veloren/assets/voxygen/shaders/include/lod.glsl
2020-02-24 12:54:55 +00:00

57 lines
1.5 KiB
GLSL

#include <random.glsl>
uniform sampler2D t_map;
vec2 pos_to_uv(vec2 pos) {
vec2 uv_pos = pos / 32768.0;
return vec2(uv_pos.x, 1.0 - uv_pos.y);
}
float alt_at(vec2 pos) {
return texture(t_map, pos_to_uv(pos)).a * (1300.0) + 140.0;
return 0.0
+ pow(texture(t_noise, pos * 0.00005).x * 1.4, 3.0) * 1000.0
+ texture(t_noise, pos * 0.001).x * 100.0
+ texture(t_noise, pos * 0.003).x * 30.0;
}
vec2 splay(vec2 pos) {
return pos * pow(length(pos) * 0.5, 3.0);
}
vec3 lod_norm(vec2 pos) {
const float SAMPLE_W = 32;
float altx0 = alt_at(pos + vec2(-1, 0) * SAMPLE_W);
float altx1 = alt_at(pos + vec2(1, 0) * SAMPLE_W);
float alty0 = alt_at(pos + vec2(0, -1) * SAMPLE_W);
float alty1 = alt_at(pos + vec2(0, 1) * SAMPLE_W);
float slope = abs(altx1 - altx0) + abs(alty0 - alty1);
return normalize(vec3(
(altx0 - altx1) / SAMPLE_W,
(alty0 - alty1) / SAMPLE_W,
SAMPLE_W / (slope + 0.00001) // Avoid NaN
));
}
vec3 lod_pos(vec2 v_pos, vec2 focus_pos) {
vec2 hpos = focus_pos.xy + splay(v_pos) * 1000000.0;
// Remove spiking by "pushing" vertices towards local optima
vec2 nhpos = hpos;
for (int i = 0; i < 3; i ++) {
nhpos -= lod_norm(hpos).xy * 15.0;
}
hpos = hpos + normalize(nhpos - hpos + 0.001) * min(length(nhpos - hpos), 32);
return vec3(hpos, alt_at(hpos));
}
vec3 lod_col(vec2 pos) {
//return vec3(0, 0.5, 0);
return texture(t_map, pos_to_uv(pos)).rgb;
//+ (texture(t_noise, pos * 0.04 + texture(t_noise, pos * 0.005).xy * 2.0 + texture(t_noise, pos * 0.06).xy * 0.6).x - 0.5) * 0.1;
}