technarchy

Twitter: @Westmaaan, Google+: Christian Westman

[techny]

Ruby Brainfuck interpreter

Brainfuck is a esoteric programming language created by Urban Müller on the Amiga back in 1993. you can read more about it in this wikipedia article http://en.wikipedia.org/wiki/Brainfuck.

I Wrote a simple brainfuck interpreter console application in Ruby because it is fun.

It accepts any number of files containing brainfuck and executes them, reading input from stdin and output to stdout (the console)

Further down you will find the "99 bottles of beer" brainfuck program but you can use this Ruby script to execute "any" brainfuck program.

I say "any" as there are several dialects of Brainfuck.

Ruby: Brainfuck interpreter program "brainfuck.rb"

require 'io/console' class Brainfuck # array for program execution state @@memory = Array.new 3000, 0 # memory pointer @@position = 0 # stack of program positions for loops @@loop = [] # flag set if skip to end of current loop @@jmp = false # keeps track of current loop jump nestling depth @@jmpi = 0 # file handle to executing brainfuck program @@file = nil # IO from where to read program input @@input # IO from where to write program output @@output def initialize(input, output) @@output = output @@input = input end def run(file) @@file = File.open(file) @@memory = Array.new 3000, 0 @@position = 0 while (m = @@file.getc) eval(m) end end def eval(m) # handle loop jumps if @@jmp == true case m when '[' @@jmpi+=1 when ']' if @@jmpi == 0 @@jmp = false else @@jmpi-=1 end else end return end # evaluate and execute brainfuck instructions case m when '>' @@position+=1 when '<' @@position-=1 when '+' @@memory[@@position]+=1 when '-' @@memory[@@position]-=1 when '.' @@output.print @@memory[@@position].chr when ',' @@memory[@@position] = @@input.getch.ord @@output.print @@memory[@@position].chr when '[' if @@memory[@@position] == 0 @@jmp = true @@jmpi = 0 else @@loop.push @@file.pos-1 end when ']' if @@memory[@@position] != 0 pos = @@loop.pop @@file.seek(pos, IO::SEEK_SET) else @@loop.pop end else end end end bf = Brainfuck.new(STDIN, STDOUT) ARGV.each do | filename | bf.run(filename) end

Brainfuck: Bottles of beer program "bottles.bf"

Example taken from https://github.com/honzasp/brainfuck/blob/master/machine/examples/ryan_beer.bf

>>>>>++++++++[<+++++++++>-]<+[>>[>]+[<]<-]>++++++++++[<+++++ +++++>-]<[>>[+>]<[<]<-]<++++++++[>++++++++[>>->->->>>>>>>>>> >->>>->>>>>>->->->->>->>>->>>>->>>>>->->>>>>>->>>>->>>>>->-> >>>>->>>->>>>>>>->-[<]<-]>>++>++>->>+>++>++>+>>>>++>>->+>>-> >>>++>>+>+>+>--->>->+>+>->++>>>->++>>+>+>+>--->>-->>+>>->+>+ >>->>+>++>+>+>->+>>++>++>->>++>->>++>+>++>+>>+>---[<]<<-]>>> ++++>++++>+++>--->++>->->->>[-]>->-->[-]>+++>++>+>+++>--->>> --->[-]>+>+>+>--->[-]>+++>++>+>+++>->+++>>+++>++>---->->->+> --->[-]>->---->-->>+++>++>+>>+++>->++>++>+>->+++>+++>---->-- >-->+++>++++>->+++>---->--->++>>+>->->---[[<]<]+++++++++[<+< +++++++++++>>-]<<[>>>>>[<]>[.>]>--[>.>]<[<<]>++>>>[.>]>[>]>[ .>]<[[<]<]>>[.>]>--[>.>]<[<<]>++>>>[.>]>[.>]>[>]>[.>]<[[<]<] <<[<]>>>+<[>-]>[>]<[+++++++++[<+<->>>>>+<<<-]+<<[>>-]>>>[<]< <<++++++++++>>[>>[-]+<<-]>>-<<]>>>-[>]>-<<[<]>[.>]>--[>.>]<[ <<]>++>>>[.>]>[>]>[.>]<.[[<]<]<<[<]>>-<-]

running ruby brainfuck.rb bottles.bf outputs

99 bottles of beer on the wall. 99 bottles of beer... Take one down, pass it around, 98 bottles of beer on the wall. 98 bottles of beer on the wall. 98 bottles of beer... Take one down, pass it around, 97 bottles of beer on the wall. 97 bottles of beer on the wall. 97 bottles of beer... Take one down, pass it around, 96 bottles of beer on the wall. 96 bottles of beer on the wall. 96 bottles of beer... Take one down, pass it around, 95 bottles of beer on the wall. 95 bottles of beer on the wall. 95 bottles of beer... Take one down, pass it around, 94 bottles of beer on the wall. 94 bottles of beer on the wall. 94 bottles of beer... Take one down, pass it around, 93 bottles of beer on the wall. 93 bottles of beer on the wall. 93 bottles of beer... Take one down, pass it around, 92 bottles of beer on the wall. 92 bottles of beer on the wall. 92 bottles of beer... Take one down, pass it around, 91 bottles of beer on the wall. 91 bottles of beer on the wall. 91 bottles of beer... Take one down, pass it around, 90 bottles of beer on the wall. 90 bottles of beer on the wall. 90 bottles of beer... Take one down, pass it around, 89 bottles of beer on the wall. 89 bottles of beer on the wall. 89 bottles of beer... Take one down, pass it around, 88 bottles of beer on the wall. 88 bottles of beer on the wall. 88 bottles of beer... Take one down, pass it around, 87 bottles of beer on the wall. 87 bottles of beer on the wall. 87 bottles of beer... Take one down, pass it around, 86 bottles of beer on the wall. 86 bottles of beer on the wall. 86 bottles of beer... Take one down, pass it around, 85 bottles of beer on the wall. 85 bottles of beer on the wall. 85 bottles of beer... Take one down, pass it around, 84 bottles of beer on the wall. 84 bottles of beer on the wall. 84 bottles of beer... Take one down, pass it around, 83 bottles of beer on the wall. 83 bottles of beer on the wall. 83 bottles of beer... Take one down, pass it around, 82 bottles of beer on the wall. 82 bottles of beer on the wall. 82 bottles of beer... Take one down, pass it around, 81 bottles of beer on the wall. 81 bottles of beer on the wall. 81 bottles of beer... Take one down, pass it around, 80 bottles of beer on the wall. 80 bottles of beer on the wall. 80 bottles of beer... Take one down, pass it around, 79 bottles of beer on the wall. 79 bottles of beer on the wall. 79 bottles of beer... Take one down, pass it around, 78 bottles of beer on the wall. 78 bottles of beer on the wall. 78 bottles of beer... Take one down, pass it around, 77 bottles of beer on the wall. 77 bottles of beer on the wall. 77 bottles of beer... Take one down, pass it around, 76 bottles of beer on the wall. 76 bottles of beer on the wall. 76 bottles of beer... Take one down, pass it around, 75 bottles of beer on the wall. 75 bottles of beer on the wall. 75 bottles of beer... Take one down, pass it around, 74 bottles of beer on the wall. 74 bottles of beer on the wall. 74 bottles of beer... Take one down, pass it around, 73 bottles of beer on the wall. 73 bottles of beer on the wall. 73 bottles of beer... Take one down, pass it around, 72 bottles of beer on the wall. 72 bottles of beer on the wall. 72 bottles of beer... Take one down, pass it around, 71 bottles of beer on the wall. 71 bottles of beer on the wall. 71 bottles of beer... Take one down, pass it around, 70 bottles of beer on the wall. 70 bottles of beer on the wall. 70 bottles of beer... Take one down, pass it around, 69 bottles of beer on the wall. 69 bottles of beer on the wall. 69 bottles of beer... Take one down, pass it around, 68 bottles of beer on the wall. 68 bottles of beer on the wall. 68 bottles of beer... Take one down, pass it around, 67 bottles of beer on the wall. 67 bottles of beer on the wall. 67 bottles of beer... Take one down, pass it around, 66 bottles of beer on the wall. 66 bottles of beer on the wall. 66 bottles of beer... Take one down, pass it around, 65 bottles of beer on the wall. 65 bottles of beer on the wall. 65 bottles of beer... Take one down, pass it around, 64 bottles of beer on the wall. 64 bottles of beer on the wall. 64 bottles of beer... Take one down, pass it around, 63 bottles of beer on the wall. 63 bottles of beer on the wall. 63 bottles of beer... Take one down, pass it around, 62 bottles of beer on the wall. 62 bottles of beer on the wall. 62 bottles of beer... Take one down, pass it around, 61 bottles of beer on the wall. 61 bottles of beer on the wall. 61 bottles of beer... Take one down, pass it around, 60 bottles of beer on the wall. 60 bottles of beer on the wall. 60 bottles of beer... Take one down, pass it around, 59 bottles of beer on the wall. 59 bottles of beer on the wall. 59 bottles of beer... Take one down, pass it around, 58 bottles of beer on the wall. 58 bottles of beer on the wall. 58 bottles of beer... Take one down, pass it around, 57 bottles of beer on the wall. 57 bottles of beer on the wall. 57 bottles of beer... Take one down, pass it around, 56 bottles of beer on the wall. 56 bottles of beer on the wall. 56 bottles of beer... Take one down, pass it around, 55 bottles of beer on the wall. 55 bottles of beer on the wall. 55 bottles of beer... Take one down, pass it around, 54 bottles of beer on the wall. 54 bottles of beer on the wall. 54 bottles of beer... Take one down, pass it around, 53 bottles of beer on the wall. 53 bottles of beer on the wall. 53 bottles of beer... Take one down, pass it around, 52 bottles of beer on the wall. 52 bottles of beer on the wall. 52 bottles of beer... Take one down, pass it around, 51 bottles of beer on the wall. 51 bottles of beer on the wall. 51 bottles of beer... Take one down, pass it around, 50 bottles of beer on the wall. 50 bottles of beer on the wall. 50 bottles of beer... Take one down, pass it around, 49 bottles of beer on the wall. 49 bottles of beer on the wall. 49 bottles of beer... Take one down, pass it around, 48 bottles of beer on the wall. 48 bottles of beer on the wall. 48 bottles of beer... Take one down, pass it around, 47 bottles of beer on the wall. 47 bottles of beer on the wall. 47 bottles of beer... Take one down, pass it around, 46 bottles of beer on the wall. 46 bottles of beer on the wall. 46 bottles of beer... Take one down, pass it around, 45 bottles of beer on the wall. 45 bottles of beer on the wall. 45 bottles of beer... Take one down, pass it around, 44 bottles of beer on the wall. 44 bottles of beer on the wall. 44 bottles of beer... Take one down, pass it around, 43 bottles of beer on the wall. 43 bottles of beer on the wall. 43 bottles of beer... Take one down, pass it around, 42 bottles of beer on the wall. 42 bottles of beer on the wall. 42 bottles of beer... Take one down, pass it around, 41 bottles of beer on the wall. 41 bottles of beer on the wall. 41 bottles of beer... Take one down, pass it around, 40 bottles of beer on the wall. 40 bottles of beer on the wall. 40 bottles of beer... Take one down, pass it around, 39 bottles of beer on the wall. 39 bottles of beer on the wall. 39 bottles of beer... Take one down, pass it around, 38 bottles of beer on the wall. 38 bottles of beer on the wall. 38 bottles of beer... Take one down, pass it around, 37 bottles of beer on the wall. 37 bottles of beer on the wall. 37 bottles of beer... Take one down, pass it around, 36 bottles of beer on the wall. 36 bottles of beer on the wall. 36 bottles of beer... Take one down, pass it around, 35 bottles of beer on the wall. 35 bottles of beer on the wall. 35 bottles of beer... Take one down, pass it around, 34 bottles of beer on the wall. 34 bottles of beer on the wall. 34 bottles of beer... Take one down, pass it around, 33 bottles of beer on the wall. 33 bottles of beer on the wall. 33 bottles of beer... Take one down, pass it around, 32 bottles of beer on the wall. 32 bottles of beer on the wall. 32 bottles of beer... Take one down, pass it around, 31 bottles of beer on the wall. 31 bottles of beer on the wall. 31 bottles of beer... Take one down, pass it around, 30 bottles of beer on the wall. 30 bottles of beer on the wall. 30 bottles of beer... Take one down, pass it around, 29 bottles of beer on the wall. 29 bottles of beer on the wall. 29 bottles of beer... Take one down, pass it around, 28 bottles of beer on the wall. 28 bottles of beer on the wall. 28 bottles of beer... Take one down, pass it around, 27 bottles of beer on the wall. 27 bottles of beer on the wall. 27 bottles of beer... Take one down, pass it around, 26 bottles of beer on the wall. 26 bottles of beer on the wall. 26 bottles of beer... Take one down, pass it around, 25 bottles of beer on the wall. 25 bottles of beer on the wall. 25 bottles of beer... Take one down, pass it around, 24 bottles of beer on the wall. 24 bottles of beer on the wall. 24 bottles of beer... Take one down, pass it around, 23 bottles of beer on the wall. 23 bottles of beer on the wall. 23 bottles of beer... Take one down, pass it around, 22 bottles of beer on the wall. 22 bottles of beer on the wall. 22 bottles of beer... Take one down, pass it around, 21 bottles of beer on the wall. 21 bottles of beer on the wall. 21 bottles of beer... Take one down, pass it around, 20 bottles of beer on the wall. 20 bottles of beer on the wall. 20 bottles of beer... Take one down, pass it around, 19 bottles of beer on the wall. 19 bottles of beer on the wall. 19 bottles of beer... Take one down, pass it around, 18 bottles of beer on the wall. 18 bottles of beer on the wall. 18 bottles of beer... Take one down, pass it around, 17 bottles of beer on the wall. 17 bottles of beer on the wall. 17 bottles of beer... Take one down, pass it around, 16 bottles of beer on the wall. 16 bottles of beer on the wall. 16 bottles of beer... Take one down, pass it around, 15 bottles of beer on the wall. 15 bottles of beer on the wall. 15 bottles of beer... Take one down, pass it around, 14 bottles of beer on the wall. 14 bottles of beer on the wall. 14 bottles of beer... Take one down, pass it around, 13 bottles of beer on the wall. 13 bottles of beer on the wall. 13 bottles of beer... Take one down, pass it around, 12 bottles of beer on the wall. 12 bottles of beer on the wall. 12 bottles of beer... Take one down, pass it around, 11 bottles of beer on the wall. 11 bottles of beer on the wall. 11 bottles of beer... Take one down, pass it around, 10 bottles of beer on the wall. 10 bottles of beer on the wall. 10 bottles of beer... Take one down, pass it around, 9 bottles of beer on the wall. 9 bottles of beer on the wall. 9 bottles of beer... Take one down, pass it around, 8 bottles of beer on the wall. 8 bottles of beer on the wall. 8 bottles of beer... Take one down, pass it around, 7 bottles of beer on the wall. 7 bottles of beer on the wall. 7 bottles of beer... Take one down, pass it around, 6 bottles of beer on the wall. 6 bottles of beer on the wall. 6 bottles of beer... Take one down, pass it around, 5 bottles of beer on the wall. 5 bottles of beer on the wall. 5 bottles of beer... Take one down, pass it around, 4 bottles of beer on the wall. 4 bottles of beer on the wall. 4 bottles of beer... Take one down, pass it around, 3 bottles of beer on the wall. 3 bottles of beer on the wall. 3 bottles of beer... Take one down, pass it around, 2 bottles of beer on the wall. 2 bottles of beer on the wall. 2 bottles of beer... Take one down, pass it around, 1 bottle of beer on the wall. 1 bottle of beer on the wall. 1 bottle of beer... Take one down, pass it around, 0 bottles of beer on the wall.

[techny]

3D Collision detection and resolution using sweeping AABB bounding boxes

In most games there must be some kind of collision detection, in this post I will explain my implementation of sweeping AABB bounding boxes detection and resolution. This implementation is based on solving collisions for each axis and finding the earliest possible collision in normalized time that satisfies all axises. This example demonstrates a 2D collision using the X and Y axises only as it is easier to visualize but as you will see, adding the z axis becomes trivial. We have two boxes, __A__ is positioned at the vector (2, 0) and __B__ at (10, 0).  After the boxes have moved the new position of __A__ is (15, 0) and the position of __B__ is (12, 0)  As you can clearly see __A__ has moved past of __B__ and is now well on the other side. Simply checking if __A__ and __B__ overlaps at their new positions will fail to detect that they have moved through one another. this is where AABB sweeping comes into play. First we need to determine the velocity of __A__ (__VA__) and __B__ (__VB__) by subtracting their previous positions from their new positions. __VA__ = (15, 0) - (2, 0) = (15-2, 0-0) = (13, 0) __VB__ = (12, 0) - (10, 0) = (12-10, 0-0) = (2, 0) This means that in __1__ time unit __A__ will have moved 11 steps to the right. We now have the velocity of __A__ relative to the velocity of __B__, again we see that there will be a collision in some point in the time since __A__ is moving towards __B__. The bounding box size (__S__) of __A__ and __B__ is set to (2, 2) and their positions are always at the center of their bounding boxes. This means that the half size (__HS__) is (1, 1)  ##Finding the earliest collision time unit on the x-axis Since the rightmost edge of __A__ is to the left of the leftmost edge of __B__ the distance between them on the x-axis (__DX__) is: __DX__ = (__B__.x - __HS__.x) - (__A__.x + __HS__.x) = (10-1) - (2+1) = 9 - 3 = 6 Note that __DX__ this is the distance __A__ needs to travel in order to collide with __B__ on the x axis, this is also the earliest possible collision distance between __A__ and __B__ on the x-axis.  Now we have the distance __DX__ between __A__ and __B__ and the relative velocity (__V__) of __A__, the time unit (__U0__.x) is the time needed to cover the distance __DX__ relative to the velocity (__V__) and can be calculated as __DX__ / __V__.x __U0__.x = __DX__ / __V__.x = 4 / 11 = 0.54545454545454545454545454545455 This means that the first collision will occur at the normalized time of __U0__.x and since normalized time spans between 0 -1 this is a valid first collision on the x axis. ##Finding the latest collision time unit for the x-axis Since __A__ is to the left of __B__ the latest collision will take place when the leftmost edge of __A__ intersects the rightmost edge of __B__.  The distance (__DX2__) between the leftmost edge of __A__ and rightmost edge of __B__ is: __DX2__ = (__B__.x + __HS__.x) - (__A__.x - __HS__.x) = (10+1) - (2-1) = 11 - 1 = 10 The time unit (__U1__.x) needed to cover that distance is: __U1__.x = __DX2__ / __V__.x = 10 / 11 = 0.90909090909090909090909090909091 Since 0.9... is well in the range of normalized time (0-1) it means that there will be a second collision as __A__ moves past __B__. ##Finding the first and last collision times on the y axis In order to find the earliest/latest collision times for the y-axis you just need to repeat the above steps described for the x-axis, replacing x for y. The vector __U0__ will contain all of the earliest possible collision times for x and y and __U1__ will contain all of the latest possible collision times for x and y. ##A word on infinity ∞ Since the position of y in this example never changes it means that the relative velocity in the y-axis (__V__.y) is 0. The distance between __A__ and __B__ on the y-axis is also zero. This means that the earliest / latest possible collision time on the y-axis is either negative or positive Infinity In order to handle this we need to add a check to the earliest collision time unit check that sets __U0__.y to zero if __V__.y is zero, we also need to add the check to the latest collision time unit check that sets __U1__.y to one if __V__.y is zero. The general rule for this is: __U0__.[axis] = 0 if __V__.[axis] is 0 __U1__.[axis] = 1 if __V__.[axis] is 0 ##Time unit sanity check A collision has occurred only if __A__ and __B__ intersects on both in the y and x axis. This means that the earliest collision time unit (__T0__) is the maximum time unit of __U0__. __T0__ = max(__U0__) = max(0.54, 0) = 0.54 This also means that the latest collision time unit (__T1__) is the minimum time unit of __U1__. __T1__ = min(__U1__) = min(0.9, 1) = 0.9 We need to make sure that the earliest collision time (__T0__) occurs earlier or at the same time as the latest collision time (__T1__), we also need to make sure that __T0__ takes place within normalized time. __C1__ = __T0__ <= __T1__ = 0,54 <= 0,9 = __true__ __C2__ = __T0__ >= 0 and __T0__ <= 1 = 0,54 >= 0 and 0,54 <= 1 = __true__ __COLLISION__ = __C1__ == true and __C2__ == true ##Collision resolution As you now know __T0__ represents the normalized point in time where the first collision between __A__ and __B__ takes place. By using __T0__ we can interpolate and position __A__ and __B__ using their respective velocities __VA__ and __VB__. To move __A__ into its first collision position __CPA__ we add __VA__ multiplied by __T0__ to its previous position __AP__ (2, 0) __CPA__ = __AP__ + (__VA__ * __T0__) = (2, 0) + ((13, 0) * 0.54) = ~ (2+7, 0 + 0) = (9, 0) We do the same to move __B__ into it’s first collision position __CPB__ __CPB__ = __BP__ + (__VB__ * __T0__) = (10, 0) + ((2, 0) * 0.54) = ~ (10+1, 0 + 0) = (11, 0) Initial positions of __A__ (2, 0) and __B__ (10, 0)  Resolved positions of __A__ (9, 0) and __B__ (11, 0)  ##Regarding collision resolution collisions As you can see in the resolution of __A__ and __B__ they are resolved into positions snugged right next to each other. A discrete collision check on __A__ and __B__ will actually detect a collision as the rightmost side of __A__ is intersecting the leftmost side of __B__. In order to counter this we can multiply the relative velocity vector (__V__) by its normal multiplied by a very small number like 0.00001 This will move __A__ and __B__ apart enough not to be touching after the collision resolution.

[techny]

##Nodejs + Ogre3D + OIS + TCP/UDP Game Server Been really busy lately with my day job, family and stuff so I've got no code for you this time, only a video. I have been playing around with a game client and game server also in Node and Ogre3d, basically the code is the same as in [my last post](http://techny.tumblr.com/post/40447747982/node-js-ogre3d-mouse-keyboard-input-using-ois) only that I added a basic TCP/UDP server written in node and after the TCP handshake is done the game client spams its current position to the game server over UDP. The server broadcasts this to all connected clients and the client then updates the position of 'the player cube' I have also moved the generation of the maze to the server, it is sent to all client at the end of the TCP handshake. I initially made the stupid mistake to assume that it all could be done over TCP but as you might suspect it was a terrible so I switched over to UDP instead. It will be interesting to see if I can get this into a complete game as all of the needed components are there. We have the Node/Ogre3D bindings for the graphis, FMOD for sound/music and OIS for user input, exciting!

[techny]

Node.js, Ogre3D, Mouse & Keyboard input using OIS, generating a maze

 I some time wish I has as much time as I used to, before I was married and had a two year old son but without throwing that away or spending less time with them. Usually I have some time during the middle of the day when my son is napping and of course in the evenings when he gone to bed for the night. He does not like me tapping away on the keyboard while he is awake and then demands that I search Google for pictures of cats. Anyway, I thought that I would continue on my progress with Node and Ogre3D and this time I am going to show a demo where I am handling mouse & keyboard input using [OIS (Object Oriented Input System)](http://en.wikipedia.org/wiki/Object_Oriented_Input_System). Again, Minecraft looking graphics as I am far from any kind of genius artist wonder :) I have created a repository for the demos over at Github so you can download and run them from there. The repository is https://github.com/creamdog/Node.Ogre and this particular demo is https://github.com/creamdog/Node.Ogre/tree/master/NO.3%20-%20OIS As usual you need only execute the `demo.bat` file or runt `node.exe demo.js` from the console. Here is a recorded video of the demo.

###Generating a maze To demonstrate this I have written a maze generator using [recursive backtracking](http://en.wikipedia.org/wiki/Maze_generation_algorithm) This generates a nice looking maze, however it could be kind of boring walking around in only narrow corridors so I've added a post step to the generation process where solid blocks with three free sides are removed in X iterations. This creates both nice open areas as well as narrow pathways.  ###Initializing OIS the OIS initialization is pretty straight forward after you have created the window. just pass it a window handle, get the mouse and keyboard object and restrict mouse movement by the width/height of the window.

ois = require('./modules/ois'); oisInputManager = ois.createInputSystem(window.getHandle()); keyboard = oisInputManager.getKeyboard(); mouse = oisInputManager.getMouse(); mouse.setHeight(window.getHeight()); mouse.setWidth(window.getWidth());

###Moving and looking around In this demo you can move around using the WASD keys and look around by moving the mouse, like in any FPS. Basically after this all you need to do is call the `.capture()` function on both the mouse and keyboard object at the beginning of each frame. After this you can check if a key is pressed by calling for example `keyboard.isKeyDown(1)` for the ESC key. The number passed to this function is the numerical representation of the [OIS::KeyCode](http://wgois.cvs.sourceforge.net/viewvc/wgois/ois/includes/OISKeyboard.h?content-type=text%2Fplain) enum. To check if the mouse cursor has moved you call `mouse.getXRel()` and `mouse.getYRel()`, both of these return the relative movement of the cursor since the last call to `mouse.capture()`. The following snippet is the "main loop" of this demo, I also added a "head bopping" simulation when you are moving using the keyboard.

var interval = 0; function mainLoop() { keyboard.capture(); mouse.capture(); if(window.isClosed() || keyboard.isKeyDown(1)) { clearInterval(interval); if(keyboard.isKeyDown(1)) { console.log("used pressed ESC, shutting down"); } else { console.log("window has been closed, shutting down"); } return; } // move around using the keyboard if(keyboard.isKeyDown(17)) { cameraNode.translate(0,0,-0.15, 0); } else if(keyboard.isKeyDown(31)) { cameraNode.translate(0,0, 0.15, 0); } if(keyboard.isKeyDown(30)) { cameraNode.translate(-0.15, 0, 0.0, 0); } else if(keyboard.isKeyDown(32)) { cameraNode.translate( 0.15, 0, 0.0, 0); } // look around using the mouse var mx = mouse.getXRel() / window.getWidth(); var my = mouse.getYRel() / window.getHeight(); cameraNode.yaw(mx*-10, 2); cameraNode.pitch(my*-10, 0); // simulate "head bopping" when player is moving var boppy = 0; var r = boppr; if(keyboard.isKeyDown(17) || keyboard.isKeyDown(31) || keyboard.isKeyDown(30) || keyboard.isKeyDown(32)) { boppr += Math.PI / 10; if(boppr>Math.PI) boppr = Math.PI - boppr; } else { boppr = 0; } boppy = Math.sin(boppr)*0.2; // adjust camera y-position to simulate "head bopping" cameraNode.setPosition(cameraNode.getPosition().x, boppy, cameraNode.getPosition().z); // move light along with the player lightNode.setPosition(cameraNode.getPosition().x, cameraNode.getPosition().y, cameraNode.getPosition().z); window.update(false); window.swapBuffers(true); root.renderOneFrame(); window.messagePump(); } interval = setInterval(mainLoop, 1);

And there you have it, feel free to poke around in the source that you can find at https://github.com/creamdog/Node.Ogre/tree/master/NO.3%20-%20OIS

[techny]

Building Ogre in Windows 7/8 using Visual Studio 2012

 Since there are no prebuilt [Ogre SDK's](http://www.ogre3d.org/download/sdk) targeting Visual Studio 2012 I decided to build it myself from source. This is a guide on how to build Ogre in Windows using CMake and Visual Studio. ##Prerequisites This guide assumes you are running Windows 7/8 and have Visual Studio 2012 installed. ##Needed software ###CMake You will need this to configure Ogre and it's dependencies. Download and install it from http://www.cmake.org/cmake/resources/software.html ###Mercurial You will need this as Ogre uses this as their source code versioning system. Install it using the big blue button over at http://mercurial.selenic.com ###DirectX SDK / Windows SDK If you want to build Ogre with support for DirectX you will need to install the DirectX SDK for Windows 7 or just the Windows SDK if you are running Windows 8. You can download the DirectX Software Development Kit from http://www.microsoft.com/en-us/download/details.aspx?id=6812 If the DirectX SDK or WindowsSDK installer fails with something like error S1023 you should follow [this](http://blogs.msdn.com/b/chuckw/archive/2011/12/09/known-issue-directx-sdk-june-2010-setup-and-the-s1023-error.aspx) guide on how to uninstall and re-install the _"Visual C++ 2010 Redistributable Package "_ You can skip this and only build the Ogre OpenGL rendering system.  ##Download and build the Ogre dependencies Here we will clone and build the Ogre dependencies project from https://bitbucket.org/cabalistic/ogredeps using Mercrial and CMake. ###clone the Ogre dependencies repository  Create the directory `c:/projects/` and open it in the windows explorer, right click and choose "TortoiseHg > Clone..." Set "https://bitbucket.org/cabalistic/ogredeps" as the source and "c:\projects\ogredeps" as the destination, click clone and let it finish. ###Configure the dependencies project using CMake  Start CMake and set "Where is the source code" to `c:/projects/ogredeps`. Click on the "Configure" button at the lower left. In the dialog choose "Visual Studio 11" in the dropdown and click "Finish" Set "CMAKE_INSTALL_PREFIX" to `c:/projects/ogredeps/install`  Set "Where to build the binaries" to "c:/projects/ogredeps/build" and click on "Generate", it will create solution files for you in `c:/projects/ogredeps/build`  ###Build the Ogre Dependencies using Visual Studio  open the solution file `c:/projects/ogredeps/build/OGREDEPS.sln` and build the "ALL_BUILD" project using both debug and release mode, then build the "INSTALL" project using both release and debug, this will build and install the dependencies to `c:/projects/ogredeps/install` ##Download and build Ogre We now have all of the tools and dependencies needed to build Ogre. ###clone the Ogre repository  Open the `c:/projects` folder in the windows explorer, using TortoiseHg clone "https://bitbucket.org/sinbad/ogre/ -u v1-8" into `c:/projects/ogre/` This will create a clone of the latest __unstable__ branch, right click on the folder `c:/projects/ogre/`, choose TortoiseHg > Update and change the branch version to "v1-8" and click the update button.  v1-8 is the latest stable version of Ogre as I am writing this, check http://www.ogre3d.org/developers/mercurial if this has changed when you are reading this. ###Configure Ogre using CMake  Start CMake and set "Where is the source code" to `c:/projects/ogre`. Click on the "Configure" button at the lower left. In the dialog choose "Visual Studio 11" in the drop-down and click "Finish" CMake will fail, this is ok, we will fix it. set "Where to build the binaries" to `c:/projects/ogre/build` set "OGRE_DEPENDENCIES_DIR" to `c:/projects/ogredeps/install` set "CMAKE_INSTALL_PREFIX" to `c:/OgreSDK` make sure to check both "OGRE_BUILD_SAMPLES" and "OGRE_INSTALL_SAMPLES" if you wanna test Ogre after the build/install. now click on "Configure" and then on "Generate" and it will generate the solution files for us in `c:/projects/ogre/build` ###Build Ogre using Visual Studio  Open the solution file `c:/projects/ogre/build/OGRE.sln` and build the "ALL_BUILD" project using both debug and release mode, then build the "INSTALL" project using both release and debug, this will build and install the Ogre SDK and Samples into `c:/OgreSDK` All done! you have now successfully built and installed Ogre into `c:/OgreSDK` Execute `C:\OgreSDK\bin\release\SampleBrowser.exe` to view the prebuilt demos.  

[techny]

Node.js, Ogre3D, Materials and Lighting

Thought that would post a quick post on my progress but limit it to basic texturing and lighting (and some music). For this demo I am going to intialize ogre3d, create a window, load some textures/materials, generate a landscape (minecraft like), position some light and spin it around. Please excuse my poor artistic skills :)  As before you can download from [here](http://creamdog.se/NodeOgreFMODPart2.zip), run it by either double-clicking the `demo.bat` file or run `./node.exe demo.js` from a console. If you can't run the demo or don't want to here is a video of it running (sorry for the choppy framerate, it is the video, not the demo)

This is the structure of this demo

resources/ -- birds_in_the_woods.mod -- sky.material -- textures.jpg -- textures.material demo.js graphics.js music.js terrain.js

As you can see there is a resource folder for the music, texture and materials. the materials are standard ogre material script files. I did start out wrapping functionality to diagrammatically generate textures in Nodejs but later decided it be best just leave it to Ogre to parse material scripts. This way you get all of the material functionality in Ogre without the need to port/wrap anything. In the material files you can specify several passes (layers) optionally along with shaders to spice things up if you really want to. ###The demo.js file this is basically the entry point of the demo, initializing the music, graphics and contains the program "main loop".

//lets have some music music = require('./music.js'); music.initialize(); //initilize Ogre, generate some terrain and set up the scene graphics = require('./graphics.js'); graphics.initialize(); //play the music music.play(); //main loop here loopInterval = null; function mainLoop() { if(graphics.isClosed()) { console.log("window closed, shutting down"); clearInterval(loopInterval); return; } graphics.update(); } loopInterval = setInterval(mainLoop, 1);

###The graphics.js file This one is a bit larger, it contains variable declarations in the beginning for what plugins to load, the window size and title, and also holder for some ogre objects such as the scene manager, a camera, a viewport and the root scene node. The following are new additions to the graphics initialize function since the last demo. ####intitializeResources this is used to point out the ./resources catalog as an additional resource in Ogre as well as initializing all resource groups. Resource groups in Ogre are used for everything, like textures, materials, shaders, fonts, etc The following will load up the two material files `textures.material` and `sky.material` into the default Ogre resource group.

function intitializeResources() { root.addResourceLocation('./resources','FileSystem'); resourceManager = root.getResourceGroupManager(); resourceManager.initializeAllResourceGroups(); }

####createLights used to first set the ambient lighting of the current scene and then creates and positions two lights that will be used to light up the terrain. Diffuse is the general color of the light, attenuation controls how far the light will "reach".

function createLights() { sceneManager.setAmbientLight(0.15, 0.1, 0.125); light = sceneManager.createLight(); light.setAttenuation(100, 1.0, 0.045, 0.0075); light.setDiffuseColour(1.0, 0.5, 0.0); light.setSpecularColour(1.0, 1.0, 0.0); lightNode = rootSceneNode.createChildSceneNode("lightNode"); lightNode.attachLight(light); lightNode.translate(5,5,-10.0); light2 = sceneManager.createLight(); light2.setAttenuation(100, 1.0, 0.045, 0.0075); light2.setDiffuseColour(0.0, 0.0, 1.0); lightNode2 = rootSceneNode.createChildSceneNode("lightNode2"); lightNode2.attachLight(light2); lightNode2.translate(-10,5,-10.0); }

after the lights has been created the last thing that happens in the graphics initialize function is to generate the terrain using the `terrain.js` file, load and position the terrain and create a "night time sky" using the `./resources/sky.material` file.

//set the mood createLights(); //generate some terrain terrain = require('./terrain.js'); terrain.createTerrainMesh('TerrainObject', 'TerrainMesh'); //create a terrain instance and position it var entity = sceneManager.createEntity("TerrainMesh"); entity.setCastsShadows(false); var node = rootSceneNode.createChildSceneNode("TerrainNode"); node.attachEntity(entity); node.translate(0,-10,-10.0); node.pitch(0.35); cubeNode = node; cubeEntity = entity; //create a sky using the 'sky' material sceneManager.setSkyDome('sky'); root.clearEventTimes(); };

###The terrain.js file This is what generates the minecraft like terrain in the demo, it is a very crude way to generate terrain using a boolean 128x128x128 array. Basically what it does is to first create a Ogre ManualObject which is used to generate a mesh. Using the boolean 128x128x128 array it first creates all of the vertices, normals, texture coordinates and colours. It skips array positions that are `false` After that is done it creates the cube sides by mapping triangles to the vertices, again using the boolean 128x128x128 array. It It skips array positions that are `false` and also do not create cube sides that touch another cube. The material used is the textured material from the file `./resources/textures.material` and the image from `./resources/textures.jpg` This texture is actually a sprite texture that contains both the dirt/grass and combination. the top of the cubes get mapped with the coordinates of the grass part and the sides of the cube get mapped with the combination of grass and dirt.  Again, you can download the demo from [here](http://creamdog.se/NodeOgreFMODPart2.zip), run it by either double-clicking the `demo.bat` file or run `./node.exe demo.js` from a console. 

[techny]

Node.js+Ogre3D+Fmod-Demo 1

_this is the first part in a series of posts where I will be posting about 3D application development in Node using Ogre (and FMOD)_ Follow [this](http://techny.tumblr.com/post/39685843785/node-js-ogre3d-materials-and-lighting) link for the second part of the series "Node.js, Ogre3D, Materials and Lighting"  Nine years ago I wrote a demo using FMOD and OpenGL direct mode in C++ using Visual Studio 6.0, sadly both the source and binaries has been lost in the myriad of disk crashes and broken CD's since then. For the last couple of years I have been doing mainly .NET development but I have felt the urge to get back to writing some C/C++ and thought that, "hey! why not pick up some Node.js as well" ? Instead of going straight OpenGL I decided to try something new and use a 3D-engine, I decided to use [Ogre3D](http://www.ogre3d.org/) as it is open source. I also had a lot of help from the Ogre3D [Mad Marx Tutorials](http://www.ogre3d.org/tikiwiki/tiki-index.php?page=Mad+Marx+Tutorials&structure=Tutorials) Since I am running Windows 8 and using Visual Studio 2012 I needed to build and install Ogre3D from source. I will not go into the details here on how to go about setting that up. the FMOD binaries and headers is a straight download from http://www.fmod.org I then installed [Node.js](http://nodejs.org/) (32-bit version because Ogre3D compiled as 32-bit) Then with the help of Node.js [API docs](http://nodejs.org/api/addons.html) I wrapped both Ogre3D and FMOD in two separate addons called _"OgreToNode.node"_ and _"fmod.node"_ I will not go into the details on how to build the addons here, they are a mess right now but they work as a proof of concept. Now, using these addons I was ready to write a simple demo in node! :) The demo is available for download from the link below, run it by executing the _"demo.bat"_ file or from a console window running _"node.exe demo.js"_ Download: [http://creamdog.se/NodeOgreFMODPart1.zip](http://creamdog.se/NodeOgreFMODPart1.zip) If you can't run the demo or don't want to here is a video of it running (sorry for the choppy framerate, it is the video, not the demo)

All of the following code is from the file _"demo.js"_ ###1. Intitialize FMOD and load the music The following code is pretty straight forward, create a fmod system instance, initialize it, create a sound channel and load a .mod file (I could have loaded a mp3 or something but this is the .mod I used in my original demo nine years ago) Note that this code does not begin playback of the .mod

music = { fmod: require('./modules/fmod'), fmodSystem: null, channel: null, sound: null, mediafile: './media/music.mod', initialize: function() { music.fmodSystem = music.fmod.createFmodSystem(); music.fmodSystem.init(); var version = music.fmodSystem.getVersion(); console.log("fmod intialized, version = "+version); music.channel = music.fmod.createChannel(); console.log("loading sound from "+music.mediafile); music.sound = music.fmodSystem.createSound(music.mediafile); }, play: function() { console.log('playing '+music.mediafile+' ('+music.sound.getLength()+'ms)'); music.fmodSystem.playSound({sound:music.sound, channel:music.channel}); } } music.initialize();

. ###2. Initialize Ogre3D This is a bit more complicated, you need to create a Ogre Root instance, load needed plugins such as OpenGL (the rendering system), creating a window, creating a scene, positioning the camera, generating, loading an positioning the spinning cube.

graphics = { ogre : require('./modules/OgreToNode'), logfile: 'demo.log', root: null, window: null, windowTitle: 'Node.js Ogre/Fmod Demo', windowWidth: 800, windowHeight: 600, sceneManager: null, rootSceneNode: null, camera: null, cameraNode: null, viewPort:null, cubeEntity: null, cubeNode: null, plugins: [ './modules/RenderSystem_GL_d', './modules/Plugin_ParticleFX_d', './modules/Plugin_CgProgramManager_d', './modules/Plugin_OctreeSceneManager_d' ], initialize: function() { console.log("intializing ogre..."); graphics.root = graphics.ogre.createRoot("", "", graphics.logfile); graphics.loadPlugins(); graphics.root.setRenderSystemByName(graphics.root.getRenderSystemNames()[0]); graphics.createWindow(); graphics.sceneManager = graphics.root.createSceneManager({name: "TheSceneManager"}); graphics.rootSceneNode = graphics.sceneManager.getRootSceneNode(); graphics.createCamera(); graphics.createViewport(); //configure the camera var ratio = graphics.viewPort.getActualWidth() / graphics.viewPort.getActualHeight(); graphics.camera.setAspectRatio(ratio); graphics.camera.setNearClipDistance(0.5); graphics.camera.setFarClipDistance(3000); //configure window graphics.window.setActive(true); graphics.window.setAutoUpdated(false); graphics.root.clearEventTimes(); //generate and load the spinning cube graphics.generateCubeMesh(); graphics.loadCubeMesh(); }, createCamera: function() { console.log("creating ogre camera..."); graphics.camera = graphics.sceneManager.createCamera({name: "TheCamera"}); graphics.cameraNode = graphics.rootSceneNode.createChildSceneNode({name: "TheCameraNode"}); graphics.cameraNode.attachCamera(graphics.camera); }, createViewport: function() { console.log("creating ogre viewport..."); var viewPortWidth = 0.98; var viewPortHeight = 0.98; var viewPortLeft = (1.0 - viewPortWidth) * 0.5; var viewPortTop = (1.0 - viewPortHeight) * 0.5; graphics.viewPort = graphics.window.addViewPort( { camera: graphics.camera, zorder: 100, top: viewPortTop, left: viewPortLeft, width: viewPortWidth, height: viewPortHeight }); graphics.viewPort.setAutoUpdated(true); graphics.viewPort.setBackgroundColour(0.0,0,0.0,1.0); }, createWindow: function() { console.log("creating ogre window..."); graphics.window = graphics.root.createRenderWindow( { title: graphics.windowTitle, width: graphics.windowWidth, height: graphics.windowHeight, fullscreen: false, params: {"FSAA":"0", "vsync":"true"} }); }, loadPlugins: function() { console.log("loading ogre plugins..."); for(var i=0;i<graphics.plugins.length;i++) { graphics.root.loadPlugin(graphics.plugins[i]); } }, loadCubeMesh: function() { var entity = graphics.sceneManager.createEntity("CubeMesh"); var node = graphics.rootSceneNode.createChildSceneNode("CubeNode"); node.attachEntity(entity); node.translate(0,0,-5.0); graphics.cubeNode = node; graphics.cubeEntity = entity; }, generateCubeMesh: function() { // Example taken from "MadMarx Tutorial 4 - ManualObject to Mesh" // http://www.ogre3d.org/tikiwiki/tiki-index.php?page=MadMarx+Tutorial+4&structure=Tutorials console.log("generating cube mesh..."); var size = 0.7; var object = graphics.sceneManager.createManualObject("CubeMeshObject"); object.setDynamic(false); object.begin({material:"BaseWhiteNoLighting",renderOperation:4}); { var cp = 1.0 * size ; var cm = -1.0 * size; object.position(cm, cp, cm);// a vertex object.colour(0.0,1.0,0.0,1.0); object.position(cp, cp, cm);// a vertex object.colour(1.0,1.0,0.0,1.0); object.position(cp, cm, cm);// a vertex object.colour(1.0,0.0,0.0,1.0); object.position(cm, cm, cm);// a vertex object.colour(0.0,0.0,0.0,1.0); object.position(cm, cp, cp);// a vertex object.colour(0.0,1.0,1.0,1.0); object.position(cp, cp, cp);// a vertex object.colour(1.0,1.0,1.0,1.0); object.position(cp, cm, cp);// a vertex object.colour(1.0,0.0,1.0,1.0); object.position(cm, cm, cp);// a vertex object.colour(0.0,0.0,1.0,1.0); // face behind / front object.triangle(0,1,2); object.triangle(2,3,0); object.triangle(4,6,5); object.triangle(6,4,7); // face top / down object.triangle(0,4,5); object.triangle(5,1,0); object.triangle(2,6,7); object.triangle(7,3,2); // face left / right object.triangle(0,7,4); object.triangle(7,0,3); object.triangle(1,5,6); object.triangle(6,2,1); } object.end(); object.convertToMesh("CubeMesh"); } } graphics.initialize();

. ###3. wrapping it all up Lastly I start playing the music and enter the main program loop. Inside the loop I fetch the spectrum from the left speaker as it it there the drums are in the playing .mod. Using that I pulse the cube along the z-axis.

music.play(); cubeBackTranslation = 0; loopInterval = null; function mainLoop() { if(graphics.window.isClosed()) { console.log("shutting down"); clearInterval(loopInterval); root.shutdown(); return; } //get left side spectrum, where the drums are var spectrum = music.channel.getSpectrum(0); //calculate median value and amplify var median = 0; for(var i=0;i<spectrum.length-1;i++) { median += spectrum[i]; } median = median / spectrum.length; median *= 300; //spinn the cube graphics.cubeNode.yaw(Math.random()*0.02); graphics.cubeNode.pitch(Math.random()*0.03); //pulsate the cube along the z-axis graphics.cubeNode.translate(0,0,median+cubeBackTranslation); cubeBackTranslation = -median; graphics.window.update(false); graphics.window.swapBuffers(true); graphics.root.renderOneFrame(); graphics.window.messagePump(); } loopInterval = setInterval(mainLoop, 1);

. Download the demo from here: [http://creamdog.se/NodeOgreFMODPart1.zip](http://creamdog.se/NodeOgreFMODPart1.zip) Follow [this](http://techny.tumblr.com/post/39685843785/node-js-ogre3d-materials-and-lighting) link for the second part of the series "Node.js, Ogre3D, Materials and Lighting"