2013-12-19 19:32:50 +01:00

46 lines
1.3 KiB
GLSL

// oceanGLSL.frag
// fragment program for Ocean water simulation
// 05 Aug 2005
// adapted for Ogre by nfz
// converted from HLSL to GLSL
// original shader source from Render Monkey 1.6 Reflections Refractions.rfx
// 06 Aug 2005: moved uvw calculation from fragment program into vertex program
uniform float fadeBias;
uniform float fadeExp;
uniform vec4 waterColor;
uniform sampler3D Noise;
uniform samplerCube skyBox;
varying vec3 uvw;
varying vec3 normal;
varying vec3 vVec;
void main(void)
{
vec3 noisy = texture3D(Noise, uvw).xyz;
// convert to signed noise
vec3 bump = 2.0 * noisy - 1.0;
bump.xz *= 0.15;
// Make sure the normal always points upwards
// note that Ogres y axis is vertical (RM Z axis is vertical)
bump.y = 0.8 * abs(bump.y) + 0.2;
// Offset the surface normal with the bump
bump = normalize(normal + bump);
// Find the reflection vector
vec3 normView = normalize(vVec);
vec3 reflVec = reflect(normView, bump);
// Ogre has z flipped for cubemaps
reflVec.z = -reflVec.z;
vec4 refl = textureCube(skyBox, reflVec);
// set up for fresnel calc
float lrp = 1.0 - dot(-normView, bump);
// Interpolate between the water color and reflection for fresnel effect
gl_FragColor = mix(waterColor, refl, clamp(fadeBias + pow(lrp, fadeExp), 0.0, 1.0) );
}