I can give a very rough explanation, since you aren't a coder (My apologies if you are).
Firstly, Why. I plan on making my own adventure game engine because I want to make commercial games, not only free games. I thought that KQ4 would be a good place to start because I didn't have to plan out a whole storyline, like I do for Arean's WIsh. Let me tell you, dedicated people are hard to find! Not that I think my staff are undedicated. It just took a long time to find them. People want new games, not just remakes of old ones

. That's why KQ2 was so much better
Secondly, I have been coding for a very long time. 9 years. I started doing this before AGS came out. And my whole goal the whole time was to make basically what AGS turned out to be. I found out about AGS when I found out about Tierra. At that point in time, I was already working on my own adventure game engine, which was very primitive, and still is (I haven't gotten very far with it: yet). I was working on a game we thought we'd call A Stand For Secrecy. I don't remember why. My brother suggested it, and I said ok. I was working on the engine before we even had a story planned out.
Thirdly, I think that if you CAN program your own engine, you should. You'll learn a lot more. It'll look a lot better when applying for a programmingi job. Basically, the experience is a lot more, shall we say, satisfying? Anyways, I *THINK* AGD2 doesn't know C++ or another suitable language to make his own engine with. I'm not positive, and I'm sorry if offense was caused. So, it's not a problem that he didn't make his own.
Now: What's different:
My engine will be a LOT like AGS. Only a few minor things will be changed for my convienience, and a different pathfinding method will be used. I believe I will use Distance Transform, but I haven't COMPLETELY researched the different possibilities. AGS uses the Djikstra algorithm.
The actual screen resolution will most likely be different. I believe I will be using 320z240 resolution, which is better supported on computers. Also, it will make me have to use less cropping, making it so you can see more of the image without stretching. Also, the engine will support Direct3d AND DirectDraw. AGS is built off DirectDraw. Therefor, all of it's alpha blending and shading routines are done by locking the individual surfaces, and adjusting them. This can be tedious, and slow, one of the reasons of those major slowdowns at alpha blending parts of the game. Direct3d is all pre-calculated, and everything is implemented in textures allowing way more effects, such as color tinting, and overall more ease in development.
I am going to completely scrap my current sprite engine. I have a much better idea of how to build it. Everything will be OOP (Object Oriented Programming) so the elements will build off one another. The sprite engine will begin by scanning in the image. It will support more formats than AGS, just because of the method I'm using.
Lastly, HOW:
I use c and C++ to code. C++ SYNTAX is very similiar to AGS, however, the actual code work is very different. For example, I believe AGS calls animations "views." These are most likely stored in an integer array pointer, which takes quite a bit of thinking to figure out how to store the individual arrays into a file, since you'd only be sending a pointer to the file, and you need to send the actual data. So it's a lot more complex, unfortunately.
The engine will probably be roughly 9,000-15,00 lines of code. This is due to the flexibility I will be implementing by making two seperate sprite engines, one for DirectDraw, and one for Direct3D.
The scripting language, I have not thoroughly researched on how I will do. Arean's wish scripting language is completely programmed by myself, but is more primitive than AGS. I have an idea about how to code an AGS-like syntax, but it could be crude to implement. There is a programm known as Yacc that I haven't looked into thoroughly, but I BELIEVE it creates scripting languages similiar to AGS-script for you. But like I said before, if you CAN do something, it's much more rewarding if you DO.
As far as scripting commands go, they will be stored in a structure that stores all the functions and scripts into a script array.
