diff options
Diffstat (limited to 'glitter.cginc')
| -rw-r--r-- | glitter.cginc | 59 |
1 files changed, 45 insertions, 14 deletions
diff --git a/glitter.cginc b/glitter.cginc index 39b735b..2744d6b 100644 --- a/glitter.cginc +++ b/glitter.cginc @@ -21,6 +21,16 @@ float2 lambert(float3 v) { return v.xy / sqrt(1 + v.z); } +// Rebuild GLSL mat2 column semantics explicitly in HLSL. +float2 mat2_col(float2x2 m, uint i) { + return float2(m[0][i], m[1][i]); +} + +float2x2 mat2_from_cols(float2 c0, float2 c1) { + return float2x2(c0.x, c1.x, + c0.y, c1.y); +} + // v is a microfacet normal that has been squished according to alpha, a // roughness parameter. float3 ndf_to_disk_ggx(float3 v, float alpha) { @@ -37,26 +47,31 @@ float3 ndf_to_disk_ggx(float3 v, float alpha) { // Computes (M^T M)^-1 float2x2 inv_quadratic(float2x2 M) { float D = determinant(M); - float A = dot(M[0] / D, M[0] / D); - float B = -dot(M[0] / D, M[1] / D); - float C = dot(M[1] / D, M[1] / D); - return float2x2(C, B, B, A); + float2 c0 = mat2_col(M, 0) / D; + float2 c1 = mat2_col(M, 1) / D; + float A = dot(c0, c0); + float B = -dot(c0, c1); + float C = dot(c1, c1); + return mat2_from_cols(float2(C, B), float2(B, A)); } float2x2 uv_ellipsoid(float2x2 uv_J) { float2x2 Q = inv_quadratic(transpose(uv_J)); - float tr = 0.5 * (Q[0][0] + Q[1][1]); + float2 q0 = mat2_col(Q, 0); + float2 q1 = mat2_col(Q, 1); + float tr = 0.5 * (q0.x + q1.y); float D = sqrt(max(0.0, tr * tr - determinant(Q))); float l1 = tr - D; float l2 = tr + D; - float2 v1 = float2(l1 - Q[1][1], Q[0][1]); - float2 v2 = float2(Q[1][0], l2 - Q[0][0]); + float2 v1 = float2(l1 - q1.y, q0.y); + float2 v2 = float2(q1.x, l2 - q0.x); float2 n = 1.f/sqrt(float2(l1, l2)); - return float2x2(normalize(v1)*n.x, normalize(v2)*n.y); + return mat2_from_cols(normalize(v1) * n.x, normalize(v2) * n.y); } float QueryLod(float2x2 uv_J, float filter_size) { - float s0 = length(uv_J[0]), s1 = length(uv_J[1]); + float s0 = length(mat2_col(uv_J, 0)); + float s1 = length(mat2_col(uv_J, 1)); return log2(max(s0, s1) * filter_size) + pow(2.0, filter_size); } @@ -64,11 +79,28 @@ float normal(float2x2 cov, float2 x) { return exp(-.5 * dot(x, mul(inverse(cov), x))) / (sqrt(determinant(cov)) * 2.0 * PI); } -float Rand2D(float2 x, float2 y, float l, uint i) { +uint2 shuffle(uint2 v) { + v = v * 1664525u + 1013904223u; + v.x += v.y * 1664525u; + v.y += v.x * 1664525u; + + v = v ^ (v>>16u); + + v.x += v.y * 1664525u; + v.y += v.x * 1664525u; + v = v ^ (v>>16u); + return v; +} + +float2 rand(uint2 v) { + return float2(shuffle(v)) * pow(0.5, 32.0); +} + +float2 Rand2D(float2 x, float2 y, float l, uint i) { uint2 ux = asuint(x); uint2 uy = asuint(y); uint ul = asuint(l); - return hash22_fast((ux>>16|ux<<16) ^ uy ^ ul ^ (i*0x124u)); + return rand((ux>>16|ux<<16) ^ uy ^ ul ^ (i*0x124u)); } float Rand1D(float2 x, float2 y, float l, uint i) { @@ -102,7 +134,7 @@ float compensation(float2 x_a, float2x2 sigma_a, float res_a) { return containing - explicitly_evaluated; } -float ndf(float3 h, float alpha, float glint_alpha, float2 uv, float2x2 uv_J, float N, float filter_size) { +float D_Kemppinen(float3 h, float alpha, float glint_alpha, float2 uv, float2x2 uv_J, float N, float filter_size) { float res = sqrt(N); float2 x_s = uv; float3 x_a_and_d = ndf_to_disk_ggx(h, alpha); @@ -121,7 +153,7 @@ float ndf(float3 h, float alpha, float glint_alpha, float2 uv, float2x2 uv_J, fl float res_a = pow(2., l); float2x2 uv_J2 = filter_size * uv_J; - float2x2 sigma_s = uv_J2 * transpose(uv_J2); + float2x2 sigma_s = mul(uv_J2, transpose(uv_J2)); float2x2 sigma_a = d * pow(glint_alpha, 2.) * float2x2(1., .0, .0, 1.); @@ -149,4 +181,3 @@ float ndf(float3 h, float alpha, float glint_alpha, float2 uv, float2x2 uv_J, fl } #endif // __GLITTER_INC - |