diff options
| -rw-r--r-- | pdf/pdf_function.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/pdf/pdf_function.c b/pdf/pdf_function.c index 5eea4125..005572df 100644 --- a/pdf/pdf_function.c +++ b/pdf/pdf_function.c @@ -1137,10 +1137,25 @@ load_exponential_func(fz_context *ctx, pdf_function *func, pdf_obj *dict) func->m = 1; obj = pdf_dict_gets(dict, "N"); - if (!pdf_is_int(obj) && !pdf_is_real(obj)) - fz_throw(ctx, "malformed /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->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->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"); + } + obj = pdf_dict_gets(dict, "C0"); if (pdf_is_array(obj)) { @@ -1181,12 +1196,9 @@ eval_exponential_func(fz_context *ctx, pdf_function *func, float in, float *out) x = fz_clamp(x, func->domain[0][0], func->domain[0][1]); - /* constraint */ + /* 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)) - { - fz_warn(ctx, "constraint error"); return; - } tmp = powf(x, func->u.e.n); for (i = 0; i < func->n; i++) |