Jack is a Fool - Potential use for platform engine

I've started toying with an idea to use with the Platform Engine. It's called 'Jack is a Fool'.

In Jack is a Fool, you won't control Jack directly at all. Instead, you'll control the machinery around him, to try to successfully get him to the exit. Think something along the lines of lemmings, where you control floating platforms to stop Jack falling in holes, and move doors around to get him through mazes. It will be almost a pure puzzle game - that happens to be with a guy who walks on platforms.

I've started doing some design drawings of levels etc. to figure out how viable this idea is in LibreOffice Draw. So far, I've designed 2 basic non interactive 'levels' (which will be a grand total of being a more entertaining way to write 'Nerdy Gentleman Games Presents' and on the next one 'Jack is a Fool' while introducing the basic start of gameplay). I've designed 1 basic level to demonstrate the moving mechanic.

I've finally so far designed 2 actual puzzles - I don't count the others as puzzles at all. The first involves moving lift doors and a lift to get Jack to the top of the level, and the second moving a series of platforms to get Jack to the other side without crushing him, or allowing him to fall off. Both are just design ideas, and as such don't look like what actual gameplay would. For your benefit, they're included below.

First fully designed level

Second fully designed level

I've got ideas for a couple of other mechanics I could add for puzzles, and a couple of unfleshed ideas I could use for the mechanics already introduced. I want to get to somewhere between 10 and 20 puzzles (probably closer to 10) before focussing on implementing the features they need, and seeing if gameplay is fun. If it is, I may more fully finish the game. If I can't figure out interesting puzzles, I won't bother.


Lachlan

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Platform Progress - Saving and loading levels

Wow... 3 posts in one day!? But - achievements get posts.

I can now save and load levels! So:

 gameexec

FatController bind_wing_keys K_LEFT "Actor inst 100" K_RIGHT "Actor inst 101" "Actor inst 102"

FatController bind_key_down K_SPACE "Actor inst 103"
FatController bind_key_up K_SPACE "Actor inst 104"
FatController bind_key_down K_ESCAPE "Game quit_signal"
FatController bind_key_down K_BACKQUOTE "Game toggle_console"
FatController bind_key_down K_e "Game toggle_editor"

run "level" "levels"

Game gravity_ddy = 400;
Game gravity_max_dy = 500;
Game gravity_ddx = 0;
Game gravity_max_dx = 0;

and

 level

Game new_feature "f_1" 
x1 = -20
x2 = 600
y1 = 500
y2 = 550
z = 0
collision_function = 1
visible = 1
.

Game new_feature "f_2" "f_1"
x1 = 150
x2 = 200
y1 = 450
y2 = 500
z = 0
collision_function = 1
visible = 1
.

Game new_feature "f_3" "f_1"
x1 = 700
x2 = 1500
y1 = 500
y2 = 550
z = 0
collision_function = 1
visible = 1
.

Game new_feature "f_4" "f_1"
x1 = 900
x2 = 950
y1 = 400
y2 = 500
z = 0
collision_function = 1
visible = 1
.

Game new_feature "f_5" "f_1"
x1 = 500
x2 = 800
y1 = 350
y2 = 400
z = 0
collision_function = 1
visible = 1
.

lead to an end result of:

Note - as well, this script is the actual save file, and was saved from within the game! Boo yeah!

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Platform Progress - SLOC

If its your sort of thing:

Files	70
Lines	5460
Statements	3117
% Branches	21.8
% Comments	3.1
Class Defs	32
Methods/Class	9.44
Avg Stmts/Method	6.1
Max Complexity	46
Max Depth	9+
Avg Depth	1.88
Avg Complexity	2.75
Functions	12

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Platform Progress - Scripts Ahoy!

I've started the process of being able to load scripts from files and (am working towards at the moment), saving them to files. As of Thursday, it loads (most of) the keyboard configuration from a script file. This script file, actually:

FatController bind_wing_keys K_LEFT "Actor inst 100" K_RIGHT "Actor inst 101" "Actor inst 102"
FatController bind_key_down K_SPACE "Actor inst 103"
FatController bind_key_up K_SPACE "Actor inst 104"
FatController bind_key_down K_ESCAPE "Game quit_signal"
FatController bind_key_down K_BACKQUOTE "Game toggle_console"
FatController bind_key_down K_e "Game toggle_editor"

This is important for a couple of reasons. The primary one is that levels are to be saved as a script which contains instructions on building levels - I've got recipe's being generated already, now I'm ensuring that I can save them.

The first step of this project was adjusting the PuppetMaster's Process Command thing to take multiple commands by splitting it by newlines and semicolons (though, in the case of the latter, providing that they're not within double-quote marks). I decided to use the same method I have for actually processing commands -  using an overly complex RegEx command that I barely understand, as processed by boost::regex.  The RegEx function I ended up using is:

"(\\.|[^\"])*\"|[^\n;]+

The sad thing is, I'm not entirely certain how this works except it does when I run it through "The RegEx Coach" (excellent piece of software btw). In reality though, RegEx seems to me to be a return to the archaic language of APL (see Wikipedia to see why I make this comparison). It's an ol' APL proverb that:
'Tis every programmers goal in life
Before his race is run
To write three lines of APL
And make the damned thing run!'

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War of the Apocalypse Samurai - A Potential Plot?

I've had a general idea of what I'd like War of the Apocalypse Samurai to be for quite some time - a prince of persia-ery sword fighting platform game owing heavy inspiration to Samurai and Revisionist Western Films (ie. Kill Bill Volume 1 and Volume 2 Respectively). I've never had a story that would tie it together.

I think I do now. I've been playing with the idea of using the platform engine to make a James Bond-ish game.  During this week I concluded that it would be a good idea for such a game to be set in a fictional version of the 1960s - middle of the Cold War. One thing has lead to another, and now I have an idea for the Samurai Game I want which is at once plausible (given the ridiculous world) and very pulpy.

In 196-, the soviets were losing the cold war. Fearing the possibility of losing a nuclear war, and unable to afford to continue to build a brand new nuclear arsenal, the soviets train and hire the 4 greatest warriors living for $250000 (~$1.8m in today's currency) each, organises and trains them as the Apocalypse Samurai and places them around the world to be able to identify and kill any person on the planet within 5 hours. A credible threat to be able to retaliate to any nuclear attack without having to just bomb a civilian population.

Unfortunately, they overestimated the inhumanity of their anonymous elite force and directed War to kill her father. She defected to the US and was further trained and offered complete immunity to remove the Apocalypse Samurai from the world, and the Dragon who controls them. The game would consist of finding and killing each of the Samurai and finally the Dragon and the Beast across the whole world.

I like this idea. I want to see how well this could work...

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Platform Progress - Collision Detection Sucks

Those red boxes? The things you can collide with. The white box?  You. Simple looking I know - but slowly getting there

I've been wrestling with collision detection quite extensively over the last week and a bit (and a bit more). I've had varying things working, but they either partially work by colliding well and not necessarily putting the actor back quite where it needs to go, or getting stuck in walls, and generally not being able to register as a collision when they're just touching - or freezing the box if it could.

I've ended up using a simplified case of the technique in http://www.metanetsoftware.com/technique/tutorialA.html - it's the one they use for 'N'. If I end up adding ramps or anything I may have to do it in more detail, but it seems to work. However, the code wasn't liberal enough in detection of collision where the platform and actor are just touching - without overlap. So, I've added a simple, more liberal check at the end. Code is below, if it's your sort of thing or you need help doing something similar.

  1 void Feature::TotalCollision(Actor* actor, float dt)
  2     //Method described in this... partially
  3     //http://www.metanetsoftware.com/technique/tutorialA.html#section5
  4 {
  5     //These shouldn't be using typecast x1() but instead x - w/2 or something - Maybe
  6     //This may change if features start being defined by x, w, y & h rather then
  7     //w and h being calculated and the feature being defined by (x1, y1) and (x2, y2).
  8     float left_a = actor->x() - (actor->w() / 2);
  9     float left_f = (float)x1();
 10     float right_a = actor->x() + (actor->w() / 2);
 11     float right_f = (float)x2();
 12     float top_a = actor->y() - (actor->h() / 2);
 13     float top_f = (float)y1();
 14     float bottom_a = actor->y() + (actor->h() / 2);
 15     float bottom_f = (float)y2();
 16     float midx_f = (left_f + right_f) / 2;
 17     float midy_f = (top_f + bottom_f) / 2;
 18
 19     //bool colliding = Collides(left_a, right_a, top_a, bottom_a, left_f, right_f, top_f, bottom_f);
 20
 21     bool colliding = true;
 22             
 23     if (bottom_a <= top_f) { colliding = false; };
 24     if (top_a >= bottom_f) { colliding = false; };
 25     if (right_a <= left_f) { colliding = false; };
 26     if (left_a >= right_f) { colliding = false; };
 27
 28
 29     if (colliding)
 30     {
 31         float x_overlap = (actor->x() > midx_f) ? left_a - right_f : right_a - left_f;
 32         float y_overlap = (actor->y() > midy_f) ? top_a - bottom_f : bottom_a - top_f;
 33         if (std::abs(x_overlap) > std::abs(y_overlap))
 34         {
 35             actor->set_y(actor->y() - y_overlap);    
 36             actor->set_dy(0);        
 37             actor->set_v_collided (true);
 38         }
 39         else
 40         {
 41             actor->set_x(actor->x() - x_overlap);
 42             actor->set_dx(0);        
 43             actor->set_h_collided (true);
 44         }        
 45     }
 46
 47     //These fill the special case uncovered by the above where there needs to be a collision
 48     //for whether or not we can jump or not, but the code doesn't need to move the actor
 49     if
 50     (
 51         ((bottom_a == top_f) || (bottom_f == top_a)) &&
 52         !((left_a > right_f) || (right_a < left_f))
 53     ) 
 54     {
 55         actor->set_v_collided(true) ;
 56     } ;
 57
 58     if
 59     (
 60         ((right_a == left_f) || (right_f == left_a)) &&
 61         !((top_a > bottom_f) || (bottom_a < top_f))
 62     ) 
 63     {
 64         actor->set_h_collided(true) ;
 65     } ;
 66
 67 }

By the way - if any of you know a good, easy way to highlight code for blogs - preferably an online utility, I'd really appreciate knowing it.



Lachlan

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Super Mario Bros: How Nintendo taught players the mechanics without a tutorial in Worlds 1-1 to 1-3.

After some excellent company watching Flying High! and MASH (the movie), as well as excellent pizza from Gary at International Pizza in Montmorency, I set my mind at playing some of Super Mario Bros on the NES... or an emulated version thereof at any rate. During which, I learnt a few things:

1.  Don't try to take screenshots through Nestopia with filters enabled. I had the NTSC filter for some old style scaling and colour bleed, but it ended up really squashed and odd
2. Nintendo games rightfully deserve their reputation for difficulty. But, I made it to the end of the second world without losing a single life, and to the castle in the third world before losing the game. Fun fact: I've been spoiled by the SNES 'Super Mario Bros All Stars' versions of these games. I was expecting to start at the start of the world. Second Fun Fact: You don't. Also - I think the physics are noticeably different between All Stars and the original.
3. The first few levels are brilliant game design.

I'm going to focus on Point #2. If what you want is difficulty, look at SMB 'The Lost Levels' or Super Meat Boy - I'm not in the mood to discuss it. And not good enough at platformers to discuss it anyway.

Super Mario Bros. has no tutorial. It has never needed one. I would, of course assume that it came with a manual - but even that (as you will soon bare witness) is not even required. I will clarify that the controls were made more intuitive by the fact that the control consisted solely of a D-Pad (The plus shaped thing with arrows on it for you non-gamer sorts), a select button, a start button, an A button and a B button. Controls weren't difficult to remember or even simply figure out. But they were improved by excellent early level design.

I'm going to demonstrate to you that the game teaches you how to play it, by playing it through the first few levels (particularly just World 1), and expose to you some of the brilliance. I'd like to forewarn that tutorial means teaches you how to play the game - not how to play it well.

World 1-1

This is about the first thing the player sees. He either runs into the Goomba and dies - and learns he can't run into the Goomba, or he successfully jumps over it. He'll usually in the process hit one of the ? blocks, and see coins come out with little numbers. You see the points go up, you see coins go up, you've been rewarded and you know that ? blocks can be rewarding.

So, you move forward, and find another couple of ? blocks, and the first has a Mushroom in it! Note how the location of the pipe means that the mushroom comes back to you, and that you actually require effort to avoid the mushroom. doesn't just fall off the screen. The Mushroom makes you bigger, at you'll probably figure out that you can now break the   Bricks.

You come across more pipes. You may figure out you can go down select pipes, you may not. I don't have a copy of the manual to check whether it hinted it or not. There is no indicator - and the first pipe doesn't let you so... brilliance has its exceptions. Or, we just take it as an old fashioned secret.

More Goomba's after returning from the secret area...

There's a staircase, and the flag. The flag moves to wherever you hit the pole which provides some feedback that higher is better. And the design of the level (staircase) hints that you should try to hit the top too.

World 1-2

A hint that something is different. At least it clearly takes control of Mario from the moment the character appears on screen.

This pair of Goomba's are the first indication that you can jump on two things successively for more points. Most people will do this on their first or second playthrough and learn.

Moving forward somewhat, you get the first clear indication (if you're still lucky/skilled enough to be big) that you can destroy blocks - as you're forced to. You also get the first introduction to turtles, and their mechanic of being able to jump on their shells.

You also get a sighting that there are the things that come out of pipes at a safe enough distance to guarantee survival - and they stop coming if you come too close. It's a good way of introducing the new enemy.

The level then introduces, in a very limited quantity, the first moving platforms. These become particularly important in the next level. You can't avoid them, forcing the player to learn of their safety.

World 1-3

Very brief comments. The world introduces the new platforms gently. Players have already encountered green turtles, but not red turtles - who turn around at the edges of platforms. The game introduces this by putting a turtle that is generally almost close to the end up top very close to the end of its platform (hence making the player feel that the turtle is going to land on the player) before the player sees it turn around. Red Turtles are used extensively in the level to emphasise the gameplay mechanic.

Studios seem to have lost the art of teaching players to play the game without an overly basic, trivial tutorial - or worse uninteractive video's. I might discuss this again. But, there are exceptions.

These problems have been most successfully avoided by Valve. I can list 3 very clear examples where Valve has been able to teach players the mechanics of the game effectively without a tutorial - being Half Life 2, Portal and Team Fortress 2. The latter two are particularly notable as Valve's customer-centric tester-centric approach to game design can most clearly be seen. If you own either game, I highly recommend playing the audio commentaries to understand how the games were designed. I was going to write more about the subject, but it is late and I'm tired. I may discuss it again later.

Lachlan

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Platform Progress - Moving White Boxes - With Control!

I've got movement working! I've made a new class called 'FatController' who can get key-bindings and issue commands. There are a couple of odd things with Collision (half fixed), and you can jump when you're not on ground - but both of those problems will be fixed this afternoon.

I did do one kind of cool thing with FatController - in addition to the typical bindings of KeyUp and KeyDown I added a new set WingKey - so buttons like Left/Right which only one can be down at a time work. The KeyDown is called when it changes, and when you take a key off it goes back to the other one if it's still down, or calls the KeyUp if its not.

Video might be coming soon. If I can get the stupid thing to work... Either way - it's not that impressive.

But it works.

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Ancient CRT Emulation

I was playing around with some idea's today about making stuff look early CRT era old. I was partially inspired by playing wee bits of fallout 2, and this article on SNES emulation - and making it work accurately rather then conveniently.

I tried to make a couple of screenshot mockups to see what could happen - not with anything I'll make (at the moment), but to see what kind of styles we could go for. I came up with these:

Completely original - except letters used from http://www.zee-3.com/pickfordbros/archive/bitmapfonts.php 

The infamous Doom title screen. Zoom in (click) for the detail

The first of these was just an idea for a piece of tiny art that I brought to fruition. The details are similar to the Doom one, which I'll explain more fully. The Doom one was me seeing what I could do to make something look old. I recommend zooming in.

What I did (all in Gimp)
- Started with the 320x240 resolution picture of the Doom title screen
- Resized it with no interpolation (ie. just making to blocks bigger) to 1280x960
- Colourised it to Amber
- Changed the colour curve to make it almost (but not quite) 4 colour - this works because the analogue screen I'm trying to emulate does have some transition between the 4 colours (but still actually 4 colours - just slightly more... antialiased) ... or something like that
- Duplicated the layer
- Blurred the top layer (lightly)
- Blurred the bottom layer more
- Added the lines at 40% opacity with a fill tool with a pattern on the top layer
- Merged layers
- Applied the lens distortion effect

It still could do with a few things to make it look more real - the colour still isn't quite right, the scanlines are in reality partially horizontal as well as vertical, there are little grey dots near the corners I couldn't be bothered with fixing and there could be some reflection on the screen, and maybe a little darker towards the edges.

I'd be fascinated to see if I could get this to run in real-time - though, I doubt it would be even remotely possible without lots of pixel shaders. It'd be fantastic to do though for a retro styled game. It's ironic it requires so much clockpower to make something look so old.


Lachlan

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Platform Progress - Moving White Boxes - With Gravity and Collision!

I've decided I'm going to post a basic list of things I'm doing whenever I'm doing them. I'm going to do some ol' fashioned devlogging. Maybe...

For those of you who never do maths, I use Δ a few times in this devlog. It is the greek letter Delta meaning (in this concept) the rate of change. ΔΔ means the rate of change, of the rate of change.

As of today, I have some working collision detection. Its not perfect yet, so if  Δx, Δy or Δt are too severe, it'll end up with the sprite either hovering or getting stuck. Maybe - I haven't got it stuck yet. Each Feature (which might be a platform or many other things) has a collision function which is as of right now either kNone or kTotal. The former being don't collide with this at all, the latter being everything collides with every facet of it. These will be expanded on later.

I've also got some basic gravity working. I define a ΔΔx and ΔΔy for gravity purposes, and a max Δx and Δy due to gravity. The result being that my white box speeds up until it reaches the max speed I've set for objects in the world, and then keeps going while the program runs, or the box runs into a feature.

A productive evening.

I've also included my current source metrics below - if that's your sort of thing. I might put it up a little more often. There won't be much from me until at least next week, owing to a take-home exam on property law over the weekend. There is a good chance of a couple of reviews coming soon. They'll likely be for:
- Rock of Ages
- Jamestown
Without giving a full review, both are cheap, fun, worthwhile and fantastic for split screen multiplayer.

Maybe also Grim Fandango - or maybe a 'Let's Play' - I dunno. Either way, it is my absolute favourite game of all time, and I highly recommend you play it (probably through Residual to get it working on a modern computer)

Cordially and Nerdily Yours,


Lachlan


Current Stats:

Files	62
Lines	4472
Statements	2552
% Branches	22.5
% Comments	2.9
Class Defs	28
Methods/Class	8.79
Avg Stmts/Method	6
Max Complexity	47
Max Depth	9+
Avg Depth	2
Avg Complexity	2.82
Functions	9

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Platform Progress - Moving White Boxes

I sense that having a good design before you start would help. Unfortunately, I doubt that is going to happen yet - mostly 'cause I have very little clue, most of the time. It would make adding more stuff easier.

I didn't think I would need Floating Point numbers when I started being able to be handled by my PuppetMaster - turns out I did. The code made a mess. The reason for all this was, I'm beginning to add 'Actors' - players, monsters etc. At the moment, this means just a white box. A white box that due to my incompetence spent quite some time being debugged this afternoon!

Result: I now have a moving white box, that will maintain pace regardless of framerate. I'm going to start dealing with logic for it soon.

Btw - apologies for running so slowly. I get distracted, and have had a take-home exam to prepare for and do over the last week or so.

Some more reviews might be coming soon though.


Lachlan

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Platform Progress

I'm slowly progressing with my platform engine - working toward getting the basis of the editor working. As of yesterday, I can finally create new platforms by cloning other platforms. I'm working on getting the platforms to be able to generate their own 'recipes' so I will be able to save the maps and load them again.

The engine is actually fairly odd. Lots of things are stored in std::map's with strings. The whole thing is built around the PuppetMaster. Greenspun's Tenth Rule (though there are no proceeding laws) states that Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp. I'm slowly seeing this become true with my platform engine. It makes at least a minimal amount of sense to me, but I'm not always really certain I've done everything the best way - as can be expected from somebody who hasn't written much like this before. It's interesting just how much time I've been spending on the editor (which will still be buggy, and likely unfit for public consumption) because as I'm building it, I'm building the infrastructure. I'm not sure yet how I'm going to handle some of the odder things specifically related to platform games - like movement functions. It is my intention to build all of these out of the same feature rather then using polymorphism as I want to be able to create new types of platforms and features without changing code. I am considering whether I could add lua scripts as an alternative, though they may be slower.


Once I get this stuff down at least basically, I'm going to start dealing with Player-Characters/Actors/Monsters etc. Then I'm going to make a basic proof of concept game to test the engine. It will likely end up being a clone of World 1-1 of the original Super Mario Bros - or something like that.


Then I'll start working on the next full game. I've had a few concepts that I'll detail soon.




Lachlan.

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Platform Progress - Consoles

I've spent the last few days getting the console up and running. And it does.

Thus far, it can now access and manipulate things in classes which are exposed to it. For instance, the Game class is exposed to the 'Puppetmaster' (as I've dubbed it). If I load the console (Quake 1 style - by pushing ~), I can check what the cameras x value is by typing

Game camera_x

which will then return something along the lines of

45

I can also set camera_x in much the same way

Game camera_x = 30

This is advantageous because it is laying the foundation for me to be able to change the game without having to recompile. If I want new types of platforms etc, I may need to add them in C++ code. However, I'll be able to place them and modify them within the game itself (or in the editor of the game - which is currently (and will stay) in the same source as the game). The program is also going to use the triggers and console itself - in what may not be particularly efficient, but is going to make my job easier. For instance, I will add a Trigger underneath a block which tells the PuppetMaster that it's time for the block to the fall.

And so far it works!

Part of this has been learning to use the boost library - which I'm impressed with. I'm impressed with how consistent it is with the C++ STL itself - accessing regex results is done exactly the same way with iterators as any of the STL containers. I'm also finding boost::lexicalcast<> an absolute lifesaver.


I'm thinking next will be a very basic GUI for accessing code and using triggers that will operate through the PuppetMaster to make my life easier. Either that or just adding the template dude to make him jump around...

 

 

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(Yet to be determined) Platform Game

You might be prone to ask 'What has Lachlan been doing since we saw the release of The (lite) night the Martians Came?' 'What masterful example of gaming is coming next?'

For a while, it looked like it might be soccer. But it's not. I've started programming a platform game of some form. I'm not sure whether this is the start of the codebase of 'The War of the Apocalypse Samurai' or not yet - but it is a platform game. I'm writing the level editor in the same engine as actual game to hopefully make it easier to keep making the game.

So far, it does a grand total of render platforms (ie. plain, red rectangles bordered by a slighter lighter red). The editor also allows you to add platforms by switching into editor mode (e) and placing a platform (p). I've started work on a console as well - which will be fairly important 'cause all scripted events, and most properties of platforms/moving things/actors etc will be changable by the console and the so-called GUI of the editor will mostly be links to the console.

At the moment, everything is going to be simply rendered as boxes until the game is playable and maybe even a little fun. Then I'll start worrying about looks.

I've no idea where or how this will finish. But the goal is set: A platform game - of some kind. Even if I do use it for War, it is likely a more simple game will be made first.

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