A game about forced loneliness, made by TACStudios
tacstudios.tngl.sh
1#ifndef DECODE_SH
2# define DECODE_SH
3
4// TODO: We're working on irradiance instead of radiance coefficients
5// Add safety margin 2 to avoid out-of-bounds values
6#define APV_L1_ENCODING_SCALE 2.0 // Should be: 3/(2*sqrt(3)) * 2, but rounding to 2 to issues we are observing.
7#define APV_L2_ENCODING_SCALE 3.5777088 // 4/sqrt(5) * 2
8
9float3 DecodeSH(float l0, float3 l1)
10{
11 return (l1 - 0.5f) * (2.0f * APV_L1_ENCODING_SCALE * l0);
12}
13
14void DecodeSH_L2(inout float3 l0, inout float4 l2_R, inout float4 l2_G, inout float4 l2_B, inout float3 l2_C)
15{
16 l2_R = (l2_R - 0.5f) * (APV_L2_ENCODING_SCALE * l0.r);
17 l2_G = (l2_G - 0.5f) * (APV_L2_ENCODING_SCALE * l0.g);
18 l2_B = (l2_B - 0.5f) * (APV_L2_ENCODING_SCALE * l0.b);
19 l2_C = (l2_C - 0.5f) * APV_L2_ENCODING_SCALE;
20
21 l2_C.rgb *= l0;
22
23 // Account for how L2 is encoded.
24 l0.r -= l2_R.z;
25 l0.g -= l2_G.z;
26 l0.b -= l2_B.z;
27 l2_R.z *= 3.0f;
28 l2_G.z *= 3.0f;
29 l2_B.z *= 3.0f;
30}
31
32void DecodeSH_L2(inout float3 l0, inout float4 l2_R, inout float4 l2_G, inout float4 l2_B, inout float4 l2_C)
33{
34 float3 outL2_C = l2_C.xyz;
35 DecodeSH_L2(l0, l2_R, l2_G, l2_B, outL2_C);
36 l2_C = float4(outL2_C.xyz, 0);
37}
38
39half3 DecodeSH(half l0, half3 l1)
40{
41 return (l1 - 0.5) * (2.0 * APV_L1_ENCODING_SCALE * l0);
42}
43
44void DecodeSH_L2(inout half3 l0, inout half4 l2_R, inout half4 l2_G, inout half4 l2_B, inout half3 l2_C)
45{
46 l2_R = (l2_R - 0.5) * (APV_L2_ENCODING_SCALE * l0.r);
47 l2_G = (l2_G - 0.5) * (APV_L2_ENCODING_SCALE * l0.g);
48 l2_B = (l2_B - 0.5) * (APV_L2_ENCODING_SCALE * l0.b);
49 l2_C = (l2_C - 0.5) * APV_L2_ENCODING_SCALE;
50
51 l2_C.rgb *= l0;
52
53 // Account for how L2 is encoded.
54 l0.r -= l2_R.z;
55 l0.g -= l2_G.z;
56 l0.b -= l2_B.z;
57 l2_R.z *= 3.0;
58 l2_G.z *= 3.0;
59 l2_B.z *= 3.0;
60}
61
62void DecodeSH_L2(inout half3 l0, inout half4 l2_R, inout half4 l2_G, inout half4 l2_B, inout half4 l2_C)
63{
64 half3 outL2_C = l2_C.xyz;
65 DecodeSH_L2(l0, l2_R, l2_G, l2_B, outL2_C);
66 l2_C = half4(outL2_C.xyz, 0);
67}
68
69float3 EncodeSH(float l0, float3 l1)
70{
71 return l0 == 0.0f ? 0.5f : l1 * rcp(l0) / (2.0f * APV_L1_ENCODING_SCALE) + 0.5f;
72}
73
74#if !HALF_IS_FLOAT
75half3 EncodeSH(half l0, half3 l1)
76{
77 return l0 == 0.0 ? 0.5 : l1 * rcp(l0) / (2.0 * APV_L1_ENCODING_SCALE) + 0.5;
78}
79#endif
80
81void EncodeSH_L2(inout float3 l0, inout float4 l2_R, inout float4 l2_G, inout float4 l2_B, inout float3 l2_C)
82{
83 // Account for how L2 is encoded.
84 l2_R.z /= 3.0f;
85 l2_G.z /= 3.0f;
86 l2_B.z /= 3.0f;
87 l0.r += l2_R.z;
88 l0.g += l2_G.z;
89 l0.b += l2_B.z;
90
91 float3 rcpl0 = rcp(l0);
92 rcpl0 = float3(l0.x == 0.0f ? 0.0f : rcpl0.x, l0.y == 0.0f ? 0.0f : rcpl0.y, l0.z == 0.0f ? 0.0f : rcpl0.z);
93
94 l2_R = 0.5f + l2_R * rcp(APV_L2_ENCODING_SCALE) * rcpl0.r;
95 l2_G = 0.5f + l2_G * rcp(APV_L2_ENCODING_SCALE) * rcpl0.g;
96 l2_B = 0.5f + l2_B * rcp(APV_L2_ENCODING_SCALE) * rcpl0.b;
97 l2_C = 0.5f + l2_C * rcp(APV_L2_ENCODING_SCALE) * rcpl0;
98}
99
100#endif // DECODE_SH