1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/data/shaders/vol.f.glsl	Sun Apr 27 18:13:44 2014 +0300
     1.3 @@ -0,0 +1,40 @@
     1.4 +varying vec3 pt;
     1.5 +
     1.6 +uniform sampler3D tex;
     1.7 +uniform float tmin;
     1.8 +uniform float tmax;
     1.9 +uniform vec3 res;
    1.10 +
    1.11 +float transfer(float x, float tmin, float tmax)
    1.12 +{
    1.13 +	float dt = 0.25 * (tmax - tmin);
    1.14 +	return smoothstep(tmin - dt, tmin + dt, x) *
    1.15 +		(1.0 - smoothstep(tmax - dt, tmax + dt, x));
    1.16 +}
    1.17 +
    1.18 +vec3 calc_normal(vec3 p, float texel)
    1.19 +{
    1.20 +	vec3 offs = 1.0 / res;
    1.21 +
    1.22 +	float dfdx = texture3D(tex, p + vec3(offs.x, 0.0, 0.0)).x - texel;
    1.23 +	float dfdy = texture3D(tex, p + vec3(0.0, offs.y, 0.0)).x - texel;
    1.24 +	float dfdz = texture3D(tex, p + vec3(0.0, 0.0, offs.z)).x - texel;
    1.25 +
    1.26 +	return normalize(vec3(dfdx, dfdy, dfdz));
    1.27 +}
    1.28 +
    1.29 +void main()
    1.30 +{
    1.31 +	const vec3 ldir = vec3(-1.0, 1.0, 2.0);
    1.32 +
    1.33 +	if(max(pt.x, max(pt.y, pt.z)) > 1.0 || min(pt.x, min(pt.y, pt.z)) < 0.0)
    1.34 +		discard;
    1.35 +
    1.36 +	float texel = texture3D(tex, pt).x;
    1.37 +	float val = transfer(texel, tmin, tmax);
    1.38 +
    1.39 +	vec3 normal = calc_normal(pt, texel);
    1.40 +	float ndotl = max(dot(normalize(ldir), normal), 0.0);
    1.41 +
    1.42 +	gl_FragColor = vec4(ndotl, ndotl, ndotl, val);
    1.43 +}