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Uberman

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Posts posted by Uberman

    Embedding LE

    in Programming

    Posted

    I'm not anywhere near this point yet with my little test game, but I'm thinking ahead a bit to the point where I'm going to need to do 2D overlays (e.g., a GUI for the game).

     

    I was wondering if anybody had attempted to embed -- or having attempted, had any success embedding -- the LE engine in a "foreign" framework? I'm thinking of something like Qt, that would provide a wrapping application framework where the LE engine's rendered output could be somehow displayed in a context (perhaps by blitting the framebuffer), and then use the framework's input handling, and 2D drawing capabilities to overlay GUI-based elements onto the context. Mouse and keyboard events would be managed, and those that were targeted for the LE engine (i.e., all events taking place directly on the non-GUI elements) would "fall through" to the game code.

     

    Anybody taken this road?

    Which field do you work in?

    in Tech Talk

    Posted

    smashthewindow,

    Yes, there have been many times of economic growth in the past when employers were desperate to get people to work for them. I have lived in such a time.

     

    As have I. This is not currently one of those times, unfortunately, and it hasn't been for years.

    Which field do you work in?

    in Tech Talk

    Posted

    For the past 15 years, I've been a Senior Software Engineer on a popular commercial 3D animation package. However, I'm not one of the "3D graphics" programmers on the project. I know enough 3D graphics programming just to be dangerous. My strengths are in systems, applications, networking and scripting.

    Physics or matrix manipulation?

    in Programming

    Posted

    Some years ago (for the original Sony PSP, to show you how long ago) I wrote some raw 3D code using that platform's SDK. The code allowed the user to "walk" a cube around a grid. The cube could be "walked" by using the arrow keys; pressing left caused the cube to roll over to the left, up caused it to roll away from the user, etc. I never did anything with this code, I just wrote it basically to see if I could, and it involved a lot of management and shifting of the object's pivot point to create the illusion.

     

    I'm thinking of doing something similar in the test program I writing with Leadwerks. I cannot see any abstracted management of an Entity's pivot point in the Leadwerks SDK, so I am assuming I'll have to do some direct matrix programming to achieve the same effect. However, Leadwerks provides something new that I've not had access to before: a physics engine. I'm not sure what approach, then, would be better in programming the effect, that of using the physics engine to cause the object to "fall over" as though it were walking, or if I should just animate the motion by hand as I did on the PSP. I would imagine I'd have greater control over the movement of the object by doing manual animation, but I'd have less complicated code if I somehow employed the physics engine to move the object.

     

    In the physics approach, I imagine I'd have some kind of hidden collision object that would "knock over" the Entity, like an invisible finger pushing over a brick, while the user holds down a key. I don't know if that would be the most elegant approach, though, and perhaps some combination of manual animation and physics might be better (e.g., manually animate until the object crosses a gravitation threshold and the let the physics engine take over).

     

    Would anybody have any opinions or insights about what might be the best approach in this situation?

    "can't load scripts/class"

    in Programming

    Posted

    I have the following code:

     

    [...]
// Set graphics mode
LEO::Engine engine(AppTitle,ScreenWidth,ScreenHeight);
if( !engine.IsValid() )
{
ErrOut( "Failed to set graphics mode.");
return 1;
}
engine.AddAbstractPath( MediaDir );

// Create framework object and set it to a global object so other scripts can access it
LEO::Framework fw;
if(fw == NULL)
{
ErrOut("Failed to initialize engine.");
return 1;
}

// Set Lua framework object
engine.SetObject( "fw", fw );

// Set Lua framework variable
LEO::Lua lua;
lua.PushObject( fw );
lua.SetGlobal( "fw" );
lua.Pop( 1 );

LEO::Model skybox("abstract::environment_atmosphere.gmf");
[...]

     

    Leadwerks is installed to "D:\Leadwerks\SDK", which is what the "MediaDir" value contains.

     

    I'm trying to add a skybox to the test, and when it hits the line that loads the one provided with the SDK, I get an error message that says "can't open scripts/class". The console has the following text regarding this problem:

     

    Loading model "d:/leadwerks/sdk/models/entities/environment/atmosphere/environment_atmosphere.gmf"...

    Loading mesh "d:/leadwerks/sdk/models/entities/environment/atmosphere/environment_atmosphere.gmf"...

    Loading material "d:/leadwerks/sdk/materials/effects/invisible.mat"...

    Loading script "d:/leadwerks/sdk/models/entities/environment/atmosphere/environment_atmosphere.lua"...

    Lua error: [string "d:/leadwerks/sdk/models/entities/environment/atmosphere/environment_atmosphere.lua"]:3: attempt to call global 'CreateClass' (a nil value)

     

    So...what am I doing wrong now?

    Problem with collision callback

    in Programming

    Posted

    I've just been playing around with this. I had pretty much the same problem with the same error.

     

    Your function prototype worked, tj. I don't get the runtime error now (because the correct number of arguments are being processed). Thank you for the concrete example. It let me see that there are definitely some disconnects in the SDK (and the documentation) for which I'll have to be prepared.

    Problem with collision callback

    in Programming

    Posted

    Here goes...

     

    Huh?! Your collision callback signature is even different from the prototype in the headers! blink.png

     

    Yours:

     

    int _stdcall CoinCollision( TEntity entity0, TEntity entity1, byte* position, byte* normal, byte* force, flt speed )

     

    LEO/leobase.h Header:

     

    typedef void (*CollisionCallback)(TEntity ent0, TEntity ent1, const TVec3& pos, const TVec3& normal, flt speed);

     

    The LEO version in leobase.h is 2.5.0, but the C headers are 2.5.1. I'm beginning to get the feeling that the LEO headers are out of date with the current version of the library. The LEO header prototype does not define the "force" parameter found in your callback, but then the C headers don't even define a typedef for the callback prototype at all, so I can't compare.

    Problem with collision callback

    in Programming

    Posted

    I have added both __stdcall and __cdecl to the callback function, and no joy.

     

    I've also tried the straight C++ code (non-LEO) from the aforementioned tutorial in a fresh VS2008-based project generated by LEBuilder, added the callback function:

     

    void __stdcall cubeCollision(TEntity e1, TEntity e2, const TVec3& pos, const TVec3& normal, flt speed) {}

     

    or:

     

    void __cdecl cubeCollision(TEntity e1, TEntity e2, const TVec3& pos, const TVec3& normal, flt speed) {}

     

    set the callback:

     

    SetEntityCallback(body, (BP)cubeCollision, ENTITYCALLBACK_COLLISION);

     

    And I still get the same runtime error with VS2008 and VS2010.

     

    I'm beginning to wonder if there's some compiler setting (like structure alignment) that the LEBuilder program is not adding when it generates the Visual Studio projects.

    Problem with collision callback

    in Programming

    Posted

    I found this in leobase.h:

     

    typedef void (*CollisionCallback)(TEntity ent0, TEntity ent1, const TVec3& pos, const TVec3& normal, flt speed);

     

    But setting the callback to this signature still generates the runtime issue with VS2008 and VS2010. sad.png

    Problem with collision callback

    in Programming

    Posted

    I have the following simple (LEO-based) LE 2.5 program that compiles and functions properly under both VS2008 and VS2010:

     

    //  ====================================================================
//  This file was generated by LEBuilder
//  http://leadwerks.com/werkspace
//  ====================================================================

#include "leo.h"
#include <string>
#include <iostream>

using namespace std;
using namespace LEO;

const int   ScreenWidth = 800;
const int   ScreenHeight = 600;
const char* MediaDir = "D:\\Leadwerks\\SDK";
const char* AppTitle = "TestLEO";

void ErrOut( const string& message ) { cerr << message << endl; }

//  --------------------------------------------
int main( int argc, char* argv[] )
{
// Set graphics mode
Engine engine(AppTitle,ScreenWidth,ScreenHeight);
if( !engine.IsValid() )
{
	ErrOut( "Failed to set graphics mode.");
	return 1;
}
engine.AddAbstractPath( MediaDir );

// Create framework object and set it to a global object so other scripts can access it
Framework fw;
if( NULL == fw )
{
	ErrOut( "Failed to initialize engine." );
	return 1;
}

// Set Lua framework object
engine.SetObject( "fw", fw );

// Set Lua framework variable
Lua lua;
lua.PushObject( fw );
lua.SetGlobal( "fw" );
lua.Pop( 1 );

// Get framework main camera
fw.main.GetCamera().SetPosition( Vec3(0,0,-5) );

Material material( "abstract::cobblestones.mat" );

Debug::SetDebugPhysics();

// Create collision cube
BodyBox cube1_body(1);
cube1_body.SetMass(1.0);
cube1_body.SetFriction(1.0, 1.0);
cube1_body.SetElasticity(0.2f);

Cube cube1;
cube1.Paint( material );
cube1.SetParent(cube1_body);

cube1_body.SetPosition(Vec3(0, 5, 0));

BodyBox cube2_body(1);
cube2_body.SetMass(1.0);
cube2_body.SetFriction(1.0, 1.0);
cube2_body.SetElasticity(0.2f);

Cube cube2;
cube2.Paint( material );
cube2.SetParent(cube2_body);

cube2_body.SetPosition(Vec3(0.5, 10, 0.5));

// Create collision ground
BodyBox ground_body(1);

Cube ground;
ground.Paint( material );
ground.SetParent(ground_body);

ground_body.SetScale(Vec3(10.0f, 0.1f, 10.0f));
ground_body.SetPosition(Vec3(0, -1, 0));

// Turn on physics
//TVec3 gravity = Vec3(0,-9.80665f*2,0);
TVec3 gravity = Vec3(0,-2.0,0);

World& back_world = fw.background.GetWorld();
back_world.SetCollisions(1, 1);
back_world.SetGravity(gravity);

World& main_world = fw.main.GetWorld();
main_world.SetCollisions(1, 1);
main_world.SetGravity(gravity);

World& trans_world = fw.transparency.GetWorld();
trans_world.SetCollisions(1, 1);
trans_world.SetGravity(gravity);

cube1_body.SetType(1);
cube2_body.SetType(1);
ground_body.SetType(1);

// Add some light
DirectionalLight light;
light.SetRotation( Vec3(45) );

// Spin cube until user hits Escape
while( !Keyboard::I****() && !engine.IsTerminated() )
{
	if( !engine.IsSuspended() )
	{
		fw.Update();
		fw.Render();

		engine.Flip( 0 );
	}
}

return engine.Free();
}

     

    This works as I expect, with both cubes falling and colliding properly.

     

    I now would like to detect a collision for each Cube body (to emit a sound, for example). I add the following module-level function to the code:

     

    int cubeCollision(TEntity e1, TEntity e2)
{
 return 0;
}

     

    And then I enable collision callbacks for each Cube toward the bottom of the main() body:

     

    cube1_body.SetType(1);
cube1_body.SetCallback((BP)cubeCollision, ENTITYCALLBACK_COLLISION);
cube2_body.SetType(1);
cube2_body.SetCallback((BP)cubeCollision, ENTITYCALLBACK_COLLISION);
ground_body.SetType(1);

     

    When the first impact occurs, and the callback is triggered, I'm getting a run-time error (the same in both VS2008 and VS2010) that states:

     

    Run-Time Check Failure #0 - The value of ESP was not properly saved across a function call. This is usually a result of calling a function declared with one calling convention with a function pointer declared with a different calling convention.

     

    Any ideas about what I might be doing wrong here?

    Terrain question

    in General Discussion

    Posted

    Right. And it comes out exactly the same as 8,192 kilometers by 8,192 kilometers (8,192*8,192=67,1).

     

     

    ... so technically the features list could say more than 67 square kilometers, as they often like to do in marketing wink.png

     

    Um, sorry? Not sure I'm understanding what you are trying to say here. There's quite a difference between 8^2 and 8,192^2.

     

    8 km * 8 km = 64 sq km

    8192 km * 8192 km = 67,108,864 sq km

     

    So, are you saying that the engine can do 67,108,864 square kilometers of continuous terrain? huh.png

    LE3 Features?

    in General Discussion

    Posted

    Is there a link to the planned feature set for LE3?

     

    Specifically, I'm interested to see if 64-bit support is anticipated. Also, I'd like to see if any kind of terrain paging will be possible.

     

    Thanks!

    Licensing question

    in General Discussion

    Posted

    Yes you will. You have come arrived at a time where LE3 is not far off its initial release and towards the end of the current LE2 product. However, having said that, the initial release of LE3 will be without support for terrain and being realistic will probably be unstable for a period of time thereafter as bugs are ironed out.

     

    LE2 is a fine game engine SDK and I suspect will be in use for some time to come yet and Josh has stated many times that the combined price of LE2 plus the upgrade to LE3 will be less than the cost of buying LE3 on its own.

     

     

    Thanks. Makes perfect sense. smile.png

    Licensing question

    in General Discussion

    Posted

    ...Josh just needs to protect all the time and effort he has invested into creating this engine (and the successor that's currently in development)...

     

    Thank you for reminding me, Mumbles. That raises another question I could not seem to find the answer to:

    • Does my purchase of a copy Leadwerks today provide me only with licensing for that copy (version)? In other words, when it's "successor" arrives, will I need to purchase a new license to use that version?

    Be aware that I'm not asking for free lifetime updates (at $200, I think requiring licensing renewals for ordinal updates to be an acceptable business model). I'm just wanting to understand my obligations regarding future releases of the engine.

    Licensing question

    in General Discussion

    Posted

    You would need to be a lot more specific and precise for there to be anything for me to agree to. It's not enough to just say "it's for the game". You need to define your terms, or there is nothing concrete for me to agree to. Your definitions of gameplay control might be wildly different from mine.

     

    But I think you understand my concerns and position.

     

    Ok. Your inability to understand precisely what I mean (even though I think I was quite precise about it) worries me. I will try another, more concrete example...

     

    Let's say I want to write an MMO using Leadwerks. In this MMO, the player has the ability to write various "macros" to aid in their game play. For example, the player can write a macro (the specific language of which is irrelevant; it may be Python, it may be Lua, it may be something proprietary that only exists within the game itself) that lets them automate an attack sequence, or lets them automate some crafting action, or simply lets them automate a greeting with another player.

     

    Is this application of "scripting" within a game based on the Leadwerks engine prohibited by the EULA? It's not entirely clear from the wording of the EULA, but the interpretation of others within this thread suggest that it is not.

    Licensing question

    in General Discussion

    Posted

    It errs on the side f protecting the company, like most of these things do. If you have a precise description of what you intend to do, feel free to run it by me.

     

    Hi, Josh.

     

    It was basically as I described to Mumbles. It was unclear to me from the description if providing "macro" capabilities within my game violated the EULA the way it was worded. However, I think the replies within this post have made the spirit of the license clearer: I cannot use the game engine to create a game engine. From that standpoint, adding a scripting system to a game for the sake of the game itself would not violate the licensing.

     

    Is that substantially correct?

    Licensing question

    in General Discussion

    Posted

    The first question is easy to answer. Once paid, you can create any number of games, commercial or free, doesn't matter...

     

    A related question some people will ask is:

     

    "Is there a free, non-commercial version" to which the answer to that is no.

     

    Absolutely understand. If you can't afford $200 for unlimited commercial game production, then you clearly aren't serious in the first place.

     

    Scripting however for the process of providing the user with some sort of automation, (as in "macros") is probably allowable, so it really depends what sort of capabilities your scripting would enable, but like I say, only one person can actually answer your question definitively...

     

    Yes, this is the very thing that concerned me. I think a game should have 'macro' capabilities, but the licensing seemed rather gray area about that. It probably just isn't worded well enough to distinguish these elements.

     

    Thanks for the reply, Mumbles.

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