diff options
Diffstat (limited to 'gerstner.cginc')
| -rw-r--r-- | gerstner.cginc | 88 |
1 files changed, 70 insertions, 18 deletions
diff --git a/gerstner.cginc b/gerstner.cginc index e6ed3c2..47843a7 100644 --- a/gerstner.cginc +++ b/gerstner.cginc @@ -1,3 +1,5 @@ +#include "globals.cginc" +#include "math.cginc" #include "pema99.cginc" #ifndef __GERSTNER_INC @@ -17,12 +19,18 @@ struct GerstnerParams { float4 k_y; // time factor float4 t_f; +#if defined(_GIMMICK_GERSTNER_WATER_COLOR_RAMP) + float4 ramp_mask; +#endif #if defined(_GIMMICK_GERSTNER_WATER_OCTAVE_1) float4 a1; float4 p1; float4 k_x1; float4 k_y1; float4 t_f1; +#if defined(_GIMMICK_GERSTNER_WATER_COLOR_RAMP) + float4 ramp_mask1; +#endif #endif // mean water depth float h; @@ -31,6 +39,14 @@ struct GerstnerParams { float3 scale; }; +struct GerstnerFragResult { + float4 tangent; + float3 normal; +#if defined(_GIMMICK_GERSTNER_WATER_COLOR_RAMP) + float3 color; +#endif +}; + GerstnerParams getGerstnerParams() { GerstnerParams p; p.M = _Gimmick_Gerstner_Water_M; @@ -44,6 +60,9 @@ GerstnerParams getGerstnerParams() { p.g = _Gimmick_Gerstner_Water_g; p.scale = _Gimmick_Gerstner_Water_Scale; p.t_f = _Gimmick_Gerstner_Water_t_f; +#if defined(_GIMMICK_GERSTNER_WATER_COLOR_RAMP) + p.ramp_mask = _Gimmick_Gerstner_Water_Color_Ramp_Mask; +#endif #if defined(_GIMMICK_GERSTNER_WATER_OCTAVE_1) p.a1 = _Gimmick_Gerstner_Water_a1; p.p1 = _Gimmick_Gerstner_Water_p1; @@ -51,17 +70,26 @@ GerstnerParams getGerstnerParams() { p.k_x1 += k_x_time_distortion; p.k_y1 = _Gimmick_Gerstner_Water_k_y1; p.t_f1 = _Gimmick_Gerstner_Water_t_f1; +#if defined(_GIMMICK_GERSTNER_WATER_COLOR_RAMP) + p.ramp_mask1 = _Gimmick_Gerstner_Water_Color_Ramp_Mask1; +#endif #endif return p; } -float3 compute_gerstner(float3 pp, GerstnerParams p) +struct GerstnerInternalResult { + float3 world_pos; + float color_ramp_pos; +}; + +GerstnerInternalResult compute_gerstner(float3 pp, GerstnerParams p) { const float g_alpha = pp.x * p.scale.x; const float g_beta = pp.y * p.scale.y; float g_xi = g_alpha; float g_eta = g_beta; float g_zeta = 0; + float g_zeta_color_ramp = 0; for (uint i = 0; i < p.M; i++) { uint i_mod_4 = glsl_mod(i, 4); @@ -79,6 +107,9 @@ float3 compute_gerstner(float3 pp, GerstnerParams p) g_xi -= (p.k_x[i] / g_k) * (p.a[i] / tanh(g_k * p.h)) * sin(g_theta); g_eta -= (p.k_y[i] / g_k) * (p.a[i] / tanh(g_k * p.h)) * sin(g_theta); g_zeta += p.a[i] * cos(g_theta); +#if defined(_GIMMICK_GERSTNER_WATER_COLOR_RAMP) + g_zeta_color_ramp += p.a[i] * cos(g_theta) * p.ramp_mask[i]; +#endif break; } #if defined(_GIMMICK_GERSTNER_WATER_OCTAVE_1) @@ -94,51 +125,72 @@ float3 compute_gerstner(float3 pp, GerstnerParams p) g_xi -= (p.k_x1[i_mod_4] / g_k) * (p.a1[i_mod_4] / tanh(g_k * p.h)) * sin(g_theta); g_eta -= (p.k_y1[i_mod_4] / g_k) * (p.a1[i_mod_4] / tanh(g_k * p.h)) * sin(g_theta); g_zeta += p.a1[i_mod_4] * cos(g_theta); +#if defined(_GIMMICK_GERSTNER_WATER_COLOR_RAMP) + g_zeta_color_ramp += p.a1[i_mod_4] * cos(g_theta) * p.ramp_mask1[i_mod_4]; +#endif break; } #endif } - } const float3 raw_result = float3(g_xi / p.scale.x, g_eta / p.scale.y, g_zeta * p.scale.z); + g_zeta_color_ramp *= p.scale.z; const float3 raw_result_world = mul(unity_ObjectToWorld, float4(raw_result, 1)).xyz; float3 result_world = raw_result_world; if (_Gimmick_Gerstner_Water_Origin_Damping_Direction > 0) { - result_world.y = max(_Gimmick_Gerstner_Water_Origin_Damping_Direction, result_world.y); + result_world.y = dmax(_Gimmick_Gerstner_Water_Origin_Damping_Direction, result_world.y, 1); } else { - result_world.y = min(_Gimmick_Gerstner_Water_Origin_Damping_Direction, result_world.y); + result_world.y = dmin(_Gimmick_Gerstner_Water_Origin_Damping_Direction, result_world.y, 1); } - result_world.y = lerp(result_world.y, raw_result_world.y, - // If within 20m cylindrical distance, apply 100m wide damping. + float3 result_obj = mul(unity_WorldToObject, float4(result_world, 1)).xyz; + + result_obj = lerp(result_obj, raw_result, + // If within 3m cylindrical distance, apply 100m wide damping. // TODO parameterize this! - saturate((length(raw_result_world.xz) - 20) * 0.01) * + dsaturate((length(raw_result_world.xz) - 20), 1) * // Only enable if mesh is on the wrong side of the damping vector. - (sign(raw_result_world.y - _Gimmick_Gerstner_Water_Origin_Damping_Direction) != sign(_Gimmick_Gerstner_Water_Origin_Damping_Direction))); + // TODO make this differentiable. As is, there's a visible seam. + dsaturate(-(raw_result_world.y - _Gimmick_Gerstner_Water_Origin_Damping_Direction) * sign(_Gimmick_Gerstner_Water_Origin_Damping_Direction), 1)); - float3 result = mul(unity_WorldToObject, float4(result_world, 1)).xyz; - return result; + GerstnerInternalResult r; + r.world_pos = result_obj; + r.color_ramp_pos = g_zeta_color_ramp; + return r; } float3 gerstner_vert(float3 pp, GerstnerParams p) { - return compute_gerstner(pp, p); + return compute_gerstner(pp, p).world_pos; } -float3 gerstner_frag(float3 pp, GerstnerParams p) +GerstnerFragResult gerstner_frag(float3 pp, GerstnerParams p) { - const float3 g0 = compute_gerstner(pp, p); - const float3 e = float3(1E-8, 0, 0); - const float3 g0_da = compute_gerstner(pp + e.xyz, p); - const float3 g0_db = compute_gerstner(pp + e.yxz, p); + const GerstnerInternalResult r0 = compute_gerstner(pp, p); + const float3 g0 = r0.world_pos; + const float3 e = float3(1E-7, 0, 0); + const float3 g0_da = compute_gerstner(pp + e.xyz, p).world_pos; + const float3 g0_db = compute_gerstner(pp + e.yxz, p).world_pos; const float3 ds_da = g0_da - g0; const float3 ds_db = g0_db - g0; - const float3 n = normalize(cross( + GerstnerFragResult r; + r.normal = normalize(cross( ds_da, ds_db)); - return n; + r.tangent = float4(normalize(ds_da), 1); + +#if defined(_GIMMICK_GERSTNER_WATER_COLOR_RAMP) + float ramp_phase = r0.color_ramp_pos; + ramp_phase *= _Gimmick_Gerstner_Water_Color_Ramp_Scale; + ramp_phase += _Gimmick_Gerstner_Water_Color_Ramp_Offset; + float3 ramp_color = _Gimmick_Gerstner_Water_Color_Ramp.Sample(linear_clamp_s, float2(ramp_phase, 0.5)); + + r.color = ramp_color; +#endif + + return r; } #endif // _GIMMICK_GERSTNER_WATER |