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Unified Diff: src/core/SkColorSpaceXform.cpp

Issue 2084673002: Use a table-based implementation of SkDefaultXform (Closed) Base URL: https://skia.googlesource.com/skia.git@master
Patch Set: quickEquals() Created 4 years, 6 months ago
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Index: src/core/SkColorSpaceXform.cpp
diff --git a/src/core/SkColorSpaceXform.cpp b/src/core/SkColorSpaceXform.cpp
index f42811a549ddaa682ae028872c25b1768c2b9044..ce9d52ac3ffca223fb4f3e2d21c2436280235d21 100644
--- a/src/core/SkColorSpaceXform.cpp
+++ b/src/core/SkColorSpaceXform.cpp
@@ -70,7 +70,7 @@ std::unique_ptr<SkColorSpaceXform> SkColorSpaceXform::New(const sk_sp<SkColorSpa
}
return std::unique_ptr<SkColorSpaceXform>(
- new SkDefaultXform(as_CSB(srcSpace)->gammas(), srcToDst, as_CSB(dstSpace)->gammas()));
+ new SkDefaultXform(srcSpace, srcToDst, dstSpace));
}
///////////////////////////////////////////////////////////////////////////////////////////////////
@@ -146,12 +146,302 @@ void SkFastXform<SkColorSpace::k2Dot2Curve_GammaNamed, SkColorSpace::k2Dot2Curve
///////////////////////////////////////////////////////////////////////////////////////////////////
-static inline float byte_to_float(uint8_t v) {
- return ((float) v) * (1.0f / 255.0f);
+extern const float sk_linear_from_srgb[256] = {
+ 0.000000000000000000f, 0.000303526983548838f, 0.000607053967097675f, 0.000910580950646513f,
+ 0.001214107934195350f, 0.001517634917744190f, 0.001821161901293030f, 0.002124688884841860f,
+ 0.002428215868390700f, 0.002731742851939540f, 0.003034518678424960f, 0.003346535763899160f,
+ 0.003676507324047440f, 0.004024717018496310f, 0.004391442037410290f, 0.004776953480693730f,
+ 0.005181516702338390f, 0.005605391624202720f, 0.006048833022857060f, 0.006512090792594470f,
+ 0.006995410187265390f, 0.007499032043226180f, 0.008023192985384990f, 0.008568125618069310f,
+ 0.009134058702220790f, 0.009721217320237850f, 0.010329823029626900f, 0.010960094006488200f,
+ 0.011612245179743900f, 0.012286488356915900f, 0.012983032342173000f, 0.013702083047289700f,
+ 0.014443843596092500f, 0.015208514422912700f, 0.015996293365509600f, 0.016807375752887400f,
+ 0.017641954488384100f, 0.018500220128379700f, 0.019382360956935700f, 0.020288563056652400f,
+ 0.021219010376003600f, 0.022173884793387400f, 0.023153366178110400f, 0.024157632448504800f,
+ 0.025186859627361600f, 0.026241221894849900f, 0.027320891639074900f, 0.028426039504420800f,
+ 0.029556834437808800f, 0.030713443732993600f, 0.031896033073011500f, 0.033104766570885100f,
+ 0.034339806808682200f, 0.035601314875020300f, 0.036889450401100000f, 0.038204371595346500f,
+ 0.039546235276732800f, 0.040915196906853200f, 0.042311410620809700f, 0.043735029256973500f,
+ 0.045186204385675500f, 0.046665086336880100f, 0.048171824226889400f, 0.049706565984127200f,
+ 0.051269458374043200f, 0.052860647023180200f, 0.054480276442442400f, 0.056128490049600100f,
+ 0.057805430191067200f, 0.059511238162981200f, 0.061246054231617600f, 0.063010017653167700f,
+ 0.064803266692905800f, 0.066625938643772900f, 0.068478169844400200f, 0.070360095696595900f,
+ 0.072271850682317500f, 0.074213568380149600f, 0.076185381481307900f, 0.078187421805186300f,
+ 0.080219820314468300f, 0.082282707129814800f, 0.084376211544148800f, 0.086500462036549800f,
+ 0.088655586285772900f, 0.090841711183407700f, 0.093058962846687500f, 0.095307466630964700f,
+ 0.097587347141862500f, 0.099898728247113900f, 0.102241733088101000f, 0.104616484091104000f,
+ 0.107023102978268000f, 0.109461710778299000f, 0.111932427836906000f, 0.114435373826974000f,
+ 0.116970667758511000f, 0.119538427988346000f, 0.122138772229602000f, 0.124771817560950000f,
+ 0.127437680435647000f, 0.130136476690364000f, 0.132868321553818000f, 0.135633329655206000f,
+ 0.138431615032452000f, 0.141263291140272000f, 0.144128470858058000f, 0.147027266497595000f,
+ 0.149959789810609000f, 0.152926151996150000f, 0.155926463707827000f, 0.158960835060880000f,
+ 0.162029375639111000f, 0.165132194501668000f, 0.168269400189691000f, 0.171441100732823000f,
+ 0.174647403655585000f, 0.177888415983629000f, 0.181164244249860000f, 0.184474994500441000f,
+ 0.187820772300678000f, 0.191201682740791000f, 0.194617830441576000f, 0.198069319559949000f,
+ 0.201556253794397000f, 0.205078736390317000f, 0.208636870145256000f, 0.212230757414055000f,
+ 0.215860500113899000f, 0.219526199729269000f, 0.223227957316809000f, 0.226965873510098000f,
+ 0.230740048524349000f, 0.234550582161005000f, 0.238397573812271000f, 0.242281122465555000f,
+ 0.246201326707835000f, 0.250158284729953000f, 0.254152094330827000f, 0.258182852921596000f,
+ 0.262250657529696000f, 0.266355604802862000f, 0.270497791013066000f, 0.274677312060385000f,
+ 0.278894263476810000f, 0.283148740429992000f, 0.287440837726918000f, 0.291770649817536000f,
+ 0.296138270798321000f, 0.300543794415777000f, 0.304987314069886000f, 0.309468922817509000f,
+ 0.313988713375718000f, 0.318546778125092000f, 0.323143209112951000f, 0.327778098056542000f,
+ 0.332451536346179000f, 0.337163615048330000f, 0.341914424908661000f, 0.346704056355030000f,
+ 0.351532599500439000f, 0.356400144145944000f, 0.361306779783510000f, 0.366252595598840000f,
+ 0.371237680474149000f, 0.376262122990906000f, 0.381326011432530000f, 0.386429433787049000f,
+ 0.391572477749723000f, 0.396755230725627000f, 0.401977779832196000f, 0.407240211901737000f,
+ 0.412542613483904000f, 0.417885070848138000f, 0.423267669986072000f, 0.428690496613907000f,
+ 0.434153636174749000f, 0.439657173840919000f, 0.445201194516228000f, 0.450785782838223000f,
+ 0.456411023180405000f, 0.462076999654407000f, 0.467783796112159000f, 0.473531496148010000f,
+ 0.479320183100827000f, 0.485149940056070000f, 0.491020849847836000f, 0.496932995060870000f,
+ 0.502886458032569000f, 0.508881320854934000f, 0.514917665376521000f, 0.520995573204354000f,
+ 0.527115125705813000f, 0.533276404010505000f, 0.539479489012107000f, 0.545724461370187000f,
+ 0.552011401512000000f, 0.558340389634268000f, 0.564711505704929000f, 0.571124829464873000f,
+ 0.577580440429651000f, 0.584078417891164000f, 0.590618840919337000f, 0.597201788363763000f,
+ 0.603827338855338000f, 0.610495570807865000f, 0.617206562419651000f, 0.623960391675076000f,
+ 0.630757136346147000f, 0.637596873994033000f, 0.644479681970582000f, 0.651405637419824000f,
+ 0.658374817279448000f, 0.665387298282272000f, 0.672443156957688000f, 0.679542469633094000f,
+ 0.686685312435314000f, 0.693871761291990000f, 0.701101891932973000f, 0.708375779891687000f,
+ 0.715693500506481000f, 0.723055128921969000f, 0.730460740090354000f, 0.737910408772731000f,
+ 0.745404209540387000f, 0.752942216776078000f, 0.760524504675292000f, 0.768151147247507000f,
+ 0.775822218317423000f, 0.783537791526194000f, 0.791297940332630000f, 0.799102738014409000f,
+ 0.806952257669252000f, 0.814846572216101000f, 0.822785754396284000f, 0.830769876774655000f,
+ 0.838799011740740000f, 0.846873231509858000f, 0.854992608124234000f, 0.863157213454102000f,
+ 0.871367119198797000f, 0.879622396887832000f, 0.887923117881966000f, 0.896269353374266000f,
+ 0.904661174391149000f, 0.913098651793419000f, 0.921581856277295000f, 0.930110858375424000f,
+ 0.938685728457888000f, 0.947306536733200000f, 0.955973353249286000f, 0.964686247894465000f,
+ 0.973445290398413000f, 0.982250550333117000f, 0.991102097113830000f, 1.000000000000000000f,
+};
+
+extern const 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 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;
+ }
+ }
+}
+
+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[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,
+};
+
// Expand range from 0-1 to 0-255, then convert.
-static inline uint8_t clamp_normalized_float_to_byte(float v) {
+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;
@@ -164,30 +454,26 @@ static inline uint8_t clamp_normalized_float_to_byte(float v) {
}
}
-// Interpolating lookup in a variably sized table.
-static inline float interp_lut(uint8_t byte, float* table, size_t tableSize) {
- float index = byte_to_float(byte) * (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;
+static void build_table_linear_to_gamma(uint8_t* outTable, int outTableSize, float exponent) {
+ float toGammaExp = 1.0f / exponent;
+
+ for (int i = 0; i < outTableSize; i++) {
+ float x = ((float) i) * (1.0f / ((float) (outTableSize - 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.
-// FIXME (msarett):
-// This is a placeholder implementation for inverting table gammas. First, I need to
-// verify if there are actually destination profiles that require this functionality.
-// Next, there are certainly faster and more robust approaches to solving this problem.
-// The LUT based approach in QCMS would be a good place to start.
-static inline float interp_lut_inv(float input, float* table, size_t tableSize) {
+static float inverse_interp_lut(float input, float* table, int tableSize) {
if (input <= table[0]) {
return table[0];
} else if (input >= table[tableSize - 1]) {
return 1.0f;
}
- for (uint32_t i = 1; i < tableSize; i++) {
+ 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];
@@ -203,46 +489,222 @@ static inline float interp_lut_inv(float input, float* table, size_t tableSize)
return 0.0f;
}
-SkDefaultXform::SkDefaultXform(const sk_sp<SkGammas>& srcGammas, const SkMatrix44& srcToDst,
- const sk_sp<SkGammas>& dstGammas)
- : fSrcGammas(srcGammas)
- , fSrcToDst(srcToDst)
- , fDstGammas(dstGammas)
-{}
+static void build_table_linear_to_gamma(uint8_t* outTable, int outTableSize, float* inTable,
+ int inTableSize) {
+ for (int i = 0; i < outTableSize; i++) {
+ float x = ((float) i) * (1.0f / ((float) (outTableSize - 1)));
+ float y = inverse_interp_lut(x, inTable, inTableSize);
+ outTable[i] = clamp_normalized_float_to_byte(y);
+ }
+}
-void SkDefaultXform::xform_RGB1_8888(uint32_t* dst, const uint32_t* src, uint32_t len) const {
- while (len-- > 0) {
- // Convert to linear.
- // FIXME (msarett):
- // Rather than support three different strategies of transforming gamma, QCMS
- // builds a 256 entry float lookup table from the gamma info. This handles
- // the gamma transform and the conversion from bytes to floats. This may
- // be simpler and faster than our current approach.
- float srcFloats[3];
- for (int i = 0; i < 3; i++) {
- uint8_t byte = (*src >> (8 * i)) & 0xFF;
- if (fSrcGammas) {
- const SkGammaCurve& gamma = (*fSrcGammas)[i];
- if (gamma.isValue()) {
- srcFloats[i] = powf(byte_to_float(byte), gamma.fValue);
- } else if (gamma.isTable()) {
- srcFloats[i] = interp_lut(byte, gamma.fTable.get(), gamma.fTableSize);
+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, int outTableSize, float g, float a,
+ float b, float c, float d, float e, float f) {
+ for (int i = 0; i < outTableSize; i++) {
+ float x = ((float) i) * (1.0f / ((float) (outTableSize - 1)));
+ float y = inverse_parametric(x, g, a, b, c, d, e, f);
+ outTable[i] = clamp_normalized_float_to_byte(y);
+ }
+}
+
+SkDefaultXform::SkDefaultXform(const sk_sp<SkColorSpace>& srcSpace, const SkMatrix44& srcToDst,
+ const sk_sp<SkColorSpace>& dstSpace)
+ : fSrcToDst(srcToDst)
+{
+ // Build tables to transform src gamma to linear.
+ switch (srcSpace->gammaNamed()) {
+ case SkColorSpace::kSRGB_GammaNamed:
+ fSrcGammaTables[0] = fSrcGammaTables[1] = fSrcGammaTables[2] = sk_linear_from_srgb;
+ break;
+ case SkColorSpace::k2Dot2Curve_GammaNamed:
+ fSrcGammaTables[0] = fSrcGammaTables[1] = fSrcGammaTables[2] = sk_linear_from_2dot2;
+ break;
+ case SkColorSpace::kLinear_GammaNamed:
+ build_table_linear_from_gamma(fSrcGammaTableStorage, 1.0f);
+ fSrcGammaTables[0] = fSrcGammaTables[1] = fSrcGammaTables[2] = fSrcGammaTableStorage;
+ break;
+ default: {
+ const SkGammas* gammas = as_CSB(srcSpace)->gammas();
+ SkASSERT(gammas);
+
+ for (int i = 0; i < 3; i++) {
+ const SkGammaCurve& curve = (*gammas)[i];
+
+ if (i > 0) {
+ // Check if this curve matches the first curve. In this case, we can
+ // share the same table pointer. Logically, 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.
+ // TODO (msarett):
+ // This comparison won't catch the case where each gamma curve has a
+ // pointer to its own look-up table, but the tables actually match.
+ // Should we perform a deep compare of gamma tables here? Or should
+ // we catch this when parsing the profile? Or should we not worry
+ // about a bit of redundant work?
+ if (curve.quickEquals((*gammas)[0])) {
+ fSrcGammaTables[i] = fSrcGammaTables[0];
+ continue;
+ }
+ }
+
+ if (curve.isNamed()) {
+ switch (curve.fNamed) {
+ case SkColorSpace::kSRGB_GammaNamed:
+ fSrcGammaTables[i] = sk_linear_from_srgb;
+ break;
+ case SkColorSpace::k2Dot2Curve_GammaNamed:
+ fSrcGammaTables[i] = sk_linear_from_2dot2;
+ break;
+ case SkColorSpace::kLinear_GammaNamed:
+ build_table_linear_from_gamma(&fSrcGammaTableStorage[i * 256], 1.0f);
+ fSrcGammaTables[i] = &fSrcGammaTableStorage[i * 256];
+ break;
+ default:
+ SkASSERT(false);
+ break;
+ }
+ } else if (curve.isValue()) {
+ build_table_linear_from_gamma(&fSrcGammaTableStorage[i * 256], curve.fValue);
+ fSrcGammaTables[i] = &fSrcGammaTableStorage[i * 256];
+ } else if (curve.isTable()) {
+ build_table_linear_from_gamma(&fSrcGammaTableStorage[i * 256],
+ curve.fTable.get(), curve.fTableSize);
+ fSrcGammaTables[i] = &fSrcGammaTableStorage[i * 256];
} else {
- SkASSERT(gamma.isParametric());
- float component = byte_to_float(byte);
- if (component < gamma.fD) {
- // Y = E * X + F
- srcFloats[i] = gamma.fE * component + gamma.fF;
- } else {
- // Y = (A * X + B)^G + C
- srcFloats[i] = powf(gamma.fA * component + gamma.fB, gamma.fG) + gamma.fC;
+ SkASSERT(curve.isParametric());
+ build_table_linear_from_gamma(&fSrcGammaTableStorage[i * 256], curve.fG,
+ curve.fA, curve.fB, curve.fC, curve.fD, curve.fE,
+ curve.fF);
+ fSrcGammaTables[i] = &fSrcGammaTableStorage[i * 256];
+ }
+ }
+ }
+ }
+
+ // Build tables to transform linear to dst gamma.
+ switch (dstSpace->gammaNamed()) {
+ case SkColorSpace::kSRGB_GammaNamed:
+ fDstGammaTables[0] = fDstGammaTables[1] = fDstGammaTables[2] = linear_to_srgb;
+ break;
+ case SkColorSpace::k2Dot2Curve_GammaNamed:
+ fDstGammaTables[0] = fDstGammaTables[1] = fDstGammaTables[2] = linear_to_2dot2;
+ break;
+ case SkColorSpace::kLinear_GammaNamed:
+ build_table_linear_to_gamma(fDstGammaTableStorage, kDstGammaTableSize, 1.0f);
+ fDstGammaTables[0] = fDstGammaTables[1] = fDstGammaTables[2] = fDstGammaTableStorage;
+ break;
+ default: {
+ const SkGammas* gammas = as_CSB(dstSpace)->gammas();
+ SkASSERT(gammas);
+
+ for (int i = 0; i < 3; i++) {
+ const SkGammaCurve& curve = (*gammas)[i];
+
+ if (i > 0) {
+ // Check if this curve matches the first curve. In this case, we can
+ // share the same table pointer. Logically, 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.
+ // TODO (msarett):
+ // This comparison won't catch the case where each gamma curve has a
+ // pointer to its own look-up table (but the tables actually match).
+ // Should we perform a deep compare of gamma tables here? Or should
+ // we catch this when parsing the profile? Or should we not worry
+ // about a bit of redundant work?
+ if (curve.quickEquals((*gammas)[0])) {
+ fDstGammaTables[i] = fDstGammaTables[0];
+ continue;
+ }
+ }
+
+ if (curve.isNamed()) {
+ switch (curve.fNamed) {
+ case SkColorSpace::kSRGB_GammaNamed:
+ fDstGammaTables[i] = linear_to_srgb;
+ break;
+ case SkColorSpace::k2Dot2Curve_GammaNamed:
+ fDstGammaTables[i] = linear_to_2dot2;
+ break;
+ case SkColorSpace::kLinear_GammaNamed:
+ build_table_linear_to_gamma(
+ &fDstGammaTableStorage[i * kDstGammaTableSize],
+ kDstGammaTableSize, 1.0f);
+ fDstGammaTables[i] = &fDstGammaTableStorage[i * kDstGammaTableSize];
+ break;
+ default:
+ SkASSERT(false);
+ break;
}
+ } else if (curve.isValue()) {
+ build_table_linear_to_gamma(&fDstGammaTableStorage[i * kDstGammaTableSize],
+ kDstGammaTableSize, curve.fValue);
+ fDstGammaTables[i] = &fDstGammaTableStorage[i * kDstGammaTableSize];
+ } else if (curve.isTable()) {
+ build_table_linear_to_gamma(&fDstGammaTableStorage[i * kDstGammaTableSize],
+ kDstGammaTableSize, curve.fTable.get(),
+ curve.fTableSize);
+ fDstGammaTables[i] = &fDstGammaTableStorage[i * kDstGammaTableSize];
+ } else {
+ SkASSERT(curve.isParametric());
+ build_table_linear_to_gamma(&fDstGammaTableStorage[i * kDstGammaTableSize],
+ kDstGammaTableSize, curve.fG, curve.fA, curve.fB,
+ curve.fC, curve.fD, curve.fE, curve.fF);
+ fDstGammaTables[i] = &fDstGammaTableStorage[i * kDstGammaTableSize];
}
- } else {
- // FIXME: Handle named gammas.
- srcFloats[i] = powf(byte_to_float(byte), 2.2f);
}
}
+ }
+}
+
+// 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;
+ }
+}
+
+void SkDefaultXform::xform_RGB1_8888(uint32_t* dst, const uint32_t* src, uint32_t len) const {
+ while (len-- > 0) {
+ // Convert to linear.
+ float srcFloats[3];
+ srcFloats[0] = fSrcGammaTables[0][(*src >> 0) & 0xFF];
+ srcFloats[1] = fSrcGammaTables[1][(*src >> 8) & 0xFF];
+ srcFloats[2] = fSrcGammaTables[2][(*src >> 16) & 0xFF];
// Convert to dst gamut.
float dstFloats[3];
@@ -256,67 +718,17 @@ void SkDefaultXform::xform_RGB1_8888(uint32_t* dst, const uint32_t* src, uint32_
srcFloats[1] * fSrcToDst.getFloat(1, 2) +
srcFloats[2] * fSrcToDst.getFloat(2, 2) + fSrcToDst.getFloat(3, 2);
+ // Clamp to 0-1.
+ dstFloats[0] = clamp_normalized_float(dstFloats[0]);
+ dstFloats[1] = clamp_normalized_float(dstFloats[1]);
+ dstFloats[2] = clamp_normalized_float(dstFloats[2]);
+
// Convert to dst gamma.
- // FIXME (msarett):
- // Rather than support three different strategies of transforming inverse gamma,
- // QCMS builds a large float lookup table from the gamma info. Is this faster or
- // better than our approach?
- for (int i = 0; i < 3; i++) {
- if (fDstGammas) {
- const SkGammaCurve& gamma = (*fDstGammas)[i];
- if (gamma.isValue()) {
- dstFloats[i] = powf(dstFloats[i], 1.0f / gamma.fValue);
- } else if (gamma.isTable()) {
- // FIXME (msarett):
- // An inverse table lookup is particularly strange and non-optimal.
- dstFloats[i] = interp_lut_inv(dstFloats[i], gamma.fTable.get(),
- gamma.fTableSize);
- } else {
- SkASSERT(gamma.isParametric());
- // FIXME (msarett):
- // This is a placeholder implementation for inverting parametric gammas.
- // First, I need to verify if there are actually destination profiles that
- // require this functionality. Next, I need to explore other possibilities
- // for this implementation. The LUT based approach in QCMS would be a good
- // place to start.
-
- // We need to take the inverse of a piecewise function. Assume that
- // the gamma function is continuous, or this won't make much sense
- // anyway.
- // Plug in |fD| to the first equation to calculate the new piecewise
- // interval. Then simply use the inverse of the original functions.
- float interval = gamma.fE * gamma.fD + gamma.fF;
- if (dstFloats[i] < interval) {
- // X = (Y - F) / E
- if (0.0f == gamma.fE) {
- // The gamma curve for this segment is constant, so the inverse
- // is undefined.
- dstFloats[i] = 0.0f;
- } else {
- dstFloats[i] = (dstFloats[i] - gamma.fF) / gamma.fE;
- }
- } else {
- // X = ((Y - C)^(1 / G) - B) / A
- if (0.0f == gamma.fA || 0.0f == gamma.fG) {
- // The gamma curve for this segment is constant, so the inverse
- // is undefined.
- dstFloats[i] = 0.0f;
- } else {
- dstFloats[i] = (powf(dstFloats[i] - gamma.fC, 1.0f / gamma.fG) -
- gamma.fB) / gamma.fA;
- }
- }
- }
- } else {
- // FIXME: Handle named gammas.
- dstFloats[i] = powf(dstFloats[i], 1.0f / 2.2f);
- }
- }
+ uint8_t r = fDstGammaTables[0][sk_float_round2int((kDstGammaTableSize - 1) * dstFloats[0])];
+ uint8_t g = fDstGammaTables[1][sk_float_round2int((kDstGammaTableSize - 1) * dstFloats[1])];
+ uint8_t b = fDstGammaTables[2][sk_float_round2int((kDstGammaTableSize - 1) * dstFloats[2])];
- *dst = SkPackARGB32NoCheck(((*src >> 24) & 0xFF),
- clamp_normalized_float_to_byte(dstFloats[0]),
- clamp_normalized_float_to_byte(dstFloats[1]),
- clamp_normalized_float_to_byte(dstFloats[2]));
+ *dst = SkPackARGB32NoCheck(0xFF, r, g, b);
dst++;
src++;
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