diff options
| -rw-r--r-- | base/fapi_ft.c | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/base/fapi_ft.c b/base/fapi_ft.c index 07b4167ca..c9fe9ff79 100644 --- a/base/fapi_ft.c +++ b/base/fapi_ft.c @@ -974,13 +974,19 @@ make_rotation(FT_Matrix * a_transform, const FT_Vector * a_vector) */ static void transform_decompose(FT_Matrix * a_transform, FT_UInt * xresp, FT_UInt * yresp, - FT_Fixed * a_x_scale, FT_Fixed * a_y_scale) + FT_Fixed * a_x_scale, FT_Fixed * a_y_scale, int units_per_EM) { double scalex, scaley, fact = 1.0; double factx = 1.0, facty = 1.0; FT_Matrix ftscale_mat; FT_UInt xres; FT_UInt yres; + /* We have to account for units_per_EM as we fiddle with the scaling + * in order to avoid underflow (mostly in the TTF hinting code), but + * we also want to clamp to a lower value (512, admittedly arrived at + * via experimentation) in order to preserve the fidelity of the outlines. + */ + double upe = units_per_EM > 512 ? (float)units_per_EM : 512.0; scalex = hypot((double)a_transform->xx, (double)a_transform->xy); scaley = hypot((double)a_transform->yx, (double)a_transform->yy); @@ -1067,10 +1073,25 @@ transform_decompose(FT_Matrix * a_transform, FT_UInt * xresp, FT_UInt * yresp, scalex *= fact; } - ftscale_mat.xx = (FT_Fixed) (65536.0 / scalex); - ftscale_mat.xy = (FT_Fixed) 0; - ftscale_mat.yx = (FT_Fixed) 0; - ftscale_mat.yy = (FT_Fixed) (65536.0 / scaley); + /* see above */ + fact = 1.0; + while (scaley * yres > (double)upe * 72.0 && (xres > 0 && yres > 0) + && (scalex > 0.0 && scaley > 0.0)) { + if (scaley < yres) { + xres >>= 1; + yres >>= 1; + fact *= 2.0; + } + else { + scalex /= 1.25; + scaley /= 1.25; + } + } + + ftscale_mat.xx = (FT_Fixed) ((65536.0 / scalex) * fact); + ftscale_mat.xy = 0; + ftscale_mat.yx = 0; + ftscale_mat.yy = (FT_Fixed) ((65536.0 / scaley) * fact); FT_Matrix_Multiply(a_transform, &ftscale_mat); memcpy(a_transform, &ftscale_mat, sizeof(FT_Matrix)); @@ -1315,7 +1336,7 @@ gs_fapi_ft_get_scaled_font(gs_fapi_server * a_server, gs_fapi_font * a_font, * transform. */ transform_decompose(&face->ft_transform, &face->horz_res, - &face->vert_res, &face->width, &face->height); + &face->vert_res, &face->width, &face->height, face->ft_face->units_per_EM); ft_error = FT_Set_Char_Size(face->ft_face, face->width, face->height, face->horz_res, face->vert_res); |