diff options
| -rw-r--r-- | include/mupdf/fitz/math.h | 14 | ||||
| -rw-r--r-- | source/fitz/draw-path.c | 3 | ||||
| -rw-r--r-- | source/fitz/geometry.c | 19 |
3 files changed, 35 insertions, 1 deletions
diff --git a/include/mupdf/fitz/math.h b/include/mupdf/fitz/math.h index 1d542964..387f73a4 100644 --- a/include/mupdf/fitz/math.h +++ b/include/mupdf/fitz/math.h @@ -400,6 +400,20 @@ fz_matrix *fz_pre_translate(fz_matrix *m, float tx, float ty); fz_matrix *fz_invert_matrix(fz_matrix *inverse, const fz_matrix *matrix); /* + fz_try_invert_matrix: Attempt to create an inverse matrix. + + inverse: Place to store inverse matrix. + + matrix: Matrix to invert. A degenerate matrix, where the + determinant is equal to zero, can not be inverted. + + Returns 1 if matrix is degenerate (singular), or 0 otherwise. + + Does not throw exceptions. +*/ + int fz_try_invert_matrix(fz_matrix *inverse, const fz_matrix *matrix); + +/* fz_is_rectilinear: Check if a transformation is rectilinear. Rectilinear means that no shearing is present and that any diff --git a/source/fitz/draw-path.c b/source/fitz/draw-path.c index 6fa6191d..b33ea8b4 100644 --- a/source/fitz/draw-path.c +++ b/source/fitz/draw-path.c @@ -971,7 +971,8 @@ fz_flatten_dash_path(fz_gel *gel, fz_path *path, const fz_stroke_state *stroke, for (i = 0; i < stroke->dash_len; i++) phase_len += stroke->dash_list[i]; fz_gel_scissor(gel, &s.rect); - fz_invert_matrix(&inv, ctm); + if (fz_try_invert_matrix(&inv, ctm)) + return; fz_transform_rect(&s.rect, &inv); s.rect.x0 -= linewidth; s.rect.x1 += linewidth; diff --git a/source/fitz/geometry.c b/source/fitz/geometry.c index 81450246..c7c3d198 100644 --- a/source/fitz/geometry.c +++ b/source/fitz/geometry.c @@ -214,6 +214,25 @@ fz_invert_matrix(fz_matrix *dst, const fz_matrix *src) } int +fz_try_invert_matrix(fz_matrix *dst, const fz_matrix *src) +{ + /* Be careful to cope with dst == src */ + float a = src->a; + float det = a * src->d - src->b * src->c; + if (det >= -FLT_EPSILON && det <= FLT_EPSILON) + return 1; + det = 1 / det; + dst->a = src->d * det; + dst->b = -src->b * det; + dst->c = -src->c * det; + dst->d = a * det; + a = -src->e * dst->a - src->f * dst->c; + dst->f = -src->e * dst->b - src->f * dst->d; + dst->e = a; + return 0; +} + +int fz_is_rectilinear(const fz_matrix *m) { return (fabsf(m->b) < FLT_EPSILON && fabsf(m->c) < FLT_EPSILON) || |