nds_color.dsd

// nds_color - Applies NDS colour correction, designed to mimic the
//             display characteristics of an NDS Phat
// 
// - Original 'nds_color' code written by hunterk, modified by Pokefan531 and
//   released into the public domain
// 
// 'Ported' (i.e. copy/paste) to DraStic format by jdgleaver
// 
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 of the License, or (at your option)
// any later version.
=============================================

<vertex>

attribute vec2 a_vertex_coordinate;
attribute vec2 a_texture_coordinate;
uniform vec4 u_texture_size;

varying vec2 v_texture_coordinate;

void main()
{
	v_texture_coordinate = a_texture_coordinate;
	gl_Position = vec4(a_vertex_coordinate.xy, 0.0, 1.0);
}

</vertex>

<fragment>

// Colour defines...
#define target_gamma 1.91
#define display_gamma 1.91
#define lum 0.89
#define r 0.87
#define g 0.645
#define b 0.73
#define rg 0.10
#define rb 0.10
#define gr 0.255
#define gb 0.17
#define br -0.125
#define bg 0.255

uniform sampler2D u_texture;
uniform vec4 u_texture_size;

varying vec2 v_texture_coordinate;

void main()
{
	// Get colour sample and apply colour correction
	vec3 colour = pow(texture2D(u_texture, v_texture_coordinate.xy).rgb, vec3(target_gamma));
	colour = clamp(colour * lum, 0.0, 1.0);
	colour = pow(
		mat3(r,  rg, rb,
			  gr, g,  gb,
			  br, bg, b) * colour,
		vec3(1.0 / display_gamma)
	);
	
	gl_FragColor = vec4(colour.rgb, 1.0);
}

</fragment>