qvolray: sdr/demo.p.glsl annotate

qvolray

- 16bit floating point textures halve gpu texture memory usage - slower transfer function change

author	John Tsiombikas <nuclear@member.fsf.org>
date	Wed, 01 Jan 2014 00:23:57 +0200
parents	2d0dfb5751dc
children

rev	line source
nuclear@36	1 #define NBALLS 3
nuclear@36	2
nuclear@36	3 uniform float energy[NBALLS];
nuclear@36	4 uniform vec3 pos[NBALLS];
nuclear@36	5
nuclear@36	6 float eval(vec3 p)
nuclear@36	7 {
nuclear@36	8 float val = 0.0;
nuclear@36	9
nuclear@36	10 for(int i=0; i<NBALLS; i++) {
nuclear@36	11 vec3 dif = p - pos[i];
nuclear@36	12 float len_sq = dot(dif, dif);
nuclear@36	13 val += 0.1 * energy[i] / len_sq;
nuclear@36	14 }
nuclear@36	15 return val;
nuclear@36	16 }
nuclear@36	17
nuclear@36	18 #define OFFS 0.01
nuclear@36	19
nuclear@18	20 void main()
nuclear@18	21 {
nuclear@21	22 vec3 pos = gl_TexCoord[0].xyz * 2.0 - 1.0;
nuclear@18	23
nuclear@36	24 float val = eval(pos);
nuclear@21	25
nuclear@36	26 vec3 grad;
nuclear@36	27 grad.x = eval(pos + vec3(OFFS, 0.0, 0.0)) - eval(pos - vec3(OFFS, 0.0, 0.0));
nuclear@36	28 grad.y = eval(pos + vec3(0.0, OFFS, 0.0)) - eval(pos - vec3(0.0, OFFS, 0.0));
nuclear@36	29 grad.z = eval(pos + vec3(0.0, 0.0, OFFS)) - eval(pos - vec3(0.0, 0.0, OFFS));
nuclear@36	30
nuclear@36	31 gl_FragColor = vec4(grad, val);
nuclear@18	32 }