Data File: Art.mul
Index File: ArtIdx.mul
There are three types of art images; land, static, and UO alpha
Land images are of flat terrain.
Static images are of items (walls, equipment, food, etc)
UO alpha images are a sort of animated characters, they used these instead of Anim.mul in the UO alpha.
Static and UO alpha images share the same format, while Land images use another.
Land:
Dim imageColors(0 To 1024 - 1) As Integer
Land images are fixed size at 44x44.
They also have fixed transparent locations, and the format is optimized for this.
To read the first 22 lines, you first initialize X to 22, Y to 0, and LineWidth to 2
Then repeat the following 22 times:
Decrease X by 1
Read and Draw (LineWidth) number of pixels
Increase Y by 1
Increase LineWidth by 2
For the last 22 lines, do the following:
Read and Draw (LineWidth) number of pixels
Increase X by 1
Increase Y by 1
Decrease LineWidth by 2
The resulting image is the diamond shaped tile.
Statics:
Dim header As Long ' Unknown
Dim width As Integer
Dim height As Integer
Dim lookupTable(0 To height - 1) As Integer
Offset-Run data...The lookup table is offset from the data start, and treats the data by 16-bits.
To get the proper byte offset, you need to add 4 + height, then multiply by two.
The static images are compressed with an offset-run encoding.
Offset-Run data:
Dim xOffset As Integer
Dim xRun As Integer
Dim runColors(0 To xRun - 1) As Integer
If xOffset is 0 and xRun is 0, the line has been completed. If not, continue reading the chunks.
Processing the Offset-Run data is simple:
Increase X by xOffset
Foreach xRun
Read and Draw the next pixel
Increase X by 1
End Foreach
When the line is completed, simply reset X to 0, increase Y, and seek to the next lookup in the lookupTable array and continue.
See Also:
- UO Color Format
- Index Files
