Android - Full Screen

I was putting some finishing touches onto a new little ap for my 2 year old and needed to make it full screen. This is what I ended up using.  Edit the AndroidManifest.xml file and change the android:theme line to this.

        android:theme="@android:style/Theme.NoTitleBar.Fullscreen"

Learning Android - Audio Volume Control

I've been spending some time learning to program using Android.  It's been on my list for a long time and I'm going slow and building fun little things for my 2 year old. Nothing commercial, just something for him to enjoy.

The first app I built had an issue that the audio controls on the device wouldn't work unless a sound was actually playing.  Found a really simple work around.

Add this call to the onCreate method in the activity.

        setVolumeControlStream(AudioManager.STREAM_MUSIC);

Pretty simple little fix.

Second Life Game Tile Testing

I've been messing around with game tile systems again using second life. Looking at the rudiments of a table top game like checkers, chess or even something as complex as monopoly. Trying to figure out how to develop something that doesn't use physics, but uses a tile based movement system.

I started by building a blank table top and adding a piece to it. Right now, the piece simply moves from corner to corner when someone clicks on the table. Under the hood there is a lot more going on than you might first think.

This is the code in the init script in the table.

default
{
  state_entry()
  {

      //list bb = llGetBoundingBox(llGetKey()); // get my bounding box
      vector sz = llList2Vector(llGetPrimitiveParams([PRIM_SIZE]),0);
      llMessageLinked(LINK_ALL_OTHERS,1,(string)sz,NULL_KEY);
  }

  touch_start(integer total_number)
  {
      //llSay(0, "Touched.");
      llSay(1024,"move");
  }
}

You might as why did I comment out llGetBoundingBox. The reason is it works great when the table is by itself, but once the piece is on the table, the piece's location is included in the bounding box. This makes the box larger than expected.

So, the script get's the actual prim size from the table top and passes it to all the other linked objects (in this case the "disc" using a linked message. The identifier of the message is the number "1" which in this case means "table size", and the size (vector) is passed as a string.


You can also see that when the table is touched, it says "move" on channel 1024 which you can guess that the "disc" is listening for. Why not use llMessageLinked for both communications? We'll I should, but the "move" message was added early on and I started using linked messages later and have to get back to change to use llMessageLinked.


This is the code for the disc

vector mysize;
vector mysizediv2;
vector tablesize;
vector min;
vector max;
integer posMinOrMax;

default
{
  state_entry()
  {
      //list bb = llGetBoundingBox(llGetLinkKey(1)); // get the bounding box of the table
      //max = llList2Vector(bb, 1); // max corner
      //min = llList2Vector(bb, 0); // min corner
      //min = >min.x,min.y,max.z<;
    
      //llWhisper(0,(string)min+" "+(string)max);
    
      posMinOrMax = 0;

      llListen(1024,"",llGetLinkKey(1),"move");
  }


  listen( integer channel, string name, key id, string message )
  {
      if (channel==1024)
      {
          if  (posMinOrMax==0)
          {
              llSetPos(max);
              //llWhisper( 0, "max" );
          }
          else
          {
              llSetPos(min);
              //llWhisper( 0, "min" );
          }
          posMinOrMax = 1 - posMinOrMax;
        
      }
  }

  link_message(integer sender_num, integer num, string str, key id)
  {
      if (num==1)
      {
          mysize = llList2Vector(llGetPrimitiveParams([PRIM_SIZE]),0);
          mysizediv2 = mysize / 2;
          mysizediv2.z = 0.0;
    
          tablesize = (vector) str;
          llWhisper(0,"got size = "+(string)tablesize);
          vector sz = tablesize / 2;
          min = >-sz.x,-sz.y,sz.z*2< + mysizediv2;
          max = >sz.x,sz.y,sz.z*2< - mysizediv2;
        
      }
  }
}

You can see that early on I calculated the min and max positions based on the bounding box which I have already said is wrong. On the listen channel when I hear "move" I toggle the position between the min and max. That should be pretty straight forward.


The interesting stuff is in the link_message function. I first get the size of the "disc" using the llGetPrimitiveParams call. All positioning is done from the center of the object, so if I use the absolute min and max sizes of the table then the disc will hang off the edge. I divide the size by two because that is how far I have to inset the position from the table's min and max.

I then convert the table size vector from the string that was passed on the link message back to a vector and calculate the min and max positions using the inset of half the disc size. The min adds half the disc size and the max subtracts. The other thing is that the table's origin is at the center, and positioning the disc has to take that into account. So the min is the table position (center) subtracting half the size of the table. The max is the table position (center) and adding half the table size.

I had a discussion with another developer about the moonphase virtual sculpture. They mentioned a technique that might improve bandwidth usage by using llSetTextureAnim instead of setting the offset of the texture directly. The idea being that llSetTextureAnim would be running on the actual client which doesn't require any bandwidth, while llOffsetTexture is run on the server and all the clients viewing that object need to receive a message that the object change.

So I did some testing with llSetTextureAnim and I couldn't get the same results. When you use ROTATE in llSetTextureAnim then you can't specify the texture offset, only which portion of the texture you want to use. It seems like it is used to have a tiled texture where each section of the tile can be used as an individual tile. In my case, I used a half transparent texture and am rotating that around the sphere. Using llSetTextureAnim I don't see a way to get the same effect. I'm a little slow most of the time so I may be missing something. Here is a screen shot of using

default
{  state_entry()
{
    llSetTextureAnim(ANIM_ON | LOOP | SMOOTH | ROTATE,ALL_SIDES, 1,1,  0, TWO_PI, TWO_PI/360);
}
}

I also tried using a non-ROTATE texture animation which only cause the texture to turn on and off when the "tile" reached the non-transparent section.

I really like the idea of reducing bandwidth by having the texture changes run on each client, but don't see a way to get this to work for this sculpture. llSetTextureAnim is definitely a good tool for the tool belt and I'll have to consider some sort of sculpture using a tiled texture. That would mean that each client would see something different on their machine so there couldn't be a discussion about the "current" look of the sculpture between two people, but I'm not sure that's a real problem.

Sensor land detection

I recently moved lands and my new neighbor asked if I could turn of my sensor that greeted visitors. I guess it was going off when people were visiting their land.

I first detected the location of the Agent who tripped the sensor. Then get the land owner key at that location. It's hard to tell what that key is so I wrote code to print that out if the sensor detected me, then went into my neighbor's land. Then took that number and hard coded it into the welcome message. Now the sensor will only greet someone if they are on a different land than my neighbors.

sensor( integer number_detected )
{
    integer i;
    for( i = 0; i < detpos =" llDetectedPos(" k =" llGetLandOwnerAt(detpos);" k ="="" k = "+(string)k);           //    }           //}                    if ( (llDetectedKey( i ) != llGetOwner()) && (k != ">

Moon Phase Second Life Sculpture

I've been working on an art gallery for an internal company sim and also building a couple of small sculptures for it as well. I built this one in the internal sim, then recreated it and improved it in SecondLife. It is a number of concentric rotating half-spheres that also change color.

"moon phase"

Virtual Second Life Sculpture

Beyond Facebook - designing outside the box

Beyond Facebook. - Design Outside The Box.

This is a great presentation on a huge transition that is happening in the game industry and gives a peak on how you can use psychological gaming techniques in everyday interfaces to improve the user experience. The presenter is Jesse Schnell from Carnegie Mellon University. I played this for my class last semester and recently watched it again. There is definitely a lot of good information in here.

lsl - Giving a notecard

I was wading back into the Second Life waters after volunteering to help build an art gallery for a group at work. I was also working on a couple of sculptures.

One of the things I wanted to add was to have my object give a notecard to someone who clicked on it.

This was simple.

First. Create a new notecard in your inventory.

Drag it into the content of the object you want to give that notecard.

Let's say it's called "Light Hand Sculpture - notecard"

Add this script and it will give the notecard to someone who clicks on your object.

default
{
 state_entry()
 {
 }
 touch_start(integer total_number)
 {
     llGiveInventory(llDetectedKey(0), "Light Hand Sculpture - notecard");

 }
}

Here is the sculpture I was working on. It is on a private sim so I can't give you a link to see it. Sorry.

"Light Hand"

Traded land

The land I was using had all the land around it purchased by one person who was trying to create a cohesive sim. I was the last hold out and not because I was being stubborn, I just haven't logged on for a long time because I've been focused on XNA. I agreed to trade the land for something comparable. It turned out this was pretty simple for her to find and I traded my land.

New location:

Stingray (226, 104, 44)

Class preparation

I've been putting all my extra time into a class I will be teaching at Chapman University next semester. We'll be using XNA and C# to build an open source game engine. I have the project all setup, the training and managment of subversion is ready and I have a pretty good outline and a good direction for the engine. I've done a few games using XNA, but for the tool side needed to figure out the WinForms integration and found these microsoft sites on WinForms/XNA to be very helpful.

I'm a blender fan, but I really need to train people on 3dsMax. I purchased an edu copy a year ago (still way to expensive) and I'm finally forcing myself to use it. I've been going through the tutorials and think it will be a good way to learn max. I also need to get through all the skeleton animation stuff so I know how to do it in Max. I've done it with Blender, but for this class I really need to use the tools that we have on the computers in class.

It starts in two weeks. I have a ton of material so far, but there is still a lot to go over.

I also went back and looked at the pinball game in second life and I have been itching to do some more work on it. I finally think I know how to fix the bumper mechanic and add a little skill to the game. Too much going on at this point, but hopefully the idea can slowly rise to the top of the queue and I can do some more work in SL since I enjoy that environment.

GameDev360 website updated

I've updated the GameDev360 website for the class. I have it on local disk so not much to show. I'm planning on mostly using the open source project on source forge for the class, but I still needed some place for the syllabus and class overview.

I also had to pick a book for the class. This is the book I'm going to use. I doesn't have anything to do on engine development, so I'll be teaching that part without a book.

I also like these books a lot and will be using them as a resource. The second one doesn't have anything to do with XNA, but it has a lot of good ideas about game engines.

  

CPSC340 Game Development

I've been working on both Project2015 and a class I am teaching this fall. The Project2015 stuff is going very slow and has seemingly lost a ton of momentum. Work has had a tough deadline and this looming class I'm teaching is starting to consume my extra time as I prepare.

The class is on Game Engine Development. My plan so far is to use XNA and C#. I had wanted to use Torque/C++, but the XNA/C# stuff has made some sense and we have been going in that direction. I still want to get in some C++ work and I'm trying to figure out how to do that at this point.

The open source engine is going to be called Panther Game Engine. I've already setup a source forge project for it and have been slowly configuring the group. I still have about 6 weeks, but that doesn't feel like much time.

I've completed all the SVN setup and have my lecture for that planned. I still want to create a screen cast of the process so it will be even clearer.

The term "Game Engine" is heavlily loaded and not well defined. For me, it's all about tools to make building games easier. So, I've been creating the shell of a level editor for xna. The toughest part was integrating XNA and Windows Forms. I have that working and ended up using a piece of Microsoft sample code and have tried to segment it from the open source project as best I could. This really should be part of the XNA release and not some separate set of code, but at least there is a sample of how to do this.

Next up is working on a terrain system, then I want to get the animation work flow down. Lots to do.

Project 2015

I've had a few meetings about the Imagine Cup game. It seems like the best option would be to develop the game under some sort of non-profit. We would finish the game by trying to get grants or just using free time, then launch it on something like Xbox live or as a pure PC game. Take the "profits" and turn them back seed funding to continue the work on the game and to build other humanitarian interest games. That is the plan.

We need to create a development plan to use on any grant requests so we can show what any grant money would be used for. This is also necessary in developing the game. I have started on this and a business plan for the game. My regular work is coming into a dead line so I think the next month will be insane so I don't think I will get very far on this. I'll continue to work on it when I have extra time.

Imagine Cup Results

We learned that we did not make the finals for the Imagine Cup. Most of the games that were selected seemed to whitewash the Millenium goals and I do think that our game, given more development, could help make a big difference in people's lives.

My goal is to somehow continue development on it and finish creating a training tool for people planning on working in impoverished communities. I'm not sure how to get that done, but I've planned a couple of meetings with some of my contacts in the game industry to see what people have to say.

Imagine Cup

Where has all my time gone?

My work got really busy and I've been mentoring a team creating a game for the Imagine Cup. Never expected it, but all those trips to Africa doing community development have been helpful in building a game that is designed to help work on the United Nations Millennium Development Goals.

The team is in the final week (two days) of development and everything is coming along. I think this is one of the most interesting projects I have worked on in years and really follows closely the work in Africa I (my wife and a lot of good friends) have been involved with over the past five years. When we started the team we were looking at a different contest and the Imagine Cup came along after that contest was delayed. Very cool to see the fruits of many years of labor multiplying into completely new avenues of opportunity.

The game is called Project 2015. The Project 2015 website is currently a month and a half old and used for the first submission. I expect it to be updated in the next week. Stay tuned.

Testing some shading options

As I've been testing lately, you can purchase all the source code for this sample for $5
(http://store.payloadz.com/go?id=254377).

I’ve been testing some shading options and working on the 3D aspects of XNA that I have been needing to learn. One of the problems is that I have 3DStudioMax, but it is only on a machine I don’t use as much. I’ve been contemplating moving the license, but that has issues. I’ve used Blender in the past and have enough knowledge to be dangerous to myself, but went back to it as I have not been able to use Max when I need it. So, this was as much a Blender session as an XNA lighting session.

I’m using Reimer Grootjan’s book XNA 2.0 Game Programming Recipesand found it very helpful in the shading and rendering aspects. I know it’s for XNA 2.0 and I’m using XNA 3.0, but the stuff I’m looking at has not changed (as is most of the book) so it is still highly relevant to learning XNA 3.0.

The section I used was on directional lighting on page 514. It shows how to get the BasicEffect to work with a directional light.

My code looked like this when I was done.

effect.LightingEnabled = true;
effect.DirectionalLight0.Direction = light0Pos;
effect.DirectionalLight0.DiffuseColor = Color.White.ToVector3();
effect.DirectionalLight0.Enabled = true;
effect.PreferPerPixelLighting = false;
effect.DirectionalLight0.SpecularColor = Color.White.ToVector3();
effect.SpecularPower = specPower;

With, specPower and light0Pos set at the top of the class definition.

Vector3 light0Pos = new Vector3(-0.5f, -1.0f, 0.0f);
float specPower = 64;

After weeks of procrastination and thinking I was going to have to create a custom shader it was nice to find out that adding a directional light was very simple. One of the games I was going to do requires a spotlight and I do think that will require a custom shader so it's off the list until I get some extra time.

So, first up with Blender. I’m trying to display a gemstone. I created a isosphere then scaled and stretched it to look like a gem stone. Then I added a red texture. You can see that I set the Col (Color), Spe (Specular Color) and the Mir (Mirror Color) for the gem.

This was fine, except that the gem came out all smooth.


I know from experience that this is caused by the rendering system using vertex normals to draw the individual triangles of the gem as smoothly as possible. This is almost always the case. But for a gemstone, you want it to have facets. I spent a ton of time trying to figure out how to get blender to remove the vertex normals and only use surface normals.

This ended up being easy inside of blender, but took a while to figure out how to get this information into the direct X file. To do this in blender, you select the object in edit mode, then click the Set Smooth button to use vertex normals for rendering and Set Solid to use surface normals for rendering.


Easy and you can see the two rendered versions here.


That’s all well and good in Blender rendering, but XNA kept displaying the gem as a smooth surface. After tons of fiddling, I noticed one of the options on the Blender DirectX exporter was “no smooth”. The tool tip says exactly what I wanted to hear “Every vertex has the face normal, no smoothing”.



Once I exported with that setting everything worked.

Getting back to Blender, I found it really hard to learn, and hard to relearn, but for the price (Free) it really is an amazing tool. I have a book on it that I've barely touched called Introducing Character Animation with Blender by Tony Mullen. I've had it for a few years and only touched the surface on it and every time I pick it up I'm always impressed. It really does look like a great book. As I write this he has a new version due out soon and another book on Blender that was just released. See below.

My real problem with Blender came in the classes I was teaching on Torque last year and the fact that we could never get the bone systems to work properly. It seemed that 3DSMax was the only real way to do modeling for Torque. Maybe that has changed?

I did find this great reference image on the Blender hotkeys (http://en.wikibooks.org/wiki/File:BlenderHotkeysObjectMode.png. If you are going to use Blender, you are going to want to learn as many as possible. It really is a fast fast tool once you get to know the UI. Mostly I only use Space Bar, B (box select), A (select/deselect all), S (scale), R (rotate X,Y,Z).

As I've been testing lately, you can purchase all the source code for this sample for $5.
(http://store.payloadz.com/go?id=254377).

Balance Air Game

This is the best one so far. Didn't have a lot of time again so I went 2D and wished I had enough time to add a little sound (like a hair dryer sound) and do some more complex goals (like a bucket), but I think it's probably the most fun so far. It's not super pretty, but good luck, it's really really hard.

The game is called Balance Air. You have a hair dryer at the bottom of the screen and you need to balance the ball on air and force it into the goal. You move the blower left or right to change the direction of the ball. There are 7 levels which are basically just different locations for the goal. The score for each goal is dropping over time.

As I did last time you can download a free executable of the game. It is available here: http://www.woodsgoods.com/gawxna/02balanceair.

The complete source and Visual Studio project is available for $5 at http://store.payloadz.com/go?id=246205 .

Enjoy and please give me some feedback.

Skeet Slider game

I didn't even think I was going to be able to get a game done this week. I was spending a bunch of time on HLSL (the XNA shader language) and not getting where I needed to get. I decided I still needed to get a game done this week and I have yet to do a 2D game using XNA so I decided (yesterday) that would be the best way to complete the project in the time left.

The game is called Skeet Slider. Not my best by far, but much better than the past few weeks while I've been learning the XNA framework. You slide a puck across the bottom of the screen trying to avoid bouncing blocks. It's all about timing. I wanted to add a feature to change the velocity of the puck, but I'm out of time. Here is a screen shot of the game on level 4, the highest level. I spent a little time at the end to add better art for the game so it is cleaner that what I've written in XNA so far.

I also messed with the publish system in XNA Game Studio 3.0 and created an installer you can use to run the game. It is available here: http://www.woodsgoods.com/gawxna/01skeetslider.

I have also been considering offering the source code to some of these games to try and cover some of my time. It's a minimal $5 to purchase the C# source code to the Skeet Slider XNA Game. Please tell me if you think this is reasonable or not? I could really use some feedback.

SpinMag game

I used the same rotating magnet from last week and added a different scoring mechanic. I also added a levels using png images to place items on the map. There are four levels, but the game is really tough. Currently it only has one life. I wanted to add more, but ran out of time. I again spent a bunch of time reading about texturing and lighting and have not made the progress I had hoped. I'm considering a game that uses spot lights as a mechanic next week.

This is a screen shot of the game.

This is the map image. Each pixel represents the location of one of the 3d spheres.

Here is the code that reads the map image and converts it to 3d objects.

protected void LoadMap(String mapname)
{
    // the map is just an image file with pixels of various colors
    // red = barrier
    // black = open space
    // cyan = closed space
    // green = starting point
    Texture2D map1 = content.Load<Texture2D>(mapname);

    mapwid = map1.Width;
    maphei = map1.Height;
    int numpix = mapwid*maphei;

    if ((map == null)  (map.Length < numpix))
    {
        map = new byte[numpix];
    }

    // want this map to fit over the circle, so calculate the size of each ball
    // scale of the ball
    mapballsz = (int)(maxballdist*2) / mapwid;
    mapxstart = -(mapwid / 2-1) * mapballsz;
    mapystart = -(maphei / 2-1) * mapballsz;

    /*
     * the sample I used to write this method
     * ms-help://MS.VSCC.v90/MS.VSIPCC.v90/MS.XNAGS30.1033/XNA/GetData``1_B8CC1053     */

    Rectangle sourceRectangle = new Rectangle(0, 0, mapwid, maphei);

    Color[] retrievedColor = new Color[numpix];


    map1.GetData<Color>(
        0,
        sourceRectangle,
        retrievedColor,
        0,
        numpix);

    goalcount = 0;
    int i;
    for (i = 0; i < numpix; i++)
    {
        if (retrievedColor[i] == Color.Cyan)
        {
            map[i] = MAP_CLOSED;
        }
        else if (retrievedColor[i] == Color.Red)
        {
            map[i] = MAP_BAR;
        }
        else if (retrievedColor[i] == Color.Blue)
        {
            map[i] = MAP_GOAL;
            goalcount++;
        }
        else
        {
            map[i] = MAP_OPEN;
        }
    }
}

SpinDart

The games are getting closer, but still have a ways to go on getting my art pipeline down in a week. That's where I spent a bunch of time this week trying to get some models out of 3ds Max which I'm new to. I got the models out, then left them on a different machine so this screen shot is untextured models.

It isn't what I started out to make and I may make a different game with this same mechanic next week. Locking the z axis and making this a 2d game helped the time constraints some, but I would like to be able to get that third axis in a week long game cycle.

The game is a "gravity" style game which is one of my favorites. Impossible to control which means the mechanic doesn't really work, but I'm not 100% sure it is impossible to control. Given a shared high score system I think I would see some different approaches to making points, but alas I haven't written the shared high score system yet...




Here is a code snipet that does the collision checking. I didn't use the XNA system which I looked into a little and decided it was easier to write this simplified code.

private void checkCollision()
{
    // check the position of the ball with that of the spinner
    Vector3 vspin; // = Vector3.Backward;  // pointed up
    Matrix m = Matrix.CreateRotationY(spinnerRot);
    vspin = Vector3.Transform(Vector3.Forward, m);

    // I know the spinner is 7.2 units before scaling (looking in milkshape)
    vspin = vspin * 7.42f * scaleXY;

    // now check the position of the ball in z space
    if ((ballPos.Length()>vspin.Length()+ballradius) && (distToOriginLineXZ(ballPos, vspin) < ballradius))
    {
        // collision

        // wwh score or death?
        score = score + 1;
    }

    // check if we are inside the center of the spinner
    // spinner sphere radius = 2
    if (ballPos.Length() < 2 * scaleXY + ballradius)
    {
        // wwh score or death?
        mode = STATE_OVER;
        if (score > highscore)
            score = highscore;
        //score = score + 1;
    }
}
private float distToOriginLineXZ(Vector3 pt, Vector3 oline)
{
    // used this reference 
    //  http://local.wasp.uwa.edu.au/~pbourke/geometry/pointline/
    // p1 = 0.0,0.0
    // p2 = oline.x,oline.z
    // p3 = pt.x,pt.z

    // oline is a line from the origin
    Vector3 vi = Vector3.Zero;
    float u = ((pt.X - 0.0f) * (oline.X - 0.0f) + (pt.Z - 0.0f) * (oline.Z - 0.0f)) / (oline.Length()*oline.Length());
    vi.X = u * (oline.X);
    vi.Z = u * (oline.Z);

    pt = pt - vi;
    return pt.Length();
}

Sphere Pong

This week's mechanic I was working on didn't really work, but it was a fun idea. I created a 3d pong game where you move the puck around a sphere and try and keep the ball in the middle. The problem is there is no reference point. I need some sort of skysphere or spherical markings or maybe also a tail on the ball so you can more easily tell direction. Ran out of time, but may come back and revisit this one someday.

I'm still learning XNA and the graphics look crummy, but for me right now this is more about learning the api than working on making a good looking game. Forward progress at any rate.

For a code sample a lot of the time was spent in positioning the puck around the sphere. I only finished the x,z plane as it didn't work for that, so no reason to add the third dimension. Here is the code to position the puck around the sphere.

// move the paddle using the upVector (true) or the cross product of the origin and up (false)
// direction is a + or - 1 for up, down, left or right
private void movePaddle(bool usingUpVector, float dir)
{

    if (!usingUpVector)
    {
        // need to take the cross between the up and the origin
        Vector3 vp = paddlePos;
        vp.Normalize();
        // vector change
        Vector3 vc = Vector3.Cross(vp, paddleUp) * dir;
        vc.Normalize();
        vc = vc * paddleSpeed;

        // find the new location, will be outside the sphere
        vp = paddlePos + vc;

        // fix up the distance ot the sphere
        vp.Normalize();
        vp = vp * radius;

        paddlePos = vp;

        // the up vector should  not have changed, right?

        // move the camera behind the puck
        fixupCamera();
    }
    else
    {
        // for this case, take the cross product
        // move in the direction of the up vector (+ or -)
        // position against the spehere
        // use the cross product to calculate the new up vector
    }
}

Bounce game

This week I was working on learning and using the physics engine JigLibX. Painful to say the least. I need to be spending my time learning XNA since this is only the third week. No documentation on JigLib and I spent a lot of time trying to figure out the connections between it and the XNA rendering system. I don't have a good understanding of the rendering system in the first place and mix that with a lack of understanding of JigLibX and it was a surprise that I actually got a game done.



In this game the ball is bouncing at a regular rate. The idea is to move the little green dot around and tilt the tiles so the bouncing ball ends up landing on the green platform with the least number of bounces. The ball started in the bottom right corner. One of the biggest time sinks was the fact that there is no hidden surface removal (as you can see in the top right corner platform) and I spent a bunch of time trying to figure that out and didn't get it done. Had to move on. For me the jury is still out on JigLibX, but it seemed like it had a lot of potential, just needed more samples (that included hidden surface removal) and documentation.

If you want the source, send me a message and I'll consider sending it to you.

First Full Circle XNA Game

After going through the tutorial last week I decided my best bet was to create a full circle game. That's a game with a main menu, the game, and a game over screen that moves back to the main menu. This is a shot of that main menu (very simple).

There also needs to be some sort of scoring or timing sytem. This will typically end up being the template for the rest of the games from this point forward. I used the art work from the tutorial and created a grid. Then added on model that could move up, down, left and right (only 2d) in the grid. One of the models is spinning and the idea is to move the red model on top of that model with as few moves as possible (looping around the other side is a key mechanic). In the screen shot, pressing the right key will move on top of the spinning ship as clicking the left key will take three moves. Get it?

For a piece of sample code, this is the row column stuff and grid keyboard movement I have written a million times. Maybe I can come back here next time and just cut and paste.

private int rowFromPos(int p)
{
    return p / tilerows;
}
private int colFromPos(int p)
{
    return p % tilecols;
}
private int posFromRowCol(int row, int col)
{
    return (row * tilecols) + col;
}

private void positionXYFromIndex(int idx, ref Vector3 vSet)
{
    vSet.X = fLeftX + colFromPos(idx)*gapX;
    vSet.Y = fTopY + rowFromPos(idx)*gapY;
    vSet.Z = 0.0f; 
}

    if ((newState.IsKeyDown(Keys.Right)) && (!oldState.IsKeyDown(Keys.Right)))
    {
        int row = rowFromPos(curSel);
        int col = colFromPos(curSel);

        col++;
        if (col >= tilecols)
        {
            col = 0;
        }

        curSel = posFromRowCol(row, col);
        positionXYFromIndex(curSel, ref selPosition);
        moves++;
        score--;
    }
    else if (oldState.IsKeyDown(Keys.Right))
    {
    }

    if ((newState.IsKeyDown(Keys.Left)) && (!oldState.IsKeyDown(Keys.Left)))
    {
        int row = rowFromPos(curSel);
        int col = colFromPos(curSel);

        col--;
        if (col < 0)
        {
            col = tilecols - 1;
        }

        curSel = posFromRowCol(row, col);
        positionXYFromIndex(curSel, ref selPosition);
        moves++;
        score--;
    }
    else if (oldState.IsKeyDown(Keys.Left))
    {
    }

    if ((newState.IsKeyDown(Keys.Up)) && (!oldState.IsKeyDown(Keys.Up)))
    {
        int row = rowFromPos(curSel);
        int col = colFromPos(curSel);

        row++;
        if (row >= tilerows)
        {
            row = 0;
        }

        curSel = posFromRowCol(row, col);
        positionXYFromIndex(curSel, ref selPosition);
        moves++;
        score--;
    }
    else if (oldState.IsKeyDown(Keys.Up))
    {
    }

    if ((newState.IsKeyDown(Keys.Down)) && (!oldState.IsKeyDown(Keys.Down)))
    {
        int row = rowFromPos(curSel);
        int col = colFromPos(curSel);

        row--;
        if (row < 0)
        {
            row = tilerows - 1;
        }

        curSel = posFromRowCol(row, col);
        positionXYFromIndex(curSel, ref selPosition);
        moves++;
        score--;
    }
    else if (oldState.IsKeyDown(Keys.Down))
    {
    }

XNA learning started

I am mentoring a group of students at Chapman in a game development contest to build a game around the U.N. Millennium goals. I'm having a ton of fun with it.(http://imaginecup.com/Competition/mycompetitionportal.aspx?competitionId=21).

That said, I don't have any code duties on that so to learn XNA I've been back to trying to write a game a week, this time using XNA instead of Java (http://www.woodsgoods.com/gaw). I don't think the quality will be there, but I'll try and post some screenshots and lessons learned moving forward.

Second Life Physics Scripting #28 - disconnecting users

I arrived at the game to find that it would not let me start because it thought someone else was still playing.

This is the code that wasn't allowing me to join.

    touch_start(integer total_number)
    {
        if (avatar_attached)
            {
                llSay(0, "Currently allows only one player at a time. Sorry.");
                return;
            }

But the real problem was in the avatar_attached flag not being reset. The user must have logged out without hitting the release keys button so I never go the disconnect event. There doesn't seem to be anyway to drop those connections so I need to at least pay attention to their distance from the table.

This is the new timer code.

   timer()
    {
    ....

        // see if we still have control
        if (avatar_attached)
        {
            if( !(llGetPermissions() & PERMISSION_TAKE_CONTROLS) )
            {
                auto_tick_count = 0;
                avatar_attached = FALSE;
            }
            else
            {
                // check the distance to the avatar...
                key curkey = llGetPermissionsKey();
                
                list    temp;
                vector  pos;
                vector  pos2;

                temp = llGetObjectDetails(curkey,[OBJECT_POS]);
                pos  = llList2Vector(temp,0);
                
                pos2 = llGetRootPosition();
                
                float dist = llVecDist(pos,pos2);
                llOwnerSay("dist = "+(string)dist);
                if (dist>15)
                {
                    llSay(0,"Player too far away - resetting");
                    auto_tick_count = 0;
                    avatar_attached = FALSE;
                    llRequestPermissions(avatar_key, 0);
                    avatar_key = NULL_KEY;
                }
            }
        }
    }

I get the key of the avatar that is currently attached. Then I check that avatar's distance. If they are too far away, I reset the avatar attached key. There was still one more problem if they walked back into the area then they could still send control events so I added some extra code to runtime permissions to save the last player that attached.

    run_time_permissions(integer perm) 
    { 
        // permissions dialog answered
        if (perm & PERMISSION_TAKE_CONTROLS)
        { 
            // we got a yes
            // take up and down controls
            llTakeControls(CONTROL_ROT_LEFT | CONTROL_ROT_RIGHT | CONTROL_UP | CONTROL_DOWN, TRUE, FALSE); 
            // remove any balls on the table
            llSay(1296,"byebye");
            in_play = FALSE;
            
            avatar_attached = TRUE;   
            avatar_key = llGetPermissionsKey();
            RestartGame();
        }            
    }

And then to the control code to double check the current key with the key sending the control event.

   control(key id, integer held, integer change)
    {
        if (id!=avatar_key)
        {
            list temp = llGetObjectDetails(id,[OBJECT_NAME]);
            string nm  = llList2String(temp,0);

            llSay(0,nm+", you have been disconected, press the Release Keys button and touch the pinball machine again.");
            return;
        }

I wanted to send them the message directly and probably can with an IM, but for now it was just easier to send it with their name attached to identify that the message was to them.