pdf_function.c.svn-base

SumatraPDF是一款小型开源的pdf阅读工具。虽然玲珑小巧（只有800多KB）

					SAFE_PUSHINT(st, abs(i1));
				}
				else {
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHREAL(st, fabs(r1));
				}
				break;

			case PSOADD:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHINT(st, i1 + i2);
				}
				else {
					SAFE_POPNUM(st, &r2);
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHREAL(st, r1 + r2);
				}
				break;

			case PSOAND:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHINT(st, i1 & i2);
				}
				else {
					SAFE_POPBOOL(st, &b2);
					SAFE_POPBOOL(st, &b1);
					SAFE_PUSHBOOL(st, b1 && b2);
				}
				break;

			case PSOATAN:
				SAFE_POPNUM(st, &r2);
				SAFE_POPNUM(st, &r1);
				SAFE_PUSHREAL(st, atan2(r1, r2)*RADIAN);
				break;

			case PSOBITSHIFT:
				SAFE_POPINT(st, &i2);
				SAFE_POPINT(st, &i1);
				if (i2 > 0) {
					SAFE_PUSHINT(st, i1 << i2);
				}
				else if (i2 < 0) {
					SAFE_PUSHINT(st, (int)((unsigned int)i1 >> i2));
				}
				else {
					SAFE_PUSHINT(st, i1);
				}
				break;

			case PSOCEILING:
				if (!pstopisint(st)) {
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHREAL(st, ceil(r1));
				}
				break;

			case PSOCOPY:
				SAFE_POPINT(st, &i1);
				SAFE_COPY(st, i1);
				break;

			case PSOCOS:
				SAFE_POPNUM(st, &r1);
				SAFE_PUSHREAL(st, cos(r1/RADIAN));
				break;

			case PSOCVI:
				if (!pstopisint(st)) {
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHINT(st, (int)r1);
				}
				break;

			case PSOCVR:
				if (!pstopisreal(st)) {
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHREAL(st, r1);
				}
				break;

			case PSODIV:
				SAFE_POPNUM(st, &r2);
				SAFE_POPNUM(st, &r1);
				SAFE_PUSHREAL(st, r1 / r2);
				break;

			case PSODUP:
				SAFE_COPY(st, 1);
				break;

			case PSOEQ:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHBOOL(st, i1 == i2);
				}
				else if (pstoptwoarenums(st)) {
					SAFE_POPNUM(st, &r1);
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHBOOL(st, r1 == r2);
				}
				else {
					SAFE_POPBOOL(st, &b2);
					SAFE_POPBOOL(st, &b2);
					SAFE_PUSHBOOL(st, b1 == b2);
				}
				break;

			case PSOEXCH:
				psroll(st, 2, 1);
				break;

			case PSOEXP:
				SAFE_POPNUM(st, &r2);
				SAFE_POPNUM(st, &r1);
				SAFE_PUSHREAL(st, pow(r1, r2));
				break;

			case PSOFALSE:
				SAFE_PUSHBOOL(st, 0);
				break;

			case PSOFLOOR:
				if (!pstopisint(st)) {
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHREAL(st, floor(r1));
				}
				break;

			case PSOGE:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHBOOL(st, i1 >= i2);
				}
				else {
					SAFE_POPNUM(st, &r2);
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHBOOL(st, r1 >= r2);
				}
				break;

			case PSOGT:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHBOOL(st, i1 > i2);
				}
				else {
					SAFE_POPNUM(st, &r2);
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHBOOL(st, r1 > r2);
				}
				break;

			case PSOIDIV:
				SAFE_POPINT(st, &i2);
				SAFE_POPINT(st, &i1);
				SAFE_PUSHINT(st, i1 / i2);
				break;

			case PSOINDEX:
				SAFE_POPINT(st, &i1);
				SAFE_INDEX(st, i1);
				break;

			case PSOLE:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHBOOL(st, i1 <= i2);
				}
				else {
					SAFE_POPNUM(st, &r2);
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHBOOL(st, r1 <= r2);
				}
				break;

			case PSOLN:
				SAFE_POPNUM(st, &r1);
				SAFE_PUSHREAL(st, log(r1));
				break;

			case PSOLOG:
				SAFE_POPNUM(st, &r1);
				SAFE_PUSHREAL(st, log10(r1));
				break;

			case PSOLT:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHBOOL(st, i1 < i2);
				}
				else {
					SAFE_POPNUM(st, &r2);
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHBOOL(st, r1 < r2);
				}
				break;

			case PSOMOD:
				SAFE_POPINT(st, &i2);
				SAFE_POPINT(st, &i1);
				SAFE_PUSHINT(st, i1 % i2);
				break;

			case PSOMUL:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					/* FIXME should check for out-of-range, and push a real instead */
					SAFE_PUSHINT(st, i1 * i2);
				}
				else {
					SAFE_POPNUM(st, &r2);
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHREAL(st, r1 * r2);
				}
				break;

			case PSONE:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHBOOL(st, i1 != i2);
				}
				else if (pstoptwoarenums(st)) {
					SAFE_POPNUM(st, &r2);
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHBOOL(st, r1 != r2);
				}
				else {
					SAFE_POPBOOL(st, &b2);
					SAFE_POPBOOL(st, &b1);
					SAFE_PUSHBOOL(st, b1 != b2);
				}
				break;

			case PSONEG:
				if (pstopisint(st)) {
					SAFE_POPINT(st, &i1);
					SAFE_PUSHINT(st, -i1);
				}
				else {
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHREAL(st, -r1);
				}
				break;

			case PSONOT:
				if (pstopisint(st)) {
					SAFE_POPINT(st, &i1);
					SAFE_PUSHINT(st, ~i1);
				}
				else {
					SAFE_POPBOOL(st, &b1);
					SAFE_PUSHBOOL(st, !b1);
				}
				break;

			case PSOOR:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHINT(st, i1 | i2);
				}
				else {
					SAFE_POPBOOL(st, &b2);
					SAFE_POPBOOL(st, &b1);
					SAFE_PUSHBOOL(st, b1 || b2);
				}
				break;

			case PSOPOP:
				SAFE_POP(st);
				break;

			case PSOROLL:
				SAFE_POPINT(st, &i2);
				SAFE_POPINT(st, &i1);
				psroll(st, i1, i2);
				break;

			case PSOROUND:
				if (!pstopisint(st)) {
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHREAL(st, (r1 >= 0) ? floor(r1 + 0.5) : ceil(r1 - 0.5));
				}
				break;

			case PSOSIN:
				SAFE_POPNUM(st, &r1);
				SAFE_PUSHREAL(st, sin(r1/RADIAN));
				break;

			case PSOSQRT:
				SAFE_POPNUM(st, &r1);
				SAFE_PUSHREAL(st, sqrt(r1));
				break;

			case PSOSUB:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHINT(st, i1 - i2);
				}
				else {
					SAFE_POPNUM(st, &r2);
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHREAL(st, r1 - r2);
				}
				break;

			case PSOTRUE:
				SAFE_PUSHBOOL(st, 1);
				break;

			case PSOTRUNCATE:
				if (!pstopisint(st)) {
					SAFE_POPNUM(st, &r1);
					SAFE_PUSHREAL(st, (r1 >= 0) ? floor(r1) : ceil(r1));
				}
				break;

			case PSOXOR:
				if (pstoptwoareints(st)) {
					SAFE_POPINT(st, &i2);
					SAFE_POPINT(st, &i1);
					SAFE_PUSHINT(st, i1 ^ i2);
				}
				else {
					SAFE_POPBOOL(st, &b2);
					SAFE_POPBOOL(st, &b1);
					SAFE_PUSHBOOL(st, b1 ^ b2);
				}
				break;

			case PSOIF:
				SAFE_POPBOOL(st, &b1);
				if (b1) {
					error = evalpostscriptfunc(func, st, codeptr + 2);
					if (error)
						return fz_rethrow(error, "runtime error in if-branch");
				}
				codeptr = func->u.p.code[codeptr + 1].u.block;
				break;

			case PSOIFELSE:
				SAFE_POPBOOL(st, &b1);
				if (b1) {
					error = evalpostscriptfunc(func, st, codeptr + 2);
					if (error)
						return fz_rethrow(error, "runtime error in if-branch");
				}
				else {
					error = evalpostscriptfunc(func, st, func->u.p.code[codeptr].u.block);
					if (error)
						return fz_rethrow(error, "runtime error in else-branch");
				}
				codeptr = func->u.p.code[codeptr + 1].u.block;
				break;

			case PSORETURN:
				return fz_okay;

			default:
				return fz_throw("foreign operator in calculator function");
			}
			break;

		default:
			return fz_throw("foreign object in calculator function");
		}
	}
}

/*
 * Sample function
 */

static int bps_supported[] = { 1, 2, 4, 8, 12, 16, 24, 32 };

static fz_error *
loadsamplefunc(pdf_function *func, pdf_xref *xref, fz_obj *dict, int oid, int gen)
{
	fz_error *error;
	fz_stream *stream;
	fz_obj *obj;
	int samplecount;
	int bps;
	int i;

	pdf_logrsrc("sampled function {\n");

	func->u.sa.samples = nil;

	obj = fz_dictgets(dict, "Size");
	if (!fz_isarray(obj) || fz_arraylen(obj) != func->m)
		return fz_throw("malformed /Size");
	for (i = 0; i < func->m; ++i)
		func->u.sa.size[i] = fz_toint(fz_arrayget(obj, i));

	obj = fz_dictgets(dict, "BitsPerSample");
	if (!fz_isint(obj))
		return fz_throw("malformed /BitsPerSample");
	func->u.sa.bps = bps = fz_toint(obj);

	pdf_logrsrc("bps %d\n", bps);

	for (i = 0; i < nelem(bps_supported); ++i)
		if (bps == bps_supported[i])
			break;
	if (i == nelem(bps_supported))
		return fz_throw("unsupported BitsPerSample (%d)", bps);

	obj = fz_dictgets(dict, "Encode");
	if (fz_isarray(obj))
	{
		if (fz_arraylen(obj) != func->m * 2)
			return fz_throw("malformed /Encode");
		for (i = 0; i < func->m; ++i)
		{
			func->u.sa.encode[i][0] = fz_toreal(fz_arrayget(obj, i*2+0));
			func->u.sa.encode[i][1] = fz_toreal(fz_arrayget(obj, i*2+1));
		}
	}
	else
	{
		for (i = 0; i < func->m; ++i)
		{
			func->u.sa.encode[i][0] = 0;
			func->u.sa.encode[i][1] = func->u.sa.size[i] - 1;
		}
	}

	obj = fz_dictgets(dict, "Decode");
	if (fz_isarray(obj))
	{
		if (fz_arraylen(obj) != func->n * 2)
			return fz_throw("malformed /Decode");
		for (i = 0; i < func->n; ++i)
		{
			func->u.sa.decode[i][0] = fz_toreal(fz_arrayget(obj, i*2+0));
			func->u.sa.decode[i][1] = fz_toreal(fz_arrayget(obj, i*2+1));
		}
	}
	else
	{
		for (i = 0; i < func->n; ++i)
		{
			func->u.sa.decode[i][0] = func->range[i][0];
			func->u.sa.decode[i][1] = func->range[i][1];
		}
	}

	for (i = 0, samplecount = func->n; i < func->m; ++i)
		samplecount *= func->u.sa.size[i];

	pdf_logrsrc("samplecount %d\n", samplecount);

	func->u.sa.samples = fz_malloc(samplecount * sizeof(int));
	if (!func->u.sa.samples)
		return fz_throw("outofmem: samples");

	error = pdf_openstream(&stream, xref, oid, gen);
	if (error)
		return fz_rethrow(error, "cannot open samples stream");

	/* read samples */
	{
		unsigned int bitmask = (1 << bps) - 1;
		unsigned int buf = 0;
		int bits = 0;
		int s;

		for (i = 0; i < samplecount; ++i)
		{
			if (fz_peekbyte(stream) == EOF && bits == 0)
			{
				fz_dropstream(stream);
				error = fz_readerror(stream);
				if (error)
					return fz_rethrow(error, "truncated sample stream");
				return fz_throw("truncated sample stream");
			}

			if (bps == 8) {
				s = fz_readbyte(stream);
			}
			else if (samplecount == 16) {
				s = fz_readbyte(stream);
				s = (s << 8) + fz_readbyte(stream);
			}
			else if (samplecount == 32) {
				s = fz_readbyte(stream);
				s = (s << 8) + fz_readbyte(stream);
				s = (s << 8) + fz_readbyte(stream);
				s = (s << 8) + fz_readbyte(stream);
			}
			else {
				while (bits < bps)
				{
					buf = (buf << 8) | (fz_readbyte(stream) & 0xff);
					bits += 8;
				}
				s = (buf >> (bits - bps)) & bitmask;
				bits -= bps;
			}

			func->u.sa.samples[i] = s;
		}

		error = fz_readerror(stream);
		if (error)
			return fz_rethrow(error, "truncated sample stream");
	}

	fz_dropstream(stream);

	pdf_logrsrc("}\n");

	return fz_okay;
}

static fz_error *
evalsamplefunc(pdf_function *func, float *in, float *out)
{
	float x;
	int e[2][MAXM];
	float efrac[MAXM];
	float static0[1 << 4];
	float static1[1 << 4];
	float *s0 = static0;
	float *s1 = static1;
	int i, j, k;
	int idx;