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skia / skia / chrome/m54 / . / src / core / SkColorSpaceXform.cpp
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/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkColorPriv.h"
#include "SkColorSpace_Base.h"
#include "SkColorSpacePriv.h"
#include "SkColorSpaceXform.h"
#include "SkHalf.h"
#include "SkOpts.h"
#include "SkSRGB.h"
static constexpr float sk_linear_from_2dot2[256] = {
0.000000000000000000f, 0.000005077051900662f, 0.000023328004666099f, 0.000056921765712193f,
0.000107187362341244f, 0.000175123977503027f, 0.000261543754548491f, 0.000367136269815943f,
0.000492503787191433f, 0.000638182842167022f, 0.000804658499513058f, 0.000992374304074325f,
0.001201739522438400f, 0.001433134589671860f, 0.001686915316789280f, 0.001963416213396470f,
0.002262953160706430f, 0.002585825596234170f, 0.002932318323938360f, 0.003302703032003640f,
0.003697239578900130f, 0.004116177093282750f, 0.004559754922526020f, 0.005028203456855540f,
0.005521744850239660f, 0.006040593654849810f, 0.006584957382581690f, 0.007155037004573030f,
0.007751027397660610f, 0.008373117745148580f, 0.009021491898012130f, 0.009696328701658230f,
0.010397802292555300f, 0.011126082368383200f, 0.011881334434813700f, 0.012663720031582100f,
0.013473396940142600f, 0.014310519374884100f, 0.015175238159625200f, 0.016067700890886900f,
0.016988052089250000f, 0.017936433339950200f, 0.018912983423721500f, 0.019917838438785700f,
0.020951131914781100f, 0.022012994919336500f, 0.023103556157921400f, 0.024222942067534200f,
0.025371276904734600f, 0.026548682828472900f, 0.027755279978126000f, 0.028991186547107800f,
0.030256518852388700f, 0.031551391400226400f, 0.032875916948383800f, 0.034230206565082000f,
0.035614369684918800f, 0.037028514161960200f, 0.038472746320194600f, 0.039947171001525600f,
0.041451891611462500f, 0.042987010162657100f, 0.044552627316421400f, 0.046148842422351000f,
0.047775753556170600f, 0.049433457555908000f, 0.051122050056493400f, 0.052841625522879000f,
0.054592277281760300f, 0.056374097551979800f, 0.058187177473685400f, 0.060031607136313200f,
0.061907475605455800f, 0.063814870948677200f, 0.065753880260330100f, 0.067724589685424300f,
0.069727084442598800f, 0.071761448846239100f, 0.073827766327784600f, 0.075926119456264800f,
0.078056589958101900f, 0.080219258736215100f, 0.082414205888459200f, 0.084641510725429500f,
0.086901251787660300f, 0.089193506862247800f, 0.091518352998919500f, 0.093875866525577800f,
0.096266123063339700f, 0.098689197541094500f, 0.101145164209600000f, 0.103634096655137000f,
0.106156067812744000f, 0.108711149979039000f, 0.111299414824660000f, 0.113920933406333000f,
0.116575776178572000f, 0.119264013005047000f, 0.121985713169619000f, 0.124740945387051000f,
0.127529777813422000f, 0.130352278056244000f, 0.133208513184300000f, 0.136098549737202000f,
0.139022453734703000f, 0.141980290685736000f, 0.144972125597231000f, 0.147998022982685000f,
0.151058046870511000f, 0.154152260812165000f, 0.157280727890073000f, 0.160443510725344000f,
0.163640671485290000f, 0.166872271890766000f, 0.170138373223312000f, 0.173439036332135000f,
0.176774321640903000f, 0.180144289154390000f, 0.183548998464951000f, 0.186988508758844000f,
0.190462878822409000f, 0.193972167048093000f, 0.197516431440340000f, 0.201095729621346000f,
0.204710118836677000f, 0.208359655960767000f, 0.212044397502288000f, 0.215764399609395000f,
0.219519718074868000f, 0.223310408341127000f, 0.227136525505149000f, 0.230998124323267000f,
0.234895259215880000f, 0.238827984272048000f, 0.242796353254002000f, 0.246800419601550000f,
0.250840236436400000f, 0.254915856566385000f, 0.259027332489606000f, 0.263174716398492000f,
0.267358060183772000f, 0.271577415438375000f, 0.275832833461245000f, 0.280124365261085000f,
0.284452061560024000f, 0.288815972797219000f, 0.293216149132375000f, 0.297652640449211000f,
0.302125496358853000f, 0.306634766203158000f, 0.311180499057984000f, 0.315762743736397000f,
0.320381548791810000f, 0.325036962521076000f, 0.329729032967515000f, 0.334457807923889000f,
0.339223334935327000f, 0.344025661302187000f, 0.348864834082879000f, 0.353740900096629000f,
0.358653905926199000f, 0.363603897920553000f, 0.368590922197487000f, 0.373615024646202000f,
0.378676250929840000f, 0.383774646487975000f, 0.388910256539059000f, 0.394083126082829000f,
0.399293299902674000f, 0.404540822567962000f, 0.409825738436323000f, 0.415148091655907000f,
0.420507926167587000f, 0.425905285707146000f, 0.431340213807410000f, 0.436812753800359000f,
0.442322948819202000f, 0.447870841800410000f, 0.453456475485731000f, 0.459079892424160000f,
0.464741134973889000f, 0.470440245304218000f, 0.476177265397440000f, 0.481952237050698000f,
0.487765201877811000f, 0.493616201311074000f, 0.499505276603030000f, 0.505432468828216000f,
0.511397818884880000f, 0.517401367496673000f, 0.523443155214325000f, 0.529523222417277000f,
0.535641609315311000f, 0.541798355950137000f, 0.547993502196972000f, 0.554227087766085000f,
0.560499152204328000f, 0.566809734896638000f, 0.573158875067523000f, 0.579546611782525000f,
0.585972983949661000f, 0.592438030320847000f, 0.598941789493296000f, 0.605484299910907000f,
0.612065599865624000f, 0.618685727498780000f, 0.625344720802427000f, 0.632042617620641000f,
0.638779455650817000f, 0.645555272444935000f, 0.652370105410821000f, 0.659223991813387000f,
0.666116968775851000f, 0.673049073280942000f, 0.680020342172095000f, 0.687030812154625000f,
0.694080519796882000f, 0.701169501531402000f, 0.708297793656032000f, 0.715465432335048000f,
0.722672453600255000f, 0.729918893352071000f, 0.737204787360605000f, 0.744530171266715000f,
0.751895080583051000f, 0.759299550695091000f, 0.766743616862161000f, 0.774227314218442000f,
0.781750677773962000f, 0.789313742415586000f, 0.796916542907978000f, 0.804559113894567000f,
0.812241489898490000f, 0.819963705323528000f, 0.827725794455034000f, 0.835527791460841000f,
0.843369730392169000f, 0.851251645184515000f, 0.859173569658532000f, 0.867135537520905000f,
0.875137582365205000f, 0.883179737672745000f, 0.891262036813419000f, 0.899384513046529000f,
0.907547199521614000f, 0.915750129279253000f, 0.923993335251873000f, 0.932276850264543000f,
0.940600707035753000f, 0.948964938178195000f, 0.957369576199527000f, 0.965814653503130000f,
0.974300202388861000f, 0.982826255053791000f, 0.991392843592940000f, 1.000000000000000000f,
};
///////////////////////////////////////////////////////////////////////////////////////////////////
static constexpr uint8_t linear_to_srgb[1024] = {
0, 3, 6, 10, 13, 15, 18, 20, 22, 23, 25, 27, 28, 30, 31, 32, 34, 35,
36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 49, 50, 51, 52,
53, 53, 54, 55, 56, 56, 57, 58, 58, 59, 60, 61, 61, 62, 62, 63, 64, 64,
65, 66, 66, 67, 67, 68, 68, 69, 70, 70, 71, 71, 72, 72, 73, 73, 74, 74,
75, 76, 76, 77, 77, 78, 78, 79, 79, 79, 80, 80, 81, 81, 82, 82, 83, 83,
84, 84, 85, 85, 85, 86, 86, 87, 87, 88, 88, 88, 89, 89, 90, 90, 91, 91,
91, 92, 92, 93, 93, 93, 94, 94, 95, 95, 95, 96, 96, 97, 97, 97, 98, 98,
98, 99, 99, 99, 100, 100, 101, 101, 101, 102, 102, 102, 103, 103, 103, 104, 104, 104,
105, 105, 106, 106, 106, 107, 107, 107, 108, 108, 108, 109, 109, 109, 110, 110, 110, 110,
111, 111, 111, 112, 112, 112, 113, 113, 113, 114, 114, 114, 115, 115, 115, 115, 116, 116,
116, 117, 117, 117, 118, 118, 118, 118, 119, 119, 119, 120, 120, 120, 121, 121, 121, 121,
122, 122, 122, 123, 123, 123, 123, 124, 124, 124, 125, 125, 125, 125, 126, 126, 126, 126,
127, 127, 127, 128, 128, 128, 128, 129, 129, 129, 129, 130, 130, 130, 130, 131, 131, 131,
131, 132, 132, 132, 133, 133, 133, 133, 134, 134, 134, 134, 135, 135, 135, 135, 136, 136,
136, 136, 137, 137, 137, 137, 138, 138, 138, 138, 138, 139, 139, 139, 139, 140, 140, 140,
140, 141, 141, 141, 141, 142, 142, 142, 142, 143, 143, 143, 143, 143, 144, 144, 144, 144,
145, 145, 145, 145, 146, 146, 146, 146, 146, 147, 147, 147, 147, 148, 148, 148, 148, 148,
149, 149, 149, 149, 150, 150, 150, 150, 150, 151, 151, 151, 151, 152, 152, 152, 152, 152,
153, 153, 153, 153, 153, 154, 154, 154, 154, 155, 155, 155, 155, 155, 156, 156, 156, 156,
156, 157, 157, 157, 157, 157, 158, 158, 158, 158, 158, 159, 159, 159, 159, 159, 160, 160,
160, 160, 160, 161, 161, 161, 161, 161, 162, 162, 162, 162, 162, 163, 163, 163, 163, 163,
164, 164, 164, 164, 164, 165, 165, 165, 165, 165, 166, 166, 166, 166, 166, 167, 167, 167,
167, 167, 168, 168, 168, 168, 168, 168, 169, 169, 169, 169, 169, 170, 170, 170, 170, 170,
171, 171, 171, 171, 171, 171, 172, 172, 172, 172, 172, 173, 173, 173, 173, 173, 173, 174,
174, 174, 174, 174, 175, 175, 175, 175, 175, 175, 176, 176, 176, 176, 176, 177, 177, 177,
177, 177, 177, 178, 178, 178, 178, 178, 178, 179, 179, 179, 179, 179, 179, 180, 180, 180,
180, 180, 181, 181, 181, 181, 181, 181, 182, 182, 182, 182, 182, 182, 183, 183, 183, 183,
183, 183, 184, 184, 184, 184, 184, 184, 185, 185, 185, 185, 185, 185, 186, 186, 186, 186,
186, 186, 187, 187, 187, 187, 187, 187, 188, 188, 188, 188, 188, 188, 189, 189, 189, 189,
189, 189, 190, 190, 190, 190, 190, 190, 191, 191, 191, 191, 191, 191, 191, 192, 192, 192,
192, 192, 192, 193, 193, 193, 193, 193, 193, 194, 194, 194, 194, 194, 194, 194, 195, 195,
195, 195, 195, 195, 196, 196, 196, 196, 196, 196, 197, 197, 197, 197, 197, 197, 197, 198,
198, 198, 198, 198, 198, 199, 199, 199, 199, 199, 199, 199, 200, 200, 200, 200, 200, 200,
200, 201, 201, 201, 201, 201, 201, 202, 202, 202, 202, 202, 202, 202, 203, 203, 203, 203,
203, 203, 203, 204, 204, 204, 204, 204, 204, 204, 205, 205, 205, 205, 205, 205, 206, 206,
206, 206, 206, 206, 206, 207, 207, 207, 207, 207, 207, 207, 208, 208, 208, 208, 208, 208,
208, 209, 209, 209, 209, 209, 209, 209, 210, 210, 210, 210, 210, 210, 210, 211, 211, 211,
211, 211, 211, 211, 212, 212, 212, 212, 212, 212, 212, 212, 213, 213, 213, 213, 213, 213,
213, 214, 214, 214, 214, 214, 214, 214, 215, 215, 215, 215, 215, 215, 215, 216, 216, 216,
216, 216, 216, 216, 216, 217, 217, 217, 217, 217, 217, 217, 218, 218, 218, 218, 218, 218,
218, 219, 219, 219, 219, 219, 219, 219, 219, 220, 220, 220, 220, 220, 220, 220, 221, 221,
221, 221, 221, 221, 221, 221, 222, 222, 222, 222, 222, 222, 222, 222, 223, 223, 223, 223,
223, 223, 223, 224, 224, 224, 224, 224, 224, 224, 224, 225, 225, 225, 225, 225, 225, 225,
225, 226, 226, 226, 226, 226, 226, 226, 227, 227, 227, 227, 227, 227, 227, 227, 228, 228,
228, 228, 228, 228, 228, 228, 229, 229, 229, 229, 229, 229, 229, 229, 230, 230, 230, 230,
230, 230, 230, 230, 231, 231, 231, 231, 231, 231, 231, 231, 232, 232, 232, 232, 232, 232,
232, 232, 233, 233, 233, 233, 233, 233, 233, 233, 234, 234, 234, 234, 234, 234, 234, 234,
235, 235, 235, 235, 235, 235, 235, 235, 236, 236, 236, 236, 236, 236, 236, 236, 236, 237,
237, 237, 237, 237, 237, 237, 237, 238, 238, 238, 238, 238, 238, 238, 238, 239, 239, 239,
239, 239, 239, 239, 239, 239, 240, 240, 240, 240, 240, 240, 240, 240, 241, 241, 241, 241,
241, 241, 241, 241, 241, 242, 242, 242, 242, 242, 242, 242, 242, 243, 243, 243, 243, 243,
243, 243, 243, 243, 244, 244, 244, 244, 244, 244, 244, 244, 245, 245, 245, 245, 245, 245,
245, 245, 245, 246, 246, 246, 246, 246, 246, 246, 246, 246, 247, 247, 247, 247, 247, 247,
247, 247, 248, 248, 248, 248, 248, 248, 248, 248, 248, 249, 249, 249, 249, 249, 249, 249,
249, 249, 250, 250, 250, 250, 250, 250, 250, 250, 250, 251, 251, 251, 251, 251, 251, 251,
251, 251, 252, 252, 252, 252, 252, 252, 252, 252, 252, 253, 253, 253, 253, 253, 253, 253,
253, 253, 254, 254, 254, 254, 254, 254, 254, 254, 254, 255, 255, 255, 255, 255
};
static constexpr uint8_t linear_to_2dot2_table[1024] = {
0, 11, 15, 18, 21, 23, 25, 26, 28, 30, 31, 32, 34, 35, 36, 37, 39, 40,
41, 42, 43, 44, 45, 45, 46, 47, 48, 49, 50, 50, 51, 52, 53, 54, 54, 55,
56, 56, 57, 58, 58, 59, 60, 60, 61, 62, 62, 63, 63, 64, 65, 65, 66, 66,
67, 68, 68, 69, 69, 70, 70, 71, 71, 72, 72, 73, 73, 74, 74, 75, 75, 76,
76, 77, 77, 78, 78, 79, 79, 80, 80, 81, 81, 81, 82, 82, 83, 83, 84, 84,
84, 85, 85, 86, 86, 87, 87, 87, 88, 88, 89, 89, 89, 90, 90, 91, 91, 91,
92, 92, 93, 93, 93, 94, 94, 94, 95, 95, 96, 96, 96, 97, 97, 97, 98, 98,
98, 99, 99, 99, 100, 100, 101, 101, 101, 102, 102, 102, 103, 103, 103, 104, 104, 104,
105, 105, 105, 106, 106, 106, 107, 107, 107, 108, 108, 108, 108, 109, 109, 109, 110, 110,
110, 111, 111, 111, 112, 112, 112, 112, 113, 113, 113, 114, 114, 114, 115, 115, 115, 115,
116, 116, 116, 117, 117, 117, 117, 118, 118, 118, 119, 119, 119, 119, 120, 120, 120, 121,
121, 121, 121, 122, 122, 122, 123, 123, 123, 123, 124, 124, 124, 124, 125, 125, 125, 125,
126, 126, 126, 127, 127, 127, 127, 128, 128, 128, 128, 129, 129, 129, 129, 130, 130, 130,
130, 131, 131, 131, 131, 132, 132, 132, 132, 133, 133, 133, 133, 134, 134, 134, 134, 135,
135, 135, 135, 136, 136, 136, 136, 137, 137, 137, 137, 138, 138, 138, 138, 138, 139, 139,
139, 139, 140, 140, 140, 140, 141, 141, 141, 141, 142, 142, 142, 142, 142, 143, 143, 143,
143, 144, 144, 144, 144, 144, 145, 145, 145, 145, 146, 146, 146, 146, 146, 147, 147, 147,
147, 148, 148, 148, 148, 148, 149, 149, 149, 149, 149, 150, 150, 150, 150, 151, 151, 151,
151, 151, 152, 152, 152, 152, 152, 153, 153, 153, 153, 154, 154, 154, 154, 154, 155, 155,
155, 155, 155, 156, 156, 156, 156, 156, 157, 157, 157, 157, 157, 158, 158, 158, 158, 158,
159, 159, 159, 159, 159, 160, 160, 160, 160, 160, 161, 161, 161, 161, 161, 162, 162, 162,
162, 162, 163, 163, 163, 163, 163, 164, 164, 164, 164, 164, 165, 165, 165, 165, 165, 165,
166, 166, 166, 166, 166, 167, 167, 167, 167, 167, 168, 168, 168, 168, 168, 168, 169, 169,
169, 169, 169, 170, 170, 170, 170, 170, 171, 171, 171, 171, 171, 171, 172, 172, 172, 172,
172, 173, 173, 173, 173, 173, 173, 174, 174, 174, 174, 174, 174, 175, 175, 175, 175, 175,
176, 176, 176, 176, 176, 176, 177, 177, 177, 177, 177, 177, 178, 178, 178, 178, 178, 179,
179, 179, 179, 179, 179, 180, 180, 180, 180, 180, 180, 181, 181, 181, 181, 181, 181, 182,
182, 182, 182, 182, 182, 183, 183, 183, 183, 183, 183, 184, 184, 184, 184, 184, 185, 185,
185, 185, 185, 185, 186, 186, 186, 186, 186, 186, 186, 187, 187, 187, 187, 187, 187, 188,
188, 188, 188, 188, 188, 189, 189, 189, 189, 189, 189, 190, 190, 190, 190, 190, 190, 191,
191, 191, 191, 191, 191, 192, 192, 192, 192, 192, 192, 192, 193, 193, 193, 193, 193, 193,
194, 194, 194, 194, 194, 194, 195, 195, 195, 195, 195, 195, 195, 196, 196, 196, 196, 196,
196, 197, 197, 197, 197, 197, 197, 197, 198, 198, 198, 198, 198, 198, 199, 199, 199, 199,
199, 199, 199, 200, 200, 200, 200, 200, 200, 201, 201, 201, 201, 201, 201, 201, 202, 202,
202, 202, 202, 202, 202, 203, 203, 203, 203, 203, 203, 204, 204, 204, 204, 204, 204, 204,
205, 205, 205, 205, 205, 205, 205, 206, 206, 206, 206, 206, 206, 206, 207, 207, 207, 207,
207, 207, 207, 208, 208, 208, 208, 208, 208, 209, 209, 209, 209, 209, 209, 209, 210, 210,
210, 210, 210, 210, 210, 211, 211, 211, 211, 211, 211, 211, 212, 212, 212, 212, 212, 212,
212, 213, 213, 213, 213, 213, 213, 213, 213, 214, 214, 214, 214, 214, 214, 214, 215, 215,
215, 215, 215, 215, 215, 216, 216, 216, 216, 216, 216, 216, 217, 217, 217, 217, 217, 217,
217, 218, 218, 218, 218, 218, 218, 218, 218, 219, 219, 219, 219, 219, 219, 219, 220, 220,
220, 220, 220, 220, 220, 221, 221, 221, 221, 221, 221, 221, 221, 222, 222, 222, 222, 222,
222, 222, 223, 223, 223, 223, 223, 223, 223, 223, 224, 224, 224, 224, 224, 224, 224, 225,
225, 225, 225, 225, 225, 225, 225, 226, 226, 226, 226, 226, 226, 226, 226, 227, 227, 227,
227, 227, 227, 227, 228, 228, 228, 228, 228, 228, 228, 228, 229, 229, 229, 229, 229, 229,
229, 229, 230, 230, 230, 230, 230, 230, 230, 230, 231, 231, 231, 231, 231, 231, 231, 232,
232, 232, 232, 232, 232, 232, 232, 233, 233, 233, 233, 233, 233, 233, 233, 234, 234, 234,
234, 234, 234, 234, 234, 235, 235, 235, 235, 235, 235, 235, 235, 236, 236, 236, 236, 236,
236, 236, 236, 237, 237, 237, 237, 237, 237, 237, 237, 238, 238, 238, 238, 238, 238, 238,
238, 238, 239, 239, 239, 239, 239, 239, 239, 239, 240, 240, 240, 240, 240, 240, 240, 240,
241, 241, 241, 241, 241, 241, 241, 241, 242, 242, 242, 242, 242, 242, 242, 242, 243, 243,
243, 243, 243, 243, 243, 243, 243, 244, 244, 244, 244, 244, 244, 244, 244, 245, 245, 245,
245, 245, 245, 245, 245, 245, 246, 246, 246, 246, 246, 246, 246, 246, 247, 247, 247, 247,
247, 247, 247, 247, 248, 248, 248, 248, 248, 248, 248, 248, 248, 249, 249, 249, 249, 249,
249, 249, 249, 249, 250, 250, 250, 250, 250, 250, 250, 250, 251, 251, 251, 251, 251, 251,
251, 251, 251, 252, 252, 252, 252, 252, 252, 252, 252, 252, 253, 253, 253, 253, 253, 253,
253, 253, 254, 254, 254, 254, 254, 254, 254, 254, 254, 255, 255, 255, 255, 255,
};
///////////////////////////////////////////////////////////////////////////////////////////////////
static void build_table_linear_from_gamma(float* outTable, float exponent) {
for (float x = 0.0f; x <= 1.0f; x += (1.0f/255.0f)) {
*outTable++ = powf(x, exponent);
}
}
// Interpolating lookup in a variably sized table.
static float interp_lut(float input, const float* table, int tableSize) {
float index = input * (tableSize - 1);
float diff = index - sk_float_floor2int(index);
return table[(int) sk_float_floor2int(index)] * (1.0f - diff) +
table[(int) sk_float_ceil2int(index)] * diff;
}
// outTable is always 256 entries, inTable may be larger or smaller.
static void build_table_linear_from_gamma(float* outTable, const float* inTable,
int inTableSize) {
if (256 == inTableSize) {
memcpy(outTable, inTable, sizeof(float) * 256);
return;
}
for (float x = 0.0f; x <= 1.0f; x += (1.0f/255.0f)) {
*outTable++ = interp_lut(x, inTable, inTableSize);
}
}
static void build_table_linear_from_gamma(float* outTable, float g, float a, float b, float c,
float d, float e, float f) {
// Y = (aX + b)^g + c for X >= d
// Y = eX + f otherwise
for (float x = 0.0f; x <= 1.0f; x += (1.0f/255.0f)) {
if (x >= d) {
*outTable++ = powf(a * x + b, g) + c;
} else {
*outTable++ = e * x + f;
}
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////
// Expand range from 0-1 to 0-255, then convert.
static uint8_t clamp_normalized_float_to_byte(float v) {
// The ordering of the logic is a little strange here in order
// to make sure we convert NaNs to 0.
v = v * 255.0f;
if (v >= 254.5f) {
return 255;
} else if (v >= 0.5f) {
return (uint8_t) (v + 0.5f);
} else {
return 0;
}
}
static const int kDstGammaTableSize =
SkColorSpaceXform_Base<SkColorSpace::kNonStandard_GammaNamed, kNone_ColorSpaceMatch>
::kDstGammaTableSize;
static void build_table_linear_to_gamma(uint8_t* outTable, float exponent) {
float toGammaExp = 1.0f / exponent;
for (int i = 0; i < kDstGammaTableSize; i++) {
float x = ((float) i) * (1.0f / ((float) (kDstGammaTableSize - 1)));
outTable[i] = clamp_normalized_float_to_byte(powf(x, toGammaExp));
}
}
// Inverse table lookup. Ex: what index corresponds to the input value? This will
// have strange results when the table is non-increasing. But any sane gamma
// function will be increasing.
static float inverse_interp_lut(float input, const float* table, int tableSize) {
if (input <= table[0]) {
return table[0];
} else if (input >= table[tableSize - 1]) {
return 1.0f;
}
for (int i = 1; i < tableSize; i++) {
if (table[i] >= input) {
// We are guaranteed that input is greater than table[i - 1].
float diff = input - table[i - 1];
float distance = table[i] - table[i - 1];
float index = (i - 1) + diff / distance;
return index / (tableSize - 1);
}
}
// Should be unreachable, since we'll return before the loop if input is
// larger than the last entry.
SkASSERT(false);
return 0.0f;
}
static void build_table_linear_to_gamma(uint8_t* outTable, const float* inTable,
int inTableSize) {
for (int i = 0; i < kDstGammaTableSize; i++) {
float x = ((float) i) * (1.0f / ((float) (kDstGammaTableSize - 1)));
float y = inverse_interp_lut(x, inTable, inTableSize);
outTable[i] = clamp_normalized_float_to_byte(y);
}
}
static float inverse_parametric(float x, float g, float a, float b, float c, float d, float e,
float f) {
// We need to take the inverse of the following piecewise function.
// Y = (aX + b)^g + c for X >= d
// Y = eX + f otherwise
// Assume that the gamma function is continuous, or this won't make much sense anyway.
// Plug in |d| to the first equation to calculate the new piecewise interval.
// Then simply use the inverse of the original functions.
float interval = e * d + f;
if (x < interval) {
// X = (Y - F) / E
if (0.0f == e) {
// The gamma curve for this segment is constant, so the inverse is undefined.
// Since this is the lower segment, guess zero.
return 0.0f;
}
return (x - f) / e;
}
// X = ((Y - C)^(1 / G) - B) / A
if (0.0f == a || 0.0f == g) {
// The gamma curve for this segment is constant, so the inverse is undefined.
// Since this is the upper segment, guess one.
return 1.0f;
}
return (powf(x - c, 1.0f / g) - b) / a;
}
static void build_table_linear_to_gamma(uint8_t* outTable, float g, float a,
float b, float c, float d, float e, float f) {
for (int i = 0; i < kDstGammaTableSize; i++) {
float x = ((float) i) * (1.0f / ((float) (kDstGammaTableSize - 1)));
float y = inverse_parametric(x, g, a, b, c, d, e, f);
outTable[i] = clamp_normalized_float_to_byte(y);
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////
template <typename T>
struct GammaFns {
const T* fSRGBTable;
const T* f2Dot2Table;
void (*fBuildFromValue)(T*, float);
void (*fBuildFromTable)(T*, const float*, int);
void (*fBuildFromParam)(T*, float, float, float, float, float, float, float);
};
static const GammaFns<float> kToLinear {
sk_linear_from_srgb,
sk_linear_from_2dot2,
&build_table_linear_from_gamma,
&build_table_linear_from_gamma,
&build_table_linear_from_gamma,
};
static const GammaFns<uint8_t> kFromLinear {
linear_to_srgb,
linear_to_2dot2_table,
&build_table_linear_to_gamma,
&build_table_linear_to_gamma,
&build_table_linear_to_gamma,
};
// Build tables to transform src gamma to linear.
template <typename T>
static void build_gamma_tables(const T* outGammaTables[3], T* gammaTableStorage, int gammaTableSize,
const sk_sp<SkColorSpace>& space, const GammaFns<T>& fns) {
switch (space->gammaNamed()) {
case SkColorSpace::kSRGB_GammaNamed:
outGammaTables[0] = outGammaTables[1] = outGammaTables[2] = fns.fSRGBTable;
break;
case SkColorSpace::k2Dot2Curve_GammaNamed:
outGammaTables[0] = outGammaTables[1] = outGammaTables[2] = fns.f2Dot2Table;
break;
case SkColorSpace::kLinear_GammaNamed:
(*fns.fBuildFromValue)(gammaTableStorage, 1.0f);
outGammaTables[0] = outGammaTables[1] = outGammaTables[2] = gammaTableStorage;
break;
default: {
const SkGammas* gammas = as_CSB(space)->gammas();
SkASSERT(gammas);
for (int i = 0; i < 3; i++) {
if (i > 0) {
// Check if this curve matches the first curve. In this case, we can
// share the same table pointer. This should almost always be true.
// I've never seen a profile where all three gamma curves didn't match.
// But it is possible that they won't.
if (gammas->type(0) == gammas->type(i) && gammas->data(0) == gammas->data(i)) {
outGammaTables[i] = outGammaTables[0];
continue;
}
}
if (gammas->isNamed(i)) {
switch (gammas->data(i).fNamed) {
case SkColorSpace::kSRGB_GammaNamed:
outGammaTables[i] = fns.fSRGBTable;
break;
case SkColorSpace::k2Dot2Curve_GammaNamed:
outGammaTables[i] = fns.f2Dot2Table;
break;
case SkColorSpace::kLinear_GammaNamed:
(*fns.fBuildFromValue)(&gammaTableStorage[i * gammaTableSize], 1.0f);
outGammaTables[i] = &gammaTableStorage[i * gammaTableSize];
break;
default:
SkASSERT(false);
break;
}
} else if (gammas->isValue(i)) {
(*fns.fBuildFromValue)(&gammaTableStorage[i * gammaTableSize],
gammas->data(i).fValue);
outGammaTables[i] = &gammaTableStorage[i * gammaTableSize];
} else if (gammas->isTable(i)) {
(*fns.fBuildFromTable)(&gammaTableStorage[i * gammaTableSize], gammas->table(i),
gammas->data(i).fTable.fSize);
outGammaTables[i] = &gammaTableStorage[i * gammaTableSize];
} else {
SkASSERT(gammas->isParametric(i));
const SkGammas::Params& params = gammas->params(i);
(*fns.fBuildFromParam)(&gammaTableStorage[i * gammaTableSize], params.fG,
params.fA, params.fB, params.fC, params.fD, params.fE,
params.fF);
outGammaTables[i] = &gammaTableStorage[i * gammaTableSize];
}
}
}
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////
static inline bool compute_gamut_xform(SkMatrix44* srcToDst, const SkMatrix44& srcToXYZ,
const SkMatrix44& dstToXYZ) {
if (!dstToXYZ.invert(srcToDst)) {
return false;
}
srcToDst->postConcat(srcToXYZ);
return true;
}
static inline bool is_almost_identity(const SkMatrix44& srcToDst) {
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
float expected = (i == j) ? 1.0f : 0.0f;
if (!color_space_almost_equal(srcToDst.getFloat(i,j), expected)) {
return false;
}
}
}
return true;
}
///////////////////////////////////////////////////////////////////////////////////////////////////
std::unique_ptr<SkColorSpaceXform> SkColorSpaceXform::New(const sk_sp<SkColorSpace>& srcSpace,
const sk_sp<SkColorSpace>& dstSpace) {
if (!srcSpace || !dstSpace) {
// Invalid input
return nullptr;
}
ColorSpaceMatch csm = kNone_ColorSpaceMatch;
SkMatrix44 srcToDst(SkMatrix44::kUninitialized_Constructor);
if (SkColorSpace::Equals(srcSpace.get(), dstSpace.get())) {
srcToDst.setIdentity();
csm = kFull_ColorSpaceMatch;
} else if (!compute_gamut_xform(&srcToDst, srcSpace->xyz(), dstSpace->xyz())) {
return nullptr;
} else if (is_almost_identity(srcToDst)) {
srcToDst.setIdentity();
csm = kGamut_ColorSpaceMatch;
}
switch (csm) {
case kNone_ColorSpaceMatch:
switch (dstSpace->gammaNamed()) {
case SkColorSpace::kSRGB_GammaNamed:
return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
<SkColorSpace::kSRGB_GammaNamed, kNone_ColorSpaceMatch>
(srcSpace, srcToDst, dstSpace));
case SkColorSpace::k2Dot2Curve_GammaNamed:
return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
<SkColorSpace::k2Dot2Curve_GammaNamed, kNone_ColorSpaceMatch>
(srcSpace, srcToDst, dstSpace));
default:
return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
<SkColorSpace::kNonStandard_GammaNamed, kNone_ColorSpaceMatch>
(srcSpace, srcToDst, dstSpace));
}
case kGamut_ColorSpaceMatch:
switch (dstSpace->gammaNamed()) {
case SkColorSpace::kSRGB_GammaNamed:
return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
<SkColorSpace::kSRGB_GammaNamed, kGamut_ColorSpaceMatch>
(srcSpace, srcToDst, dstSpace));
case SkColorSpace::k2Dot2Curve_GammaNamed:
return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
<SkColorSpace::k2Dot2Curve_GammaNamed, kGamut_ColorSpaceMatch>
(srcSpace, srcToDst, dstSpace));
default:
return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
<SkColorSpace::kNonStandard_GammaNamed, kGamut_ColorSpaceMatch>
(srcSpace, srcToDst, dstSpace));
}
case kFull_ColorSpaceMatch:
switch (dstSpace->gammaNamed()) {
case SkColorSpace::kSRGB_GammaNamed:
return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
<SkColorSpace::kSRGB_GammaNamed, kFull_ColorSpaceMatch>
(srcSpace, srcToDst, dstSpace));
case SkColorSpace::k2Dot2Curve_GammaNamed:
return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
<SkColorSpace::k2Dot2Curve_GammaNamed, kFull_ColorSpaceMatch>
(srcSpace, srcToDst, dstSpace));
default:
return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
<SkColorSpace::kNonStandard_GammaNamed, kFull_ColorSpaceMatch>
(srcSpace, srcToDst, dstSpace));
}
default:
SkASSERT(false);
return nullptr;
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////
static float byte_to_float(uint8_t byte) {
return ((float) byte) * (1.0f / 255.0f);
}
// Clamp to the 0-1 range.
static float clamp_normalized_float(float v) {
if (v > 1.0f) {
return 1.0f;
} else if ((v < 0.0f) || (v != v)) {
return 0.0f;
} else {
return v;
}
}
static void interp_3d_clut(float dst[3], float src[3], const SkColorLookUpTable* colorLUT) {
// Call the src components x, y, and z.
uint8_t maxX = colorLUT->fGridPoints[0] - 1;
uint8_t maxY = colorLUT->fGridPoints[1] - 1;
uint8_t maxZ = colorLUT->fGridPoints[2] - 1;
// An approximate index into each of the three dimensions of the table.
float x = src[0] * maxX;
float y = src[1] * maxY;
float z = src[2] * maxZ;
// This gives us the low index for our interpolation.
int ix = sk_float_floor2int(x);
int iy = sk_float_floor2int(y);
int iz = sk_float_floor2int(z);
// Make sure the low index is not also the max index.
ix = (maxX == ix) ? ix - 1 : ix;
iy = (maxY == iy) ? iy - 1 : iy;
iz = (maxZ == iz) ? iz - 1 : iz;
// Weighting factors for the interpolation.
float diffX = x - ix;
float diffY = y - iy;
float diffZ = z - iz;
// Constants to help us navigate the 3D table.
// Ex: Assume x = a, y = b, z = c.
// table[a * n001 + b * n010 + c * n100] logically equals table[a][b][c].
const int n000 = 0;
const int n001 = 3 * colorLUT->fGridPoints[1] * colorLUT->fGridPoints[2];
const int n010 = 3 * colorLUT->fGridPoints[2];
const int n011 = n001 + n010;
const int n100 = 3;
const int n101 = n100 + n001;
const int n110 = n100 + n010;
const int n111 = n110 + n001;
// Base ptr into the table.
const float* ptr = &(colorLUT->table()[ix*n001 + iy*n010 + iz*n100]);
// The code below performs a tetrahedral interpolation for each of the three
// dst components. Once the tetrahedron containing the interpolation point is
// identified, the interpolation is a weighted sum of grid values at the
// vertices of the tetrahedron. The claim is that tetrahedral interpolation
// provides a more accurate color conversion.
// blogs.mathworks.com/steve/2006/11/24/tetrahedral-interpolation-for-colorspace-conversion/
//
// I have one test image, and visually I can't tell the difference between
// tetrahedral and trilinear interpolation. In terms of computation, the
// tetrahedral code requires more branches but less computation. The
// SampleICC library provides an option for the client to choose either
// tetrahedral or trilinear.
for (int i = 0; i < 3; i++) {
if (diffZ < diffY) {
if (diffZ < diffX) {
dst[i] = (ptr[n000] + diffZ * (ptr[n110] - ptr[n010]) +
diffY * (ptr[n010] - ptr[n000]) +
diffX * (ptr[n111] - ptr[n110]));
} else if (diffY < diffX) {
dst[i] = (ptr[n000] + diffZ * (ptr[n111] - ptr[n011]) +
diffY * (ptr[n011] - ptr[n001]) +
diffX * (ptr[n001] - ptr[n000]));
} else {
dst[i] = (ptr[n000] + diffZ * (ptr[n111] - ptr[n011]) +
diffY * (ptr[n010] - ptr[n000]) +
diffX * (ptr[n011] - ptr[n010]));
}
} else {
if (diffZ < diffX) {
dst[i] = (ptr[n000] + diffZ * (ptr[n101] - ptr[n001]) +
diffY * (ptr[n111] - ptr[n101]) +
diffX * (ptr[n001] - ptr[n000]));
} else if (diffY < diffX) {
dst[i] = (ptr[n000] + diffZ * (ptr[n100] - ptr[n000]) +
diffY * (ptr[n111] - ptr[n101]) +
diffX * (ptr[n101] - ptr[n100]));
} else {
dst[i] = (ptr[n000] + diffZ * (ptr[n100] - ptr[n000]) +
diffY * (ptr[n110] - ptr[n100]) +
diffX * (ptr[n111] - ptr[n110]));
}
}
// Increment the table ptr in order to handle the next component.
// Note that this is the how table is designed: all of nXXX
// variables are multiples of 3 because there are 3 output
// components.
ptr++;
}
}
static void handle_color_lut(uint32_t* dst, const uint32_t* src, int len,
SkColorLookUpTable* colorLUT) {
while (len-- > 0) {
uint8_t r = (*src >> 0) & 0xFF,
g = (*src >> 8) & 0xFF,
b = (*src >> 16) & 0xFF;
float in[3];
float out[3];
in[0] = byte_to_float(r);
in[1] = byte_to_float(g);
in[2] = byte_to_float(b);
interp_3d_clut(out, in, colorLUT);
r = sk_float_round2int(255.0f * clamp_normalized_float(out[0]));
g = sk_float_round2int(255.0f * clamp_normalized_float(out[1]));
b = sk_float_round2int(255.0f * clamp_normalized_float(out[2]));
*dst = SkPackARGB_as_RGBA(0xFF, r, g, b);
src++;
dst++;
}
}
enum SwapRB {
kNo_SwapRB,
kYes_SwapRB,
};
static inline void load_matrix(const float matrix[16],
Sk4f& rXgXbX, Sk4f& rYgYbY, Sk4f& rZgZbZ, Sk4f& rTgTbT) {
rXgXbX = Sk4f::Load(matrix + 0);
rYgYbY = Sk4f::Load(matrix + 4);
rZgZbZ = Sk4f::Load(matrix + 8);
rTgTbT = Sk4f::Load(matrix + 12);
}
static inline void load_rgb_from_tables(const uint32_t* src,
Sk4f& r, Sk4f& g, Sk4f& b, Sk4f& a,
const float* const srcTables[3]) {
r = { srcTables[0][(src[0] >> 0) & 0xFF],
srcTables[0][(src[1] >> 0) & 0xFF],
srcTables[0][(src[2] >> 0) & 0xFF],
srcTables[0][(src[3] >> 0) & 0xFF], };
g = { srcTables[1][(src[0] >> 8) & 0xFF],
srcTables[1][(src[1] >> 8) & 0xFF],
srcTables[1][(src[2] >> 8) & 0xFF],
srcTables[1][(src[3] >> 8) & 0xFF], };
b = { srcTables[2][(src[0] >> 16) & 0xFF],
srcTables[2][(src[1] >> 16) & 0xFF],
srcTables[2][(src[2] >> 16) & 0xFF],
srcTables[2][(src[3] >> 16) & 0xFF], };
a = 0.0f; // Don't let the compiler complain that |a| is uninitialized.
}
static inline void load_rgba_from_tables(const uint32_t* src,
Sk4f& r, Sk4f& g, Sk4f& b, Sk4f& a,
const float* const srcTables[3]) {
r = { srcTables[0][(src[0] >> 0) & 0xFF],
srcTables[0][(src[1] >> 0) & 0xFF],
srcTables[0][(src[2] >> 0) & 0xFF],
srcTables[0][(src[3] >> 0) & 0xFF], };
g = { srcTables[1][(src[0] >> 8) & 0xFF],
srcTables[1][(src[1] >> 8) & 0xFF],
srcTables[1][(src[2] >> 8) & 0xFF],
srcTables[1][(src[3] >> 8) & 0xFF], };
b = { srcTables[2][(src[0] >> 16) & 0xFF],
srcTables[2][(src[1] >> 16) & 0xFF],
srcTables[2][(src[2] >> 16) & 0xFF],
srcTables[2][(src[3] >> 16) & 0xFF], };
a = (1.0f / 255.0f) * SkNx_cast<float>(Sk4u::Load(src) >> 24);
}
static inline void load_rgb_from_tables_1(const uint32_t* src,
Sk4f& r, Sk4f& g, Sk4f& b, Sk4f&,
const float* const srcTables[3]) {
// Splat r,g,b across a register each.
r = Sk4f(srcTables[0][(*src >> 0) & 0xFF]);
g = Sk4f(srcTables[1][(*src >> 8) & 0xFF]);
b = Sk4f(srcTables[2][(*src >> 16) & 0xFF]);
}
static inline void load_rgba_from_tables_1(const uint32_t* src,
Sk4f& r, Sk4f& g, Sk4f& b, Sk4f& a,
const float* const srcTables[3]) {
// Splat r,g,b across a register each.
r = Sk4f(srcTables[0][(*src >> 0) & 0xFF]);
g = Sk4f(srcTables[1][(*src >> 8) & 0xFF]);
b = Sk4f(srcTables[2][(*src >> 16) & 0xFF]);
a = (1.0f / 255.0f) * Sk4f(*src >> 24);
}
static inline void transform_gamut(const Sk4f& r, const Sk4f& g, const Sk4f& b, const Sk4f& a,
const Sk4f& rXgXbX, const Sk4f& rYgYbY, const Sk4f& rZgZbZ,
Sk4f& dr, Sk4f& dg, Sk4f& db, Sk4f& da) {
dr = rXgXbX[0]*r + rYgYbY[0]*g + rZgZbZ[0]*b;
dg = rXgXbX[1]*r + rYgYbY[1]*g + rZgZbZ[1]*b;
db = rXgXbX[2]*r + rYgYbY[2]*g + rZgZbZ[2]*b;
da = a;
}
static inline void transform_gamut_1(const Sk4f& r, const Sk4f& g, const Sk4f& b,
const Sk4f& rXgXbX, const Sk4f& rYgYbY, const Sk4f& rZgZbZ,
Sk4f& rgba) {
rgba = rXgXbX*r + rYgYbY*g + rZgZbZ*b;
}
static inline void translate_gamut(const Sk4f& rTgTbT, Sk4f& dr, Sk4f& dg, Sk4f& db) {
dr = dr + rTgTbT[0];
dg = dg + rTgTbT[1];
db = db + rTgTbT[2];
}
static inline void translate_gamut_1(const Sk4f& rTgTbT, Sk4f& rgba) {
rgba = rgba + rTgTbT;
}
static inline void premultiply(Sk4f& dr, Sk4f& dg, Sk4f& db, const Sk4f& da) {
dr = da * dr;
dg = da * dg;
db = da * db;
}
static inline void premultiply_1(const Sk4f& a, Sk4f& rgba) {
rgba = a * rgba;
}
static inline void store_srgb(void* dst, const uint32_t* src,
Sk4f& dr, Sk4f& dg, Sk4f& db, Sk4f&,
const uint8_t* const[3], SwapRB kSwapRB) {
int kRShift = 0;
int kGShift = 8;
int kBShift = 16;
if (kYes_SwapRB == kSwapRB) {
kBShift = 0;
kRShift = 16;
}
dr = sk_linear_to_srgb_needs_trunc(dr);
dg = sk_linear_to_srgb_needs_trunc(dg);
db = sk_linear_to_srgb_needs_trunc(db);
dr = sk_clamp_0_255(dr);
dg = sk_clamp_0_255(dg);
db = sk_clamp_0_255(db);
Sk4i da = Sk4i::Load(src) & 0xFF000000;
Sk4i rgba = (SkNx_cast<int>(dr) << kRShift)
| (SkNx_cast<int>(dg) << kGShift)
| (SkNx_cast<int>(db) << kBShift)
| (da );
rgba.store(dst);
}
static inline void store_srgb_1(void* dst, const uint32_t* src,
Sk4f& rgba, const Sk4f&,
const uint8_t* const[3], SwapRB kSwapRB) {
rgba = sk_clamp_0_255(sk_linear_to_srgb_needs_trunc(rgba));
uint32_t tmp;
SkNx_cast<uint8_t>(SkNx_cast<int32_t>(rgba)).store(&tmp);
tmp = (*src & 0xFF000000) | (tmp & 0x00FFFFFF);
if (kYes_SwapRB == kSwapRB) {
tmp = SkSwizzle_RB(tmp);
}
*(uint32_t*)dst = tmp;
}
static inline Sk4f linear_to_2dot2(const Sk4f& x) {
// x^(29/64) is a very good approximation of the true value, x^(1/2.2).
auto x2 = x.rsqrt(), // x^(-1/2)
x32 = x2.rsqrt().rsqrt().rsqrt().rsqrt(), // x^(-1/32)
x64 = x32.rsqrt(); // x^(+1/64)
// 29 = 32 - 2 - 1
return 255.0f * x2.invert() * x32 * x64.invert();
}
static inline void store_2dot2(void* dst, const uint32_t* src,
Sk4f& dr, Sk4f& dg, Sk4f& db, Sk4f&,
const uint8_t* const[3], SwapRB kSwapRB) {
int kRShift = 0;
int kGShift = 8;
int kBShift = 16;
if (kYes_SwapRB == kSwapRB) {
kBShift = 0;
kRShift = 16;
}
dr = linear_to_2dot2(dr);
dg = linear_to_2dot2(dg);
db = linear_to_2dot2(db);
dr = sk_clamp_0_255(dr);
dg = sk_clamp_0_255(dg);
db = sk_clamp_0_255(db);
Sk4i da = Sk4i::Load(src) & 0xFF000000;
Sk4i rgba = (Sk4f_round(dr) << kRShift)
| (Sk4f_round(dg) << kGShift)
| (Sk4f_round(db) << kBShift)
| (da );
rgba.store(dst);
}
static inline void store_2dot2_1(void* dst, const uint32_t* src,
Sk4f& rgba, const Sk4f&,
const uint8_t* const[3], SwapRB kSwapRB) {
rgba = sk_clamp_0_255(linear_to_2dot2(rgba));
uint32_t tmp;
SkNx_cast<uint8_t>(Sk4f_round(rgba)).store(&tmp);
tmp = (*src & 0xFF000000) | (tmp & 0x00FFFFFF);
if (kYes_SwapRB == kSwapRB) {
tmp = SkSwizzle_RB(tmp);
}
*(uint32_t*)dst = tmp;
}
static inline void store_f16(void* dst, const uint32_t* src,
Sk4f& dr, Sk4f& dg, Sk4f& db, Sk4f& da,
const uint8_t* const[3], SwapRB) {
Sk4h_store4(dst, SkFloatToHalf_finite_ftz(dr),
SkFloatToHalf_finite_ftz(dg),
SkFloatToHalf_finite_ftz(db),
SkFloatToHalf_finite_ftz(da));
}
static inline void store_f16_1(void* dst, const uint32_t* src,
Sk4f& rgba, const Sk4f& a,
const uint8_t* const[3], SwapRB kSwapRB) {
rgba = Sk4f(rgba[0], rgba[1], rgba[2], a[3]);
SkFloatToHalf_finite_ftz(rgba).store((uint64_t*) dst);
}
static inline void store_f16_opaque(void* dst, const uint32_t* src,
Sk4f& dr, Sk4f& dg, Sk4f& db, Sk4f& da,
const uint8_t* const[3], SwapRB) {
Sk4h_store4(dst, SkFloatToHalf_finite_ftz(dr),
SkFloatToHalf_finite_ftz(dg),
SkFloatToHalf_finite_ftz(db),
SK_Half1);
}
static inline void store_f16_1_opaque(void* dst, const uint32_t* src,
Sk4f& rgba, const Sk4f& a,
const uint8_t* const[3], SwapRB kSwapRB) {
uint64_t tmp;
SkFloatToHalf_finite_ftz(rgba).store(&tmp);
tmp |= static_cast<uint64_t>(SK_Half1) << 48;
*((uint64_t*) dst) = tmp;
}
static inline void store_generic(void* dst, const uint32_t* src,
Sk4f& dr, Sk4f& dg, Sk4f& db, Sk4f&,
const uint8_t* const dstTables[3], SwapRB kSwapRB) {
int kRShift = 0;
int kGShift = 8;
int kBShift = 16;
if (kYes_SwapRB == kSwapRB) {
kBShift = 0;
kRShift = 16;
}
dr = Sk4f::Min(Sk4f::Max(1023.0f * dr, 0.0f), 1023.0f);
dg = Sk4f::Min(Sk4f::Max(1023.0f * dg, 0.0f), 1023.0f);
db = Sk4f::Min(Sk4f::Max(1023.0f * db, 0.0f), 1023.0f);
Sk4i ir = Sk4f_round(dr);
Sk4i ig = Sk4f_round(dg);
Sk4i ib = Sk4f_round(db);
Sk4i da = Sk4i::Load(src) & 0xFF000000;
uint32_t* dst32 = (uint32_t*) dst;
dst32[0] = dstTables[0][ir[0]] << kRShift
| dstTables[1][ig[0]] << kGShift
| dstTables[2][ib[0]] << kBShift
| da[0];
dst32[1] = dstTables[0][ir[1]] << kRShift
| dstTables[1][ig[1]] << kGShift
| dstTables[2][ib[1]] << kBShift
| da[1];
dst32[2] = dstTables[0][ir[2]] << kRShift
| dstTables[1][ig[2]] << kGShift
| dstTables[2][ib[2]] << kBShift
| da[2];
dst32[3] = dstTables[0][ir[3]] << kRShift
| dstTables[1][ig[3]] << kGShift
| dstTables[2][ib[3]] << kBShift
| da[3];
}
static inline void store_generic_1(void* dst, const uint32_t* src,
Sk4f& rgba, const Sk4f&,
const uint8_t* const dstTables[3], SwapRB kSwapRB) {
int kRShift = 0;
int kGShift = 8;
int kBShift = 16;
if (kYes_SwapRB == kSwapRB) {
kBShift = 0;
kRShift = 16;
}
rgba = Sk4f::Min(Sk4f::Max(1023.0f * rgba, 0.0f), 1023.0f);
Sk4i indices = Sk4f_round(rgba);
*((uint32_t*) dst) = dstTables[0][indices[0]] << kRShift
| dstTables[1][indices[1]] << kGShift
| dstTables[2][indices[2]] << kBShift
| (*src & 0xFF000000);
}
template <SkColorSpace::GammaNamed kDstGamma,
ColorSpaceMatch kCSM,
SkAlphaType kAlphaType,
SwapRB kSwapRB>
static void color_xform_RGBA(void* dst, const uint32_t* src, int len,
const float* const srcTables[3], const float matrix[16],
const uint8_t* const dstTables[3]) {
decltype(store_srgb )* store;
decltype(store_srgb_1 )* store_1;
decltype(load_rgb_from_tables )* load;
decltype(load_rgb_from_tables_1)* load_1;
size_t sizeOfDstPixel;
switch (kDstGamma) {
case SkColorSpace::kSRGB_GammaNamed:
load = (kPremul_SkAlphaType == kAlphaType) ? load_rgba_from_tables :
load_rgb_from_tables;
load_1 = (kPremul_SkAlphaType == kAlphaType) ? load_rgba_from_tables_1 :
load_rgb_from_tables_1;
store = store_srgb;
store_1 = store_srgb_1;
sizeOfDstPixel = 4;
break;
case SkColorSpace::k2Dot2Curve_GammaNamed:
load = (kPremul_SkAlphaType == kAlphaType) ? load_rgba_from_tables :
load_rgb_from_tables;
load_1 = (kPremul_SkAlphaType == kAlphaType) ? load_rgba_from_tables_1 :
load_rgb_from_tables_1;
store = store_2dot2;
store_1 = store_2dot2_1;
sizeOfDstPixel = 4;
break;
case SkColorSpace::kLinear_GammaNamed:
load = load_rgba_from_tables;
load_1 = load_rgba_from_tables_1;
store = (kOpaque_SkAlphaType == kAlphaType) ? store_f16_opaque :
store_f16;
store_1 = (kOpaque_SkAlphaType == kAlphaType) ? store_f16_1_opaque :
store_f16_1;
sizeOfDstPixel = 8;
break;
case SkColorSpace::kNonStandard_GammaNamed:
load = (kPremul_SkAlphaType == kAlphaType) ? load_rgba_from_tables :
load_rgb_from_tables;
load_1 = (kPremul_SkAlphaType == kAlphaType) ? load_rgba_from_tables_1 :
load_rgb_from_tables_1;
store = store_generic;
store_1 = store_generic_1;
sizeOfDstPixel = 4;
break;
}
Sk4f rXgXbX, rYgYbY, rZgZbZ, rTgTbT;
load_matrix(matrix, rXgXbX, rYgYbY, rZgZbZ, rTgTbT);
if (len >= 4) {
// Naively this would be a loop of load-transform-store, but we found it faster to
// move the N+1th load ahead of the Nth store. We don't bother doing this for N<4.
Sk4f r, g, b, a;
load(src, r, g, b, a, srcTables);
src += 4;
len -= 4;
Sk4f dr, dg, db, da;
while (len >= 4) {
if (kNone_ColorSpaceMatch == kCSM) {
transform_gamut(r, g, b, a, rXgXbX, rYgYbY, rZgZbZ, dr, dg, db, da);
translate_gamut(rTgTbT, dr, dg, db);
} else {
dr = r;
dg = g;
db = b;
da = a;
}
if (kPremul_SkAlphaType == kAlphaType) {
premultiply(dr, dg, db, da);
}
load(src, r, g, b, a, srcTables);
store(dst, src - 4, dr, dg, db, da, dstTables, kSwapRB);
dst = SkTAddOffset<void>(dst, 4 * sizeOfDstPixel);
src += 4;
len -= 4;
}
if (kNone_ColorSpaceMatch == kCSM) {
transform_gamut(r, g, b, a, rXgXbX, rYgYbY, rZgZbZ, dr, dg, db, da);
translate_gamut(rTgTbT, dr, dg, db);
} else {
dr = r;
dg = g;
db = b;
da = a;
}
if (kPremul_SkAlphaType == kAlphaType) {
premultiply(dr, dg, db, da);
}
store(dst, src - 4, dr, dg, db, da, dstTables, kSwapRB);
dst = SkTAddOffset<void>(dst, 4 * sizeOfDstPixel);
}
while (len > 0) {
Sk4f r, g, b, a;
load_1(src, r, g, b, a, srcTables);
Sk4f rgba;
if (kNone_ColorSpaceMatch == kCSM) {
transform_gamut_1(r, g, b, rXgXbX, rYgYbY, rZgZbZ, rgba);
translate_gamut_1(rTgTbT, rgba);
} else {
rgba = Sk4f(r[0], g[0], b[0], a[0]);
}
if (kPremul_SkAlphaType == kAlphaType) {
premultiply_1(a, rgba);
}
store_1(dst, src, rgba, a, dstTables, kSwapRB);
src += 1;
len -= 1;
dst = SkTAddOffset<void>(dst, sizeOfDstPixel);
}
}
///////////////////////////////////////////////////////////////////////////////////////////////////
template <SkColorSpace::GammaNamed kDst, ColorSpaceMatch kCSM>
SkColorSpaceXform_Base<kDst, kCSM>::SkColorSpaceXform_Base(const sk_sp<SkColorSpace>& srcSpace,
const SkMatrix44& srcToDst,
const sk_sp<SkColorSpace>& dstSpace)
: fColorLUT(sk_ref_sp((SkColorLookUpTable*) as_CSB(srcSpace)->colorLUT()))
{
srcToDst.asRowMajorf(fSrcToDst);
build_gamma_tables(fSrcGammaTables, fSrcGammaTableStorage, 256, srcSpace, kToLinear);
build_gamma_tables(fDstGammaTables, fDstGammaTableStorage, kDstGammaTableSize, dstSpace,
kFromLinear);
}
template <SkColorSpace::GammaNamed kDst, ColorSpaceMatch kCSM>
void SkColorSpaceXform_Base<kDst, kCSM>
::apply(void* dst, const uint32_t* src, int len, SkColorType dstColorType, SkAlphaType dstAlphaType)
const
{
if (kFull_ColorSpaceMatch == kCSM) {
switch (dstAlphaType) {
case kPremul_SkAlphaType:
// We can't skip the xform since we need to perform a premultiply in the
// linear space.
break;
default:
switch (dstColorType) {
case kRGBA_8888_SkColorType:
return (void) memcpy(dst, src, len * sizeof(uint32_t));
case kBGRA_8888_SkColorType:
return SkOpts::RGBA_to_BGRA((uint32_t*) dst, src, len);
case kRGBA_F16_SkColorType:
// There's still work to do to xform to linear F16.
break;
default:
SkASSERT(false);
return;
}
}
}
if (fColorLUT) {
size_t storageBytes = len * sizeof(uint32_t);
#if defined(GOOGLE3)
// Stack frame size is limited in GOOGLE3.
SkAutoSMalloc<256 * sizeof(uint32_t)> storage(storageBytes);
#else
SkAutoSMalloc<1024 * sizeof(uint32_t)> storage(storageBytes);
#endif
handle_color_lut((uint32_t*) storage.get(), src, len, fColorLUT.get());
src = (const uint32_t*) storage.get();
}
switch (dstAlphaType) {
case kPremul_SkAlphaType:
switch (dstColorType) {
case kRGBA_8888_SkColorType:
return color_xform_RGBA<kDst, kCSM, kPremul_SkAlphaType, kNo_SwapRB>
(dst, src, len, fSrcGammaTables, fSrcToDst, fDstGammaTables);
case kBGRA_8888_SkColorType:
return color_xform_RGBA<kDst, kCSM, kPremul_SkAlphaType, kYes_SwapRB>
(dst, src, len, fSrcGammaTables, fSrcToDst, fDstGammaTables);
case kRGBA_F16_SkColorType:
return color_xform_RGBA<SkColorSpace::kLinear_GammaNamed, kCSM,
kPremul_SkAlphaType, kNo_SwapRB>
(dst, src, len, fSrcGammaTables, fSrcToDst, fDstGammaTables);
default:
SkASSERT(false);
return;
}
break;
case kUnpremul_SkAlphaType:
switch (dstColorType) {
case kRGBA_8888_SkColorType:
return color_xform_RGBA<kDst, kCSM, kUnpremul_SkAlphaType, kNo_SwapRB>
(dst, src, len, fSrcGammaTables, fSrcToDst, fDstGammaTables);
case kBGRA_8888_SkColorType:
return color_xform_RGBA<kDst, kCSM, kUnpremul_SkAlphaType, kYes_SwapRB>
(dst, src, len, fSrcGammaTables, fSrcToDst, fDstGammaTables);
case kRGBA_F16_SkColorType:
return color_xform_RGBA<SkColorSpace::kLinear_GammaNamed, kCSM,
kUnpremul_SkAlphaType, kNo_SwapRB>
(dst, src, len, fSrcGammaTables, fSrcToDst, fDstGammaTables);
default:
SkASSERT(false);
return;
}
case kOpaque_SkAlphaType:
switch (dstColorType) {
case kRGBA_8888_SkColorType:
return color_xform_RGBA<kDst, kCSM, kOpaque_SkAlphaType, kNo_SwapRB>
(dst, src, len, fSrcGammaTables, fSrcToDst, fDstGammaTables);
case kBGRA_8888_SkColorType:
return color_xform_RGBA<kDst, kCSM, kOpaque_SkAlphaType, kYes_SwapRB>
(dst, src, len, fSrcGammaTables, fSrcToDst, fDstGammaTables);
case kRGBA_F16_SkColorType:
return color_xform_RGBA<SkColorSpace::kLinear_GammaNamed, kCSM,
kOpaque_SkAlphaType, kNo_SwapRB>
(dst, src, len, fSrcGammaTables, fSrcToDst, fDstGammaTables);
default:
SkASSERT(false);
return;
}
default:
SkASSERT(false);
return;
}
}
std::unique_ptr<SkColorSpaceXform> SlowIdentityXform(const sk_sp<SkColorSpace>& space) {
return std::unique_ptr<SkColorSpaceXform>(new SkColorSpaceXform_Base
<SkColorSpace::kNonStandard_GammaNamed, kNone_ColorSpaceMatch>
(space, SkMatrix::I(), space));
}