Article: Functional image processing in D

[Vladimir Panteleev]

On Friday, 21 March 2014 at 12:27:57 UTC, Rikki Cattermole wrote:
> On Friday, 21 March 2014 at 11:04:58 UTC, Vladimir Panteleev 
> wrote:
>> http://blog.thecybershadow.net/2014/03/21/functional-image-processing-in-d/
>>
>> Some highlights from a recent overhaul of the graphics package 
>> from my D library. It makes use of a number of D-specific 
>> language features, so I've tried to make the article 
>> accessible to people new to D as well.
>
> Are you planning on adding a font rasterizer

Parsing vector font files is a big undertaking. I'd likely use a 
text rendering library, such as FreeType. Hardcoding a small 
bitmap font for ASCII only is also a possibility.

> and can it work at CTFE?

This program almost works:

string drawSmiley()
{
	import std.range;
	import std.math;

	import ae.utils.graphics.draw;
	import ae.utils.graphics.image;

	auto smiley = Image!char(20, 20);
	smiley.fill(' ');
	smiley.fillCircle(10, 10, 10, '#');
	smiley.fillCircle( 6, 6, 2, ' ');
	smiley.fillCircle(14, 6, 2, ' ');
	smiley.fillSector(10, 10, 6, 8, 0, PI, ' ');

	return smiley.h.iota.map!(y => 
smiley.scanline(y)).join("\n").idup;
}

pragma(msg, drawSmiley);

"almost" because fillSector calls atan2, which doesn't work in 
CTFE. :(

(And yeah, I totally did just declare an image with a colorspace 
of "char".)