Programming stuff

Link: C++ Template Metaprogramming - Concepts, Tools, and Techniques from Boost and Beyond

Template Metaprogramming is a compile-time C++ technique that became extremely popular in the last few years. Before the arrival of this book there was nevertheless no comprehensive source about template programming available. Interested C++ programmers who wanted to read more about this topic were mostly limited to Modern C++ Design (uses template metaprogramming a lot; doesn't explain too much about it though), C++ Templates - The complete guide (dedicates one chapter to template metaprogramming), the source and documentation of the Boost library and some other, minor sources. David Abrahams and Aleksey Gurtovoy attempted to fill this void and they've been succesful.

Continue reading "Book review - C++ Template Metaprogramming"

In one of my first updates about the level data of Faxanadu levels I've explained how to decode the compressed screen data of the screens of a level. What I didn't mention back then was how the game itself actually decompresses that data. That's what this update is all about and I have to admit that the decompression code of the original game is better than the one I wrote. To my defence I want to mention that the original code uses nice tricks with the carry flag which wouldn't have been easy to use in my C++ code.
Continue reading "Faxanadu internals - The screen data decompression algorithm"

Besides the wing boots there's a second equippable item which has an effect limited by time: The hour glass. The hour glass freezes enemy sprites for a given amount of time. Unlike using the wing boots, using the hour glass has a negative effect. It decreases the player's health by 50% making it rather costly when the player still has a lot of health. Nevertheless the code for activating the hour glass is remarkably similar to the code for activating the wing boots. The hour glass code also follows right after the wing boots code.

Continue reading "Faxanadu internals - Hour glass"

When playing Faxanadu the wing boots allow a player to fly. Let's have a closer look at how they work under the hood. Wing boots are an item the player can buy or find and once it's in the player's inventory the player can select the item and use it. For a brief amount of time the player can fly then.

The code responsible for equipping wing boots can be found between the offsets $C579 and $C598.
Continue reading "Faxanadu Internals - Wing Boots"

Now that all necessary parts of parsing Faxanadu level data have been explained it's time to end this mini-series. The final step is to combine the knowledge gathered in the first five parts of the mini-series which in turn allows us to draw the entire Faxanadu world in the level editor.

Let's recall what we have so far. Drawing a screen from the Faxanadu world is a process that is comprised of several different steps: The first step is to read and parse the actual level data from the Faxanadu ROM file (see update one). The second step is to find the four 8x8 pixel tiles belonging to the 16x13 block that form one screen (see update two). Then it's necessary to find out which color the pixels in the individual tiles have (see update five) but because the color is stored independently from the tiles and because of some other oddities of the Faxanadu level data it's necessary to know how doors and scrolling work (see the updates three and four). And that last step, finding the correct color for the tiles and drawing the screens is what this update is all about. Continue reading "Faxanadu level data VI - Putting it all together"

PeLib.NET is the .NET version of PeLib I'm currently working on as part of a bigger project. It's basically a Managed C++ wrapper for PeLib that makes PeLib usable from every .NET language. So far most of the MZ header, the PE header and the export directory have been included in PeLib.NET.

This first example program demonstrates how to use PeLib.NET in C# 2005 to code a small program to convert between RVA, VA and physical offset.

The source for PeLib.NET is not yet included (it'll be released later when everything's been cleaned up), it's based on a CVS snapshot of something between PeLib 0.09 and PeLib 0.10 (which will hopefully be released soon).

The .NET 2.0 framework is necessary to run the program.

C++ Coding Standards - 101 Rules, Guidelines and Best Practices is the latest book from the two C++ heavyweights Herb Sutter and Andrei Alexandrescu. The content of the book is organized in the good tradition of Scott Meyer's "Effective C++" and Herb Sutter's "Exceptional C++" series which I'm sure most C++ programmers are familiar with.

As the title of the book implies it contains 101 guidelines which are themselves organized into 12 bigger chapters. Like in all other books of this kind the content is more or less organized from simple to difficult starting with very general advice that can be just as useful in non-C++ projects in chapter 1 and going right down into the messy details of standard C++ in later chapters.

During the 12 chapters the book discusses the following issues (I give the chapter names here): Organizational and Policy Issues; Design Style; Coding Style; Functions and Operators; Class Design and Inheritance; Construction, Destruction and Copying; Namespaces and Modules; Templates and Genericity; Error Handling and Exceptions; STL Containers; STL Algorithms; Type Safety.

Continue reading "Book review - C++ Coding Standards"