1 const float epsilon = 0.0001; 2 const vec3 lumConv = vec3(0.27, 0.67, 0.06); 3 4 float HDR_GetLum(in vec3 color){ 5 return dot(color, lumConv); 6 } 7 8 vec4 HDR_EncodeLum(in float lum){ 9 float Le = 2.0 * log2(lum + epsilon) + 127.0; 10 vec4 result = vec4(0.0); 11 result.a = fract(Le); 12 result.rgb = vec3((Le - (floor(result.a * 255.0)) / 255.0) / 255.0); 13 return result; 14 } 15 16 float HDR_DecodeLum(in vec4 logLum){ 17 float Le = logLum.r * 255.0 + logLum.a; 18 return exp2((Le - 127.0) / 2.0); 19 } 20 21 const mat3 rgbToXyz = mat3( 22 0.2209, 0.3390, 0.4184, 23 0.1138, 0.6780, 0.7319, 24 0.0102, 0.1130, 0.2969); 25 26 const mat3 xyzToRgb = mat3( 27 6.0013, -2.700, -1.7995, 28 -1.332, 3.1029, -5.7720, 29 .3007, -1.088, 5.6268); 30 31 vec4 HDR_LogLuvEncode(in vec3 rgb){ 32 vec4 result; 33 vec3 Xp_Y_XYZp = rgb * rgbToXyz; 34 Xp_Y_XYZp = max(Xp_Y_XYZp, vec3(1e-6, 1e-6, 1e-6)); 35 result.xy = Xp_Y_XYZp.xy / Xp_Y_XYZp.z; 36 float Le = 2.0 * log2(Xp_Y_XYZp.y) + 127.0; 37 result.w = fract(Le); 38 result.z = (Le - (floor(result.w * 255.0)) / 255.0) / 255.0; 39 return result; 40 } 41 42 vec3 HDR_LogLuvDecode(in vec4 logLuv){ 43 float Le = logLuv.z * 255.0 + logLuv.w; 44 vec3 Xp_Y_XYZp; 45 Xp_Y_XYZp.y = exp2((Le - 127.0) / 2.0); 46 Xp_Y_XYZp.z = Xp_Y_XYZp.y / logLuv.y; 47 Xp_Y_XYZp.x = logLuv.x * Xp_Y_XYZp.z; 48 vec3 rgb = Xp_Y_XYZp * xyzToRgb; 49 return max(rgb, 0.0); 50 } 51 52 vec3 HDR_ToneMap(in vec3 color, in float lumAvg, in float a, in float white){ 53 white *= white; 54 float lumHDR = HDR_GetLum(color); 55 float L = (a / lumAvg) * lumHDR; 56 float Ld = 1.0 + (L / white); 57 Ld = (Ld * L) / (1.0 + L); 58 return (color / lumHDR) * Ld; 59 //return color * vec3(Ld); 60 } 61 62 vec3 HDR_ToneMap2(in vec3 color, in float lumAvg, in float a, in float white){ 63 float scale = a / (lumAvg + 0.001); 64 return (vec3(scale) * color) / (color + vec3(1.0)); 65 }
