Swan Song - Isometric T2D Project

Greetings, fellow Torquers!

Last month I decided to create a game in a month. AH! No matter the results, you, the audience, will reap the fruits of my hard labor and be thankful for it!

Isometric Tile Editor

First up, I made an isometric map editor.


How to make CompositeSprite handle Isometric Maps, where 0,0 is in the upperLeft corner?

function Isometric::onCustomLayout(%this, %logicalpos)
{
   //As long as we keep the correct ratio!

   %TilesizeX = Level.LevelInfo.BaseTileSize.x;
   %TilesizeY = Level.LevelInfo.BaseTileSize.y;
   
   %logicalX = getWord(%logicalpos,0);
   %logicalY = getWord(%logicalpos,1);
   %LogicalZ = getWord(%logicalpos,2);
   
   %x = (%logicalX/2 * %TilesizeX) - (%logicalY/2 * %TilesizeX);
   %y = (%logicalY/2 * %TilesizeY) + (%logicalX/2 * %TilesizeY);
   %y -= %TilesizeX * %LogicalZ;
   
   return(%x SPC -%y);
}

In my case, I skip the next-to-last line as each layer of my map sits on an independent Composite Sprite for added flexibility.

SceneLayerDepth

The tricky thing with Isometric perspectives is the order in which tiles are drawn; it gets even trickier when you have objects moving through these tiles. I use BatchSortMode = "Z" which draws items based on their SceneLayerDepth.

Results are that the lower-right tile is at SceneDepth 0.00, the tile to its left 0.01, 0.02,0.03. When we change rows, the tile to the extreme right is at 1.00. This makes Isometric tiles draw correctly.

function Isometric::calculateDepth(%this, %position)
{
   %fraction = (Level.LevelInfo.MapSize.x-1) - %position.x;
   %fraction = %fraction/100;
   
   %unit = (Level.LevelInfo.MapSize.y-1) - %position.y;
   return(%unit + %fraction);
}

In my setup, Switching layers is not problem, since each layer exists as a separate Composite Sprite on its own scenelayer so we just change SceneLayers, keep the same SceneLayerDepth.

Lighting

As you can see in the above screenshot, I tried my hand at a very simplified Lighting system. I simply calculate a radius around each candle and fade out with each ring. The lighting is applied via the SpriteBlendColour. Problem is that a sprite cannot be partially lit so directional lights and shadows are completely incoherent. Cool effect but highly impractical.

Screenshot functionality

How did I take all these screenshots? Directly from T2D, of course!

Here is the entire script for doing so. It will save screenshots to a directory (which you can specify with $pref::Video::ScreenShotDir) and increment the filename so that nothing gets overwritten.

Just put this in a script file and exec it. Call init_Screenshot at the start of your game and ta-dam!

GlobalActionMap.bindCmd("keyboard", "F5", "do_ScreenShot();", "");

if($pref::Video::ScreenShotDir $= "")
   $pref::Video::ScreenShotDir = "Screenshots/";

function init_ScreenShot()
{
   %filelist = getFileList($pref::Video::ScreenShotDir);
   %count = %filelist.count;
   $ScreenShotSuffix = %count;   
}

function do_ScreenShot()
{
   screenShot($pref::Video::ScreenShotDir @ "screenshot" @ $ScreenShotSuffix @ ".png", "PNG");
   $ScreenShotSuffix++;
}

Asset Tags

Sorting Assets is hard but thanks to the wisdom of T2D's creators, there is a rather elegant way of doing so.

In your Assets definition module (ToyAssets for instance), add the following line at the end of your module.taml file

AssetTagsManifest="^MyModule/AssetTags.Manifest.taml";

The file should be an XML file structured as such

<AssetTagsManifest>
    <AssetTagsManifest.Tags>
        <tag
            Name="Traps" />
    </AssetTagsManifest.Tags>
    <AssetTagsManifest.Assets>
        <tag
            assetID="PlatformerAssets:FloorIzLava"
            Name="Traps" />
    </AssetTagsManifest.Assets>
</AssetTagsManifest>

In Tags, you specify all your tags, in this case, "traps".
Under Assets, you associate a declared asset with a specific tag.

In your game script, load the asset tags as follows

%AM = AssetDatabase.getAssetTags();

You can then perform sorting and filtering operations with tags.

In my case, I wanted to see if an image asset had the Traps tag associated with it.

if( %AM.hasTag(%assetID,"Traps") )
{
//do something clever.
}

Make sure to read the WIKI for functions to try.

Closing Comments

There you have it, a few quick tips for those still using T2D. It would be extremely laborious to get into the details of the editor and of everything I've done but if you guys have questions on any aspect. Feel free to ask!