

Andrew Branscom at 22:34, 14 April 2019

2019-04-14T22:34:43Z

Andrew Branscom at 22:34, 14 April 2019

2019-04-14T22:34:26Z

Andrew Branscom at 22:28, 14 April 2019

2019-04-14T22:28:23Z

Andrew Branscom at 22:27, 14 April 2019

2019-04-14T22:27:35Z

Andrew Branscom at 17:33, 24 March 2019

2019-03-24T17:33:57Z

Andrew Branscom at 23:22, 28 December 2013

2013-12-28T23:22:36Z

Andrew Branscom at 19:43, 28 December 2013

2013-12-28T19:43:17Z

Andrew Branscom at 21:39, 26 December 2013

2013-12-26T21:39:36Z

Andrew Branscom at 21:39, 26 December 2013

2013-12-26T21:39:16Z

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 [[Category:References]]
 [[Category:AGI Picture Resources]]
 [[Category:AGI View Resources]]

← Older revision		Revision as of 22:34, 14 April 2019
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	[[Category:AGI View Resources]]		[[Category:AGI View Resources]]
	[[Category:AGI View Resources]]		[[Category:AGI View Resources]]
−	~~[[Category:View Resources (AGI)]]~~

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 [[Category:References]]
 [[Category:AGI Picture Resources]]
-[[Category:View Resources]]
+[[Category:AGI View Resources]]
 [[Category:AGI View Resources]]
 [[Category:View Resources (AGI)]]

@@ Line 76: / Line 76: @@
 [[Category:References]]
 [[Category:AGI Picture Resources]]
 [[Category:AGI View Resources]]
 [[Category:View Resources (AGI)]]

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 </syntaxhighlight>
-This forces ego’s priority to change to 8 behind the boulder regardless of the priority bands. This is not a very good idea, however. First of all, you have to experiment somewhat to get the right coordinates for the <code>posn()</code> command to avoid ending up with weird graphics errors. This could also cause problems if there are other characters in the room. The idea might prove useful in some special cases, though. The last and perhaps the most interesting approach – definitely the most flexible one – is to create the boulder as a [[View Resource]] and make it appear as a screen object (''not'' an <code>add.to.pic</code> which wouldn’t help at all). This is achieved by leaving the area the boulder will cover blank in the background drawing and overlaying the object, stored as a View, on the screen during the game. In this example, the following image is stored as View number 2 (the transparency color is cyan)
+This forces ego’s priority to change to 8 behind the boulder regardless of the priority bands. This is not a very good idea, however. First of all, you have to experiment somewhat to get the right coordinates for the <code>posn()</code> command to avoid ending up with weird graphics errors. This could also cause problems if there are other characters in the room. The idea might prove useful in some special cases, though. The last and perhaps the most interesting approach – definitely the most flexible one – is to create the boulder as a [[View Resource (AGI)|View resource]] and make it appear as a screen object (''not'' an <code>add.to.pic</code> which wouldn’t help at all). This is achieved by leaving the area the boulder will cover blank in the background drawing and overlaying the object, stored as a View, on the screen during the game. In this example, the following image is stored as View number 2 (the transparency color is cyan)
 <div align="center">[[File:agiboulderview.png|the boulder as a View object]]</div>
@@ Line 77: / Line 77: @@
 [[Category:AGI Picture Resources]]
 [[Category:AGI View Resources]]

@@ Line 34: / Line 34: @@
 </syntaxhighlight>
-This forces ego’s priority to change to 8 behind the boulder regardless of the priority bands. This is not a very good idea, however. First of all, you have to experiment somewhat to get the right coordinates for the <code>posn()</code> command to avoid ending up with weird graphics errors. This could also cause problems if there are other characters in the room. The idea might prove useful in some special cases, though. The last and perhaps the most interesting approach – definitely the most flexible one – is to create the boulder as a VIEW resource and make it appear as a screen object (''not'' an <code>add.to.pic</code> which wouldn’t help at all). This is achieved by leaving the area the boulder will cover blank in the background drawing and overlaying the object, stored as a VIEW, on the screen during the game. In this example, the following image is stored as VIEW number 2 (the transparency color is cyan)
+This forces ego’s priority to change to 8 behind the boulder regardless of the priority bands. This is not a very good idea, however. First of all, you have to experiment somewhat to get the right coordinates for the <code>posn()</code> command to avoid ending up with weird graphics errors. This could also cause problems if there are other characters in the room. The idea might prove useful in some special cases, though. The last and perhaps the most interesting approach – definitely the most flexible one – is to create the boulder as a [[View Resource]] and make it appear as a screen object (''not'' an <code>add.to.pic</code> which wouldn’t help at all). This is achieved by leaving the area the boulder will cover blank in the background drawing and overlaying the object, stored as a View, on the screen during the game. In this example, the following image is stored as View number 2 (the transparency color is cyan)
-<div align="center">[[File:agiboulderview.png|the boulder as a VIEW object]]</div>
+<div align="center">[[File:agiboulderview.png|the boulder as a View object]]</div>
 Then, in the background drawing, the area where the object will go is left blank with only the shadow remaining.
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 </syntaxhighlight>
-This code places the VIEW of the boulder in the appropriate position. Here’s how the combination of a VIEW and the background will look like in the game.
+This code places the View of the boulder in the appropriate position. Here’s how the combination of a View and the background will look like in the game.
-<div align="center">[[File:agifinishedboulder.png|the boulder VIEW added to the background]]</div>
+<div align="center">[[File:agifinishedboulder.png|the boulder View added to the background]]</div>
 This is the best way to create objects in the middle of a priority band. However, there are some drawbacks to it:
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 * Each screen object takes up memory. Remember that AGI has an internal 64 kB resource limit.
 *Too many objects can seriously slow down the gameplay if you use an ancient computer – one that AGI games were originally designed for. Of course, this isn’t a problem on modern hardware.
-*The designing of the background is complicated by the fact that some features have to be drawn in a picture editor as vector pictures and some in a VIEW editor as bitmap sprites, and the coordination between these two kinds of image creation can slow down the development of the game.
+*The designing of the background is complicated by the fact that some features have to be drawn in a picture editor as vector pictures and some in a View editor as bitmap sprites, and the coordination between these two kinds of image creation can slow down the development of the game.
 *The shadow of the object usually has to be drawn into the background image or else it too will limit the movement of screen objects. (Of course, you could always apply the <code>ignore.objs</code> command to it – but why bother? Of course, if you want the shadow to move, that’s a different story altogether.)
-*The object can only have a “depth” of one pixel like all screen objects (which, although the original boulder example wasn’t any “deeper”, could look a bit silly for a big object) unless you  want to draw control lines in the background image – which again complicates image creation because of the coordination that is required between VIEW and picture editing.
+*The object can only have a “depth” of one pixel like all screen objects (which, although the original boulder example wasn’t any “deeper”, could look a bit silly for a big object) unless you  want to draw control lines in the background image – which again complicates image creation because of the coordination that is required between View and picture editing.
-This method works because of the way the interpreter deals with animated objects: if two objects have the same priority, their Y coordinates are used to determine which one goes in front. This is something that wouldn’t work with background objects, because they have no coordinates at all (in fact, they are objects only in the mind of the viewer). By creating the boulder as a VIEW instead of making it a part of the background drawing, we can give it coordinates and thus place it anywhere we desire, ignoring the limitations of priority bands.
+This method works because of the way the interpreter deals with animated objects: if two objects have the same priority, their Y coordinates are used to determine which one goes in front. This is something that wouldn’t work with background objects, because they have no coordinates at all (in fact, they are objects only in the mind of the viewer). By creating the boulder as a View instead of making it a part of the background drawing, we can give it coordinates and thus place it anywhere we desire, ignoring the limitations of priority bands.
 &nbsp;
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 [[Category:References]]
 [[Category:Picture Resources]]
-[[Category:VIEW Resources]]
+[[Category:View Resources]]

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 [[Category:Tutorials]]
 [[Category:References]]
-<!-- [[Category:PIC Resources]]
+[[Category:PIC Resources]]
-[[Category:VIEW Resources]] -->
+[[Category:VIEW Resources]]