precision highp float; varying vec2 vUv; attribute vec2 a_position; varying vec2 vL; varying vec2 vR; varying vec2 vT; varying vec2 vB; uniform vec2 u_texel; void main () { vUv = .5 * (a_position + 1.); vL = vUv - vec2(u_texel.x, 0.); vR = vUv + vec2(u_texel.x, 0.); vT = vUv + vec2(0., u_texel.y); vB = vUv - vec2(0., u_texel.y); gl_Position = vec4(a_position, 0., 1.); }

precision highp float; precision highp sampler2D; varying vec2 vUv; uniform sampler2D u_velocity_texture; uniform sampler2D u_input_texture; uniform vec2 u_texel; uniform float u_dt; uniform float u_use_text; uniform sampler2D u_text_texture; vec4 bilerp (sampler2D sam, vec2 uv, vec2 tsize) { vec2 st = uv / tsize - 0.5; vec2 iuv = floor(st); vec2 fuv = fract(st); vec4 a = texture2D(sam, (iuv + vec2(0.5, 0.5)) * tsize); vec4 b = texture2D(sam, (iuv + vec2(1.5, 0.5)) * tsize); vec4 c = texture2D(sam, (iuv + vec2(0.5, 1.5)) * tsize); vec4 d = texture2D(sam, (iuv + vec2(1.5, 1.5)) * tsize); return mix(mix(a, b, fuv.x), mix(c, d, fuv.x), fuv.y); } void main () { vec2 coord = vUv - u_dt * bilerp(u_velocity_texture, vUv, u_texel).xy * u_texel; float text = texture2D(u_text_texture, vec2(vUv.x, 1. - vUv.y)).r; float dissipation = (.96 + text * .04 * u_use_text); gl_FragColor = dissipation * bilerp(u_input_texture, coord, u_texel); gl_FragColor.a = 1.; }

precision highp float; precision highp sampler2D; varying highp vec2 vUv; varying highp vec2 vL; varying highp vec2 vR; varying highp vec2 vT; varying highp vec2 vB; uniform sampler2D u_velocity_texture; void main () { float L = texture2D(u_velocity_texture, vL).x; float R = texture2D(u_velocity_texture, vR).x; float T = texture2D(u_velocity_texture, vT).y; float B = texture2D(u_velocity_texture, vB).y; float div = .6 * (R - L + T - B); gl_FragColor = vec4(div, 0., 0., 1.); }

precision highp float; precision highp sampler2D; varying highp vec2 vUv; varying highp vec2 vL; varying highp vec2 vR; varying highp vec2 vT; varying highp vec2 vB; uniform sampler2D u_pressure_texture; uniform sampler2D u_divergence_texture; uniform sampler2D u_text_texture; void main () { float text = texture2D(u_text_texture, vec2(vUv.x, 1. - vUv.y)).r; float L = texture2D(u_pressure_texture, vL).x; float R = texture2D(u_pressure_texture, vR).x; float T = texture2D(u_pressure_texture, vT).x; float B = texture2D(u_pressure_texture, vB).x; float C = texture2D(u_pressure_texture, vUv).x; float divergence = texture2D(u_divergence_texture, vUv).x; float pressure = (L + R + B + T - divergence) * 0.25; pressure += (.2 * text); gl_FragColor = vec4(pressure, 0., 0., 1.); }

precision highp float; precision highp sampler2D; varying highp vec2 vUv; varying highp vec2 vL; varying highp vec2 vR; varying highp vec2 vT; varying highp vec2 vB; uniform sampler2D u_pressure_texture; uniform sampler2D u_velocity_texture; uniform sampler2D u_text_texture; void main () { float L = texture2D(u_pressure_texture, vL).x; float R = texture2D(u_pressure_texture, vR).x; float T = texture2D(u_pressure_texture, vT).x; float B = texture2D(u_pressure_texture, vB).x; vec2 velocity = texture2D(u_velocity_texture, vUv).xy; velocity.xy -= vec2(R - L, T - B); gl_FragColor = vec4(velocity, 0., 1.); }

precision highp float; precision highp sampler2D; varying vec2 vUv; uniform sampler2D u_input_texture; uniform float u_ratio; uniform vec3 u_point_value; uniform vec2 u_point; uniform float u_point_size; uniform sampler2D u_text_texture; void main () { vec2 p = vUv - u_point.xy; p.x *= u_ratio; vec3 splat = pow(2., -dot(p, p) / u_point_size) * u_point_value; float text = texture2D(u_text_texture, vec2(vUv.x, 1. - vUv.y)).r; splat *= (.7 + .2 * text); vec3 base = texture2D(u_input_texture, vUv).xyz; gl_FragColor = vec4(base + splat, 1.); }

precision highp float; precision highp sampler2D; varying vec2 vUv; uniform sampler2D u_output_texture; uniform sampler2D u_text_texture; void main () { vec3 C = texture2D(u_output_texture, vUv).rgb; float text = texture2D(u_text_texture, vec2(vUv.x, 1. - vUv.y)).r; gl_FragColor = vec4(vec3(1.) - C, 1.); }