// Copyright (C) 2014 NVIDIA Corporation.
// Copyright (C) 2023 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only

#ifndef SHADOW_MAPPING_GLSLLIB
#define SHADOW_MAPPING_GLSLLIB

#include "depthpass.glsllib"

// https://github.com/bartwronski/PoissonSamplingGenerator
const vec2 POISSON_SAMPLES[124 /*4+8+16+32+64*/] = {
    // 4
    vec2( 0.23640461642415603f, -0.7455790794965167f ),
    vec2( -0.524523693183717f, 0.8360051250157925f ),
    vec2( -0.8303867012956179f, -0.22100142699203368f ),
    vec2( 0.8316259303685443f, 0.3983087509528287f ),
    // 8
    vec2( -0.0874674259750227f, -0.7211290298533339f ),
    vec2( 0.12554010991848777f, 0.969408902746625f ),
    vec2( 0.9267513490906857f, -0.24897870637254021f ),
    vec2( -0.9054894676343846f, 0.34600599115357455f ),
    vec2( -0.8178505628144991f, -0.40138762250327864f ),
    vec2( 0.10942236848429054f, 0.07217625956749806f ),
    vec2( 0.861975194360118f, 0.4425266420410188f ),
    vec2( -0.33944946656315295f, 0.5509253616181038f ),
    // 16
    vec2( -0.8706486263306604f, 0.29306121613135f ),
    vec2( 0.9133375480173374f, 0.15086697583928435f ),
    vec2( 0.02197503960070916f, -0.9340974876813268f ),
    vec2( -0.026143912634373823f, 0.2642260889014032f ),
    vec2( -0.5793670131538275f, -0.5167505662963623f ),
    vec2( -0.23053981430283804f, 0.8077614627936293f ),
    vec2( 0.39960043495074177f, -0.2045760409607943f ),
    vec2( 0.5809502755699385f, 0.7696930884669377f ),
    vec2( 0.6096170857392385f, -0.791637809856054f ),
    vec2( -0.4788580330837991f, 0.3668196169738974f ),
    vec2( -0.5400324102392389f, -0.1135665329722174f ),
    vec2( -0.032606987036329485f, -0.30546143641964013f ),
    vec2( 0.41507180983866865f, 0.23290979538051837f ),
    vec2( -0.39037522026642774f, -0.8645330401408355f ),
    vec2( 0.2285381977385323f, 0.7940269386679456f ),
    vec2( 0.8696012264365776f, -0.33202273416645656f ),
    // 32
    vec2( -0.1119962878026457f, -0.5925237363556031f ),
    vec2( 0.47571682749031224f, -0.20934024818626265f ),
    vec2( -0.0497337873197139f, 0.9821551594584884f ),
    vec2( -0.758932140284425f, 0.46354995755196127f ),
    vec2( 0.4325966870184971f, -0.6388677670720698f ),
    vec2( 0.7366824377575745f, 0.5081297060337813f ),
    vec2( -0.13145265154415242f, 0.24953275365571043f ),
    vec2( 0.2007480179521731f, 0.5804136111059729f ),
    vec2( -0.594194121061706f, -0.4430036959643385f ),
    vec2( -0.3220635244610025f, 0.5286773727816093f ),
    vec2( 0.9680248209906945f, -0.22449924910011218f ),
    vec2( -0.6564942867812043f, 0.0327877994091015f ),
    vec2( -0.26549345548708136f, -0.13651797315206687f ),
    vec2( 0.4719899406491344f, 0.8768113130384265f ),
    vec2( 0.18581597399488906f, -0.04419664810096702f ),
    vec2( 0.44596551134789697f, 0.20712921746074858f ),
    vec2( -0.22817457383344453f, 0.7334279998629781f ),
    vec2( 0.1427691568311827f, 0.22421627059021498f ),
    vec2( -0.3279828303935567f, -0.8698684535365524f ),
    vec2( -0.9423049500696031f, -0.1457340275179852f ),
    vec2( 0.06207958411346048f, -0.9358457962896854f ),
    vec2( 0.7185162827437339f, 0.2085484829657599f ),
    vec2( 0.7512563698363448f, -0.5191738312189818f ),
    vec2( 0.17733175603860138f, -0.6673744413513492f ),
    vec2( -0.9426131847313582f, 0.17968743552714408f ),
    vec2( -0.7151303324675325f, -0.6705279521154474f ),
    vec2( -0.00904793792378128f, 0.4735870990940633f ),
    vec2( 0.8122560702060787f, -0.01955271921761288f ),
    vec2( -0.03078416899123267f, -0.2570883354754169f ),
    vec2( -0.4018134376544835f, 0.15614420626520636f ),
    vec2( -0.3738722572700239f, -0.5947955856212755f ),
    vec2( 0.15852305329831748f, 0.9011261825254757f ),
    // 64
    vec2( -0.7399826935513734f, 0.2152938831212798f ),
    vec2( 0.34437990853843525f, -0.7932083303628226f ),
    vec2( 0.7243032872336335f, 0.5098872220424266f ),
    vec2( 0.769505703690554f, -0.2508251489390572f ),
    vec2( -0.26075298451631035f, 0.9045055487383383f ),
    vec2( -0.3934154071036747f, 0.32968264287509236f ),
    vec2( -0.15642665286955218f, -0.30452037407933846f ),
    vec2( -0.6712612799401013f, -0.7212906474979998f ),
    vec2( 0.2318989089430838f, 0.5682132607853351f ),
    vec2( 0.3812030213794879f, 0.9126259946547066f ),
    vec2( -0.7072386006642044f, -0.29476255675495483f ),
    vec2( -0.30846609278740056f, -0.8774001568523211f ),
    vec2( 0.3549362710781743f, -0.3984172672957127f ),
    vec2( -0.035206681299566674f, -0.6971563322470683f ),
    vec2( 0.9573755029686247f, 0.18611474624023477f ),
    vec2( -0.9222399024595912f, -0.02324330286047885f ),
    vec2( 0.1105214413816167f, 0.33702355684333724f ),
    vec2( -0.5779033283277037f, 0.7044148231099682f ),
    vec2( 0.28201314105292297f, -0.03852890427854218f ),
    vec2( 0.0014749550907479146f, -0.0013031709796645218f ),
    vec2( 0.4030275009776176f, 0.42661659787834955f ),
    vec2( 0.748809880116374f, 0.011286053587297815f ),
    vec2( -0.8304540460336253f, -0.529810943767509f ),
    vec2( 0.12842548152877592f, -0.47541572682133015f ),
    vec2( -0.16290552256348545f, 0.5027495898061879f ),
    vec2( 0.4622565205733403f, 0.6681454303000667f ),
    vec2( -0.3172026040724947f, 0.13254119656035013f ),
    vec2( 0.7958019376147858f, -0.5406112374667381f ),
    vec2( 0.10427264538501442f, -0.8082489949983173f ),
    vec2( 0.27482257176538333f, 0.18498734987810514f ),
    vec2( 0.2373347921583017f, -0.5842495326272807f ),
    vec2( -0.9276222569420903f, -0.33405260225577876f ),
    vec2( 0.5730919654394195f, -0.6010672444825778f ),
    vec2( 0.10964923428873828f, 0.7153263403767308f ),
    vec2( 0.5032238159620449f, 0.018451247521665468f ),
    vec2( -0.4188410110227276f, -0.24418102772454264f ),
    vec2( -0.038737840812325036f, 0.2143811997743573f ),
    vec2( -0.07939854894246146f, 0.8963890732170482f ),
    vec2( -0.6026795264710081f, -0.059999679418307354f ),
    vec2( 0.19597724904768493f, -0.9791400680775438f ),
    vec2( 0.5374866426787607f, -0.28636649300616956f ),
    vec2( -0.32531620462001704f, 0.5967983504280451f ),
    vec2( 0.14978599900778694f, 0.9214996545609654f ),
    vec2( 0.5713147466478504f, 0.24520634473806158f ),
    vec2( 0.9520976984765883f, -0.08363259251554482f ),
    vec2( -0.12086180998953151f, 0.715884215195216f ),
    vec2( -0.4055595769367884f, -0.039997226386994135f ),
    vec2( 0.6248294486436189f, -0.7743352989133929f ),
    vec2( 0.1246472844548065f, 0.09016787227316245f ),
    vec2( -0.3541479829800732f, -0.41533491005757284f ),
    vec2( 0.6135165665992666f, -0.08413359326954067f ),
    vec2( -0.48092653976673916f, -0.8399075959778608f ),
    vec2( -0.4995379433683242f, -0.4794062627623045f ),
    vec2( 0.3641672373550888f, -0.23946093499564322f ),
    vec2( 0.9165490661933687f, -0.2980264303499448f ),
    vec2( 0.013660818565102553f, -0.9377291251500764f ),
    vec2( -0.5567254232166509f, 0.14827130149768358f ),
    vec2( -0.013230486748802058f, 0.5490561267442035f ),
    vec2( -0.6452500652885336f, -0.4305298013597207f ),
    vec2( 0.25718749821872966f, 0.4072287132599995f ),
    vec2( -0.6107480885910956f, 0.36928034931290354f ),
    vec2( 0.10778972290853645f, -0.6434978101573962f ),
    vec2( -0.17425112716408775f, -0.48134457129954794f ),
    vec2( 0.016665876823853197f, -0.20591567591862048f ),
};

// https://github.com/matt77hias/fibpy
const vec3 CUBEMAP_SAMPLE_DIRECTIONS[124 /*4+8+16+32+64*/] = {
    // 4
    vec3(-0.4877236689784852, 0.44679483291345823, -0.75),
    vec3(0.08464959396472493, -0.9645384628108966, -0.25),
    vec3(0.5891183939391361, 0.7684006233226082, 0.25),
    vec3(0.6614378277661477, 0.0, 0.75),
    // 8
    vec3(-0.3569771731011225, 0.32702033252495366, -0.875),
    vec3(0.06824668448324298, -0.7776357695329124, -0.625),
    vec3(0.5640379200352061, 0.7356875863859321, -0.375),
    vec3(-0.9769901230486042, -0.17281579634244423, -0.125),
    vec3(0.8371375040503463, -0.5325183558454643, 0.125),
    vec3(-0.2406596316567426, 0.8952418341938904, 0.375),
    vec3(-0.359795430847844, -0.6927642080398022, 0.625),
    vec3(0.4841229182759271, 0.0, 0.875),
    // 16
    vec3(-0.2565935101015265, 0.2350606742391798, -0.9375),
    vec3(0.05096580458913004, -0.5807290562410173, -0.8125),
    vec3(0.44183879545435206, 0.5763004674919561, -0.6875),
    vec3(-0.8141584358738368, -0.1440131636187035, -0.5625),
    vec3(0.758720295154371, -0.4826357464184188, -0.4375),
    vec3(-0.24660273969406132, 0.9173498998612161, -0.3125),
    vec3(-0.45273265557802134, -0.8717091788969947, -0.1875),
    vec3(0.9374848892962336, 0.3423679779728655, -0.0625),
    vec3(-0.9225384272223549, 0.3808104519286515, 0.0625),
    vec3(0.4163289179926954, -0.8896707155139094, 0.1875),
    vec3(0.28429505799735505, 0.9063774434518329, 0.3125),
    vec3(-0.7780138488858889, -0.4508749282692101, 0.4375),
    vec3(0.8075128776755531, -0.17752944090529632, 0.5625),
    vec3(-0.4176500064322479, 0.5940641565749807, 0.6875),
    vec3(-0.07491674475807025, -0.5781273487345623, 0.8125),
    vec3(0.34798527267687634, 0.0, 0.9375),
    // 32
    vec3(-0.18289637586693194, 0.16754806234254682, -0.96875),
    vec3(0.03695854008471691, -0.42112350185522346, -0.90625),
    vec3(0.3265712693604711, 0.42595439137106045, -0.84375),
    vec3(-0.6146761394926465, -0.10872755418207684, -0.78125),
    vec3(0.5866365694562489, -0.3731701661127315, -0.71875),
    vec3(-0.19588274842317752, 0.7286740604482791, -0.65625),
    vec3(-0.37086864125006885, -0.714085000848868, -0.59375),
    vec3(0.7958071925565281, 0.2906275103552604, -0.53125),
    vec3(-0.8165029703557842, 0.3370405567586508, -0.46875),
    vec3(0.38729435133777224, -0.8276255330291921, -0.40625),
    vec3(0.28104586491086925, 0.896018503891801, -0.34375),
    vec3(-0.8302865554766088, -0.48116803020856275, -0.28125),
    vec3(0.9530216017800259, -0.20951912571560968, -0.21875),
    vec3(-0.5680654245461388, 0.8080146105951395, -0.15625),
    vec3(-0.12794469918031795, -0.9873404131563024, -0.09375),
    vec3(0.7642755404909315, 0.6441322346438614, -0.03125),
    vec3(-0.9986580705574145, 0.04129764654967721, 0.03125),
    vec3(0.7057075666239392, -0.7022732857725106, 0.09375),
    vec3(-0.045624101322307785, 0.9866632550564207, 0.15625),
    vec3(-0.625191769977158, -0.7491886866823526, 0.21875),
    vec3(0.951064433355107, 0.12796437436618524, 0.28125),
    vec3(-0.7708362150087417, 0.5363277609177033, 0.34375),
    vec3(0.20055372830264656, -0.8914814297358684, 0.40625),
    vec3(0.4391752180963922, 0.766419314285585, 0.46875),
    vec3(-0.807135713154504, -0.25749830688874437, 0.53125),
    vec3(0.7304537492364624, -0.33748815938695576, 0.59375),
    vec3(-0.2912998914641671, 0.6960461987059225, 0.65625),
    vec3(-0.23531524528078632, -0.65423632797212, 0.71875),
    vec3(0.5525514113665125, 0.290405535926702, 0.78125),
    vec3(-0.5190079764603671, 0.13680883696061083, 0.84375),
    vec3(0.2286349160632575, -0.35557982599797083, 0.90625),
    vec3(0.24803918541230538, 0.0, 0.96875),
    // 64
    vec3(-0.12983945683291254, 0.11894357832322953, -0.984375),
    vec3(0.026452998113976542, -0.3014182696284052, -0.953125),
    vec3(0.23576239168432472, 0.3075102909534688, -0.921875),
    vec3(-0.44778713973061024, -0.07920723999028692, -0.890625),
    vec3(0.4314507940456887, -0.2744536785913876, -0.859375),
    vec3(-0.1455194985020436, 0.5413252810748024, -0.828125),
    vec3(-0.27845431334181786, -0.536146836003288, -0.796875),
    vec3(0.6042533211213496, 0.22067234373346195, -0.765625),
    vec3(-0.627393960552002, 0.2589791065662885, -0.734375),
    vec3(0.30138258897784437, -0.6440370870035449, -0.703125),
    vec3(0.22166895054880598, 0.7067155444290093, -0.671875),
    vec3(-0.6643558003973694, -0.38500776596501346, -0.640625),
    vec3(0.7743887906878839, -0.1702472033014249, -0.609375),
    vec3(-0.4692758292725949, 0.667496577096481, -0.578125),
    vec3(-0.10759098338435852, -0.8302721931206577, -0.546875),
    vec3(0.6551622449641447, 0.5521714336585534, -0.515625),
    vec3(-0.8741133963470501, 0.0361473332574475, -0.484375),
    vec3(0.6318838471661148, -0.628808824735746, -0.453125),
    vec3(-0.04187965944818988, 0.9056862472730297, -0.421875),
    vec3(-0.5898047361881581, -0.7067831934511581, -0.390625),
    vec3(0.9248592690018653, 0.12443850656583447, -0.359375),
    vec3(-0.7754109508095051, 0.5395107429326125, -0.328125),
    vec3(0.20958634788477798, -0.9316323293849998, -0.296875),
    vec3(0.47932036209664347, 0.8364779434357743, -0.265625),
    vec3(-0.9261567244668057, -0.29546925576092875, -0.234375),
    vec3(0.8888662435347233, -0.41067874972960294, -0.203125),
    vec3(-0.3803160171467355, 0.9087456803070064, -0.171875),
    vec3(-0.33508905616822526, -0.9316329394194303, -0.140625),
    vec3(0.87987879474598, 0.46243963490531564, -0.109375),
    vec3(-0.9640145303478175, 0.254111136421206, -0.078125),
    vec3(0.5402432295193479, -0.840202349040697, -0.046875),
    vec3(0.16935549543945927, 0.9854311622530797, -0.015625),
    vec3(-0.790526657433399, -0.6122282770847631, 0.015625),
    vec3(0.9954901906560397, -0.08247432741527275, 0.046875),
    vec3(-0.6770037888550495, 0.731821258403244, 0.078125),
    vec3(0.004849010222716528, -0.9939887305572734, 0.109375),
    vec3(0.6652085983613412, 0.7332953907131421, 0.140625),
    vec3(-0.980914969955694, -0.0909109789399485, 0.171875),
    vec3(0.7799534193949288, -0.5919568379106356, 0.203125),
    vec3(-0.1739982217177348, 0.9564481053429224, 0.234375),
    vec3(-0.5134724986790146, -0.8159591610340123, 0.265625),
    vec3(0.9209568136982018, 0.25239608094789356, 0.296875),
    vec3(-0.840428208080025, 0.431293880594657, 0.328125),
    vec3(0.32439366278023923, -0.8749962062335016, 0.359375),
    vec3(0.3470865761131722, 0.8526095343456083, 0.390625),
    vec3(-0.8193032017850962, -0.3882830770452015, 0.421875),
    vec3(0.8518781145087908, -0.26264312744853496, 0.453125),
    vec3(-0.44234901628806483, 0.7547901742630077, 0.484375),
    vec3(-0.17989021469904729, -0.8377173568874712, 0.515625),
    vec3(0.6825364686297848, 0.48484193647557233, 0.546875),
    vec3(-0.8096843685433692, 0.10090940348414251, 0.578125),
    vec3(0.5139220166617468, -0.6037766724255942, 0.609375),
    vec3(0.027983070994103954, 0.7673438323937574, 0.640625),
    vec3(-0.5198825852769636, -0.5275472319145847, 0.671875),
    vec3(0.7101385978501072, 0.03630986392819048, 0.703125),
    vec3(-0.5232437905790681, 0.4323300764409624, 0.734375),
    vec3(0.08888949088758348, -0.6371161729109897, 0.765625),
    vec3(0.3426226790094996, 0.49759414607022195, 0.796875),
    vec3(-0.5462688918455557, -0.12569519552006989, 0.828125),
    vec3(0.4449026101500658, -0.2520640332468291, 0.859375),
    vec3(-0.14032269145405407, 0.4325467045743041, 0.890625),
    vec3(-0.16080303981293154, -0.35254626187483645, 0.921875),
    vec3(0.2785458488746204, 0.11817336607593573, 0.953125),
    vec3(0.17608480733726006, 0.0, 0.984375)
};

float normalizedShadowFactor(float shadow, float factor) {
    float normalized = clamp(factor, 0, 100) * 0.01;
    return min(1.0, 1.0 - normalized*(1.0 - shadow));
}

// Point + Spot Light
float qt_samplePointLight_hard( in samplerCube shadowCube, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos ) {
    float dist = length(worldPos - lightPos);
    float mapSizeInv = 1.0f / (shadowData.shadowMapFar - shadowData.clipNear);
    float currentDepth = clamp((dist - shadowData.clipNear) / (shadowData.shadowMapFar - shadowData.clipNear), 0.0, 1.0);
    vec3 smpCoord = worldPos - lightPos;
    // reverse Y if shadowData.isYUp == 1 (not enough on its own, also expects +Y and -Y swapped in shadowCube)
    smpCoord.y = mix(smpCoord.y, -smpCoord.y, shadowData.isYUp);
    float depth = texture( shadowCube, smpCoord ).x + shadowData.bias * mapSizeInv;
    float shadow = currentDepth < depth ? 1.0 : 0.0;
    return normalizedShadowFactor(shadow, shadowData.factor);
}

float qt_samplePointLight_pcf( in samplerCube shadowCube, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos, in int numSamples )
{
    vec3 cubePos = (worldPos - lightPos);
    float dist = length(worldPos - lightPos);
    float mapSizeInv = 1.0f / (shadowData.shadowMapFar - shadowData.clipNear);
    float currentDepth = clamp((dist - shadowData.clipNear) / (shadowData.shadowMapFar - shadowData.clipNear), 0.0, 1.0);
    float shadow = 0.0f;

    for (int i = 0; i < numSamples; ++i)
    {
        vec3 smpCoord = cubePos + CUBEMAP_SAMPLE_DIRECTIONS[i + numSamples - 4] * shadowData.pcfFactor;
        // reverse Y if shadowData.yUp == 1 (not enough on its own, also expects +Y and -Y swapped in shadowCube)
        smpCoord.y = mix(smpCoord.y, -smpCoord.y, shadowData.isYUp);

        float sampleDepth = texture(shadowCube, smpCoord).x + shadowData.bias * mapSizeInv;
        if(currentDepth < sampleDepth)
            shadow += 1.0;
    }
    shadow /= float(numSamples);
    return normalizedShadowFactor(shadow, shadowData.factor);
}

float qt_samplePointLight_pcf_4( in samplerCube shadowCube, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos ) {
    return qt_samplePointLight_pcf(shadowCube, shadowData, lightPos, worldPos, 4);
}

float qt_samplePointLight_pcf_8( in samplerCube shadowCube, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos ) {
    return qt_samplePointLight_pcf(shadowCube, shadowData, lightPos, worldPos, 8);
}

float qt_samplePointLight_pcf_16( in samplerCube shadowCube, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos ) {
    return qt_samplePointLight_pcf(shadowCube, shadowData, lightPos, worldPos, 16);
}

float qt_samplePointLight_pcf_32( in samplerCube shadowCube, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos ) {
    return qt_samplePointLight_pcf(shadowCube, shadowData, lightPos, worldPos, 32);
}

float qt_samplePointLight_pcf_64( in samplerCube shadowCube, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos ) {
    return qt_samplePointLight_pcf(shadowCube, shadowData, lightPos, worldPos, 64);
}

// Directional
int findSplitIndex(in float depth, in vec4 splits, in vec4 splitActive, in int numSplits) {
    for (int i = 0; i < min(numSplits + 1, 4); i++) {
        if (depth < splits[i]) {
            return splitActive[i] > 0.f ? i : -1;
        }
    }

    return -1;
}

float qt_sampleDirectionalLight_splitIndex(in sampler2DArray shadowMap,
                                       in int splitIndex,
                                       in float shadowBias,
                                       in float shadowFactor,
                                       in vec3 dimensionsInverted,
                                       in float flipY,
                                       in float pcfFactor,
                                       in int numSamples,
                                       in vec4 projCoord,
                                       in vec3 worldPos,
                                       in float layerIndex)
{
    vec3 smpCoord = projCoord.xyz / projCoord.w;
    smpCoord.y = mix(smpCoord.y, 1.0 - smpCoord.y, flipY);

    float shadow = 0.0;
    vec2 texelSize = pcfFactor * dimensionsInverted.xy;

    for(int i = 0; i < numSamples; ++i) {
        float pcfDepth = texture(shadowMap, vec3(smpCoord.xy + POISSON_SAMPLES[i + numSamples - 4] * texelSize, float(layerIndex))).r + shadowBias * dimensionsInverted.z;
        shadow += smpCoord.z < pcfDepth ? 1.0 : 0.0;
    }
    shadow /= numSamples;

    return normalizedShadowFactor(shadow, shadowFactor);
}

float qt_sampleDirectionalLight_pcf( in sampler2DArray shadowMap, in ShadowData shadowData, in float zDepthViewSpace, in vec3 worldPos, in int numSamples )
{
    int splitIndex = findSplitIndex(zDepthViewSpace, shadowData.csmSplits, shadowData.csmActive, shadowData.csmNumSplits);

    if (splitIndex == -1)
        return 1.0f;

    vec4 projCoord = shadowData.matrices[splitIndex] * vec4( worldPos, 1.0 );
    vec3 dimensions = shadowData.dimensionsInverted[splitIndex].xyz;
    float shadow = qt_sampleDirectionalLight_splitIndex(shadowMap, splitIndex, shadowData.bias, shadowData.factor, dimensions, float(shadowData.isYUp), shadowData.pcfFactor, numSamples, projCoord, worldPos, float(shadowData.layerIndex + splitIndex));

    if (splitIndex == 0) {
        return shadow;
    }

    float splitPrev = shadowData.csmSplits[splitIndex - 1];
    float split = shadowData.csmSplits[splitIndex];

    float bandLength = shadowData.shadowMapFar * shadowData.csmBlendRatio;
    if (zDepthViewSpace < splitPrev + bandLength && shadowData.csmActive[splitIndex - 1] > 0.0) {
        vec4 projCoordPrev = shadowData.matrices[splitIndex - 1] * vec4(worldPos, 1.0 );
        vec3 dimensionsPrev = shadowData.dimensionsInverted[splitIndex - 1].xyz;
        float shadowPrev = qt_sampleDirectionalLight_splitIndex(shadowMap, splitIndex, shadowData.bias, shadowData.factor, dimensionsPrev, float(shadowData.isYUp), shadowData.pcfFactor, numSamples, projCoordPrev, worldPos, float(shadowData.layerIndex + splitIndex - 1));
        float t = (splitPrev + bandLength - zDepthViewSpace) / bandLength;
        shadow = mix(shadow, shadowPrev, t);
    }
    return shadow;
}

float qt_sampleDirectionalLight_pcf_no_cascades( in sampler2DArray shadowMap, in ShadowData shadowData, in float zDepthViewSpace, in vec3 worldPos, in int numSamples )
{
    if (shadowData.csmActive[0] == 0.0f || zDepthViewSpace >= shadowData.csmSplits[3])
        return 1.0;

    int splitIndex = 0;
    vec4 projCoord = shadowData.matrices[splitIndex] * vec4( worldPos, 1.0 );
    vec3 dimensions = shadowData.dimensionsInverted[splitIndex].xyz;
    float shadow = qt_sampleDirectionalLight_splitIndex(shadowMap, splitIndex, shadowData.bias, shadowData.factor, dimensions, float(shadowData.isYUp), shadowData.pcfFactor, numSamples, projCoord, worldPos, float(shadowData.layerIndex + splitIndex));
    return shadow;
}

float qt_sampleDirectionalLight_hard_cascades(in sampler2DArray shadowMap, in ShadowData shadowData, in float zDepthViewSpace, in vec3 worldPos ) {
    if (zDepthViewSpace >= shadowData.csmSplits[3])
        return 1.0;
    int splitIndex = findSplitIndex(zDepthViewSpace, shadowData.csmSplits, shadowData.csmActive, shadowData.csmNumSplits);
    if (splitIndex == -1)
        return 1.0f;
    vec4 projCoord = shadowData.matrices[splitIndex] * vec4( worldPos, 1.0 );
    vec3 smpCoord = projCoord.xyz / projCoord.w;
    smpCoord.y = mix(smpCoord.y, 1.0 - smpCoord.y, shadowData.isYUp);
    float depth = texture(shadowMap, vec3(smpCoord.xy, float(shadowData.layerIndex + splitIndex))).x + shadowData.bias * shadowData.dimensionsInverted[splitIndex].z;
    float shadow = smpCoord.z < depth ? 1.0 : 0.0;
    return normalizedShadowFactor(shadow, shadowData.factor);
}

float qt_sampleDirectionalLight_hard_no_cascades(in sampler2DArray shadowMap, in ShadowData shadowData, in float zDepthViewSpace, in vec3 worldPos ) {
    if (shadowData.csmActive[0] == 0.0f || zDepthViewSpace >= shadowData.csmSplits[3])
        return 1.0;

    int splitIndex = 0;
    vec4 projCoord = shadowData.matrices[splitIndex] * vec4( worldPos, 1.0 );
    vec3 smpCoord = projCoord.xyz / projCoord.w;
    smpCoord.y = mix(smpCoord.y, 1.0 - smpCoord.y, shadowData.isYUp);
    float depth = texture(shadowMap, vec3(smpCoord.xy, float(shadowData.layerIndex + splitIndex))).x + shadowData.bias * shadowData.dimensionsInverted[splitIndex].z;
    float shadow = smpCoord.z < depth ? 1.0 : 0.0;
    return normalizedShadowFactor(shadow, shadowData.factor);
}

float qt_sampleDirectionalLight_hard(in sampler2DArray shadowMap, in ShadowData shadowData, in float zDepthViewSpace, in vec3 worldPos ) {
    if (shadowData.csmNumSplits == 0)
        return qt_sampleDirectionalLight_hard_no_cascades(shadowMap, shadowData, zDepthViewSpace, worldPos);
    return qt_sampleDirectionalLight_hard_cascades(shadowMap, shadowData, zDepthViewSpace, worldPos);
}

float qt_sampleDirectionalLight_pcf_4( in sampler2DArray shadowMap, in ShadowData shadowData, in float zDepthViewSpace, in vec3 worldPos  ) {
    if (shadowData.csmNumSplits == 0)
        return qt_sampleDirectionalLight_pcf_no_cascades(shadowMap, shadowData, zDepthViewSpace, worldPos, 4);
    return qt_sampleDirectionalLight_pcf(shadowMap, shadowData, zDepthViewSpace, worldPos, 4);
}

float qt_sampleDirectionalLight_pcf_8( in sampler2DArray shadowMap, in ShadowData shadowData, in float zDepthViewSpace, in vec3 worldPos  ) {
    if (shadowData.csmNumSplits == 0)
        return qt_sampleDirectionalLight_pcf_no_cascades(shadowMap, shadowData, zDepthViewSpace, worldPos, 8);
    return qt_sampleDirectionalLight_pcf(shadowMap, shadowData, zDepthViewSpace, worldPos, 8);
}

float qt_sampleDirectionalLight_pcf_16( in sampler2DArray shadowMap, in ShadowData shadowData, in float zDepthViewSpace, in vec3 worldPos  ) {
    if (shadowData.csmNumSplits == 0)
        return qt_sampleDirectionalLight_pcf_no_cascades(shadowMap, shadowData, zDepthViewSpace, worldPos, 16);
    return qt_sampleDirectionalLight_pcf(shadowMap, shadowData, zDepthViewSpace, worldPos, 16);
}

float qt_sampleDirectionalLight_pcf_32( in sampler2DArray shadowMap, in ShadowData shadowData, in float zDepthViewSpace, in vec3 worldPos  ) {
    if (shadowData.csmNumSplits == 0)
        return qt_sampleDirectionalLight_pcf_no_cascades(shadowMap, shadowData, zDepthViewSpace, worldPos, 32);
    return qt_sampleDirectionalLight_pcf(shadowMap, shadowData, zDepthViewSpace, worldPos, 32);
}

float qt_sampleDirectionalLight_pcf_64( in sampler2DArray shadowMap, in ShadowData shadowData, in float zDepthViewSpace, in vec3 worldPos  ) {
    if (shadowData.csmNumSplits == 0)
        return qt_sampleDirectionalLight_pcf_no_cascades(shadowMap, shadowData, zDepthViewSpace, worldPos, 64);
    return qt_sampleDirectionalLight_pcf(shadowMap, shadowData, zDepthViewSpace, worldPos, 64);
}

// SpotLight

float qt_sampleSpotLight_pcf( in sampler2DArray shadowMap, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos, in vec3 lightDir, in float coneAngle, in int numSamples )
{
    vec3 dir = worldPos - lightPos;
    float lightAngle = dot(normalize(dir), normalize(lightDir));
    if (lightAngle < coneAngle)
        return 1.f;

    float dist = length(dir);
    float mapSizeInv = 1.0f / (shadowData.shadowMapFar - shadowData.clipNear);
    float currentDepth = clamp((dist - shadowData.clipNear) / (shadowData.shadowMapFar - shadowData.clipNear), 0.0, 1.0) - shadowData.bias * mapSizeInv;
    float shadow = 0.0f;
    for (int i = 0; i < numSamples; ++i)
    {
        vec3 worldPosPCF = worldPos + CUBEMAP_SAMPLE_DIRECTIONS[i + numSamples - 4] * shadowData.pcfFactor;
        vec4 projCoord = shadowData.matrices[0] * vec4(worldPosPCF, 1.0);
        vec3 smpCoord = projCoord.xyz / projCoord.w;
        smpCoord.y = mix(smpCoord.y, 1.0 - smpCoord.y, shadowData.isYUp);

        float sampleDepth = texture(shadowMap, vec3(smpCoord.xy, float(shadowData.layerIndex))).x ;
        if (currentDepth < sampleDepth)
            shadow += 1.0;
    }
    shadow /= float(numSamples);
    return normalizedShadowFactor(shadow, shadowData.factor);
}

float qt_sampleSpotLight_hard( in sampler2DArray shadowMap, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos, in vec3 lightDir, in float coneAngle) {
    vec3 dir = worldPos - lightPos;
    float lightAngle = dot(normalize(dir), normalize(lightDir));
    if (lightAngle < coneAngle)
        return 1.0;

    float dist = length(dir);
    float mapSizeInv = 1.0f / (shadowData.shadowMapFar - shadowData.clipNear);
    float currentDepth = clamp((dist - shadowData.clipNear) / (shadowData.shadowMapFar - shadowData.clipNear), 0.0, 1.0) - shadowData.bias * mapSizeInv;
    vec4 projCoord = shadowData.matrices[0] * vec4(worldPos, 1.0);
    vec3 smpCoord = projCoord.xyz / projCoord.w;
    smpCoord.y = mix(smpCoord.y, 1.0 - smpCoord.y, shadowData.isYUp);
    float sampleDepth = texture(shadowMap, vec3(smpCoord.xy, float(shadowData.layerIndex))).x;
    float shadow = currentDepth < sampleDepth ? 1.0 : 0.0;
    return normalizedShadowFactor(shadow, shadowData.factor);
}

float qt_sampleSpotLight_pcf_4( in sampler2DArray shadowMap, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos, in vec3 lightDir, in float coneAngle) {
    return qt_sampleSpotLight_pcf(shadowMap, shadowData, lightPos, worldPos, lightDir, coneAngle, 4);
}

float qt_sampleSpotLight_pcf_8( in sampler2DArray shadowMap, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos, in vec3 lightDir, in float coneAngle) {
    return qt_sampleSpotLight_pcf(shadowMap, shadowData, lightPos, worldPos, lightDir, coneAngle, 8);
}

float qt_sampleSpotLight_pcf_16( in sampler2DArray shadowMap, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos, in vec3 lightDir, in float coneAngle) {
    return qt_sampleSpotLight_pcf(shadowMap, shadowData, lightPos, worldPos, lightDir, coneAngle, 16);
}

float qt_sampleSpotLight_pcf_32( in sampler2DArray shadowMap, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos, in vec3 lightDir, in float coneAngle) {
    return qt_sampleSpotLight_pcf(shadowMap, shadowData, lightPos, worldPos, lightDir, coneAngle, 32);
}

float qt_sampleSpotLight_pcf_64( in sampler2DArray shadowMap, in ShadowData shadowData, in vec3 lightPos, in vec3 worldPos, in vec3 lightDir, in float coneAngle) {
    return qt_sampleSpotLight_pcf(shadowMap, shadowData, lightPos, worldPos, lightDir, coneAngle, 64);
}

#endif