workin' on a scripting engine....

**jverkoey** · 03-14-2003

Hey everyone, I've started working on a scripting engine for OpenGL and it's going along REALLY nicely. Here's the commands you can use in it so far:

DrawLine
EnableTextures
DisableTextures
Reset
SetColor
Rotate
EnableCulling
DrawMode
DisableCulling
Box

Each command can either take parameters or just be a normal command, for example, this code will draw an untextured line to the screen:

Code:

/*  Script-and-Go code by Jeff Verkoeyen,
	created 2003	*/

VARIABLES;
	@int rot1;
	@float rot2;
	@char testing;
	@bool myBool;

	myBool=true;
	testing="hey";

	rot1=1;
	rot2=1;
BEGIN;
	rot1+1;
	rot2+1;
	DisableTextures;				// Disables the textures

	Reset;
	Move(0,0,-100);
	SetColor(1.0f,1.0f,0.0f,0.5f);
	Rotate(rot1,1.0f,0.0f,0.0f);
	Move(10,20,0);
	Box(-10,10,0,10,10,0,10,-10,0,-10,-10,0);

	Reset;
	Move(0,0,-100);
	SetColor(0.0f,0.0f,1.0f,0.5f);
	Rotate(rot2,0.0f,0.0f,1.0f);
	Move(-10,0,0);
	Box(-10,10,0,10,10,0,10,-10,0,-10,-10,0);
END;

my goal with the engine is to make it so virtually anyone can do OpenGL, even if you don't have a compiler (or you stink at programming, lol)

the rules of the engine are these:

1) You must begin your main code with BEGIN, and you may have a section to declare variables, ABOVE the BEGIN-END section by declaring VARIABLES;
2) All commands must be ended with a semicolon (kinda like C/C++)
3) Comments include Long Comments and Line Comments, EX:
Long Comments begin with a /* and end with a */ and can go for multiple lines
Line Comments are just // and can be placed anywhere in a line and will comment everything from that point on to the end of the line
4) All commands that have parameters must have the parameters inside of parenthesis ( )
5) Any command without parameters must NOT have any parenthesis....that should make logical sense, lol (for example: Reset; does not take any parameters, so Reset(3); would return an error)
6) Any errors found in the code will generate an error inside the program, and then the program will quit (well, you have to handle the quitting and do it however you prefer)
7) To declare variables, you must do so in the VARIABLES; section. It would also be wise to initialize your variables at the top, also. You may do normal math operations to each of the variables whether in the VARIABLES; section or the BEGIN-END; section.
8) All programs MUST end with END

So, yah, I'm hoping to get this finished by Monday, because I'll be using it in my games from now on probably to quickly be able to test OpenGL code without having to recompile anything

lemme know what you think, and I'm looking for ideas of more commands I should put in the engine......

-edit-
updated the comment part

-edit 2-
updated everything that was needed to be updated (code, requirements, etc.)

**RoD** · 03-14-2003

>>2) All commands must be ended with a semicolon (kinda like visual studio)

Correct if wrong, but i was under the impression that ending code with a ';' is all c++ not jusr VC++?

**jverkoey** · 03-14-2003

ahh, i just realized that.............well, i'll fix it, lol

**RoD** · 03-14-2003

I wasnt trying to nit-pick or anything, it just seemed wrong to me, and wanted to make sure that either i was wrong or you were wrong, so that the two of us were correct in our knowledge of that statement. Sorry if i came across as a jerk, i think the idea is a very good one, congratulations!

-RoD

**XSquared** · 03-14-2003

If a comment is begun with a single /, how will the person do division?

**jverkoey** · 03-14-2003

lol......that's true, isn't it, once i get the variables in there I won't be able to divide very easily.....hmm, and it's kinda hard to look at two characters at the same time without having to jump back....well, there is peek.....hmm..........i could use @ signs.......that would work......well, wait, if they wanted to output an @ sign......ggrgfggrfgrgfgf

rfgfdtrfgrfgfrtgf, well, i guess i could just use C++'s way of doing it, I was trying to be as little like C++ as I could.....but I guess the comments will just have to resemble.....UNLESS

i could use an /@ for long comments and a @/ to close 'em, and for the single line comments, i could use @*

bwahhaa, that works

**RoD** · 03-14-2003

Just use /*

*/

:P

**jverkoey** · 03-14-2003

*sigh*, lol, i guess i'll just use that then, hehe, it'll give more familiarity to C++ developers anyways.....

doop doop, gotta wait till my mom's off the puter so i can go back to work on it......

**RoD** · 03-14-2003

what comp are you on?

Well this is a C/C++ oriented community, making my suggestion more than expected : )

**jverkoey** · 03-14-2003

i'm on my puter, but the thing is, my mouse is dead (i took it apart and now the chip is hanging off the side of my desk) and it's really frustrating trying to use the mouse thing where you use the number pad...cuz it keeps randomly clicking....

I have visual studio on here, but this computer is so da#$ slow it's not even funny, OpenGL goes about 3 frames per second, unless I shrink the window down to about the size of your thumb......

so yah, I realize i'm in a C++ dev community, I develop in C++ too, but use the OpenGL API, thing is, I just wanted to make my scripting program as simple as possible (the comments don't matter, they're always simple, lol) sooo........i think i answered everything

**RoD** · 03-14-2003

Comments in general very simple, but if the idea is too have people who are lower knowleged in programming to use your script then i would devise a comment system that ran together as smoothly as possible.

For example, its in my opinion that

/*
*/

runs together much better than

&*
*&

See what i mean? I think the C++ method would tend to make a little more sense to the programmer. Just a suggestion, however.

**jverkoey** · 03-14-2003

aah, yes, that makes logical sense.....I think I've got it in my head as to how to read the two characters.......but one question: does peek look at the VERY next character in the stream, without moving forward in it? cuz i know when you use <stream name>.get(buffer); it takes one letter from the file taken from the current position, and stores it to that character, then moves the stream position over one....what I'm thinking of doing is this (forgive me if it doesn't work, i'm doing this off the top of my head...)

Code:

file.get(buff);
if(buff=='/')
{
   if(file.peek(buff)=='*')
        comment=true;     // set this so I know I'm in a comment
}

that way, if it ISN'T a comment, then it won't have moved forward at all and I can test later on if they wanted to divide or whatever....

that, in my head, theoretically works, I don't know if you can use peek like that though (I'm not exactly an expert on file i/o yet....)

**jverkoey** · 03-14-2003

aah ha, i'm back at the good puter, I remade the comment code now so it reads like this:

Code:

/*  Script-and-Go code by Jeff Verkoeyen,
	created 2003	*/

BEGIN;
	Reset;		// Equivalent to LoadIdentity
	DisableTextures;	// Disables the textures
	DrawLine(0,0,-80,30,0,-80);	// Draws the line
END;

found that the seek thing didn't work at all, so i just used tellg and seekg....that works about the same...

Code:

			if(buff2=='/')	//Test for comments
			{
				char buff3;
				script.get(buff3);
				if(buff3=='*')
					comment=true;
				else if(buff3=='/')
					comment2=true;
				else
					script.seekg(filepos);
			}
//to find if the comment has started


			if(buff2=='*')
			{
				char buff3;
				script.get(buff3);
				if(buff3=='/')
					comment=false;
				else
					script.seekg(filepos);
			}
			if(buff2=='\n')
				comment2=false;
//to end it

and that works fine and dandy

**jverkoey** · 03-14-2003

you guys can check out the program and tell me what you think....there's still only the basic commands..........(look above for basic instructions) this is a REALLY BASIC demo, so don't expect too much, you can draw a line, and that's about it, lol

**jverkoey** · 03-14-2003

ok, just added quite a few more commands:

SetColor
Move
Box

they're self-explanatory........

anyways, what I was wondering was, how is it possible for users of the script to make their own variables? the only way I've been able to think of implementing variables is to have pre-defined variables that they could use........but that wouldn't add much funtionality..

thing is, I can't figure out how............*SMACK* *idea hits his head*

just got a revelation.....!! what do you all think about this? I'll have a huge matrix of integers, maybe about 1024 of them (int vars[1024]) then, if the user wanted to use one of 'em, he/she'd just type in:

@<variable number>

for example:

@102=35;

would store 35 to slot 102 on the array.........you guys think that would work? i think it would add a pretty nice feature to the program...........

lookin' for feedback, I won't put it in if it's not a good idea

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