Remove the separate clamping step from forest pond fluid simulation

[libs/gl.git] / demos / forestpond / data / fluidsim_velocity.glsl

diff --git a/demos/forestpond/data/fluidsim_velocity.glsl b/demos/forestpond/data/fluidsim_velocity.glsl
index b564b23147f17eabb829205ca38f0c3143a19ffa..375e205e3077aea311de3ed025085011cd625f7d 100644 (file)
--- a/demos/forestpond/data/fluidsim_velocity.glsl
+++ b/demos/forestpond/data/fluidsim_velocity.glsl
@@ -8,30 +8,24 @@ void main()
        if(coord.x>=size.x-1 || coord.y>=size.y-1)
                return;
 
-       float surface = texelFetch(surface_in, coord, 0).x;
-       float depth = surface-texelFetch(bottom_in, coord, 0).x;
-       float surface_left = texelFetch(surface_in, coord-ivec2(1, 0), 0).x;
-       float surface_right = texelFetch(surface_in, coord+ivec2(1, 0), 0).x;
-       float depth_right = surface_right-texelFetch(bottom_in, coord+ivec2(1, 0), 0).x;
-       float surface_down = texelFetch(surface_in, coord-ivec2(0, 1), 0).x;
-       float surface_up = texelFetch(surface_in, coord+ivec2(0, 1), 0).x;
-       float depth_up = surface_up-texelFetch(bottom_in, coord+ivec2(0, 1), 0).x;
-       vec2 velocity = texelFetch(velocity_in, coord, 0).xy;
+       vec4 data = get_data(coord);
+       vec2 sd_right = get_depth(coord+ivec2(1, 0));
+       vec2 sd_up = get_depth(coord+ivec2(0, 1));
 
        // Advection step: move velocity vectors 
        vec2 uv_coord = (vec2(coord)+vec2(0.5))/size;
        vec2 offset = vec2(0.5, -0.5)/size;
        vec2 multi = delta_time/size;
-       vec2 v_right = vec2(velocity.x, textureLod(velocity_in, uv_coord+offset, 0).y);
-       vec2 v_up = vec2(textureLod(velocity_in, uv_coord-offset, 0).x, velocity.y);
+       vec2 v_right = vec2(data.x, textureLod(velocity_in, uv_coord+offset, 0).y);
+       vec2 v_up = vec2(textureLod(velocity_in, uv_coord-offset, 0).x, data.y);
        vec2 new_velocity = vec2(textureLod(velocity_in, uv_coord-v_right*multi, 0).x,
                textureLod(velocity_in, uv_coord-v_up*multi, 0).y)*velocity_damping;
 
        // Update step: change velocities based on surface level differences
-       vec2 source_depth = mix(vec2(depth_right, depth_up), vec2(depth), greaterThan(vec2(surface), vec2(surface_right, surface_up)));
-       new_velocity += (vec2(surface)-vec2(surface_right, surface_up))*0.1*gravity*delta_time*min(source_depth/residual_depth, 1.0);
+       vec2 source_depth = mix(vec2(sd_right.y, sd_up.y), vec2(data.w), greaterThan(vec2(data.z), vec2(sd_right.x, sd_up.x)));
+       new_velocity += (vec2(data.z)-vec2(sd_right.x, sd_up.x))*0.1*gravity*delta_time*min(source_depth/residual_depth, 1.0);
 
-       if(time>=drop_time && time<=drop_time+0.01 && depth>1.0)
+       if(time>=drop_time && time<=drop_time+0.01 && data.w>1.0)
        {
                ivec2 d = coord-drop_pos;
                if(d.x*d.x+d.y*d.y<4)