3 #pragma MSP stage(compute)
4 float get_clamping(float depth, float v_right, float v_up, float v_left, float v_down)
6 float total_out = max(v_right, 0.0)+max(v_up, 0.0)-min(v_left, 0.0)-min(v_down, 0.0);
7 return min(max_flow_fraction/max(total_out*delta_time, max_flow_fraction), depth/residual_depth);
12 ivec2 size = imageSize(surface_out);
13 ivec2 coord = ivec2(gl_GlobalInvocationID.xy)+1;
14 if(coord.x>=size.x-1 || coord.y>=size.y-1)
17 vec4 data = get_data(coord);
18 vec4 right_data = get_data(coord+ivec2(1, 0));
19 vec4 up_data = get_data(coord+ivec2(0, 1));
20 vec4 left_data = get_data(coord-ivec2(1, 0));
21 vec4 down_data = get_data(coord-ivec2(0, 1));
23 float ul_vx = texelFetch(velocity_in, coord+ivec2(-1, 1), 0).x;
24 float left2_vx = texelFetch(velocity_in, coord-ivec2(2, 0), 0).x;
25 vec2 dl_velocity = texelFetch(velocity_in, coord-ivec2(1, 1), 0).xy;
26 float down2_vy = texelFetch(velocity_in, coord-ivec2(0, 2), 0).y;
27 float dr_vy = texelFetch(velocity_in, coord+ivec2(1, -1), 0).y;
29 float clamping = get_clamping(data.w, data.x, data.y, left_data.x, down_data.y);
30 float right_cl = get_clamping(right_data.w, right_data.x, right_data.y, data.x, dr_vy);
31 float up_cl = get_clamping(up_data.w, up_data.x, up_data.y, ul_vx, data.y);
32 float left_cl = get_clamping(left_data.w, left_data.x, left_data.y, left2_vx, dl_velocity.y);
33 float down_cl = get_clamping(down_data.w, down_data.x, down_data.y, dl_velocity.x, down2_vy);
35 // Integration step: change surface level based on velocities
36 float total_flow_out = data.x*mix(data.w*clamping, right_data.w*right_cl, data.x<0)+
37 data.y*mix(data.w*clamping, up_data.w*up_cl, data.y<0)-
38 left_data.x*mix(data.w*clamping, left_data.w*left_cl, left_data.x>0)-
39 down_data.y*mix(data.w*clamping, down_data.w*down_cl, down_data.y>0);
40 float new_surface = data.z-total_flow_out*delta_time;
42 imageStore(surface_out, coord, vec4(new_surface, 0.0, 0.0, 0.0));