Ambient Occlusion Fields Janne Kontkanen, Samuli Laine in ACM Siggraph 2005 Symposium on Interactive 3D Graphics and Games We present a novel real-time technique for computing inter-object ambient occlusion. For each occluding object, we precompute a field in the surrounding space that encodes an approximation of the occlusion caused by the object. This volumetric information is then used at run-time in a fragment program for quickly determining the shadow cast on the receiving objects. According to our results, both the computational and storage requirements are low enough for the technique to be directly applicable to computer games running on the current graphics hardware. Downloads Janne Kontkanen, 14.2.2005
25 Free Computer Science Books | Coderholic As a computer scientist I'm always looking to improve my knowledge of the subject. There are lots of great sources of information available online, but nothing really beats the depth of knowledge that you can find in a book. It is possible to get the best of both worlds though, as many books are now available online in full, and free of charge! Below is a selection of 25 of the best free computer science books that I've found online, with a brief description of each one. Become An X coder A guide to MacOSX development with Cocoa using Objective-C. The Cathedral and the Bazaar Eric Raymond's brilliant book about Open Source software, and its impact on software development projects. Data Structures and Algorithms with Object-Oriented Design Patterns in Java Also available in C#, Python, Perl, Ruby, Lua, C++ and PHP versions. Dive Into Accessibility Another Mark Pilgrim guide, on creating accessible websites. Getting Started with awk Awk is the perfect tool for many system admin tasks.
Test Driven Development and Design By Contract - friend or foe? in this post i’ll try to answer a legitimate question, relating to a comment due to my last statement that interfaces are poor contracts: why do we need contracts (in the sense of invariants, pre- and postconditions) when we’ve got unit tests right at hand, that could also test the stated conditions? in fact, it’s very tempting to see unit tests as an all-embracing instrument to check and show that a class will behave correctly, making contracts kind of unnecessary. i’ll try to show you that unit tests (as an instrument for test driven development) and contracts (as an instrument for Design By Contract) indeed share the same goals but aren’t competing techniques, rather than methods that could complement each other. it’s not about verification – it’s about specification that said, both methods share the same main incitement – the specification of a system that will drive its design. don’t bear away collaboration includes clients and supplier reliance on a proper context clear Design reuse
Programming from the Ground Up Regular Expression Matching Can Be Simple And Fast Russ Coxrsc@swtch.com January 2007 Introduction This is a tale of two approaches to regular expression matching. One of them is in widespread use in the standard interpreters for many languages, including Perl. The other is used only in a few places, notably most implementations of awk and grep. The two approaches have wildly different performance characteristics: Let's use superscripts to denote string repetition, so that a? Notice that Perl requires over sixty seconds to match a 29-character string. It may be hard to believe the graphs: perhaps you've used Perl, and it never seemed like regular expression matching was particularly slow. Historically, regular expressions are one of computer science's shining examples of how using good theory leads to good programs. Today, regular expressions have also become a shining example of how ignoring good theory leads to bad programs. Regular Expressions Regular expressions are a notation for describing sets of character strings. Finite Automata
Software Architecture Document Guidelines Update, 27th October 2009: Please see Software architecture document guidelines for an updated version of the guidelines. Regardless of the development process that you use, a description of the software architecture can be essential for any project, big or small. If software architecture is about the structure of a system and is the vehicle for satisfying the requirements, then the software architecture document is a written description of this. An outline description of the software architecture, including major software components and their interactions.A common understanding of the architectural principles used during design and implementation.A description of the hardware and software platforms on which the system is built and deployed.Explicit justification of how the architecture meets the non-functional requirements. It's worth remembering that the software architecture doesn't have to be a huge weighty tome and it doesn't even need to be a traditional Word document.
Department of English Languages and Literature - Courses This is a collection of ideas from various authors gathered together by Professor John Lye for the use of his students. This document is copyright John Lye 1996, but may be freely used for non-proft purposes. If you have any suggestions for improvement, please mail me. I.General Principles 1. 2. 3. 4. 5. 6. 7. The term 'subject' foregrounds the relationship between ethnology, psychoanalysis, and semiotics. The value of the conception is that it allows us to 'open up', conceptually, the inner world of humans, to see the relation of human experience to cultural experience, to talk cogently of meaning as something that is structured into our 'selves'. There is no attempt here to challenge the meaningfulness of persons; there is an attempt to dethrone the ideology of the ego, the idea that the self is an eternal, indivisible essence, and an attempt to redefine what it is to be a person. 8. 9. 10. II. 1. 2. 3. 4. 5. III. 1. 2. require certain conventions of reading. 3. 4. 5. 6. 7. 8. 9. 10.
guide-things-you-shouldnt-be-doing-in-rails edit Posted by kev Wed, 30 Aug 2006 05:32:00 GMT Koz recently checked code into core that kicks and screams all the way home if you’re using deprecated methods or instance variables. In honor of this I’ve decided to give you a list of things I still see over and over in Rails code that you really shouldn’t be doing anymore. Update: There’s been enough controversy over this article that I’ve responded. Accessing Instance Variables You Didn’t Create It’s time to stop using the instance variables for params, flash, session, request, response and all of their formerly preceded by an @ friends. rabble (who you’ll hear more from later) also suggests that you not intermix usages of flash[:notice] with flash['notice'] and the like. Using Deprecated Finders find_all and find_first have been deprecated over a year now. Getting Ahead of Yourself Stop trying to write “neato ajax driven thingies” before you understand how to write it properly without ajax. Fallin’ off the wagon Using Components See?
Again Abstract class vs Interface... Again Abstract class vs Interface...While pairing with a fellow thoughtworker ( we ended up discussing Abstract class vs Interface and he found this explanation useful. A Class (abstract or not) defines a type while an interface does not. In my domain anything that can be drawn is a shape(including a point) and thus behaviour defines a type. abstract class Shape{ public abstract draw();} In another domain which includes a Robots, Humans and Pets,If I need to treat all objects that can walk similarly, I would like to have an abstract handle to of all the above and that ends up in a interface Walkable{ void walk();} ...Robot implements Walkable{...}...Human implements Walkable{...}...Pet implements Walkable{...} and merely something that can walk does not define a type here.
Reference Books Improve Your Photography: How Budding Photographers Can Get Pro Results "Improve Your Photography" has been purchased by thousands of beginning photographers across the world and has been recently updated in this second edition. The book has been widely acclaimed as easily explaining the most important fundamentals of photography in straight-forward language. The book is packed full of quick and easy tips to encourage beginning and intermediate photographers to improve while learning concepts and technical information on photography. Unlike most photography books that confuse beginning and intermediate photographers with difficult concepts and too much technical data, this book is designed specifically to teach photographers who are just learning how shutter speed, aperture, and ISO work together, composition, and lighting. Improve Your Photography is a resource for budding hobbyist photographers who want to learn to take photographs of professional quality. . List Price: $ 5.99 Price:
textmate regexp manual 20.1 Introduction A regular expression is a domain specific language for matching text. Naively we could write a small program to match text, but this is error-prone, tedious and not very portable or flexible. Instead we use regular expressions which describe the match as a string which (in a simple case) consists of the character types to match and quantifiers for how many times we want to have the character type matched. For example normal letters and digits match literally. Something like \w will match word characters, where \s will match whitespace characters (space, tab, newline, etc.). The basic quantifiers are the asterisk (*) to specify that the match should happen zero or more times, plus (+) for one or more times, or a range can be given as {min,max}. This alone gives us capabilities like finding words (\w+) or finding an image tag with an alt argument (<img. Matching longer text sequences is one thing, but often we are interested in the subset of the match. 20.4.1 Captures
philosophy pages T he Philosophy Pages is an online library of philosophy and theology texts, including selected writings of philosophers from anicent times to the contemporary period, including Plato, Aristotle, Friedrich Nietzsche, Ralph Waldo Emerson and Pythagoras, amongst many others. The site has been active since 2006 and is currently undergoing redesign work. If you would like to contribute to the site or have any questions, email philosophy@davemckay.co.uk . Facebook Page - Visit the Philosophy page on Facebook ! Anaximander - Surviving Fragments. Aristotle - Collected Works. Bertrand Russell - Selected Writings. Chinese Classics - The Four Books, Five Classics and the Classics of Military Science. David Hume - Complete Writings, including posthumous works. Diogenes of Sinope - Biography from Diogenes Laërtius’ “Lives and Opinions of the Eminent Philosophers”. Ralph Waldo Emerson - Complete Works in twelve volumes. Epicurus - Surviving Fragments, Letters and Documents. Heraclitus - Surviving Fragments.