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forked from 0ad/0ad
0ad/binaries/data/mods/public/shaders/water_high.fs
2008-09-18 04:38:42 +00:00

66 lines
2.6 KiB
GLSL

uniform vec3 ambient;
uniform vec3 sunDir;
uniform vec3 sunColor;
uniform vec3 cameraPos;
uniform sampler2D normalMap;
uniform sampler2D reflectionMap;
uniform sampler2D refractionMap;
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 w;
varying float waterDepth;
varying float losMod;
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 myMurkiness; // Murkiness and tint at this pixel (tweaked based on lighting and depth)
float t; // Temporary variable
vec2 reflCoords, refrCoords;
vec3 reflColor, refrColor, specular;
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);
myMurkiness = murkiness * min(waterDepth / fullDepth, 1.0);
fresnel = pow(1.0 - ndotv, 0.8); // A rather random Fresnel approximation
refrCoords = 0.5 * (gl_TexCoord[2].xy / gl_TexCoord[2].w) + 0.5; // Unbias texture coords
refrCoords -= 0.8 * waviness * n.xz / w; // Refractions can be slightly less wavy
reflCoords = 0.5 * (gl_TexCoord[1].xy / gl_TexCoord[1].w) + 0.5; // Unbias texture coords
reflCoords += waviness * n.xz / w;
reflColor = mix(texture2D(reflectionMap, reflCoords).rgb, sunColor * reflectionTint,
reflectionTintStrength);
refrColor = (0.5 + 0.5*ndotl) * mix(texture2D(refractionMap, refrCoords).rgb, sunColor * tint,
myMurkiness);
specular = pow(max(0.0, ndoth), shininess) * sunColor * specularStrength;
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);
}