| #version 330 core |
| |
| in vec3 vertexPosition; |
| in vec3 vertexNormal; |
| |
| out EyeSpaceVertex { |
| vec3 position; |
| vec3 normal; |
| } vs_out; |
| |
| uniform mat4 modelView; |
| uniform mat3 modelViewNormal; |
| uniform mat4 mvp; |
| |
| uniform float time; |
| uniform float amplitude = 1.0; |
| uniform float lambda = 20.0; |
| uniform float period = 15.0; |
| |
| // |
| // Description : Array and textureless GLSL 3D simplex noise function. |
| // Author : Ian McEwan, Ashima Arts. |
| // Maintainer : ijm |
| // Lastmod : 20110409 (stegu) |
| // License : Copyright (C) 2011 Ashima Arts. All rights reserved. |
| // Distributed under the MIT License. See LICENSE file. |
| // |
| |
| vec4 permute( vec4 x ) |
| { |
| return mod(((x*34.0)+1.0)*x, 289.0); |
| } |
| |
| vec4 taylorInvSqrt( vec4 r ) |
| { |
| return 1.79284291400159 - 0.85373472095314 * r; |
| } |
| |
| float snoise(vec3 v) |
| { |
| const vec2 C = vec2(1.0/6.0, 1.0/3.0) ; |
| const vec4 D = vec4(0.0, 0.5, 1.0, 2.0); |
| |
| // First corner |
| vec3 i = floor(v + dot(v, C.yyy) ); |
| vec3 x0 = v - i + dot(i, C.xxx) ; |
| |
| // Other corners |
| vec3 g = step(x0.yzx, x0.xyz); |
| vec3 l = 1.0 - g; |
| vec3 i1 = min( g.xyz, l.zxy ); |
| vec3 i2 = max( g.xyz, l.zxy ); |
| |
| // x0 = x0 - 0. + 0.0 * C |
| vec3 x1 = x0 - i1 + 1.0 * C.xxx; |
| vec3 x2 = x0 - i2 + 2.0 * C.xxx; |
| vec3 x3 = x0 - 1. + 3.0 * C.xxx; |
| |
| // Permutations |
| i = mod(i, 289.0 ); |
| vec4 p = permute( permute( permute( |
| i.z + vec4(0.0, i1.z, i2.z, 1.0 )) |
| + i.y + vec4(0.0, i1.y, i2.y, 1.0 )) |
| + i.x + vec4(0.0, i1.x, i2.x, 1.0 )); |
| |
| // Gradients |
| // ( N*N points uniformly over a square, mapped onto an octahedron.) |
| float n_ = 1.0/7.0; // N=7 |
| vec3 ns = n_ * D.wyz - D.xzx; |
| |
| vec4 j = p - 49.0 * floor(p * ns.z *ns.z); // mod(p,N*N) |
| |
| vec4 x_ = floor(j * ns.z); |
| vec4 y_ = floor(j - 7.0 * x_ ); // mod(j,N) |
| |
| vec4 x = x_ *ns.x + ns.yyyy; |
| vec4 y = y_ *ns.x + ns.yyyy; |
| vec4 h = 1.0 - abs(x) - abs(y); |
| |
| vec4 b0 = vec4( x.xy, y.xy ); |
| vec4 b1 = vec4( x.zw, y.zw ); |
| |
| //vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0; |
| //vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0; |
| vec4 s0 = floor(b0)*2.0 + 1.0; |
| vec4 s1 = floor(b1)*2.0 + 1.0; |
| vec4 sh = -step(h, vec4(0.0)); |
| |
| vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ; |
| vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ; |
| |
| vec3 p0 = vec3(a0.xy,h.x); |
| vec3 p1 = vec3(a0.zw,h.y); |
| vec3 p2 = vec3(a1.xy,h.z); |
| vec3 p3 = vec3(a1.zw,h.w); |
| |
| //Normalise gradients |
| vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3))); |
| p0 *= norm.x; |
| p1 *= norm.y; |
| p2 *= norm.z; |
| p3 *= norm.w; |
| |
| // Mix final noise value |
| vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0); |
| m = m * m; |
| return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1), |
| dot(p2,x2), dot(p3,x3) ) ); |
| } |
| |
| float height( const in vec3 pos ) |
| { |
| // Perturb the y position by a wave function in (x, t) |
| const float twoPi = 2.0 * 3.14159265358979323846; |
| float k = twoPi / lambda; |
| float omega = twoPi / period; |
| |
| float y = amplitude * sin( k * pos.x - omega * time ); |
| |
| // Further perturb by a noise function |
| y += snoise( 0.27 * vec3( 0.4 * pos.x, 3.0, 2.0 * pos.z - 0.5 * time ) ); |
| |
| return y; |
| } |
| |
| void main() |
| { |
| // Calculate y value based upon input coordinates and time |
| vec3 pos = vertexPosition; |
| pos.y = height( pos ); |
| |
| // Estimate normal vector by calculating the y value at small offsets |
| // and then taking the cross product of the differences |
| float offset = 0.5; |
| vec3 posOffsetX = vertexPosition + vec3( offset, 0.0, 0.0 ); |
| posOffsetX.y = height( posOffsetX ); |
| vec3 posOffsetZ = vertexPosition + vec3( 0.0, 0.0, offset ); |
| posOffsetZ.y = height( posOffsetZ ); |
| |
| vec3 dydx = posOffsetX - pos; |
| vec3 dydz = posOffsetZ - pos; |
| vec3 normal = cross( dydz, dydx ); |
| |
| // Transform the position and normal to eye space for lighting |
| vs_out.normal = normalize( modelViewNormal * normal ); |
| vs_out.position = vec3( modelView * vec4( pos, 1.0 ) ); |
| |
| gl_Position = mvp * vec4( pos, 1.0 ); |
| } |