Rearrange source files.

1 files changed, 1718 insertions, 0 deletions

diff --git a/source/pdf/pdf-function.c b/source/pdf/pdf-function.c
new file mode 100644
index 00000000..4771fbfd
--- /dev/null
+++ b/source/pdf/pdf-function.c
@@ -0,0 +1,1718 @@
+#include "mupdf/pdf.h"
+
+typedef struct psobj_s psobj;
+
+enum
+{
+	SAMPLE = 0,
+	EXPONENTIAL = 2,
+	STITCHING = 3,
+	POSTSCRIPT = 4
+};
+
+typedef struct pdf_function_s pdf_function;
+
+struct pdf_function_s
+{
+	fz_function base;
+	int type;				/* 0=sample 2=exponential 3=stitching 4=postscript */
+	float domain[FZ_FN_MAXM][2];	/* even index : min value, odd index : max value */
+	float range[FZ_FN_MAXN][2];	/* even index : min value, odd index : max value */
+	int has_range;
+
+	union
+	{
+		struct {
+			unsigned short bps;
+			int size[FZ_FN_MAXM];
+			float encode[FZ_FN_MAXM][2];
+			float decode[FZ_FN_MAXN][2];
+			float *samples;
+		} sa;
+
+		struct {
+			float n;
+			float c0[FZ_FN_MAXN];
+			float c1[FZ_FN_MAXN];
+		} e;
+
+		struct {
+			int k;
+			fz_function **funcs; /* k */
+			float *bounds; /* k - 1 */
+			float *encode; /* k * 2 */
+		} st;
+
+		struct {
+			psobj *code;
+			int cap;
+		} p;
+	} u;
+};
+
+#define RADIAN 57.2957795
+
+static inline float lerp(float x, float xmin, float xmax, float ymin, float ymax)
+{
+	if (xmin == xmax)
+		return ymin;
+	if (ymin == ymax)
+		return ymin;
+	return ymin + (x - xmin) * (ymax - ymin) / (xmax - xmin);
+}
+
+/*
+ * PostScript calculator
+ */
+
+enum { PS_BOOL, PS_INT, PS_REAL, PS_OPERATOR, PS_BLOCK };
+
+enum
+{
+	PS_OP_ABS, PS_OP_ADD, PS_OP_AND, PS_OP_ATAN, PS_OP_BITSHIFT,
+	PS_OP_CEILING, PS_OP_COPY, PS_OP_COS, PS_OP_CVI, PS_OP_CVR,
+	PS_OP_DIV, PS_OP_DUP, PS_OP_EQ, PS_OP_EXCH, PS_OP_EXP,
+	PS_OP_FALSE, PS_OP_FLOOR, PS_OP_GE, PS_OP_GT, PS_OP_IDIV, PS_OP_IF,
+	PS_OP_IFELSE, PS_OP_INDEX, PS_OP_LE, PS_OP_LN, PS_OP_LOG, PS_OP_LT,
+	PS_OP_MOD, PS_OP_MUL, PS_OP_NE, PS_OP_NEG, PS_OP_NOT, PS_OP_OR,
+	PS_OP_POP, PS_OP_RETURN, PS_OP_ROLL, PS_OP_ROUND, PS_OP_SIN,
+	PS_OP_SQRT, PS_OP_SUB, PS_OP_TRUE, PS_OP_TRUNCATE, PS_OP_XOR
+};
+
+static char *ps_op_names[] =
+{
+	"abs", "add", "and", "atan", "bitshift", "ceiling", "copy",
+	"cos", "cvi", "cvr", "div", "dup", "eq", "exch", "exp",
+	"false", "floor", "ge", "gt", "idiv", "if", "ifelse", "index", "le", "ln",
+	"log", "lt", "mod", "mul", "ne", "neg", "not", "or", "pop", "return",
+	"roll", "round", "sin", "sqrt", "sub", "true", "truncate", "xor"
+};
+
+struct psobj_s
+{
+	int type;
+	union
+	{
+		int b;				/* boolean (stack only) */
+		int i;				/* integer (stack and code) */
+		float f;			/* real (stack and code) */
+		int op;				/* operator (code only) */
+		int block;			/* if/ifelse block pointer (code only) */
+	} u;
+};
+
+typedef struct ps_stack_s ps_stack;
+
+struct ps_stack_s
+{
+	psobj stack[100];
+	int sp;
+};
+
+#ifndef NDEBUG
+void
+pdf_debug_ps_stack(ps_stack *st)
+{
+	int i;
+
+	printf("stack: ");
+
+	for (i = 0; i < st->sp; i++)
+	{
+		switch (st->stack[i].type)
+		{
+		case PS_BOOL:
+			if (st->stack[i].u.b)
+				printf("true ");
+			else
+				printf("false ");
+			break;
+
+		case PS_INT:
+			printf("%d ", st->stack[i].u.i);
+			break;
+
+		case PS_REAL:
+			printf("%g ", st->stack[i].u.f);
+			break;
+		}
+	}
+	printf("\n");
+
+}
+#endif
+
+static void
+ps_init_stack(ps_stack *st)
+{
+	memset(st->stack, 0, sizeof(st->stack));
+	st->sp = 0;
+}
+
+static inline int ps_overflow(ps_stack *st, int n)
+{
+	return n < 0 || st->sp + n >= nelem(st->stack);
+}
+
+static inline int ps_underflow(ps_stack *st, int n)
+{
+	return n < 0 || st->sp - n < 0;
+}
+
+static inline int ps_is_type(ps_stack *st, int t)
+{
+	return !ps_underflow(st, 1) && st->stack[st->sp - 1].type == t;
+}
+
+static inline int ps_is_type2(ps_stack *st, int t)
+{
+	return !ps_underflow(st, 2) && st->stack[st->sp - 1].type == t && st->stack[st->sp - 2].type == t;
+}
+
+static void
+ps_push_bool(ps_stack *st, int b)
+{
+	if (!ps_overflow(st, 1))
+	{
+		st->stack[st->sp].type = PS_BOOL;
+		st->stack[st->sp].u.b = b;
+		st->sp++;
+	}
+}
+
+static void
+ps_push_int(ps_stack *st, int n)
+{
+	if (!ps_overflow(st, 1))
+	{
+		st->stack[st->sp].type = PS_INT;
+		st->stack[st->sp].u.i = n;
+		st->sp++;
+	}
+}
+
+static void
+ps_push_real(ps_stack *st, float n)
+{
+	if (!ps_overflow(st, 1))
+	{
+		st->stack[st->sp].type = PS_REAL;
+		if (isnan(n))
+		{
+			/* Push 1.0, as it's a small known value that won't
+			 * cause a divide by 0. Same reason as in fz_atof. */
+			n = 1.0;
+		}
+		st->stack[st->sp].u.f = fz_clamp(n, -FLT_MAX, FLT_MAX);
+		st->sp++;
+	}
+}
+
+static int
+ps_pop_bool(ps_stack *st)
+{
+	if (!ps_underflow(st, 1))
+	{
+		if (ps_is_type(st, PS_BOOL))
+			return st->stack[--st->sp].u.b;
+	}
+	return 0;
+}
+
+static int
+ps_pop_int(ps_stack *st)
+{
+	if (!ps_underflow(st, 1))
+	{
+		if (ps_is_type(st, PS_INT))
+			return st->stack[--st->sp].u.i;
+		if (ps_is_type(st, PS_REAL))
+			return st->stack[--st->sp].u.f;
+	}
+	return 0;
+}
+
+static float
+ps_pop_real(ps_stack *st)
+{
+	if (!ps_underflow(st, 1))
+	{
+		if (ps_is_type(st, PS_INT))
+			return st->stack[--st->sp].u.i;
+		if (ps_is_type(st, PS_REAL))
+			return st->stack[--st->sp].u.f;
+	}
+	return 0;
+}
+
+static void
+ps_copy(ps_stack *st, int n)
+{
+	if (!ps_underflow(st, n) && !ps_overflow(st, n))
+	{
+		memcpy(st->stack + st->sp, st->stack + st->sp - n, n * sizeof(psobj));
+		st->sp += n;
+	}
+}
+
+static void
+ps_roll(ps_stack *st, int n, int j)
+{
+	psobj tmp;
+	int i;
+
+	if (ps_underflow(st, n) || j == 0 || n == 0)
+		return;
+
+	if (j >= 0)
+	{
+		j %= n;
+	}
+	else
+	{
+		j = -j % n;
+		if (j != 0)
+			j = n - j;
+	}
+
+	for (i = 0; i < j; i++)
+	{
+		tmp = st->stack[st->sp - 1];
+		memmove(st->stack + st->sp - n + 1, st->stack + st->sp - n, n * sizeof(psobj));
+		st->stack[st->sp - n] = tmp;
+	}
+}
+
+static void
+ps_index(ps_stack *st, int n)
+{
+	if (!ps_overflow(st, 1) && !ps_underflow(st, n))
+	{
+		st->stack[st->sp] = st->stack[st->sp - n - 1];
+		st->sp++;
+	}
+}
+
+static void
+ps_run(fz_context *ctx, psobj *code, ps_stack *st, int pc)
+{
+	int i1, i2;
+	float r1, r2;
+	int b1, b2;
+
+	while (1)
+	{
+		switch (code[pc].type)
+		{
+		case PS_INT:
+			ps_push_int(st, code[pc++].u.i);
+			break;
+
+		case PS_REAL:
+			ps_push_real(st, code[pc++].u.f);
+			break;
+
+		case PS_OPERATOR:
+			switch (code[pc++].u.op)
+			{
+			case PS_OP_ABS:
+				if (ps_is_type(st, PS_INT))
+					ps_push_int(st, abs(ps_pop_int(st)));
+				else
+					ps_push_real(st, fabsf(ps_pop_real(st)));
+				break;
+
+			case PS_OP_ADD:
+				if (ps_is_type2(st, PS_INT)) {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_int(st, i1 + i2);
+				}
+				else {
+					r2 = ps_pop_real(st);
+					r1 = ps_pop_real(st);
+					ps_push_real(st, r1 + r2);
+				}
+				break;
+
+			case PS_OP_AND:
+				if (ps_is_type2(st, PS_INT)) {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_int(st, i1 & i2);
+				}
+				else {
+					b2 = ps_pop_bool(st);
+					b1 = ps_pop_bool(st);
+					ps_push_bool(st, b1 && b2);
+				}
+				break;
+
+			case PS_OP_ATAN:
+				r2 = ps_pop_real(st);
+				r1 = ps_pop_real(st);
+				r1 = atan2f(r1, r2) * RADIAN;
+				if (r1 < 0)
+					r1 += 360;
+				ps_push_real(st, r1);
+				break;
+
+			case PS_OP_BITSHIFT:
+				i2 = ps_pop_int(st);
+				i1 = ps_pop_int(st);
+				if (i2 > 0 && i2 < 8 * sizeof (i2))
+					ps_push_int(st, i1 << i2);
+				else if (i2 < 0 && i2 > -8 * (int)sizeof (i2))
+					ps_push_int(st, (int)((unsigned int)i1 >> -i2));
+				else
+					ps_push_int(st, i1);
+				break;
+
+			case PS_OP_CEILING:
+				r1 = ps_pop_real(st);
+				ps_push_real(st, ceilf(r1));
+				break;
+
+			case PS_OP_COPY:
+				ps_copy(st, ps_pop_int(st));
+				break;
+
+			case PS_OP_COS:
+				r1 = ps_pop_real(st);
+				ps_push_real(st, cosf(r1/RADIAN));
+				break;
+
+			case PS_OP_CVI:
+				ps_push_int(st, ps_pop_int(st));
+				break;
+
+			case PS_OP_CVR:
+				ps_push_real(st, ps_pop_real(st));
+				break;
+
+			case PS_OP_DIV:
+				r2 = ps_pop_real(st);
+				r1 = ps_pop_real(st);
+				if (fabsf(r2) >= FLT_EPSILON)
+					ps_push_real(st, r1 / r2);
+				else
+					ps_push_real(st, DIV_BY_ZERO(r1, r2, -FLT_MAX, FLT_MAX));
+				break;
+
+			case PS_OP_DUP:
+				ps_copy(st, 1);
+				break;
+
+			case PS_OP_EQ:
+				if (ps_is_type2(st, PS_BOOL)) {
+					b2 = ps_pop_bool(st);
+					b1 = ps_pop_bool(st);
+					ps_push_bool(st, b1 == b2);
+				}
+				else if (ps_is_type2(st, PS_INT)) {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_bool(st, i1 == i2);
+				}
+				else {
+					r2 = ps_pop_real(st);
+					r1 = ps_pop_real(st);
+					ps_push_bool(st, r1 == r2);
+				}
+				break;
+
+			case PS_OP_EXCH:
+				ps_roll(st, 2, 1);
+				break;
+
+			case PS_OP_EXP:
+				r2 = ps_pop_real(st);
+				r1 = ps_pop_real(st);
+				ps_push_real(st, powf(r1, r2));
+				break;
+
+			case PS_OP_FALSE:
+				ps_push_bool(st, 0);
+				break;
+
+			case PS_OP_FLOOR:
+				r1 = ps_pop_real(st);
+				ps_push_real(st, floorf(r1));
+				break;
+
+			case PS_OP_GE:
+				if (ps_is_type2(st, PS_INT)) {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_bool(st, i1 >= i2);
+				}
+				else {
+					r2 = ps_pop_real(st);
+					r1 = ps_pop_real(st);
+					ps_push_bool(st, r1 >= r2);
+				}
+				break;
+
+			case PS_OP_GT:
+				if (ps_is_type2(st, PS_INT)) {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_bool(st, i1 > i2);
+				}
+				else {
+					r2 = ps_pop_real(st);
+					r1 = ps_pop_real(st);
+					ps_push_bool(st, r1 > r2);
+				}
+				break;
+
+			case PS_OP_IDIV:
+				i2 = ps_pop_int(st);
+				i1 = ps_pop_int(st);
+				if (i2 != 0)
+					ps_push_int(st, i1 / i2);
+				else
+					ps_push_int(st, DIV_BY_ZERO(i1, i2, INT_MIN, INT_MAX));
+				break;
+
+			case PS_OP_INDEX:
+				ps_index(st, ps_pop_int(st));
+				break;
+
+			case PS_OP_LE:
+				if (ps_is_type2(st, PS_INT)) {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_bool(st, i1 <= i2);
+				}
+				else {
+					r2 = ps_pop_real(st);
+					r1 = ps_pop_real(st);
+					ps_push_bool(st, r1 <= r2);
+				}
+				break;
+
+			case PS_OP_LN:
+				r1 = ps_pop_real(st);
+				/* Bug 692941 - logf as separate statement */
+				r2 = logf(r1);
+				ps_push_real(st, r2);
+				break;
+
+			case PS_OP_LOG:
+				r1 = ps_pop_real(st);
+				ps_push_real(st, log10f(r1));
+				break;
+
+			case PS_OP_LT:
+				if (ps_is_type2(st, PS_INT)) {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_bool(st, i1 < i2);
+				}
+				else {
+					r2 = ps_pop_real(st);
+					r1 = ps_pop_real(st);
+					ps_push_bool(st, r1 < r2);
+				}
+				break;
+
+			case PS_OP_MOD:
+				i2 = ps_pop_int(st);
+				i1 = ps_pop_int(st);
+				if (i2 != 0)
+					ps_push_int(st, i1 % i2);
+				else
+					ps_push_int(st, DIV_BY_ZERO(i1, i2, INT_MIN, INT_MAX));
+				break;
+
+			case PS_OP_MUL:
+				if (ps_is_type2(st, PS_INT)) {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_int(st, i1 * i2);
+				}
+				else {
+					r2 = ps_pop_real(st);
+					r1 = ps_pop_real(st);
+					ps_push_real(st, r1 * r2);
+				}
+				break;
+
+			case PS_OP_NE:
+				if (ps_is_type2(st, PS_BOOL)) {
+					b2 = ps_pop_bool(st);
+					b1 = ps_pop_bool(st);
+					ps_push_bool(st, b1 != b2);
+				}
+				else if (ps_is_type2(st, PS_INT)) {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_bool(st, i1 != i2);
+				}
+				else {
+					r2 = ps_pop_real(st);
+					r1 = ps_pop_real(st);
+					ps_push_bool(st, r1 != r2);
+				}
+				break;
+
+			case PS_OP_NEG:
+				if (ps_is_type(st, PS_INT))
+					ps_push_int(st, -ps_pop_int(st));
+				else
+					ps_push_real(st, -ps_pop_real(st));
+				break;
+
+			case PS_OP_NOT:
+				if (ps_is_type(st, PS_BOOL))
+					ps_push_bool(st, !ps_pop_bool(st));
+				else
+					ps_push_int(st, ~ps_pop_int(st));
+				break;
+
+			case PS_OP_OR:
+				if (ps_is_type2(st, PS_BOOL)) {
+					b2 = ps_pop_bool(st);
+					b1 = ps_pop_bool(st);
+					ps_push_bool(st, b1 || b2);
+				}
+				else {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_int(st, i1 | i2);
+				}
+				break;
+
+			case PS_OP_POP:
+				if (!ps_underflow(st, 1))
+					st->sp--;
+				break;
+
+			case PS_OP_ROLL:
+				i2 = ps_pop_int(st);
+				i1 = ps_pop_int(st);
+				ps_roll(st, i1, i2);
+				break;
+
+			case PS_OP_ROUND:
+				if (!ps_is_type(st, PS_INT)) {
+					r1 = ps_pop_real(st);
+					ps_push_real(st, (r1 >= 0) ? floorf(r1 + 0.5f) : ceilf(r1 - 0.5f));
+				}
+				break;
+
+			case PS_OP_SIN:
+				r1 = ps_pop_real(st);
+				ps_push_real(st, sinf(r1/RADIAN));
+				break;
+
+			case PS_OP_SQRT:
+				r1 = ps_pop_real(st);
+				ps_push_real(st, sqrtf(r1));
+				break;
+
+			case PS_OP_SUB:
+				if (ps_is_type2(st, PS_INT)) {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_int(st, i1 - i2);
+				}
+				else {
+					r2 = ps_pop_real(st);
+					r1 = ps_pop_real(st);
+					ps_push_real(st, r1 - r2);
+				}
+				break;
+
+			case PS_OP_TRUE:
+				ps_push_bool(st, 1);
+				break;
+
+			case PS_OP_TRUNCATE:
+				if (!ps_is_type(st, PS_INT)) {
+					r1 = ps_pop_real(st);
+					ps_push_real(st, (r1 >= 0) ? floorf(r1) : ceilf(r1));
+				}
+				break;
+
+			case PS_OP_XOR:
+				if (ps_is_type2(st, PS_BOOL)) {
+					b2 = ps_pop_bool(st);
+					b1 = ps_pop_bool(st);
+					ps_push_bool(st, b1 ^ b2);
+				}
+				else {
+					i2 = ps_pop_int(st);
+					i1 = ps_pop_int(st);
+					ps_push_int(st, i1 ^ i2);
+				}
+				break;
+
+			case PS_OP_IF:
+				b1 = ps_pop_bool(st);
+				if (b1)
+					ps_run(ctx, code, st, code[pc + 1].u.block);
+				pc = code[pc + 2].u.block;
+				break;
+
+			case PS_OP_IFELSE:
+				b1 = ps_pop_bool(st);
+				if (b1)
+					ps_run(ctx, code, st, code[pc + 1].u.block);
+				else
+					ps_run(ctx, code, st, code[pc + 0].u.block);
+				pc = code[pc + 2].u.block;
+				break;
+
+			case PS_OP_RETURN:
+				return;
+
+			default:
+				fz_warn(ctx, "foreign operator in calculator function");
+				return;
+			}
+			break;
+
+		default:
+			fz_warn(ctx, "foreign object in calculator function");
+			return;
+		}
+	}
+}
+
+static void
+resize_code(fz_context *ctx, pdf_function *func, int newsize)
+{
+	if (newsize >= func->u.p.cap)
+	{
+		int new_cap = func->u.p.cap + 64;
+		func->u.p.code = fz_resize_array(ctx, func->u.p.code, new_cap, sizeof(psobj));
+		func->u.p.cap = new_cap;
+	}
+}
+
+static void
+parse_code(pdf_function *func, fz_stream *stream, int *codeptr, pdf_lexbuf *buf)
+{
+	pdf_token tok;
+	int opptr, elseptr, ifptr;
+	int a, b, mid, cmp;
+	fz_context *ctx = stream->ctx;
+
+	while (1)
+	{
+		tok = pdf_lex(stream, buf);
+
+		switch (tok)
+		{
+		case PDF_TOK_EOF:
+			fz_throw(ctx, FZ_ERROR_GENERIC, "truncated calculator function");
+
+		case PDF_TOK_INT:
+			resize_code(ctx, func, *codeptr);
+			func->u.p.code[*codeptr].type = PS_INT;
+			func->u.p.code[*codeptr].u.i = buf->i;
+			++*codeptr;
+			break;
+
+		case PDF_TOK_TRUE:
+			resize_code(ctx, func, *codeptr);
+			func->u.p.code[*codeptr].type = PS_BOOL;
+			func->u.p.code[*codeptr].u.b = 1;
+			++*codeptr;
+			break;
+
+		case PDF_TOK_FALSE:
+			resize_code(ctx, func, *codeptr);
+			func->u.p.code[*codeptr].type = PS_BOOL;
+			func->u.p.code[*codeptr].u.b = 0;
+			++*codeptr;
+			break;
+
+		case PDF_TOK_REAL:
+			resize_code(ctx, func, *codeptr);
+			func->u.p.code[*codeptr].type = PS_REAL;
+			func->u.p.code[*codeptr].u.f = buf->f;
+			++*codeptr;
+			break;
+
+		case PDF_TOK_OPEN_BRACE:
+			opptr = *codeptr;
+			*codeptr += 4;
+
+			resize_code(ctx, func, *codeptr);
+
+			ifptr = *codeptr;
+			parse_code(func, stream, codeptr, buf);
+
+			tok = pdf_lex(stream, buf);
+
+			if (tok == PDF_TOK_OPEN_BRACE)
+			{
+				elseptr = *codeptr;
+				parse_code(func, stream, codeptr, buf);
+
+				tok = pdf_lex(stream, buf);
+			}
+			else
+			{
+				elseptr = -1;
+			}
+
+			if (tok != PDF_TOK_KEYWORD)
+				fz_throw(ctx, FZ_ERROR_GENERIC, "missing keyword in 'if-else' context");
+
+			if (!strcmp(buf->scratch, "if"))
+			{
+				if (elseptr >= 0)
+					fz_throw(ctx, FZ_ERROR_GENERIC, "too many branches for 'if'");
+				func->u.p.code[opptr].type = PS_OPERATOR;
+				func->u.p.code[opptr].u.op = PS_OP_IF;
+				func->u.p.code[opptr+2].type = PS_BLOCK;
+				func->u.p.code[opptr+2].u.block = ifptr;
+				func->u.p.code[opptr+3].type = PS_BLOCK;
+				func->u.p.code[opptr+3].u.block = *codeptr;
+			}
+			else if (!strcmp(buf->scratch, "ifelse"))
+			{
+				if (elseptr < 0)
+					fz_throw(ctx, FZ_ERROR_GENERIC, "not enough branches for 'ifelse'");
+				func->u.p.code[opptr].type = PS_OPERATOR;
+				func->u.p.code[opptr].u.op = PS_OP_IFELSE;
+				func->u.p.code[opptr+1].type = PS_BLOCK;
+				func->u.p.code[opptr+1].u.block = elseptr;
+				func->u.p.code[opptr+2].type = PS_BLOCK;
+				func->u.p.code[opptr+2].u.block = ifptr;
+				func->u.p.code[opptr+3].type = PS_BLOCK;
+				func->u.p.code[opptr+3].u.block = *codeptr;
+			}
+			else
+			{
+				fz_throw(ctx, FZ_ERROR_GENERIC, "unknown keyword in 'if-else' context: '%s'", buf->scratch);
+			}
+			break;
+
+		case PDF_TOK_CLOSE_BRACE:
+			resize_code(ctx, func, *codeptr);
+			func->u.p.code[*codeptr].type = PS_OPERATOR;
+			func->u.p.code[*codeptr].u.op = PS_OP_RETURN;
+			++*codeptr;
+			return;
+
+		case PDF_TOK_KEYWORD:
+			cmp = -1;
+			a = -1;
+			b = nelem(ps_op_names);
+			while (b - a > 1)
+			{
+				mid = (a + b) / 2;
+				cmp = strcmp(buf->scratch, ps_op_names[mid]);
+				if (cmp > 0)
+					a = mid;
+				else if (cmp < 0)
+					b = mid;
+				else
+					a = b = mid;
+			}
+			if (cmp != 0)
+				fz_throw(ctx, FZ_ERROR_GENERIC, "unknown operator: '%s'", buf->scratch);
+
+			resize_code(ctx, func, *codeptr);
+			func->u.p.code[*codeptr].type = PS_OPERATOR;
+			func->u.p.code[*codeptr].u.op = a;
+			++*codeptr;
+			break;
+
+		default:
+			fz_throw(ctx, FZ_ERROR_GENERIC, "calculator function syntax error");
+		}
+	}
+}
+
+static void
+load_postscript_func(pdf_function *func, pdf_document *xref, pdf_obj *dict, int num, int gen)
+{
+	fz_stream *stream = NULL;
+	int codeptr;
+	pdf_lexbuf buf;
+	pdf_token tok;
+	fz_context *ctx = xref->ctx;
+	int locked = 0;
+
+	pdf_lexbuf_init(ctx, &buf, PDF_LEXBUF_SMALL);
+
+	fz_var(stream);
+	fz_var(locked);
+
+	fz_try(ctx)
+	{
+		stream = pdf_open_stream(xref, num, gen);
+
+		tok = pdf_lex(stream, &buf);
+		if (tok != PDF_TOK_OPEN_BRACE)
+		{
+			fz_throw(ctx, FZ_ERROR_GENERIC, "stream is not a calculator function");
+		}
+
+		func->u.p.code = NULL;
+		func->u.p.cap = 0;
+
+		codeptr = 0;
+		parse_code(func, stream, &codeptr, &buf);
+	}
+	fz_always(ctx)
+	{
+		fz_close(stream);
+		pdf_lexbuf_fin(&buf);
+	}
+	fz_catch(ctx)
+	{
+		fz_rethrow_message(ctx, "cannot parse calculator function (%d %d R)", num, gen);
+	}
+
+	func->base.size += func->u.p.cap * sizeof(psobj);
+}
+
+static void
+eval_postscript_func(fz_context *ctx, pdf_function *func, float *in, float *out)
+{
+	ps_stack st;
+	float x;
+	int i;
+
+	ps_init_stack(&st);
+
+	for (i = 0; i < func->base.m; i++)
+	{
+		x = fz_clamp(in[i], func->domain[i][0], func->domain[i][1]);
+		ps_push_real(&st, x);
+	}
+
+	ps_run(ctx, func->u.p.code, &st, 0);
+
+	for (i = func->base.n - 1; i >= 0; i--)
+	{
+		x = ps_pop_real(&st);
+		out[i] = fz_clamp(x, func->range[i][0], func->range[i][1]);
+	}
+}
+
+/*
+ * Sample function
+ */
+
+#define MAX_SAMPLE_FUNCTION_SIZE (100 << 20)
+
+static void
+load_sample_func(pdf_function *func, pdf_document *xref, pdf_obj *dict, int num, int gen)
+{
+	fz_context *ctx = xref->ctx;
+	fz_stream *stream;
+	pdf_obj *obj;
+	int samplecount;
+	int bps;
+	int i;
+
+	func->u.sa.samples = NULL;
+
+	obj = pdf_dict_gets(dict, "Size");
+	if (pdf_array_len(obj) < func->base.m)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "too few sample function dimension sizes");
+	if (pdf_array_len(obj) > func->base.m)
+		fz_warn(ctx, "too many sample function dimension sizes");
+	for (i = 0; i < func->base.m; i++)
+	{
+		func->u.sa.size[i] = pdf_to_int(pdf_array_get(obj, i));
+		if (func->u.sa.size[i] <= 0)
+		{
+			fz_warn(ctx, "non-positive sample function dimension size");
+			func->u.sa.size[i] = 1;
+		}
+	}
+
+	obj = pdf_dict_gets(dict, "BitsPerSample");
+	func->u.sa.bps = bps = pdf_to_int(obj);
+
+	for (i = 0; i < func->base.m; i++)
+	{
+		func->u.sa.encode[i][0] = 0;
+		func->u.sa.encode[i][1] = func->u.sa.size[i] - 1;
+	}
+	obj = pdf_dict_gets(dict, "Encode");
+	if (pdf_is_array(obj))
+	{
+		int ranges = fz_mini(func->base.m, pdf_array_len(obj) / 2);
+		if (ranges != func->base.m)
+			fz_warn(ctx, "wrong number of sample function input mappings");
+
+		for (i = 0; i < ranges; i++)
+		{
+			func->u.sa.encode[i][0] = pdf_to_real(pdf_array_get(obj, i * 2 + 0));
+			func->u.sa.encode[i][1] = pdf_to_real(pdf_array_get(obj, i * 2 + 1));
+		}
+	}
+
+	for (i = 0; i < func->base.n; i++)
+	{
+		func->u.sa.decode[i][0] = func->range[i][0];
+		func->u.sa.decode[i][1] = func->range[i][1];
+	}
+
+	obj = pdf_dict_gets(dict, "Decode");
+	if (pdf_is_array(obj))
+	{
+		int ranges = fz_mini(func->base.n, pdf_array_len(obj) / 2);
+		if (ranges != func->base.n)
+			fz_warn(ctx, "wrong number of sample function output mappings");
+
+		for (i = 0; i < ranges; i++)
+		{
+			func->u.sa.decode[i][0] = pdf_to_real(pdf_array_get(obj, i * 2 + 0));
+			func->u.sa.decode[i][1] = pdf_to_real(pdf_array_get(obj, i * 2 + 1));
+		}
+	}
+
+	for (i = 0, samplecount = func->base.n; i < func->base.m; i++)
+		samplecount *= func->u.sa.size[i];
+
+	if (samplecount > MAX_SAMPLE_FUNCTION_SIZE)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "sample function too large");
+
+	func->u.sa.samples = fz_malloc_array(ctx, samplecount, sizeof(float));
+	func->base.size += samplecount * sizeof(float);
+
+	stream = pdf_open_stream(xref, num, gen);
+
+	/* read samples */
+	for (i = 0; i < samplecount; i++)
+	{
+		unsigned int x;
+		float s;
+
+		if (fz_is_eof_bits(stream))
+		{
+			fz_close(stream);
+			fz_throw(ctx, FZ_ERROR_GENERIC, "truncated sample function stream");
+		}
+
+		switch (bps)
+		{
+		case 1: s = fz_read_bits(stream, 1); break;
+		case 2: s = fz_read_bits(stream, 2) / 3.0f; break;
+		case 4: s = fz_read_bits(stream, 4) / 15.0f; break;
+		case 8: s = fz_read_byte(stream) / 255.0f; break;
+		case 12: s = fz_read_bits(stream, 12) / 4095.0f; break;
+		case 16:
+			x = fz_read_byte(stream) << 8;
+			x |= fz_read_byte(stream);
+			s = x / 65535.0f;
+			break;
+		case 24:
+			x = fz_read_byte(stream) << 16;
+			x |= fz_read_byte(stream) << 8;
+			x |= fz_read_byte(stream);
+			s = x / 16777215.0f;
+			break;
+		case 32:
+			x = fz_read_byte(stream) << 24;
+			x |= fz_read_byte(stream) << 16;
+			x |= fz_read_byte(stream) << 8;
+			x |= fz_read_byte(stream);
+			s = x / 4294967295.0f;
+			break;
+		default:
+			fz_close(stream);
+			fz_throw(ctx, FZ_ERROR_GENERIC, "sample stream bit depth %d unsupported", bps);
+		}
+
+		func->u.sa.samples[i] = s;
+	}
+
+	fz_close(stream);
+}
+
+static float
+interpolate_sample(pdf_function *func, int *scale, int *e0, int *e1, float *efrac, int dim, int idx)
+{
+	float a, b;
+	int idx0, idx1;
+
+	idx0 = e0[dim] * scale[dim] + idx;
+	idx1 = e1[dim] * scale[dim] + idx;
+
+	if (dim == 0)
+	{
+		a = func->u.sa.samples[idx0];
+		b = func->u.sa.samples[idx1];
+	}
+	else
+	{
+		a = interpolate_sample(func, scale, e0, e1, efrac, dim - 1, idx0);
+		b = interpolate_sample(func, scale, e0, e1, efrac, dim - 1, idx1);
+	}
+
+	return a + (b - a) * efrac[dim];
+}
+
+static void
+eval_sample_func(fz_context *ctx, pdf_function *func, float *in, float *out)
+{
+	int e0[FZ_FN_MAXM], e1[FZ_FN_MAXM], scale[FZ_FN_MAXM];
+	float efrac[FZ_FN_MAXM];
+	float x;
+	int i;
+
+	/* encode input coordinates */
+	for (i = 0; i < func->base.m; i++)
+	{
+		x = fz_clamp(in[i], func->domain[i][0], func->domain[i][1]);
+		x = lerp(x, func->domain[i][0], func->domain[i][1],
+			func->u.sa.encode[i][0], func->u.sa.encode[i][1]);
+		x = fz_clamp(x, 0, func->u.sa.size[i] - 1);
+		e0[i] = floorf(x);
+		e1[i] = ceilf(x);
+		efrac[i] = x - floorf(x);
+	}
+
+	scale[0] = func->base.n;
+	for (i = 1; i < func->base.m; i++)
+		scale[i] = scale[i - 1] * func->u.sa.size[i];
+
+	for (i = 0; i < func->base.n; i++)
+	{
+		if (func->base.m == 1)
+		{
+			float a = func->u.sa.samples[e0[0] * func->base.n + i];
+			float b = func->u.sa.samples[e1[0] * func->base.n + i];
+
+			float ab = a + (b - a) * efrac[0];
+
+			out[i] = lerp(ab, 0, 1, func->u.sa.decode[i][0], func->u.sa.decode[i][1]);
+			out[i] = fz_clamp(out[i], func->range[i][0], func->range[i][1]);
+		}
+
+		else if (func->base.m == 2)
+		{
+			int s0 = func->base.n;
+			int s1 = s0 * func->u.sa.size[0];
+
+			float a = func->u.sa.samples[e0[0] * s0 + e0[1] * s1 + i];
+			float b = func->u.sa.samples[e1[0] * s0 + e0[1] * s1 + i];
+			float c = func->u.sa.samples[e0[0] * s0 + e1[1] * s1 + i];
+			float d = func->u.sa.samples[e1[0] * s0 + e1[1] * s1 + i];
+
+			float ab = a + (b - a) * efrac[0];
+			float cd = c + (d - c) * efrac[0];
+			float abcd = ab + (cd - ab) * efrac[1];
+
+			out[i] = lerp(abcd, 0, 1, func->u.sa.decode[i][0], func->u.sa.decode[i][1]);
+			out[i] = fz_clamp(out[i], func->range[i][0], func->range[i][1]);
+		}
+
+		else
+		{
+			x = interpolate_sample(func, scale, e0, e1, efrac, func->base.m - 1, i);
+			out[i] = lerp(x, 0, 1, func->u.sa.decode[i][0], func->u.sa.decode[i][1]);
+			out[i] = fz_clamp(out[i], func->range[i][0], func->range[i][1]);
+		}
+	}
+}
+
+/*
+ * Exponential function
+ */
+
+static void
+load_exponential_func(fz_context *ctx, pdf_function *func, pdf_obj *dict)
+{
+	pdf_obj *obj;
+	int i;
+
+	if (func->base.m > 1)
+		fz_warn(ctx, "exponential functions have at most one input");
+	func->base.m = 1;
+
+	obj = pdf_dict_gets(dict, "N");
+	func->u.e.n = pdf_to_real(obj);
+
+	/* See exponential functions (PDF 1.7 section 3.9.2) */
+	if (func->u.e.n != (int) func->u.e.n)
+	{
+		/* If N is non-integer, input values may never be negative */
+		for (i = 0; i < func->base.m; i++)
+			if (func->domain[i][0] < 0 || func->domain[i][1] < 0)
+				fz_warn(ctx, "exponential function input domain includes illegal negative input values");
+	}
+	else if (func->u.e.n < 0)
+	{
+		/* if N is negative, input values may never be zero */
+		for (i = 0; i < func->base.m; i++)
+			if (func->domain[i][0] == 0 || func->domain[i][1] == 0 ||
+				(func->domain[i][0] < 0 && func->domain[i][1] > 0))
+				fz_warn(ctx, "exponential function input domain includes illegal input value zero");
+	}
+
+	for (i = 0; i < func->base.n; i++)
+	{
+		func->u.e.c0[i] = 0;
+		func->u.e.c1[i] = 1;
+	}
+
+	obj = pdf_dict_gets(dict, "C0");
+	if (pdf_is_array(obj))
+	{
+		int ranges = fz_mini(func->base.n, pdf_array_len(obj));
+		if (ranges != func->base.n)
+			fz_warn(ctx, "wrong number of C0 constants for exponential function");
+
+		for (i = 0; i < ranges; i++)
+			func->u.e.c0[i] = pdf_to_real(pdf_array_get(obj, i));
+	}
+
+	obj = pdf_dict_gets(dict, "C1");
+	if (pdf_is_array(obj))
+	{
+		int ranges = fz_mini(func->base.n, pdf_array_len(obj));
+		if (ranges != func->base.n)
+			fz_warn(ctx, "wrong number of C1 constants for exponential function");
+
+		for (i = 0; i < ranges; i++)
+			func->u.e.c1[i] = pdf_to_real(pdf_array_get(obj, i));
+	}
+}
+
+static void
+eval_exponential_func(fz_context *ctx, pdf_function *func, float in, float *out)
+{
+	float x = in;
+	float tmp;
+	int i;
+
+	x = fz_clamp(x, func->domain[0][0], func->domain[0][1]);
+
+	/* Default output is zero, which is suitable for violated constraints */
+	if ((func->u.e.n != (int)func->u.e.n && x < 0) || (func->u.e.n < 0 && x == 0))
+		return;
+
+	tmp = powf(x, func->u.e.n);
+	for (i = 0; i < func->base.n; i++)
+	{
+		out[i] = func->u.e.c0[i] + tmp * (func->u.e.c1[i] - func->u.e.c0[i]);
+		if (func->has_range)
+			out[i] = fz_clamp(out[i], func->range[i][0], func->range[i][1]);
+	}
+}
+
+/*
+ * Stitching function
+ */
+
+static void
+load_stitching_func(pdf_function *func, pdf_document *xref, pdf_obj *dict)
+{
+	fz_context *ctx = xref->ctx;
+	fz_function **funcs;
+	pdf_obj *obj;
+	pdf_obj *sub;
+	pdf_obj *num;
+	int k;
+	int i;
+
+	func->u.st.k = 0;
+
+	if (func->base.m > 1)
+		fz_warn(ctx, "stitching functions have at most one input");
+	func->base.m = 1;
+
+	obj = pdf_dict_gets(dict, "Functions");
+	if (!pdf_is_array(obj))
+		fz_throw(ctx, FZ_ERROR_GENERIC, "stitching function has no input functions");
+
+	fz_try(ctx)
+	{
+		pdf_obj_mark(obj);
+		k = pdf_array_len(obj);
+
+		func->u.st.funcs = fz_malloc_array(ctx, k, sizeof(fz_function*));
+		func->u.st.bounds = fz_malloc_array(ctx, k - 1, sizeof(float));
+		func->u.st.encode = fz_malloc_array(ctx, k * 2, sizeof(float));
+		funcs = func->u.st.funcs;
+
+		for (i = 0; i < k; i++)
+		{
+			sub = pdf_array_get(obj, i);
+			funcs[i] = pdf_load_function(xref, sub, 1, func->base.n);
+
+			func->base.size += fz_function_size(funcs[i]);
+			func->u.st.k ++;
+
+			if (funcs[i]->m != func->base.m)
+				fz_warn(ctx, "wrong number of inputs for sub function %d", i);
+			if (funcs[i]->n != func->base.n)
+				fz_warn(ctx, "wrong number of outputs for sub function %d", i);
+		}
+	}
+	fz_always(ctx)
+	{
+		pdf_obj_unmark(obj);
+	}
+	fz_catch(ctx)
+	{
+		fz_rethrow(ctx);
+	}
+
+	obj = pdf_dict_gets(dict, "Bounds");
+	if (!pdf_is_array(obj))
+		fz_throw(ctx, FZ_ERROR_GENERIC, "stitching function has no bounds");
+	{
+		if (pdf_array_len(obj) < k - 1)
+			fz_throw(ctx, FZ_ERROR_GENERIC, "too few subfunction boundaries");
+		if (pdf_array_len(obj) > k)
+			fz_warn(ctx, "too many subfunction boundaries");
+
+		for (i = 0; i < k - 1; i++)
+		{
+			num = pdf_array_get(obj, i);
+			func->u.st.bounds[i] = pdf_to_real(num);
+			if (i && func->u.st.bounds[i - 1] > func->u.st.bounds[i])
+				fz_throw(ctx, FZ_ERROR_GENERIC, "subfunction %d boundary out of range", i);
+		}
+
+		if (k > 1 && (func->domain[0][0] > func->u.st.bounds[0] ||
+			func->domain[0][1] < func->u.st.bounds[k - 2]))
+			fz_warn(ctx, "subfunction boundaries outside of input mapping");
+	}
+
+	for (i = 0; i < k; i++)
+	{
+		func->u.st.encode[i * 2 + 0] = 0;
+		func->u.st.encode[i * 2 + 1] = 0;
+	}
+
+	obj = pdf_dict_gets(dict, "Encode");
+	if (pdf_is_array(obj))
+	{
+		int ranges = fz_mini(k, pdf_array_len(obj) / 2);
+		if (ranges != k)
+			fz_warn(ctx, "wrong number of stitching function input mappings");
+
+		for (i = 0; i < ranges; i++)
+		{
+			func->u.st.encode[i * 2 + 0] = pdf_to_real(pdf_array_get(obj, i * 2 + 0));
+			func->u.st.encode[i * 2 + 1] = pdf_to_real(pdf_array_get(obj, i * 2 + 1));
+		}
+	}
+}
+
+static void
+eval_stitching_func(fz_context *ctx, pdf_function *func, float in, float *out)
+{
+	float low, high;
+	int k = func->u.st.k;
+	float *bounds = func->u.st.bounds;
+	int i;
+
+	in = fz_clamp(in, func->domain[0][0], func->domain[0][1]);
+
+	for (i = 0; i < k - 1; i++)
+	{
+		if (in < bounds[i])
+			break;
+	}
+
+	if (i == 0 && k == 1)
+	{
+		low = func->domain[0][0];
+		high = func->domain[0][1];
+	}
+	else if (i == 0)
+	{
+		low = func->domain[0][0];
+		high = bounds[0];
+	}
+	else if (i == k - 1)
+	{
+		low = bounds[k - 2];
+		high = func->domain[0][1];
+	}
+	else
+	{
+		low = bounds[i - 1];
+		high = bounds[i];
+	}
+
+	in = lerp(in, low, high, func->u.st.encode[i * 2 + 0], func->u.st.encode[i * 2 + 1]);
+
+	fz_eval_function(ctx, func->u.st.funcs[i], &in, 1, out, func->u.st.funcs[i]->n);
+}
+
+/*
+ * Common
+ */
+
+static void
+pdf_free_function_imp(fz_context *ctx, fz_storable *func_)
+{
+	pdf_function *func = (pdf_function *)func_;
+	int i;
+
+	switch (func->type)
+	{
+	case SAMPLE:
+		fz_free(ctx, func->u.sa.samples);
+		break;
+	case EXPONENTIAL:
+		break;
+	case STITCHING:
+		for (i = 0; i < func->u.st.k; i++)
+			fz_drop_function(ctx, func->u.st.funcs[i]);
+		fz_free(ctx, func->u.st.funcs);
+		fz_free(ctx, func->u.st.bounds);
+		fz_free(ctx, func->u.st.encode);
+		break;
+	case POSTSCRIPT:
+		fz_free(ctx, func->u.p.code);
+		break;
+	}
+	fz_free(ctx, func);
+}
+
+static void
+pdf_eval_function(fz_context *ctx, fz_function *func_, float *in, float *out)
+{
+	pdf_function *func = (pdf_function *)func_;
+
+	switch (func->type)
+	{
+	case SAMPLE: eval_sample_func(ctx, func, in, out); break;
+	case EXPONENTIAL: eval_exponential_func(ctx, func, *in, out); break;
+	case STITCHING: eval_stitching_func(ctx, func, *in, out); break;
+	case POSTSCRIPT: eval_postscript_func(ctx, func, in, out); break;
+	}
+}
+
+/*
+ * Debugging prints
+ */
+
+#ifndef NDEBUG
+static void
+pdf_debug_indent(char *prefix, int level, char *suffix)
+{
+	int i;
+
+	printf("%s", prefix);
+
+	for (i = 0; i < level; i++)
+		printf("\t");
+
+	printf("%s", suffix);
+}
+
+static void
+pdf_debug_ps_func_code(psobj *funccode, psobj *code, int level)
+{
+	int eof, wasop;
+
+	pdf_debug_indent("", level, "{");
+
+	/* Print empty blocks as { }, instead of separating braces on different lines. */
+	if (code->type == PS_OPERATOR && code->u.op == PS_OP_RETURN)
+	{
+		printf(" } ");
+		return;
+	}
+
+	pdf_debug_indent("\n", ++level, "");
+
+	eof = 0;
+	wasop = 0;
+	while (!eof)
+	{
+		switch (code->type)
+		{
+		case PS_INT:
+			if (wasop)
+				pdf_debug_indent("\n", level, "");
+
+			printf("%d ", code->u.i);
+			wasop = 0;
+			code++;
+			break;
+
+		case PS_REAL:
+			if (wasop)
+				pdf_debug_indent("\n", level, "");
+
+			printf("%g ", code->u.f);
+			wasop = 0;
+			code++;
+			break;
+
+		case PS_OPERATOR:
+			if (code->u.op == PS_OP_RETURN)
+			{
+				printf("\n");
+				eof = 1;
+			}
+			else if (code->u.op == PS_OP_IF)
+			{
+				printf("\n");
+				pdf_debug_ps_func_code(funccode, &funccode[(code + 2)->u.block], level);
+
+				printf("%s", ps_op_names[code->u.op]);
+				code = &funccode[(code + 3)->u.block];
+				if (code->type != PS_OPERATOR || code->u.op != PS_OP_RETURN)
+					pdf_debug_indent("\n", level, "");
+
+				wasop = 0;
+			}
+			else if (code->u.op == PS_OP_IFELSE)
+			{
+				printf("\n");
+				pdf_debug_ps_func_code(funccode, &funccode[(code + 2)->u.block], level);
+
+				printf("\n");
+				pdf_debug_ps_func_code(funccode, &funccode[(code + 1)->u.block], level);
+
+				printf("%s", ps_op_names[code->u.op]);
+				code = &funccode[(code + 3)->u.block];
+				if (code->type != PS_OPERATOR || code->u.op != PS_OP_RETURN)
+					pdf_debug_indent("\n", level, "");
+
+				wasop = 0;
+			}
+			else
+			{
+				printf("%s ", ps_op_names[code->u.op]);
+				code++;
+				wasop = 1;
+			}
+			break;
+		}
+	}
+
+	pdf_debug_indent("", --level, "} ");
+}
+
+static void
+pdf_debug_function_imp(fz_function *func_, int level)
+{
+	int i;
+	pdf_function *func = (pdf_function *)func_;
+
+	pdf_debug_indent("", level, "function {\n");
+
+	pdf_debug_indent("", ++level, "");
+	switch (func->type)
+	{
+	case SAMPLE:
+		printf("sampled");
+		break;
+	case EXPONENTIAL:
+		printf("exponential");
+		break;
+	case STITCHING:
+		printf("stitching");
+		break;
+	case POSTSCRIPT:
+		printf("postscript");
+		break;
+	}
+
+	pdf_debug_indent("\n", level, "");
+	printf("%d input -> %d output\n", func->base.m, func->base.n);
+
+	pdf_debug_indent("", level, "domain ");
+	for (i = 0; i < func->base.m; i++)
+		printf("%g %g ", func->domain[i][0], func->domain[i][1]);
+	printf("\n");
+
+	if (func->has_range)
+	{
+		pdf_debug_indent("", level, "range ");
+		for (i = 0; i < func->base.n; i++)
+			printf("%g %g ", func->range[i][0], func->range[i][1]);
+		printf("\n");
+	}
+
+	switch (func->type)
+	{
+	case SAMPLE:
+		pdf_debug_indent("", level, "");
+		printf("bps: %d\n", func->u.sa.bps);
+
+		pdf_debug_indent("", level, "");
+		printf("size: [ ");
+		for (i = 0; i < func->base.m; i++)
+			printf("%d ", func->u.sa.size[i]);
+		printf("]\n");
+
+		pdf_debug_indent("", level, "");
+		printf("encode: [ ");
+		for (i = 0; i < func->base.m; i++)
+			printf("%g %g ", func->u.sa.encode[i][0], func->u.sa.encode[i][1]);
+		printf("]\n");
+
+		pdf_debug_indent("", level, "");
+		printf("decode: [ ");
+		for (i = 0; i < func->base.m; i++)
+			printf("%g %g ", func->u.sa.decode[i][0], func->u.sa.decode[i][1]);
+		printf("]\n");
+		break;
+
+	case EXPONENTIAL:
+		pdf_debug_indent("", level, "");
+		printf("n: %g\n", func->u.e.n);
+
+		pdf_debug_indent("", level, "");
+		printf("c0: [ ");
+		for (i = 0; i < func->base.n; i++)
+			printf("%g ", func->u.e.c0[i]);
+		printf("]\n");
+
+		pdf_debug_indent("", level, "");
+		printf("c1: [ ");
+		for (i = 0; i < func->base.n; i++)
+			printf("%g ", func->u.e.c1[i]);
+		printf("]\n");
+		break;
+
+	case STITCHING:
+		pdf_debug_indent("", level, "");
+		printf("%d functions\n", func->u.st.k);
+
+		pdf_debug_indent("", level, "");
+		printf("bounds: [ ");
+		for (i = 0; i < func->u.st.k - 1; i++)
+			printf("%g ", func->u.st.bounds[i]);
+		printf("]\n");
+
+		pdf_debug_indent("", level, "");
+		printf("encode: [ ");
+		for (i = 0; i < func->u.st.k * 2; i++)
+			printf("%g ", func->u.st.encode[i]);
+		printf("]\n");
+
+		for (i = 0; i < func->u.st.k; i++)
+			pdf_debug_function_imp(func->u.st.funcs[i], level);
+		break;
+
+	case POSTSCRIPT:
+		pdf_debug_ps_func_code(func->u.p.code, func->u.p.code, level);
+		printf("\n");
+		break;
+	}
+
+	pdf_debug_indent("", --level, "}\n");
+}
+
+void
+pdf_debug_function(fz_function *func)
+{
+	pdf_debug_function_imp(func, 0);
+}
+#endif
+
+fz_function *
+pdf_load_function(pdf_document *xref, pdf_obj *dict, int in, int out)
+{
+	fz_context *ctx = xref->ctx;
+	pdf_function *func;
+	pdf_obj *obj;
+	int i;
+
+	if (pdf_obj_marked(dict))
+		fz_throw(ctx, FZ_ERROR_GENERIC, "Recursion in function definition");
+
+	if ((func = pdf_find_item(ctx, pdf_free_function_imp, dict)))
+	{
+		return (fz_function *)func;
+	}
+
+	func = fz_malloc_struct(ctx, pdf_function);
+	FZ_INIT_STORABLE(&func->base, 1, pdf_free_function_imp);
+	func->base.size = sizeof(*func);
+	func->base.evaluate = pdf_eval_function;
+#ifndef NDEBUG
+	func->base.debug = pdf_debug_function;
+#endif
+
+	obj = pdf_dict_gets(dict, "FunctionType");
+	func->type = pdf_to_int(obj);
+
+	/* required for all */
+	obj = pdf_dict_gets(dict, "Domain");
+	func->base.m = fz_clampi(pdf_array_len(obj) / 2, 1, FZ_FN_MAXM);
+	for (i = 0; i < func->base.m; i++)
+	{
+		func->domain[i][0] = pdf_to_real(pdf_array_get(obj, i * 2 + 0));
+		func->domain[i][1] = pdf_to_real(pdf_array_get(obj, i * 2 + 1));
+	}
+
+	/* required for type0 and type4, optional otherwise */
+	obj = pdf_dict_gets(dict, "Range");
+	if (pdf_is_array(obj))
+	{
+		func->has_range = 1;
+		func->base.n = fz_clampi(pdf_array_len(obj) / 2, 1, FZ_FN_MAXN);
+		for (i = 0; i < func->base.n; i++)
+		{
+			func->range[i][0] = pdf_to_real(pdf_array_get(obj, i * 2 + 0));
+			func->range[i][1] = pdf_to_real(pdf_array_get(obj, i * 2 + 1));
+		}
+	}
+	else
+	{
+		func->has_range = 0;
+		func->base.n = out;
+	}
+
+	if (func->base.m != in)
+		fz_warn(ctx, "wrong number of function inputs");
+	if (func->base.n != out)
+		fz_warn(ctx, "wrong number of function outputs");
+
+	fz_try(ctx)
+	{
+		switch (func->type)
+		{
+		case SAMPLE:
+			load_sample_func(func, xref, dict, pdf_to_num(dict), pdf_to_gen(dict));
+			break;
+
+		case EXPONENTIAL:
+			load_exponential_func(ctx, func, dict);
+			break;
+
+		case STITCHING:
+			load_stitching_func(func, xref, dict);
+			break;
+
+		case POSTSCRIPT:
+			load_postscript_func(func, xref, dict, pdf_to_num(dict), pdf_to_gen(dict));
+			break;
+
+		default:
+			fz_free(ctx, func);
+			fz_throw(ctx, FZ_ERROR_GENERIC, "unknown function type (%d %d R)", pdf_to_num(dict), pdf_to_gen(dict));
+		}
+
+		pdf_store_item(ctx, dict, func, func->base.size);
+	}
+	fz_catch(ctx)
+	{
+		int type = func->type;
+		fz_drop_function(ctx, (fz_function *)func);
+		fz_rethrow_message(ctx, "cannot load %s function (%d %d R)",
+					type == SAMPLE ? "sampled" :
+					type == EXPONENTIAL ? "exponential" :
+					type == STITCHING ? "stitching" :
+					type == POSTSCRIPT ? "calculator" :
+					"unknown",
+					pdf_to_num(dict), pdf_to_gen(dict));
+	}
+
+	return (fz_function *)func;
+}