bg_lib.c

quakeIII源码这个不用我多说吧

0.788346,0.789289,0.790230,0.791169,0.792107,0.793042,0.793975,0.794907,
0.795837,0.796765,0.797691,0.798615,0.799537,0.800458,0.801376,0.802293,
0.803208,0.804120,0.805031,0.805940,0.806848,0.807753,0.808656,0.809558,
0.810457,0.811355,0.812251,0.813144,0.814036,0.814926,0.815814,0.816701,
0.817585,0.818467,0.819348,0.820226,0.821103,0.821977,0.822850,0.823721,
0.824589,0.825456,0.826321,0.827184,0.828045,0.828904,0.829761,0.830616,
0.831470,0.832321,0.833170,0.834018,0.834863,0.835706,0.836548,0.837387,
0.838225,0.839060,0.839894,0.840725,0.841555,0.842383,0.843208,0.844032,
0.844854,0.845673,0.846491,0.847307,0.848120,0.848932,0.849742,0.850549,
0.851355,0.852159,0.852961,0.853760,0.854558,0.855354,0.856147,0.856939,
0.857729,0.858516,0.859302,0.860085,0.860867,0.861646,0.862424,0.863199,
0.863973,0.864744,0.865514,0.866281,0.867046,0.867809,0.868571,0.869330,
0.870087,0.870842,0.871595,0.872346,0.873095,0.873842,0.874587,0.875329,
0.876070,0.876809,0.877545,0.878280,0.879012,0.879743,0.880471,0.881197,
0.881921,0.882643,0.883363,0.884081,0.884797,0.885511,0.886223,0.886932,
0.887640,0.888345,0.889048,0.889750,0.890449,0.891146,0.891841,0.892534,
0.893224,0.893913,0.894599,0.895284,0.895966,0.896646,0.897325,0.898001,
0.898674,0.899346,0.900016,0.900683,0.901349,0.902012,0.902673,0.903332,
0.903989,0.904644,0.905297,0.905947,0.906596,0.907242,0.907886,0.908528,
0.909168,0.909806,0.910441,0.911075,0.911706,0.912335,0.912962,0.913587,
0.914210,0.914830,0.915449,0.916065,0.916679,0.917291,0.917901,0.918508,
0.919114,0.919717,0.920318,0.920917,0.921514,0.922109,0.922701,0.923291,
0.923880,0.924465,0.925049,0.925631,0.926210,0.926787,0.927363,0.927935,
0.928506,0.929075,0.929641,0.930205,0.930767,0.931327,0.931884,0.932440,
0.932993,0.933544,0.934093,0.934639,0.935184,0.935726,0.936266,0.936803,
0.937339,0.937872,0.938404,0.938932,0.939459,0.939984,0.940506,0.941026,
0.941544,0.942060,0.942573,0.943084,0.943593,0.944100,0.944605,0.945107,
0.945607,0.946105,0.946601,0.947094,0.947586,0.948075,0.948561,0.949046,
0.949528,0.950008,0.950486,0.950962,0.951435,0.951906,0.952375,0.952842,
0.953306,0.953768,0.954228,0.954686,0.955141,0.955594,0.956045,0.956494,
0.956940,0.957385,0.957826,0.958266,0.958703,0.959139,0.959572,0.960002,
0.960431,0.960857,0.961280,0.961702,0.962121,0.962538,0.962953,0.963366,
0.963776,0.964184,0.964590,0.964993,0.965394,0.965793,0.966190,0.966584,
0.966976,0.967366,0.967754,0.968139,0.968522,0.968903,0.969281,0.969657,
0.970031,0.970403,0.970772,0.971139,0.971504,0.971866,0.972226,0.972584,
0.972940,0.973293,0.973644,0.973993,0.974339,0.974684,0.975025,0.975365,
0.975702,0.976037,0.976370,0.976700,0.977028,0.977354,0.977677,0.977999,
0.978317,0.978634,0.978948,0.979260,0.979570,0.979877,0.980182,0.980485,
0.980785,0.981083,0.981379,0.981673,0.981964,0.982253,0.982539,0.982824,
0.983105,0.983385,0.983662,0.983937,0.984210,0.984480,0.984749,0.985014,
0.985278,0.985539,0.985798,0.986054,0.986308,0.986560,0.986809,0.987057,
0.987301,0.987544,0.987784,0.988022,0.988258,0.988491,0.988722,0.988950,
0.989177,0.989400,0.989622,0.989841,0.990058,0.990273,0.990485,0.990695,
0.990903,0.991108,0.991311,0.991511,0.991710,0.991906,0.992099,0.992291,
0.992480,0.992666,0.992850,0.993032,0.993212,0.993389,0.993564,0.993737,
0.993907,0.994075,0.994240,0.994404,0.994565,0.994723,0.994879,0.995033,
0.995185,0.995334,0.995481,0.995625,0.995767,0.995907,0.996045,0.996180,
0.996313,0.996443,0.996571,0.996697,0.996820,0.996941,0.997060,0.997176,
0.997290,0.997402,0.997511,0.997618,0.997723,0.997825,0.997925,0.998023,
0.998118,0.998211,0.998302,0.998390,0.998476,0.998559,0.998640,0.998719,
0.998795,0.998870,0.998941,0.999011,0.999078,0.999142,0.999205,0.999265,
0.999322,0.999378,0.999431,0.999481,0.999529,0.999575,0.999619,0.999660,
0.999699,0.999735,0.999769,0.999801,0.999831,0.999858,0.999882,0.999905,
0.999925,0.999942,0.999958,0.999971,0.999981,0.999989,0.999995,0.999999
};

double sin( double x ) {
	int	index;
	int	quad;

	index = 1024 * x / (M_PI * 0.5);
	quad = ( index >> 10 ) & 3;
	index &= 1023;
	switch ( quad ) {
	case 0:
		return sintable[index];
	case 1:
		return sintable[1023-index];
	case 2:
		return -sintable[index];
	case 3:
		return -sintable[1023-index];
	}
	return 0;
}


double cos( double x ) {
	int	index;
	int	quad;

	index = 1024 * x / (M_PI * 0.5);
	quad = ( index >> 10 ) & 3;
	index &= 1023;
	switch ( quad ) {
	case 3:
		return sintable[index];
	case 0:
		return sintable[1023-index];
	case 1:
		return -sintable[index];
	case 2:
		return -sintable[1023-index];
	}
	return 0;
}


/*
void create_acostable( void ) {
	int i;
	FILE *fp;
	float a;

	fp = fopen("c:\\acostable.txt", "w");
	fprintf(fp, "float acostable[] = {");
	for (i = 0; i < 1024; i++) {
		if (!(i & 7))
			fprintf(fp, "\n");
		a = acos( (float) -1 + i / 512 );
		fprintf(fp, "%1.8f,", a);
	}
	fprintf(fp, "\n}\n");
	fclose(fp);
}
*/

float acostable[] = {
3.14159265,3.07908248,3.05317551,3.03328655,3.01651113,3.00172442,2.98834964,2.97604422,
2.96458497,2.95381690,2.94362719,2.93393068,2.92466119,2.91576615,2.90720289,2.89893629,
2.89093699,2.88318015,2.87564455,2.86831188,2.86116621,2.85419358,2.84738169,2.84071962,
2.83419760,2.82780691,2.82153967,2.81538876,2.80934770,2.80341062,2.79757211,2.79182724,
2.78617145,2.78060056,2.77511069,2.76969824,2.76435988,2.75909250,2.75389319,2.74875926,
2.74368816,2.73867752,2.73372510,2.72882880,2.72398665,2.71919677,2.71445741,2.70976688,
2.70512362,2.70052613,2.69597298,2.69146283,2.68699438,2.68256642,2.67817778,2.67382735,
2.66951407,2.66523692,2.66099493,2.65678719,2.65261279,2.64847088,2.64436066,2.64028133,
2.63623214,2.63221238,2.62822133,2.62425835,2.62032277,2.61641398,2.61253138,2.60867440,
2.60484248,2.60103507,2.59725167,2.59349176,2.58975488,2.58604053,2.58234828,2.57867769,
2.57502832,2.57139977,2.56779164,2.56420354,2.56063509,2.55708594,2.55355572,2.55004409,
2.54655073,2.54307530,2.53961750,2.53617701,2.53275354,2.52934680,2.52595650,2.52258238,
2.51922417,2.51588159,2.51255441,2.50924238,2.50594525,2.50266278,2.49939476,2.49614096,
2.49290115,2.48967513,2.48646269,2.48326362,2.48007773,2.47690482,2.47374472,2.47059722,
2.46746215,2.46433933,2.46122860,2.45812977,2.45504269,2.45196720,2.44890314,2.44585034,
2.44280867,2.43977797,2.43675809,2.43374890,2.43075025,2.42776201,2.42478404,2.42181622,
2.41885841,2.41591048,2.41297232,2.41004380,2.40712480,2.40421521,2.40131491,2.39842379,
2.39554173,2.39266863,2.38980439,2.38694889,2.38410204,2.38126374,2.37843388,2.37561237,
2.37279910,2.36999400,2.36719697,2.36440790,2.36162673,2.35885335,2.35608768,2.35332964,
2.35057914,2.34783610,2.34510044,2.34237208,2.33965094,2.33693695,2.33423003,2.33153010,
2.32883709,2.32615093,2.32347155,2.32079888,2.31813284,2.31547337,2.31282041,2.31017388,
2.30753373,2.30489988,2.30227228,2.29965086,2.29703556,2.29442632,2.29182309,2.28922580,
2.28663439,2.28404881,2.28146900,2.27889490,2.27632647,2.27376364,2.27120637,2.26865460,
2.26610827,2.26356735,2.26103177,2.25850149,2.25597646,2.25345663,2.25094195,2.24843238,
2.24592786,2.24342836,2.24093382,2.23844420,2.23595946,2.23347956,2.23100444,2.22853408,
2.22606842,2.22360742,2.22115104,2.21869925,2.21625199,2.21380924,2.21137096,2.20893709,
2.20650761,2.20408248,2.20166166,2.19924511,2.19683280,2.19442469,2.19202074,2.18962092,
2.18722520,2.18483354,2.18244590,2.18006225,2.17768257,2.17530680,2.17293493,2.17056692,
2.16820274,2.16584236,2.16348574,2.16113285,2.15878367,2.15643816,2.15409630,2.15175805,
2.14942338,2.14709226,2.14476468,2.14244059,2.14011997,2.13780279,2.13548903,2.13317865,
2.13087163,2.12856795,2.12626757,2.12397047,2.12167662,2.11938600,2.11709859,2.11481435,
2.11253326,2.11025530,2.10798044,2.10570867,2.10343994,2.10117424,2.09891156,2.09665185,
2.09439510,2.09214129,2.08989040,2.08764239,2.08539725,2.08315496,2.08091550,2.07867884,
2.07644495,2.07421383,2.07198545,2.06975978,2.06753681,2.06531651,2.06309887,2.06088387,
2.05867147,2.05646168,2.05425445,2.05204979,2.04984765,2.04764804,2.04545092,2.04325628,
2.04106409,2.03887435,2.03668703,2.03450211,2.03231957,2.03013941,2.02796159,2.02578610,
2.02361292,2.02144204,2.01927344,2.01710710,2.01494300,2.01278113,2.01062146,2.00846399,
2.00630870,2.00415556,2.00200457,1.99985570,1.99770895,1.99556429,1.99342171,1.99128119,
1.98914271,1.98700627,1.98487185,1.98273942,1.98060898,1.97848051,1.97635399,1.97422942,
1.97210676,1.96998602,1.96786718,1.96575021,1.96363511,1.96152187,1.95941046,1.95730088,
1.95519310,1.95308712,1.95098292,1.94888050,1.94677982,1.94468089,1.94258368,1.94048818,
1.93839439,1.93630228,1.93421185,1.93212308,1.93003595,1.92795046,1.92586659,1.92378433,
1.92170367,1.91962459,1.91754708,1.91547113,1.91339673,1.91132385,1.90925250,1.90718266,
1.90511432,1.90304746,1.90098208,1.89891815,1.89685568,1.89479464,1.89273503,1.89067683,
1.88862003,1.88656463,1.88451060,1.88245794,1.88040664,1.87835668,1.87630806,1.87426076,
1.87221477,1.87017008,1.86812668,1.86608457,1.86404371,1.86200412,1.85996577,1.85792866,
1.85589277,1.85385809,1.85182462,1.84979234,1.84776125,1.84573132,1.84370256,1.84167495,
1.83964848,1.83762314,1.83559892,1.83357582,1.83155381,1.82953289,1.82751305,1.82549429,
1.82347658,1.82145993,1.81944431,1.81742973,1.81541617,1.81340362,1.81139207,1.80938151,
1.80737194,1.80536334,1.80335570,1.80134902,1.79934328,1.79733848,1.79533460,1.79333164,
1.79132959,1.78932843,1.78732817,1.78532878,1.78333027,1.78133261,1.77933581,1.77733985,
1.77534473,1.77335043,1.77135695,1.76936428,1.76737240,1.76538132,1.76339101,1.76140148,
1.75941271,1.75742470,1.75543743,1.75345090,1.75146510,1.74948002,1.74749565,1.74551198,
1.74352900,1.74154672,1.73956511,1.73758417,1.73560389,1.73362426,1.73164527,1.72966692,
1.72768920,1.72571209,1.72373560,1.72175971,1.71978441,1.71780969,1.71583556,1.71386199,
1.71188899,1.70991653,1.70794462,1.70597325,1.70400241,1.70203209,1.70006228,1.69809297,
1.69612416,1.69415584,1.69218799,1.69022062,1.68825372,1.68628727,1.68432127,1.68235571,
1.68039058,1.67842588,1.67646160,1.67449772,1.67253424,1.67057116,1.66860847,1.66664615,
1.66468420,1.66272262,1.66076139,1.65880050,1.65683996,1.65487975,1.65291986,1.65096028,
1.64900102,1.64704205,1.64508338,1.64312500,1.64116689,1.63920905,1.63725148,1.63529416,
1.63333709,1.63138026,1.62942366,1.62746728,1.62551112,1.62355517,1.62159943,1.61964388,
1.61768851,1.61573332,1.61377831,1.61182346,1.60986877,1.60791422,1.60595982,1.60400556,
1.60205142,1.60009739,1.59814349,1.59618968,1.59423597,1.59228235,1.59032882,1.58837536,
1.58642196,1.58446863,1.58251535,1.58056211,1.57860891,1.57665574,1.57470259,1.57274945,
1.57079633,1.56884320,1.56689007,1.56493692,1.56298375,1.56103055,1.55907731,1.55712403,
1.55517069,1.55321730,1.55126383,1.54931030,1.54735668,1.54540297,1.54344917,1.54149526,
1.53954124,1.53758710,1.53563283,1.53367843,1.53172389,1.52976919,1.52781434,1.52585933,
1.52390414,1.52194878,1.51999323,1.51803748,1.51608153,1.51412537,1.51216900,1.51021240,
1.50825556,1.50629849,1.50434117,1.50238360,1.50042576,1.49846765,1.49650927,1.49455060,
1.49259163,1.49063237,1.48867280,1.48671291,1.48475270,1.48279215,1.48083127,1.47887004,
1.47690845,1.47494650,1.47298419,1.47102149,1.46905841,1.46709493,1.46513106,1.46316677,
1.46120207,1.45923694,1.45727138,1.45530538,1.45333893,1.45137203,1.44940466,1.44743682,
1.44546850,1.44349969,1.44153038,1.43956057,1.43759024,1.43561940,1.43364803,1.43167612,
1.42970367,1.42773066,1.42575709,1.42378296,1.42180825,1.41983295,1.41785705,1.41588056,
1.41390346,1.41192573,1.40994738,1.40796840,1.40598877,1.40400849,1.40202755,1.40004594,
1.39806365,1.39608068,1.39409701,1.39211264,1.39012756,1.38814175,1.38615522,1.38416795,
1.38217994,1.38019117,1.37820164,1.37621134,1.37422025,1.37222837,1.37023570,1.36824222,
1.36624792,1.36425280,1.36225684,1.36026004,1.35826239,1.35626387,1.35426449,1.35226422,
1.35026307,1.34826101,1.34625805,1.34425418,1.34224937,1.34024364,1.33823695,1.33622932,
1.33422072,1.33221114,1.33020059,1.32818904,1.32617649,1.32416292,1.32214834,1.32013273,
1.31811607,1.31609837,1.31407960,1.31205976,1.31003885,1.30801684,1.30599373,1.30396951,
1.30194417,1.29991770,1.29789009,1.29586133,1.29383141,1.29180031,1.28976803,1.28773456,
1.28569989,1.28366400,1.28162688,1.27958854,1.27754894,1.27550809,1.27346597,1.27142257,
1.26937788,1.26733189,1.26528459,1.26323597,1.26118602,1.25913471,1.25708205,1.25502803,
1.25297262,1.25091583,1.24885763,1.24679802,1.24473698,1.24267450,1.24061058,1.23854519,
1.23647833,1.23440999,1.23234015,1.23026880,1.22819593,1.22612152,1.22404557,1.22196806,
1.21988898,1.21780832,1.21572606,1.21364219,1.21155670,1.20946958,1.20738080,1.20529037,
1.20319826,1.20110447,1.19900898,1.19691177,1.19481283,1.19271216,1.19060973,1.18850553,
1.18639955,1.18429178,1.18218219,1.18007079,1.17795754,1.17584244,1.17372548,1.17160663,
1.16948589,1.16736324,1.16523866,1.16311215,1.16098368,1.15885323,1.15672081,1.15458638,
1.15244994,1.15031147,1.14817095,1.14602836,1.14388370,1.14173695,1.13958808,1.13743709,
1.13528396,1.13312866,1.13097119,1.12881153,1.12664966,1.12448556,1.12231921,1.12015061,
1.11797973,1.11580656,1.11363107,1.11145325,1.10927308,1.10709055,1.10490563,1.10271831,
1.10052856,1.09833638,1.09614174,1.09394462,1.09174500,1.08954287,1.08733820,1.08513098,
1.08292118,1.08070879,1.07849378,1.07627614,1.07405585,1.07183287,1.06960721,1.06737882,
1.06514770,1.06291382,1.06067715,1.05843769,1.05619540,1.05395026,1.05170226,1.04945136,
1.04719755,1.04494080,1.04268110,1.04041841,1.03815271,1.03588399,1.03361221,1.03133735,
1.02905939,1.02677830,1.02449407,1.02220665,1.01991603,1.01762219,1.01532509,1.01302471,
1.01072102,1.00841400,1.00610363,1.00378986,1.00147268,0.99915206,0.99682798,0.99450039,
0.99216928,0.98983461,0.98749636,0.98515449,0.98280898,0.98045980,0.97810691,0.97575030,
0.97338991,0.97102573,0.96865772,0.96628585,0.96391009,0.96153040,0.95914675,0.95675912,
0.95436745,0.95197173,0.94957191,0.94716796,0.94475985,0.94234754,0.93993099,0.93751017,
0.93508504,0.93265556,0.93022170,0.92778341,0.92534066,0.92289341,0.92044161,0.91798524,
0.91552424,0.91305858,0.91058821,0.90811309,0.90563319,0.90314845,0.90065884,0.89816430,
0.89566479,0.89316028,0.89065070,0.88813602,0.88561619,0.88309116,0.88056088,0.87802531,
0.87548438,0.87293806,0.87038629,0.86782901,0.86526619,0.86269775,0.86012366,0.85754385,
0.85495827,0.85236686,0.84976956,0.84716633,0.84455709,0.84194179,0.83932037,0.83669277,
0.83405893,0.83141877,0.82877225,0.82611928,0.82345981,0.82079378,0.81812110,0.81544172,
0.81275556,0.81006255,0.80736262,0.80465570,0.80194171,0.79922057,0.79649221,0.79375655,
0.79101352,0.78826302,0.78550497,0.78273931,0.77996593,0.77718475,0.77439569,0.77159865,
0.76879355,0.76598029,0.76315878,0.76032891,0.75749061,0.75464376,0.75178826,0.74892402,
0.74605092,0.74316887,0.74027775,0.73737744,0.73446785,0.73154885,0.72862033,0.72568217,
0.72273425,0.71977644,0.71680861,0.71383064,0.71084240,0.70784376,0.70483456,0.70181469,
0.69878398,0.69574231,0.69268952,0.68962545,0.68654996,0.68346288,0.68036406,0.67725332,
0.67413051,0.67099544,0.66784794,0.66468783,0.66151492,0.65832903,0.65512997,0.65191753,
0.64869151,0.64545170,0.64219789,0.63892987,0.63564741,0.63235028,0.62903824,0.62571106,
0.62236849,0.61901027,0.61563615,0.61224585,0.60883911,0.60541564,0.60197515,0.59851735,
0.59504192,0.59154856,0.58803694,0.58450672,0.58095756,0.57738911,0.57380101,0.57019288,
0.56656433,0.56291496,0.55924437,0.55555212,0.55183778,0.54810089,0.54434099,0.54055758,
0.53675018,0.53291825,0.52906127,0.52517867,0.52126988,0.51733431,0.51337132,0.50938028,
0.50536051,0.50131132,0.49723200,0.49312177,0.48897987,0.48480547,0.48059772,0.47635573,
0.47207859,0.46776530,0.46341487,0.45902623,0.45459827,0.45012983,0.44561967,0.44106652,
0.43646903,0.43182577,0.42713525,0.42239588,0.41760600,0.41276385,0.40786755,0.40291513,
0.39790449,0.39283339,0.38769946,0.38250016,0.37723277,0.37189441,0.36648196,0.36099209,
0.35542120,0.34976542,0.34402054,0.33818204,0.33224495,0.32620390,0.32005298,0.31378574,
0.30739505,0.30087304,0.29421096,0.28739907,0.28042645,0.27328078,0.26594810,0.25841250,
0.25065566,0.24265636,0.23438976,0.22582651,0.21693146,0.20766198,0.19796546,0.18777575,
0.17700769,0.16554844,0.15324301,0.13986823,0.12508152,0.10830610,0.08841715,0.06251018,
}

double acos( double x ) {
	int index;

	if (x < -1)
		x = -1;
	if (x > 1)
		x = 1;
	index = (float) (1.0 + x) * 511.9;
	return acostable[index];
}

double atan2( double y, double x ) {
	float	base;
	float	temp;
	float	dir;
	float	test;
	int		i;

	if ( x < 0 ) {
		if ( y >= 0 ) {
			// quad 1
			base = M_PI / 2;
			temp = x;
			x = y;
			y = -temp;
		} else {
			// quad 2
			base = M_PI;
			x = -x;
			y = -y;
		}
	} else {
		if ( y < 0 ) {
			// quad 3
			base = 3 * M_PI / 2;
			temp = x;
			x = -y;
			y = temp;
		}
	}

	if ( y > x ) {
		base += M_PI/2;
		temp = x;
		x = y;
		y = temp;
		dir = -1;
	} else {
		dir = 1;
	}

	// calcualte angle in octant 0
	if ( x == 0 ) {
		return base;
	}
	y /= x;

	for ( i = 0 ; i < 512 ; i++ ) {
		test = sintable[i] / sintable[1023-i];
		if ( test > y ) {
			break;
		}
	}

	return base + dir * i * ( M_PI/2048); 
}


#endif

#ifdef Q3_VM
// bk001127 - guarded this tan replacement 
// ld: undefined versioned symbol name tan@@GLIBC_2.0
double tan( double x ) {
	return sin(x) / cos(x);
}
#endif


static int randSeed = 0;

void	srand( unsigned seed ) {
	randSeed = seed;
}

int		rand( void ) {
	randSeed = (69069 * randSeed + 1);
	return randSeed & 0x7fff;
}

double atof( const char *string ) {
	float sign;
	float value;
	int		c;


	// skip whitespace
	while ( *string <= ' ' ) {
		if ( !*string ) {
			return 0;
		}
		string++;
	}

	// check sign
	switch ( *string ) {
	case '+':
		string++;
		sign = 1;
		break;
	case '-':
		string++;
		sign = -1;
		break;
	default:
		sign = 1;
		break;
	}

	// read digits
	value = 0;
	c = string[0];
	if ( c != '.' ) {
		do {
			c = *string++;
			if ( c < '0' || c > '9' ) {
				break;
			}
			c -= '0';
			value = value * 10 + c;
		} while ( 1 );
	} else {
		string++;
	}

	// check for decimal point
	if ( c == '.' ) {
		double fraction;

		fraction = 0.1;
		do {
			c = *string++;
			if ( c < '0' || c > '9' ) {
				break;
			}
			c -= '0';
			value += c * fraction;
			fraction *= 0.1;
		} while ( 1 );

	}

	// not handling 10e10 notation...

	return value * sign;
}

double _atof( const char **stringPtr ) {
	const char	*string;
	float sign;
	float value;
	int		c = '0'; // bk001211 - uninitialized use possible

	string = *stringPtr;

	// skip whitespace
	while ( *string <= ' ' ) {
		if ( !*string ) {
			*stringPtr = string;
			return 0;
		}
		string++;
	}

	// check sign
	switch ( *string ) {
	case '+':
		string++;
		sign = 1;
		break;
	case '-':
		string++;
		sign = -1;
		break;
	default:
		sign = 1;
		break;
	}

	// read digits
	value = 0;
	if ( string[0] != '.' ) {
		do {
			c = *string++;