0ad/binaries/data/mods/public/shaders/water_high.fs
Ykkrosh a3f168b887 Initial support for GLSL generic vertex attributes in shader API, for GLES compatibility.
Specify GLSL version in shader files, for better error detection.

This was SVN commit r11040.
2012-02-09 17:55:25 +00:00

64 lines
2.6 KiB
GLSL

#version 110
uniform vec3 ambient;
uniform vec3 sunDir;
uniform vec3 sunColor;
uniform vec3 cameraPos;
uniform sampler2D normalMap;
uniform sampler2D reflectionMap;
uniform sampler2D refractionMap;
uniform sampler2D losMap;
uniform float shininess; // Blinn-Phong specular strength
uniform float specularStrength; // Scaling for specular reflection (specular color is (this,this,this))
uniform float waviness; // "Wildness" of the reflections and refractions; choose based on texture
uniform vec3 tint; // Tint for refraction (used to simulate particles in water)
uniform float murkiness; // Amount of tint to blend in with the refracted colour
uniform float fullDepth; // Depth at which to use full murkiness (shallower water will be clearer)
uniform vec3 reflectionTint; // Tint for reflection (used for really muddy water)
uniform float reflectionTintStrength; // Strength of reflection tint (how much of it to mix in)
varying vec3 worldPos;
varying float waterDepth;
void main()
{
vec3 n, l, h, v; // Normal, light vector, half-vector and view vector (vector to eye)
float ndotl, ndoth, ndotv;
float fresnel;
float t; // Temporary variable
vec2 reflCoords, refrCoords;
vec3 reflColor, refrColor, specular;
float losMod;
n = normalize(texture2D(normalMap, gl_TexCoord[0].st).xzy - vec3(0.5, 0.5, 0.5));
l = -sunDir;
v = normalize(cameraPos - worldPos);
h = normalize(l + v);
ndotl = dot(n, l);
ndoth = dot(n, h);
ndotv = dot(n, v);
fresnel = pow(1.0 - ndotv, 0.8); // A rather random Fresnel approximation
refrCoords = (0.5*gl_TexCoord[2].xy - 0.8*waviness*n.xz) / gl_TexCoord[2].w + 0.5; // Unbias texture coords
reflCoords = (0.5*gl_TexCoord[1].xy + waviness*n.xz) / gl_TexCoord[1].w + 0.5; // Unbias texture coords
reflColor = mix(texture2D(reflectionMap, reflCoords).rgb, sunColor * reflectionTint,
reflectionTintStrength);
refrColor = (0.5 + 0.5*ndotl) * mix(texture2D(refractionMap, refrCoords).rgb, sunColor * tint,
murkiness * clamp(waterDepth / fullDepth, 0.0, 1.0)); // Murkiness and tint at this pixel (tweaked based on lighting and depth)
specular = pow(max(0.0, ndoth), shininess) * sunColor * specularStrength;
losMod = texture2D(losMap, gl_TexCoord[3].st).a;
gl_FragColor.rgb = mix(refrColor + 0.3*specular, reflColor + specular, fresnel) * losMod;
// Make alpha vary based on both depth (so it blends with the shore) and view angle (make it
// become opaque faster at lower view angles so we can't look "underneath" the water plane)
t = 18.0 * max(0.0, 0.7 - v.y);
gl_FragColor.a = 0.15 * waterDepth * (1.2 + t + fresnel);
}