So I’m in the process of learning the Metal API, which is Apple’s replacement for OpenGL ES. The principles are fairly similar, though the Metal API is much lower level.
There are several web sites devoted to Metal, but my eventual goal is to implement image-based CSG (Constructive Solid Geometry) in Metal for an update to the Kythera application.
And that requires a deeper understanding of Metal than most introductions which seem to stop at drawing an object on the screen and perhaps adding a texture map to the object.
The best way to learn something is to try to explain it–so I’ve started writing a document showing how to build a Macintosh-based Metal API application in Objective C, and going from a blank screen to a deferred shading example.
In this case, the deferred shading example results in a rotating teapot with fairy lights and indirect illumination rendering at 60 frames/second:
The sample code is uploaded at GitHub, with the different examples in their own branches.
And the first draft of the Metal Introduction Document (as a PDF with links to relevant documents) can be downloaded from here.
Feedback is appreciated.
OCTools is a suite of tools which serve as a plug-in replacement for yacc and lex. The goal
is to provide a (roughly) source compatible tool which can convert yacc and lex
grammars into Objective C output for building parsers that run on MacOS and iOS.
The source kit can be found on GitHub.
Both tools can be compiled on the Macintosh using Xcode, and generate a command-line tool which can be run from the terminal or included into an Xcode project. (Both tools are built in C, so they should be portable to other platforms; however, I haven’t done the port so I’m not sure how successful porting would be.)
The goal of this project was to create Yacc and Lex analogs which generate re-entrant Objective C classes which implement the parsers, and for the Lex analog to use an Objective-C protocol definition for the input file, for maximum flexibility.
More information can be found here: OCTools.
Wouldn’t it be great to have a drawing program on the Macintosh which, after you’ve composed the artwork, can export the drawing commands for Cocoa’s Quartz or the iPhone, so you can cut and paste code to draw the same thing in your program?
I thought that would be so cool. And now it turns out someone beat me to it: Opacity.
Now if only there were exporters for Java AWT, Android’s UI toolkit, and Microsoft Windows…
So the designer I work with gives me colors to use in our application as a web hex color specification, and I need to put it into my iPhone application as RGB values in the range [0,1]. Or I need to pick some color, and I pick an H=210° color, but I need to plug in the color into my application as integer RGB values. Or I need to type in [UIColor colorWithRed:xxx green:yyy blue:zzz alpha:1.0], and I’ve got r=110, g=250, b=155.
So out goes the calculator, and a lot of “155 [Enter] 255 [div]” and typing in the first three digits past the decimal place.
I’m a programmer. I can create tools.
So I built ColorPicker, a Macintosh-only program which allows you to set and adjust colors, and copy them in four different ways, so they can be quickly pasted into Mac, Windows or Java code.
Redistribute as you please, hopefully it will be useful to folks.