Extractor is a utility for graphical machine code programmers, designed to make the conversion of sprites (into raw screen data) much easier and more intuitive, and as part of this aim, it works on the desktop. To make learning how to use Extractor easier, there is a short tutorial included on the disc. Open the 'Tutorial' directory and run the '!ReadMe' file to get started. The tutorial has some examples, which include example code for plotting sprites from machine code.
If you have any helpful suggestions to make, or have spotted any bugs, feel free to write to me at this address;
Andrew Jackson,
15 Crabtree Close,
Wirksworth,
Matlock,
Derbyshire.
DE4 4AP.
ps As I point out in the tutorial, there is one known bug in Extractor. When a sprite files is merged into the sprite file in memory, any sprites of the same name are replaced by the new copies. However, if the new sprite is in an unacceptable mode (not 9, 12, 13 or 15), then both copies of the sprite are lost, thus causing extraction instructions concerning that sprite to be invalid. This will result in either:
- The extraction instruction changing so that a different sprite is concerned, or...
- The program will crash out, with an unhelpful error.
To solve this rarely occuring problem would entail a re-write of many parts of Extractor. When I started it my programming skills were quite poor, and I couldn't cope with handling multiple sprite files. Unless there's an easy way out, I'll need two sprite files in the application memory to sift through, and then get the program to merge them. It may possibly be easier to make Extractor cope with sprites on any screen mode, but I'm not sure how this will apply to the new RiscPC 24 bpp screen modes. There may be a general solution.
Also, of the 448k Extractor uses, 320k is only used during the extraction process. Future versions may make Extractor only grab the extra 320k when it needs to.
