115 lines
3.4 KiB
GLSL
115 lines
3.4 KiB
GLSL
#define VORT_CH xy
|
|
#define VORT_SAMPLER iChannel0
|
|
#define POIS_SAMPLER iChannel1
|
|
#define POIS_CH x
|
|
#define DEGREE POISSON_SCALES
|
|
|
|
#define D(d) textureLod(VORT_SAMPLER, fract(uv+d), mip).VORT_CH
|
|
#define P(d) textureLod(POIS_SAMPLER, fract(uv+d), mip).POIS_CH
|
|
|
|
float laplacian_poisson(vec2 fragCoord) {
|
|
const float _K0 = -20.0/6.0, _K1 = 4.0/6.0, _K2 = 1.0/6.0;
|
|
vec2 texel = 1.0/iResolution.xy;
|
|
vec2 uv = fragCoord * texel;
|
|
vec4 t = vec4(texel, -texel.y, 0);
|
|
float mip = 0.0;
|
|
|
|
float p = P( t.ww); float p_n = P( t.wy); float p_e = P( t.xw);
|
|
float p_s = P( t.wz); float p_w = P(-t.xw); float p_nw = P(-t.xz);
|
|
float p_sw = P(-t.xy); float p_ne = P( t.xy); float p_se = P( t.xz);
|
|
|
|
return _K0 * p + _K1 * (p_e + p_w + p_n + p_s) + _K2 * (p_ne + p_nw + p_se + p_sw);
|
|
}
|
|
|
|
void tex(vec2 uv, inout mat3 mx, inout mat3 my, inout mat3 mp, int degree) {
|
|
vec2 texel = 1.0/iResolution.xy;
|
|
float stride = float(1 << degree);
|
|
float mip = float(degree);
|
|
vec4 t = stride * vec4(texel, -texel.y, 0);
|
|
|
|
vec2 d = D( t.ww); vec2 d_n = D( t.wy); vec2 d_e = D( t.xw);
|
|
vec2 d_s = D( t.wz); vec2 d_w = D(-t.xw); vec2 d_nw = D(-t.xz);
|
|
vec2 d_sw = D(-t.xy); vec2 d_ne = D( t.xy); vec2 d_se = D( t.xz);
|
|
|
|
float p = P( t.ww); float p_n = P( t.wy); float p_e = P( t.xw);
|
|
float p_s = P( t.wz); float p_w = P(-t.xw); float p_nw = P(-t.xz);
|
|
float p_sw = P(-t.xy); float p_ne = P( t.xy); float p_se = P( t.xz);
|
|
|
|
mx = mat3(d_nw.x, d_n.x, d_ne.x,
|
|
d_w.x, d.x, d_e.x,
|
|
d_sw.x, d_s.x, d_se.x);
|
|
|
|
my = mat3(d_nw.y, d_n.y, d_ne.y,
|
|
d_w.y, d.y, d_e.y,
|
|
d_sw.y, d_s.y, d_se.y);
|
|
|
|
mp = mat3(p_nw, p_n, p_ne,
|
|
p_w, p, p_e,
|
|
p_sw, p_s, p_se);
|
|
}
|
|
|
|
float reduce(mat3 a, mat3 b) {
|
|
mat3 p = matrixCompMult(a, b);
|
|
return p[0][0] + p[0][1] + p[0][2] +
|
|
p[1][0] + p[1][1] + p[1][2] +
|
|
p[2][0] + p[2][1] + p[2][2];
|
|
}
|
|
|
|
vec2 pois(vec2 fragCoord)
|
|
{
|
|
vec2 uv = fragCoord.xy / iResolution.xy;
|
|
|
|
float k0 = POIS_ISOTROPY;
|
|
float k1 = 1.0 - 2.0*(POIS_ISOTROPY);
|
|
|
|
mat3 pois_x = mat3(
|
|
k0, 0.0, -k0,
|
|
k1, 0.0, -k1,
|
|
k0, 0.0, -k0
|
|
);
|
|
|
|
mat3 pois_y = mat3(
|
|
-k0, -k1, -k0,
|
|
0.0, 0.0, 0.0,
|
|
k0, k1, k0
|
|
);
|
|
|
|
mat3 gauss = mat3(
|
|
0.0625, 0.125, 0.0625,
|
|
0.125, 0.25, 0.125,
|
|
0.0625, 0.125, 0.0625
|
|
);
|
|
|
|
mat3 mx, my, mp;
|
|
vec2 v = vec2(0);
|
|
|
|
float wc = 0.0;
|
|
for (int i = 0; i < DEGREE; i++) {
|
|
tex(uv, mx, my, mp, i);
|
|
float w = POIS_W_FUNCTION;
|
|
wc += w;
|
|
v += w * vec2(reduce(pois_x, mx) + reduce(pois_y, my), reduce(gauss, mp));
|
|
}
|
|
|
|
return v / wc;
|
|
|
|
}
|
|
|
|
#define V(d) textureLod(VORT_SAMPLER, fract(uv+d), mip).zw
|
|
|
|
void mainImage( out vec4 fragColor, in vec2 fragCoord )
|
|
{
|
|
|
|
vec2 p = pois(fragCoord);
|
|
#ifdef USE_PRESSURE_ADVECTION
|
|
float mip = 0.0;
|
|
vec2 tx = 1.0 / iResolution.xy;
|
|
vec2 uv = fragCoord * tx;
|
|
float prev = P(0.0002 * PRESSURE_ADVECTION * tx * V(vec2(0)));
|
|
fragColor = vec4(mix(p.x + p.y, prev + PRESSURE_LAPLACIAN * laplacian_poisson(fragCoord), PRESSURE_UPDATE_SMOOTHING));
|
|
#else
|
|
fragColor = vec4(p.x + p.y);
|
|
#endif
|
|
// Adding a very small amount of noise on init fixes subtle numerical precision blowup problems
|
|
if (iFrame==0) fragColor=1e-6*rand4(fragCoord, iResolution.xy, iFrame);
|
|
} |