Use fixed array for lut generation

The old version that was generated at runtime didn’t actually contain 1.0 as a value, so getting full white output for int input was impossible.
2 years ago · 146743d2c7
parent 0499d6e166
commit 146743d2c7
4 changed files with 20 additions and 11 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@ -6,7 +6,6 @@ version = "0.3.0"
 dependencies = [
 "criterion",
 "failure",
- "lazy_static",
 "vapoursynth",
 "vapoursynth-sys",
 ]
--- a/Cargo.toml
+++ b/Cargo.toml
@ -6,7 +6,6 @@ edition = "2018"

 [dependencies]
 failure = "0.1.8"
-lazy_static = "1.4.0"
 vapoursynth = "0.3.0"
 vapoursynth-sys = "0.3.0"

--- a/src/lib.rs
+++ b/src/lib.rs
@ -1,8 +1,6 @@
 #[macro_use]
 extern crate failure;
 #[macro_use]
-extern crate lazy_static;
-#[macro_use]
 extern crate vapoursynth;

 pub mod mask;
--- a/src/mask.rs
+++ b/src/mask.rs
@ -12,9 +12,8 @@ pub struct Mask<'core> {
    pub luma_scaling: f32,
 }

-lazy_static! {
-    pub static ref FLOAT_RANGE: Vec<f32> = (0..256).map(|i| (i as f32) / 256.0).collect();
-}
+#[rustfmt::skip]
+static FLOAT_RANGE: [f32; 256] = [0.0, 0.003921569, 0.007843138, 0.011764706, 0.015686275, 0.019607844, 0.023529412, 0.02745098, 0.03137255, 0.03529412, 0.039215688, 0.043137256, 0.047058824, 0.050980393, 0.05490196, 0.05882353, 0.0627451, 0.06666667, 0.07058824, 0.07450981, 0.078431375, 0.08235294, 0.08627451, 0.09019608, 0.09411765, 0.09803922, 0.101960786, 0.105882354, 0.10980392, 0.11372549, 0.11764706, 0.12156863, 0.1254902, 0.12941177, 0.13333334, 0.13725491, 0.14117648, 0.14509805, 0.14901961, 0.15294118, 0.15686275, 0.16078432, 0.16470589, 0.16862746, 0.17254902, 0.1764706, 0.18039216, 0.18431373, 0.1882353, 0.19215687, 0.19607843, 0.2, 0.20392157, 0.20784314, 0.21176471, 0.21568628, 0.21960784, 0.22352941, 0.22745098, 0.23137255, 0.23529412, 0.23921569, 0.24313726, 0.24705882, 0.2509804, 0.25490198, 0.25882354, 0.2627451, 0.26666668, 0.27058825, 0.27450982, 0.2784314, 0.28235295, 0.28627452, 0.2901961, 0.29411766, 0.29803923, 0.3019608, 0.30588236, 0.30980393, 0.3137255, 0.31764707, 0.32156864, 0.3254902, 0.32941177, 0.33333334, 0.3372549, 0.34117648, 0.34509805, 0.34901962, 0.3529412, 0.35686275, 0.36078432, 0.3647059, 0.36862746, 0.37254903, 0.3764706, 0.38039216, 0.38431373, 0.3882353, 0.39215687, 0.39607844, 0.4, 0.40392157, 0.40784314, 0.4117647, 0.41568628, 0.41960785, 0.42352942, 0.42745098, 0.43137255, 0.43529412, 0.4392157, 0.44313726, 0.44705883, 0.4509804, 0.45490196, 0.45882353, 0.4627451, 0.46666667, 0.47058824, 0.4745098, 0.47843137, 0.48235294, 0.4862745, 0.49019608, 0.49411765, 0.49803922, 0.5019608, 0.5058824, 0.50980395, 0.5137255, 0.5176471, 0.52156866, 0.5254902, 0.5294118, 0.53333336, 0.5372549, 0.5411765, 0.54509807, 0.54901963, 0.5529412, 0.5568628, 0.56078434, 0.5647059, 0.5686275, 0.57254905, 0.5764706, 0.5803922, 0.58431375, 0.5882353, 0.5921569, 0.59607846, 0.6, 0.6039216, 0.60784316, 0.6117647, 0.6156863, 0.61960787, 0.62352943, 0.627451, 0.6313726, 0.63529414, 0.6392157, 0.6431373, 0.64705884, 0.6509804, 0.654902, 0.65882355, 0.6627451, 0.6666667, 0.67058825, 0.6745098, 0.6784314, 0.68235296, 0.6862745, 0.6901961, 0.69411767, 0.69803923, 0.7019608, 0.7058824, 0.70980394, 0.7137255, 0.7176471, 0.72156864, 0.7254902, 0.7294118, 0.73333335, 0.7372549, 0.7411765, 0.74509805, 0.7490196, 0.7529412, 0.75686276, 0.7607843, 0.7647059, 0.76862746, 0.77254903, 0.7764706, 0.78039217, 0.78431374, 0.7882353, 0.7921569, 0.79607844, 0.8, 0.8039216, 0.80784315, 0.8117647, 0.8156863, 0.81960785, 0.8235294, 0.827451, 0.83137256, 0.8352941, 0.8392157, 0.84313726, 0.84705883, 0.8509804, 0.85490197, 0.85882354, 0.8627451, 0.8666667, 0.87058824, 0.8745098, 0.8784314, 0.88235295, 0.8862745, 0.8901961, 0.89411765, 0.8980392, 0.9019608, 0.90588236, 0.9098039, 0.9137255, 0.91764706, 0.92156863, 0.9254902, 0.92941177, 0.93333334, 0.9372549, 0.9411765, 0.94509804, 0.9490196, 0.9529412, 0.95686275, 0.9607843, 0.9647059, 0.96862745, 0.972549, 0.9764706, 0.98039216, 0.9843137, 0.9882353, 0.99215686, 0.99607843, 1.0];

 #[inline]
 pub fn get_mask_value(x: f32, luma_scaling: f32) -> f32 {
@ -232,9 +231,9 @@ mod tests {

    // Just in case this isn’t the last time I rewrite the lut builder:
    #[rustfmt::skip]
-    static EXPECTED_MASK_02: [f32; 256] = [1.0, 0.99829847, 0.99670357, 0.9952108, 0.99381596, 0.99251467, 0.9913026, 0.99017555, 0.98912925, 0.9881595, 0.9872621, 0.98643315, 0.98566836, 0.98496383, 0.98431563, 0.98371994, 0.9831729, 0.9826707, 0.98220986, 0.9817866, 0.9813975, 0.9810391, 0.980708, 0.980401, 0.9801147, 0.9798461, 0.97959214, 0.97934985, 0.9791162, 0.9788885, 0.9786639, 0.97843987, 0.9782137, 0.97798294, 0.97774506, 0.9774978, 0.9772388, 0.97696584, 0.9766768, 0.97636956, 0.9760422, 0.97569263, 0.97531915, 0.97491974, 0.97449285, 0.9740367, 0.9735496, 0.9730301, 0.9724766, 0.9718877, 0.97126204, 0.9705982, 0.96989495, 0.96915096, 0.9683652, 0.9675364, 0.9666635, 0.9657455, 0.96478134, 0.9637701, 0.96271086, 0.96160275, 0.9604449, 0.9592366, 0.95797706, 0.9566655, 0.9553014, 0.95388395, 0.95241266, 0.95088685, 0.949306, 0.9476697, 0.9459774, 0.9442286, 0.9424229, 0.94056, 0.93863946, 0.93666095, 0.93462414, 0.9325288, 0.93037456, 0.9281613, 0.9258888, 0.9235568, 0.92116517, 0.9187138, 0.9162025, 0.9136312, 0.91099983, 0.9083083, 0.9055567, 0.90274477, 0.8998728, 0.8969405, 0.8939482, 0.8908958, 0.88778335, 0.88461095, 0.8813788, 0.87808704, 0.87473565, 0.871325, 0.8678552, 0.8643263, 0.8607387, 0.8570925, 0.85338813, 0.8496256, 0.84580535, 0.8419277, 0.83799297, 0.83400136, 0.8299533, 0.8258492, 0.8216893, 0.8174741, 0.81320417, 0.80887955, 0.8045011, 0.80006903, 0.79558396, 0.7910463, 0.78645676, 0.7818155, 0.7771236, 0.7723811, 0.76758915, 0.7627478, 0.75785816, 0.75292087, 0.7479362, 0.74290544, 0.7378288, 0.7327075, 0.72754174, 0.72233313, 0.71708167, 0.7117891, 0.7064553, 0.7010822, 0.6956699, 0.69022, 0.6847333, 0.6792108, 0.67365366, 0.668063, 0.6624399, 0.65678567, 0.65110123, 0.6453887, 0.63964826, 0.63388246, 0.6280915, 0.622278, 0.61644244, 0.6105874, 0.6047135, 0.5988235, 0.5929182, 0.58700025, 0.58107054, 0.57513213, 0.5691858, 0.56323487, 0.55728036, 0.5513258, 0.54537195, 0.5394228, 0.5334794, 0.52754575, 0.52162296, 0.5157146, 0.50982434, 0.5039534, 0.49810678, 0.4922856, 0.48649472, 0.48073623, 0.47501534, 0.46933344, 0.46369645, 0.4581058, 0.45256722, 0.44708318, 0.4416599, 0.4362986, 0.4310061, 0.42578426, 0.42064053, 0.41557512, 0.41059688, 0.4057069, 0.4009107, 0.39621186, 0.39161587, 0.3871265, 0.38274762, 0.37848303, 0.37433672, 0.37031212, 0.36641234, 0.36264044, 0.35899892, 0.35549006, 0.35211465, 0.34887564, 0.3457732, 0.34280726, 0.33997762, 0.33728316, 0.3347223, 0.33229122, 0.32998928, 0.3278117, 0.32575342, 0.32380822, 0.32197225, 0.32023716, 0.31859392, 0.31703717, 0.3155556, 0.31413817, 0.31277677, 0.31145856, 0.3101692, 0.3088991, 0.30763134, 0.30635372, 0.30504793, 0.30370083, 0.30229148, 0.30080518, 0.29921892, 0.29751524, 0.29566884, 0.29365554, 0.29145348, 0.28903463, 0.28636503, 0.28341296, 0.2801431, 0.27650893, 0.27246484, 0.2679581, 0.26291874, 0.25727344, 0.25092778, 0.24376981, 0.23564698, 0.22636926, 0.2156733, 0.20318091, 0.18831593, 0.17008513, 0.14654778, 0.11254175];
+    static EXPECTED_MASK_02: [f32; 256] = [1.0, 0.998292, 0.99669147, 0.99519384, 0.9937948, 0.99249005, 0.99127513, 0.99014574, 0.98909765, 0.98812664, 0.9872284, 0.9863988, 0.98563385, 0.9849295, 0.9842816, 0.98368645, 0.9831401, 0.9826388, 0.9821788, 0.9817565, 0.98136836, 0.98101085, 0.98068064, 0.98037434, 0.9800887, 0.97982067, 0.979567, 0.97932476, 0.9790909, 0.9788629, 0.97863764, 0.97841257, 0.97818506, 0.9779526, 0.9777127, 0.977463, 0.97720116, 0.97692496, 0.97663224, 0.97632086, 0.97598886, 0.9756343, 0.9752552, 0.97484976, 0.97441626, 0.973953, 0.9734583, 0.97293067, 0.9723685, 0.97177035, 0.9711349, 0.9704607, 0.96974653, 0.96899116, 0.9681933, 0.9673519, 0.9664658, 0.965534, 0.9645555, 0.9635293, 0.96245456, 0.9613303, 0.96015584, 0.9589302, 0.9576528, 0.9563228, 0.95493966, 0.9535026, 0.9520111, 0.95046455, 0.9488624, 0.9472042, 0.94548935, 0.94371754, 0.9418882, 0.94000113, 0.9380558, 0.936052, 0.93398947, 0.9318677, 0.9296866, 0.9274459, 0.9251454, 0.92278486, 0.92036426, 0.91788334, 0.91534203, 0.91274023, 0.9100778, 0.9073548, 0.9045712, 0.9017268, 0.89882183, 0.8958562, 0.89282995, 0.8897432, 0.886596, 0.8833886, 0.88012075, 0.876793, 0.8734053, 0.8699578, 0.8664507, 0.8628842, 0.85925865, 0.8555742, 0.85183114, 0.8480296, 0.84417003, 0.8402527, 0.836278, 0.8322462, 0.82815754, 0.8240127, 0.81981164, 0.8155552, 0.8112436, 0.8068773, 0.8024568, 0.79798263, 0.7934552, 0.788875, 0.78424263, 0.77955866, 0.77482367, 0.7700382, 0.76520306, 0.7603186, 0.7553858, 0.750405, 0.74537706, 0.7403031, 0.73518324, 0.73001873, 0.72480994, 0.7195582, 0.714264, 0.7089286, 0.70355237, 0.6981368, 0.6926824, 0.6871906, 0.68166244, 0.6760984, 0.67050064, 0.66486925, 0.65920633, 0.6535124, 0.64778924, 0.6420377, 0.63625985, 0.6304561, 0.62462854, 0.6187791, 0.61290854, 0.60701925, 0.60111195, 0.5951895, 0.58925253, 0.5833042, 0.57734525, 0.5713786, 0.5654054, 0.55942863, 0.5534506, 0.5474728, 0.54149866, 0.5355294, 0.5295689, 0.52361876, 0.51768285, 0.5117627, 0.50586176, 0.49998415, 0.49413142, 0.48830834, 0.48251665, 0.47676167, 0.4710447, 0.4653721, 0.45974478, 0.45416957, 0.44864753, 0.44318435, 0.43778518, 0.4324514, 0.4271907, 0.42200384, 0.4168986, 0.41187632, 0.40694392, 0.4021045, 0.39736322, 0.39272374, 0.38819104, 0.38376838, 0.37945992, 0.3752701, 0.37120032, 0.36725762, 0.36344275, 0.35975853, 0.3562081, 0.35279226, 0.34951332, 0.3463715, 0.3433669, 0.34050032, 0.33777085, 0.3351737, 0.3327109, 0.33037695, 0.32816976, 0.32608336, 0.32411364, 0.32225302, 0.32049632, 0.31883442, 0.31725863, 0.31575835, 0.31432915, 0.31295443, 0.31162542, 0.31032994, 0.30905154, 0.30778122, 0.30649903, 0.30519295, 0.3038461, 0.30243647, 0.3009518, 0.29937094, 0.29767165, 0.29583326, 0.2938297, 0.29163584, 0.28922495, 0.28656486, 0.28362364, 0.28036165, 0.27673277, 0.2726987, 0.26819843, 0.2631695, 0.25753176, 0.25119466, 0.24403761, 0.23592123, 0.2266435, 0.2159501, 0.20344463, 0.18856688, 0.17031908, 0.1467575, 0.11270576, 0.00323677];
    #[rustfmt::skip]
-    static EXPECTED_MASK_08: [f32; 256] = [1.0, 0.97312033, 0.94854075, 0.92606485, 0.9055145, 0.88672876, 0.86956084, 0.8538767, 0.839554, 0.82648087, 0.8145538, 0.8036785, 0.793767, 0.7847378, 0.7765157, 0.7690307, 0.76221645, 0.7560116, 0.7503583, 0.7452015, 0.7404903, 0.73617536, 0.73221, 0.72855055, 0.7251544, 0.72198164, 0.7189933, 0.71615267, 0.7134242, 0.7107743, 0.70816976, 0.7055801, 0.7029752, 0.7003262, 0.69760597, 0.6947885, 0.69184875, 0.68876356, 0.6855104, 0.68206835, 0.6784181, 0.6745413, 0.6704213, 0.66604257, 0.6613911, 0.65645486, 0.65122217, 0.6456841, 0.6398328, 0.6336617, 0.6271661, 0.6203427, 0.6131898, 0.6057077, 0.5978976, 0.5897622, 0.5813064, 0.57253623, 0.56345886, 0.55408335, 0.54441965, 0.5344795, 0.52427536, 0.5138211, 0.5031317, 0.4922232, 0.48111236, 0.46981704, 0.45835546, 0.4467467, 0.4350106, 0.42316702, 0.4112368, 0.39924026, 0.38719845, 0.37513202, 0.36306223, 0.35100925, 0.33899403, 0.32703626, 0.31515577, 0.30337203, 0.29170325, 0.28016755, 0.268782, 0.25756323, 0.2465265, 0.23568656, 0.22505718, 0.21465099, 0.20447965, 0.19455387, 0.18488336, 0.17547633, 0.1663404, 0.15748179, 0.14890584, 0.14061676, 0.13261788, 0.1249111, 0.11749773, 0.11037807, 0.10355142, 0.09701606, 0.09076972, 0.08480923, 0.07913076, 0.07372954, 0.06860047, 0.06373775, 0.05913521, 0.05478584, 0.05068255, 0.046817873, 0.043183923, 0.039772622, 0.03657578, 0.03358472, 0.030791199, 0.0281864, 0.025761817, 0.02350881, 0.021418924, 0.019483581, 0.017694633, 0.01604377, 0.014523158, 0.013124882, 0.011841504, 0.010665701, 0.009590316, 0.008608681, 0.0077141733, 0.0069006504, 0.0061620683, 0.005492886, 0.0048876274, 0.004341311, 0.0038490645, 0.003406462, 0.0030092031, 0.002653386, 0.0023353002, 0.0020515076, 0.0017988166, 0.0015742666, 0.0013751301, 0.0011988885, 0.0010432207, 0.0009060293, 0.0007853431, 0.0006794224, 0.000586633, 0.0005055344, 0.00043479103, 0.00037322083, 0.00031973835, 0.000273389, 0.00023330118, 0.00019870678, 0.00016891248, 0.00014331177, 0.00012135691, 0.00010257295, 0.00008653258, 0.00007286733, 0.000061247025, 0.000051388823, 0.00004304101, 0.000035988374, 0.0000300405, 0.000025035166, 0.000020831892, 0.000017307977, 0.000014360154, 0.000011898005, 0.000009845784, 0.000008137849, 0.0000067192714, 0.0000055424794, 0.0000045681495, 0.0000037622924, 0.000003096917, 0.0000025480817, 0.000002096078, 0.0000017240154, 0.0000014181916, 0.0000011669001, 0.0000009606775, 0.0000007913941, 0.0000006526048, 0.00000053876414, 0.00000044541238, 0.0000003688414, 0.0000003060302, 0.0000002544758, 0.0000002121291, 0.00000017731381, 0.0000001486616, 0.00000012505093, 0.00000010556544, 0.00000008945813, 0.000000076118496, 0.00000006504881, 0.000000055840008, 0.000000048164882, 0.000000041750454, 0.000000036374765, 0.000000031857045, 0.00000002804884, 0.000000024828736, 0.0000000220954, 0.000000019769583, 0.000000017782428, 0.000000016077687, 0.000000014608518, 0.000000013338133, 0.000000012233408, 0.000000011266786, 0.00000001041748, 0.000000009665278, 0.000000008993553, 0.000000008389807, 0.000000007841596, 0.000000007338018, 0.0000000068717365, 0.0000000064341195, 0.000000006019636, 0.0000000056219833, 0.000000005237641, 0.0000000048619975, 0.0000000044932946, 0.000000004128811, 0.0000000037683177, 0.0000000034110592, 0.0000000030578147, 0.000000002710866, 0.0000000023724578, 0.0000000020451252, 0.0000000017326667, 0.0000000014390599, 0.0000000011677407, 0.00000000092250246, 0.00000000070643236, 0.00000000052136806, 0.00000000036839945, 0.00000000024704733, 0.00000000015548153, 0.0000000000904045, 0.000000000047542185, 0.000000000021915018, 0.000000000008435807, 0.0000000000025014576, 0.0000000000004905257, 0.00000000000004525513, 0.0000000000000006622447];
+    static EXPECTED_MASK_08: [f32; 256] = [1.0, 0.97301966, 0.9483565, 0.92581207, 0.9052065, 0.8863773, 0.86917543, 0.8534658, 0.8391256, 0.82604086, 0.81410825, 0.80323166, 0.79332286, 0.78429985, 0.7760863, 0.7686117, 0.7618097, 0.7556182, 0.7499784, 0.7448358, 0.74013805, 0.735836, 0.7318828, 0.7282341, 0.724847, 0.7216812, 0.7186976, 0.7158591, 0.7131299, 0.71047634, 0.70786506, 0.705265, 0.7026458, 0.6999789, 0.69723636, 0.69439274, 0.6914226, 0.68830246, 0.6850099, 0.6815241, 0.6778255, 0.6738958, 0.66971844, 0.6652776, 0.6605602, 0.65555304, 0.650246, 0.6446294, 0.6386957, 0.6324387, 0.6258541, 0.6189384, 0.6116908, 0.60411143, 0.59620154, 0.5879653, 0.5794071, 0.5705335, 0.5613522, 0.55187273, 0.5421053, 0.532062, 0.52175605, 0.5112014, 0.5004138, 0.4894094, 0.47820586, 0.46682078, 0.45527333, 0.44358265, 0.43176922, 0.41985318, 0.4078552, 0.39579678, 0.38369834, 0.37158158, 0.35946706, 0.3473761, 0.33532932, 0.3233465, 0.31144762, 0.29965213, 0.28797832, 0.27644426, 0.2650672, 0.2538632, 0.24284792, 0.23203576, 0.22144021, 0.21107364, 0.20094803, 0.19107313, 0.18145862, 0.17211263, 0.1630422, 0.15425344, 0.14575136, 0.13753979, 0.12962131, 0.121998124, 0.11467082, 0.107639365, 0.100902446, 0.09445834, 0.08830449, 0.08243708, 0.076852135, 0.07154449, 0.06650879, 0.061738882, 0.05722833, 0.052969858, 0.048956152, 0.045179587, 0.041631833, 0.03830488, 0.035190117, 0.032279003, 0.029562855, 0.027033038, 0.02468074, 0.022497335, 0.020474205, 0.018602902, 0.016875094, 0.015282571, 0.013817431, 0.012471816, 0.0112383105, 0.0101095475, 0.009078545, 0.008138663, 0.0072833193, 0.006506449, 0.0058021126, 0.0051648114, 0.004589231, 0.004070427, 0.0036036533, 0.0031845558, 0.0028089648, 0.0024730647, 0.0021732512, 0.0019061574, 0.0016687337, 0.0014580758, 0.0012715748, 0.001106781, 0.0009614784, 0.0008336202, 0.00072136015, 0.00062298466, 0.00053696934, 0.00046192406, 0.00039657977, 0.00033981237, 0.00029059322, 0.00024801854, 0.00021126306, 0.00017960659, 0.00015239452, 0.00012905747, 0.0001090837, 0.000092026974, 0.000077492776, 0.00006513292, 0.000054645934, 0.00004576495, 0.00003826129, 0.000031933254, 0.000026608495, 0.000022135933, 0.000018386958, 0.000015251044, 0.000012632214, 0.000010449756, 0.000008633694, 0.000007125597, 0.000005874811, 0.0000048395545, 0.000003983536, 0.0000032770909, 0.0000026945397, 0.0000022148818, 0.0000018204425, 0.0000014962245, 0.000001230123, 0.000001011725, 0.00000083269754, 0.00000068591316, 0.0000005656565, 0.00000046711415, 0.0000003863694, 0.00000032018005, 0.00000026590607, 0.00000022136388, 0.00000018477976, 0.0000001547046, 0.00000012993713, 0.000000109530006, 0.000000092677915, 0.00000007873675, 0.00000006718318, 0.00000005758441, 0.00000004959293, 0.000000042921464, 0.000000037336587, 0.000000032649805, 0.000000028704813, 0.0000000253699, 0.000000022546159, 0.00000002014448, 0.000000018095754, 0.000000016340236, 0.000000014830539, 0.000000013525465, 0.000000012392772, 0.00000001140364, 0.000000010534523, 0.0000000097651105, 0.000000009081434, 0.000000008466379, 0.000000007909084, 0.000000007399097, 0.000000006926191, 0.000000006484458, 0.0000000060654903, 0.000000005664892, 0.000000005277865, 0.00000000489944, 0.0000000045284674, 0.0000000041625015, 0.0000000038001398, 0.0000000034415308, 0.0000000030869618, 0.000000002738131, 0.000000002397576, 0.0000000020680777, 0.0000000017533902, 0.0000000014571282, 0.0000000011829588, 0.0000000009352538, 0.00000000071663736, 0.0000000005293817, 0.00000000037436287, 0.00000000025128466, 0.00000000015823709, 0.000000000092102735, 0.000000000048472164, 0.000000000022369412, 0.000000000008612706, 0.000000000002555328, 0.00000000000050143293, 0.00000000000004630252, 0.0000000000000006778562, 0.000000000000000000000000000000000000000145141];

    #[test]
    fn test_mask_values() {
@ -242,13 +241,27 @@ mod tests {
            .iter()
            .zip(EXPECTED_MASK_02.iter())
            .for_each(|(&x, &exp)| {
-                assert!((get_mask_value(x, calc_luma_scaling(0.2, 10.0)) - exp).abs() < 0.0001);
+                let value = get_mask_value(x, calc_luma_scaling(0.2, 10.0));
+                assert!(
+                    (value - exp).abs() < 0.0001,
+                    "luma scaling 0.2: Mask was wrong at position {}, expected {}, got {}",
+                    x,
+                    exp,
+                    value
+                );
            });
        FLOAT_RANGE
            .iter()
            .zip(EXPECTED_MASK_08.iter())
            .for_each(|(&x, &exp)| {
-                assert!((get_mask_value(x, calc_luma_scaling(0.8, 10.0)) - exp).abs() < 0.0001);
+                let value = get_mask_value(x, calc_luma_scaling(0.8, 10.0));
+                assert!(
+                    (value - exp).abs() < 0.0001,
+                    "luma scaling 0.8: Mask was wrong at position {}, expected {}, got {}",
+                    x,
+                    exp,
+                    value
+                );
            });
    }