问题描述
朋友
我需要帮助优化以下片段着色器：它看起来很长，但实际上没有。它将初始化一个包含256个元素的长数组。
片段：
#version 410
//#extension GL_ARB_shading_language_420pack : enable
layout (location = 0) in vec3 colorOut;
uniform int colorBands;
uniform int computeDiff;
uniform float diffScaling;
uniform sampler2D textureD;
//layout (location = 0) out vec4 colorOut;
out vec4 fColor;
vec3 computeplasmaColormap(float value,vec3 p[256]) {
return p[int(255 * clamp(value,1))];
}
float computeColordistance() {
vec2 texSize;
texSize = textureSize(textureD,0);
vec3 texColor = texture(textureD,gl_FragCoord.xy / texSize).xyz;
return texColor == vec3(0) ? 0 : length(colorOut - texColor);
}
void main() {
vec3 plasmaColormap[256];
plasmaColormap[0]=vec3(0.050383,0.029803,0.527975);
plasmaColormap[1]=vec3(0.063536,0.028426,0.533124);
plasmaColormap[2]=vec3(0.075353,0.027206,0.538007);
plasmaColormap[3]=vec3(0.086222,0.026125,0.542658);
plasmaColormap[4]=vec3(0.096379,0.025165,0.547103);
plasmaColormap[5]=vec3(0.10598,0.024309,0.551368);
plasmaColormap[6]=vec3(0.115124,0.023556,0.555468);
plasmaColormap[7]=vec3(0.123903,0.022878,0.559423);
plasmaColormap[8]=vec3(0.132381,0.022258,0.56325);
plasmaColormap[9]=vec3(0.140603,0.021687,0.566959);
plasmaColormap[10]=vec3(0.148607,0.021154,0.570562);
plasmaColormap[11]=vec3(0.156421,0.020651,0.574065);
plasmaColormap[12]=vec3(0.16407,0.020171,0.577478);
plasmaColormap[13]=vec3(0.171574,0.019706,0.580806);
plasmaColormap[14]=vec3(0.17895,0.019252,0.584054);
plasmaColormap[15]=vec3(0.186213,0.018803,0.587228);
plasmaColormap[16]=vec3(0.193374,0.018354,0.59033);
plasmaColormap[17]=vec3(0.200445,0.017902,0.593364);
plasmaColormap[18]=vec3(0.207435,0.017442,0.596333);
plasmaColormap[19]=vec3(0.21435,0.016973,0.599239);
plasmaColormap[20]=vec3(0.221197,0.016497,0.602083);
plasmaColormap[21]=vec3(0.227983,0.016007,0.604867);
plasmaColormap[22]=vec3(0.234715,0.015502,0.607592);
plasmaColormap[23]=vec3(0.241396,0.014979,0.610259);
plasmaColormap[24]=vec3(0.248032,0.014439,0.612868);
plasmaColormap[25]=vec3(0.254627,0.013882,0.615419);
plasmaColormap[26]=vec3(0.261183,0.013308,0.617911);
plasmaColormap[27]=vec3(0.267703,0.012716,0.620346);
plasmaColormap[28]=vec3(0.274191,0.012109,0.622722);
plasmaColormap[29]=vec3(0.280648,0.011488,0.625038);
plasmaColormap[30]=vec3(0.287076,0.010855,0.627295);
plasmaColormap[31]=vec3(0.293478,0.010213,0.62949);
plasmaColormap[32]=vec3(0.299855,0.009561,0.631624);
plasmaColormap[33]=vec3(0.30621,0.008902,0.633694);
plasmaColormap[34]=vec3(0.312543,0.008239,0.6357);
plasmaColormap[35]=vec3(0.318856,0.007576,0.63764);
plasmaColormap[36]=vec3(0.32515,0.006915,0.639512);
plasmaColormap[37]=vec3(0.331426,0.006261,0.641316);
plasmaColormap[38]=vec3(0.337683,0.005618,0.643049);
plasmaColormap[39]=vec3(0.343925,0.004991,0.64471);
plasmaColormap[40]=vec3(0.35015,0.004382,0.646298);
plasmaColormap[41]=vec3(0.356359,0.003798,0.64781);
plasmaColormap[42]=vec3(0.362553,0.003243,0.649245);
plasmaColormap[43]=vec3(0.368733,0.002724,0.650601);
plasmaColormap[44]=vec3(0.374897,0.002245,0.651876);
plasmaColormap[45]=vec3(0.381047,0.001814,0.653068);
plasmaColormap[46]=vec3(0.387183,0.001434,0.654177);
plasmaColormap[47]=vec3(0.393304,0.001114,0.655199);
plasmaColormap[48]=vec3(0.399411,0.000859,0.656133);
plasmaColormap[49]=vec3(0.405503,0.000678,0.656977);
plasmaColormap[50]=vec3(0.41158,0.000577,0.65773);
plasmaColormap[51]=vec3(0.417642,0.000564,0.65839);
plasmaColormap[52]=vec3(0.423689,0.000646,0.658956);
plasmaColormap[53]=vec3(0.429719,0.000831,0.659425);
plasmaColormap[54]=vec3(0.435734,0.001127,0.659797);
plasmaColormap[55]=vec3(0.441732,0.00154,0.660069);
plasmaColormap[56]=vec3(0.447714,0.00208,0.66024);
plasmaColormap[57]=vec3(0.453677,0.002755,0.66031);
plasmaColormap[58]=vec3(0.459623,0.003574,0.660277);
plasmaColormap[59]=vec3(0.46555,0.004545,0.660139);
plasmaColormap[60]=vec3(0.471457,0.005678,0.659897);
plasmaColormap[61]=vec3(0.477344,0.00698,0.659549);
plasmaColormap[62]=vec3(0.48321,0.00846,0.659095);
plasmaColormap[63]=vec3(0.489055,0.010127,0.658534);
plasmaColormap[64]=vec3(0.494877,0.01199,0.657865);
plasmaColormap[65]=vec3(0.500678,0.014055,0.657088);
plasmaColormap[66]=vec3(0.506454,0.016333,0.656202);
plasmaColormap[67]=vec3(0.512206,0.018833,0.655209);
plasmaColormap[68]=vec3(0.517933,0.021563,0.654109);
plasmaColormap[69]=vec3(0.523633,0.024532,0.652901);
plasmaColormap[70]=vec3(0.529306,0.027747,0.651586);
plasmaColormap[71]=vec3(0.534952,0.031217,0.650165);
plasmaColormap[72]=vec3(0.54057,0.03495,0.64864);
plasmaColormap[73]=vec3(0.546157,0.038954,0.64701);
plasmaColormap[74]=vec3(0.551715,0.043136,0.645277);
plasmaColormap[75]=vec3(0.557243,0.047331,0.643443);
plasmaColormap[76]=vec3(0.562738,0.051545,0.641509);
plasmaColormap[77]=vec3(0.568201,0.055778,0.639477);
plasmaColormap[78]=vec3(0.573632,0.060028,0.637349);
plasmaColormap[79]=vec3(0.579029,0.064296,0.635126);
plasmaColormap[80]=vec3(0.584391,0.068579,0.632812);
plasmaColormap[81]=vec3(0.589719,0.072878,0.630408);
plasmaColormap[82]=vec3(0.595011,0.07719,0.627917);
plasmaColormap[83]=vec3(0.600266,0.081516,0.625342);
plasmaColormap[84]=vec3(0.605485,0.085854,0.622686);
plasmaColormap[85]=vec3(0.610667,0.090204,0.619951);
plasmaColormap[86]=vec3(0.615812,0.094564,0.61714);
plasmaColormap[87]=vec3(0.620919,0.098934,0.614257);
plasmaColormap[88]=vec3(0.625987,0.103312,0.611305);
plasmaColormap[89]=vec3(0.631017,0.107699,0.608287);
plasmaColormap[90]=vec3(0.636008,0.112092,0.605205);
plasmaColormap[91]=vec3(0.640959,0.116492,0.602065);
plasmaColormap[92]=vec3(0.645872,0.120898,0.598867);
plasmaColormap[93]=vec3(0.650746,0.125309,0.595617);
plasmaColormap[94]=vec3(0.65558,0.129725,0.592317);
plasmaColormap[95]=vec3(0.660374,0.134144,0.588971);
plasmaColormap[96]=vec3(0.665129,0.138566,0.585582);
plasmaColormap[97]=vec3(0.669845,0.142992,0.582154);
plasmaColormap[98]=vec3(0.674522,0.147419,0.578688);
plasmaColormap[99]=vec3(0.67916,0.151848,0.575189);
plasmaColormap[100]=vec3(0.683758,0.156278,0.57166);
plasmaColormap[101]=vec3(0.688318,0.160709,0.568103);
plasmaColormap[102]=vec3(0.69284,0.165141,0.564522);
plasmaColormap[103]=vec3(0.697324,0.169573,0.560919);
plasmaColormap[104]=vec3(0.701769,0.174005,0.557296);
plasmaColormap[105]=vec3(0.706178,0.178437,0.553657);
plasmaColormap[106]=vec3(0.710549,0.182868,0.550004);
plasmaColormap[107]=vec3(0.714883,0.187299,0.546338);
plasmaColormap[108]=vec3(0.719181,0.191729,0.542663);
plasmaColormap[109]=vec3(0.723444,0.196158,0.538981);
plasmaColormap[110]=vec3(0.72767,0.200586,0.535293);
plasmaColormap[111]=vec3(0.731862,0.205013,0.531601);
plasmaColormap[112]=vec3(0.736019,0.209439,0.527908);
plasmaColormap[113]=vec3(0.740143,0.213864,0.524216);
plasmaColormap[114]=vec3(0.744232,0.218288,0.520524);
plasmaColormap[115]=vec3(0.748289,0.222711,0.516834);
plasmaColormap[116]=vec3(0.752312,0.227133,0.513149);
plasmaColormap[117]=vec3(0.756304,0.231555,0.509468);
plasmaColormap[118]=vec3(0.760264,0.235976,0.505794);
plasmaColormap[119]=vec3(0.764193,0.240396,0.502126);
plasmaColormap[120]=vec3(0.76809,0.244817,0.498465);
plasmaColormap[121]=vec3(0.771958,0.249237,0.494813);
plasmaColormap[122]=vec3(0.775796,0.253658,0.491171);
plasmaColormap[123]=vec3(0.779604,0.258078,0.487539);
plasmaColormap[124]=vec3(0.783383,0.2625,0.483918);
plasmaColormap[125]=vec3(0.787133,0.266922,0.480307);
plasmaColormap[126]=vec3(0.790855,0.271345,0.476706);
plasmaColormap[127]=vec3(0.794549,0.27577,0.473117);
plasmaColormap[128]=vec3(0.798216,0.280197,0.469538);
plasmaColormap[129]=vec3(0.801855,0.284626,0.465971);
plasmaColormap[130]=vec3(0.805467,0.289057,0.462415);
plasmaColormap[131]=vec3(0.809052,0.293491,0.45887);
plasmaColormap[132]=vec3(0.812612,0.297928,0.455338);
plasmaColormap[133]=vec3(0.816144,0.302368,0.451816);
plasmaColormap[134]=vec3(0.819651,0.306812,0.448306);
plasmaColormap[135]=vec3(0.823132,0.311261,0.444806);
plasmaColormap[136]=vec3(0.826588,0.315714,0.441316);
plasmaColormap[137]=vec3(0.830018,0.320172,0.437836);
plasmaColormap[138]=vec3(0.833422,0.324635,0.434366);
plasmaColormap[139]=vec3(0.836801,0.329105,0.430905);
plasmaColormap[140]=vec3(0.840155,0.33358,0.427455);
plasmaColormap[141]=vec3(0.843484,0.338062,0.424013);
plasmaColormap[142]=vec3(0.846788,0.342551,0.420579);
plasmaColormap[143]=vec3(0.850066,0.347048,0.417153);
plasmaColormap[144]=vec3(0.853319,0.351553,0.413734);
plasmaColormap[145]=vec3(0.856547,0.356066,0.410322);
plasmaColormap[146]=vec3(0.85975,0.360588,0.406917);
plasmaColormap[147]=vec3(0.862927,0.365119,0.403519);
plasmaColormap[148]=vec3(0.866078,0.36966,0.400126);
plasmaColormap[149]=vec3(0.869203,0.374212,0.396738);
plasmaColormap[150]=vec3(0.872303,0.378774,0.393355);
plasmaColormap[151]=vec3(0.875376,0.383347,0.389976);
plasmaColormap[152]=vec3(0.878423,0.387932,0.3866);
plasmaColormap[153]=vec3(0.881443,0.392529,0.383229);
plasmaColormap[154]=vec3(0.884436,0.397139,0.37986);
plasmaColormap[155]=vec3(0.887402,0.401762,0.376494);
plasmaColormap[156]=vec3(0.89034,0.406398,0.37313);
plasmaColormap[157]=vec3(0.89325,0.411048,0.369768);
plasmaColormap[158]=vec3(0.896131,0.415712,0.366407);
plasmaColormap[159]=vec3(0.898984,0.420392,0.363047);
plasmaColormap[160]=vec3(0.901807,0.425087,0.359688);
plasmaColormap[161]=vec3(0.904601,0.429797,0.356329);
plasmaColormap[162]=vec3(0.907365,0.434524,0.35297);
plasmaColormap[163]=vec3(0.910098,0.439268,0.34961);
plasmaColormap[164]=vec3(0.9128,0.444029,0.346251);
plasmaColormap[165]=vec3(0.915471,0.448807,0.34289);
plasmaColormap[166]=vec3(0.918109,0.453603,0.339529);
plasmaColormap[167]=vec3(0.920714,0.458417,0.336166);
plasmaColormap[168]=vec3(0.923287,0.463251,0.332801);
plasmaColormap[169]=vec3(0.925825,0.468103,0.329435);
plasmaColormap[170]=vec3(0.928329,0.472975,0.326067);
plasmaColormap[171]=vec3(0.930798,0.477867,0.322697);
plasmaColormap[172]=vec3(0.933232,0.48278,0.319325);
plasmaColormap[173]=vec3(0.93563,0.487712,0.315952);
plasmaColormap[174]=vec3(0.93799,0.492667,0.312575);
plasmaColormap[175]=vec3(0.940313,0.497642,0.309197);
plasmaColormap[176]=vec3(0.942598,0.502639,0.305816);
plasmaColormap[177]=vec3(0.944844,0.507658,0.302433);
plasmaColormap[178]=vec3(0.947051,0.512699,0.299049);
plasmaColormap[179]=vec3(0.949217,0.517763,0.295662);
plasmaColormap[180]=vec3(0.951344,0.52285,0.292275);
plasmaColormap[181]=vec3(0.953428,0.52796,0.288883);
plasmaColormap[182]=vec3(0.95547,0.533093,0.28549);
plasmaColormap[183]=vec3(0.957469,0.53825,0.282096);
plasmaColormap[184]=vec3(0.959424,0.543431,0.278701);
plasmaColormap[185]=vec3(0.961336,0.548636,0.275305);
plasmaColormap[186]=vec3(0.963203,0.553865,0.271909);
plasmaColormap[187]=vec3(0.965024,0.559118,0.268513);
plasmaColormap[188]=vec3(0.966798,0.564396,0.265118);
plasmaColormap[189]=vec3(0.968526,0.5697,0.261721);
plasmaColormap[190]=vec3(0.970205,0.575028,0.258325);
plasmaColormap[191]=vec3(0.971835,0.580382,0.254931);
plasmaColormap[192]=vec3(0.973416,0.585761,0.25154);
plasmaColormap[193]=vec3(0.974947,0.591165,0.248151);
plasmaColormap[194]=vec3(0.976428,0.596595,0.244767);
plasmaColormap[195]=vec3(0.977856,0.602051,0.241387);
plasmaColormap[196]=vec3(0.979233,0.607532,0.238013);
plasmaColormap[197]=vec3(0.980556,0.613039,0.234646);
plasmaColormap[198]=vec3(0.981826,0.618572,0.231287);
plasmaColormap[199]=vec3(0.983041,0.624131,0.227937);
plasmaColormap[200]=vec3(0.984199,0.629718,0.224595);
plasmaColormap[201]=vec3(0.985301,0.63533,0.221265);
plasmaColormap[202]=vec3(0.986345,0.640969,0.217948);
plasmaColormap[203]=vec3(0.987332,0.646633,0.214648);
plasmaColormap[204]=vec3(0.98826,0.652325,0.211364);
plasmaColormap[205]=vec3(0.989128,0.658043,0.2081);
plasmaColormap[206]=vec3(0.989935,0.663787,0.204859);
plasmaColormap[207]=vec3(0.990681,0.669558,0.201642);
plasmaColormap[208]=vec3(0.991365,0.675355,0.198453);
plasmaColormap[209]=vec3(0.991985,0.681179,0.195295);
plasmaColormap[210]=vec3(0.992541,0.68703,0.19217);
plasmaColormap[211]=vec3(0.993032,0.692907,0.189084);
plasmaColormap[212]=vec3(0.993456,0.69881,0.186041);
plasmaColormap[213]=vec3(0.993814,0.704741,0.183043);
plasmaColormap[214]=vec3(0.994103,0.710698,0.180097);
plasmaColormap[215]=vec3(0.994324,0.716681,0.177208);
plasmaColormap[216]=vec3(0.994474,0.722691,0.174381);
plasmaColormap[217]=vec3(0.994553,0.728728,0.171622);
plasmaColormap[218]=vec3(0.994561,0.734791,0.168938);
plasmaColormap[219]=vec3(0.994495,0.74088,0.166335);
plasmaColormap[220]=vec3(0.994355,0.746995,0.163821);
plasmaColormap[221]=vec3(0.994141,0.753137,0.161404);
plasmaColormap[222]=vec3(0.993851,0.759304,0.159092);
plasmaColormap[223]=vec3(0.993482,0.765499,0.156891);
plasmaColormap[224]=vec3(0.993033,0.77172,0.154808);
plasmaColormap[225]=vec3(0.992505,0.777967,0.152855);
plasmaColormap[226]=vec3(0.991897,0.784239,0.151042);
plasmaColormap[227]=vec3(0.991209,0.790537,0.149377);
plasmaColormap[228]=vec3(0.990439,0.796859,0.14787);
plasmaColormap[229]=vec3(0.989587,0.803205,0.146529);
plasmaColormap[230]=vec3(0.988648,0.809579,0.145357);
plasmaColormap[231]=vec3(0.987621,0.815978,0.144363);
plasmaColormap[232]=vec3(0.986509,0.822401,0.143557);
plasmaColormap[233]=vec3(0.985314,0.828846,0.142945);
plasmaColormap[234]=vec3(0.984031,0.835315,0.142528);
plasmaColormap[235]=vec3(0.982653,0.841812,0.142303);
plasmaColormap[236]=vec3(0.98119,0.848329,0.142279);
plasmaColormap[237]=vec3(0.979644,0.854866,0.142453);
plasmaColormap[238]=vec3(0.977995,0.861432,0.142808);
plasmaColormap[239]=vec3(0.976265,0.868016,0.143351);
plasmaColormap[240]=vec3(0.974443,0.874622,0.144061);
plasmaColormap[241]=vec3(0.97253,0.88125,0.144923);
plasmaColormap[242]=vec3(0.970533,0.887896,0.145919);
plasmaColormap[243]=vec3(0.968443,0.894564,0.147014);
plasmaColormap[244]=vec3(0.966271,0.901249,0.14818);
plasmaColormap[245]=vec3(0.964021,0.90795,0.14937);
plasmaColormap[246]=vec3(0.961681,0.914672,0.15052);
plasmaColormap[247]=vec3(0.959276,0.921407,0.151566);
plasmaColormap[248]=vec3(0.956808,0.928152,0.152409);
plasmaColormap[249]=vec3(0.954287,0.934908,0.152921);
plasmaColormap[250]=vec3(0.951726,0.941671,0.152925);
plasmaColormap[251]=vec3(0.949151,0.948435,0.152178);
plasmaColormap[252]=vec3(0.946602,0.95519,0.150328);
plasmaColormap[253]=vec3(0.944152,0.961916,0.146861);
plasmaColormap[254]=vec3(0.941896,0.96859,0.140956);
plasmaColormap[255]=vec3(0.940015,0.975158,0.131326);
if (computeDiff == 0) // Compute color
fColor = colorBands == 0 ? vec4(colorOut,1) : vec4(floor(.5 + colorBands * colorOut) / colorBands,1);
else if (computeDiff == 1) // Compute colormapped distance
fColor = vec4(computeplasmaColormap(diffScaling * computeColordistance(),plasmaColormap),1);
else if (computeDiff == 2) { // Compute distance
float distance = computeColordistance();
float r = floor(distance * 255);
float g = floor((distance - r / 255) * pow(255,2));
float b = floor((distance - r / 255 - g / pow(255,2)) * pow(255,3));
fColor = vec4(r / 255,g / 255,b / 255,1);
}
// colorOut = vec4(0.7,0.2,0.3,1);
}
我的问题是，您对改进此着色器有什么建议吗？也许我可以对变体plasmaColormap做些什么。我真的不知道在哪里看或可以在这里进行优化。
解决方法
您至少可以做的就是将plasmaColors[256]放入这样的常量数组中。
const vec3 plasmaColormap[256] = vec3[256](
vec3(0.050383,0.029803,0.527975),vec3(0.063536,0.028426,0.533124),... all the rest of the values
);
并在computePlasmaColormap函数中更改引用。
第二种方法是按照注释中的建议将颜色图放入纹理或均匀的缓冲区中。
希望这可以澄清一些问题。