diff options
| -rw-r--r-- | draw/draw_affine.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/draw/draw_affine.c b/draw/draw_affine.c index 4e21ced0..52b8a847 100644 --- a/draw/draw_affine.c +++ b/draw/draw_affine.c @@ -653,14 +653,18 @@ fz_paint_image_imp(fz_pixmap *dst, fz_bbox scissor, fz_pixmap *shape, fz_pixmap inv = fz_concat(inv, ctm); inv = fz_invert_matrix(inv); - fa = inv.a * 65536; - fb = inv.b * 65536; - fc = inv.c * 65536; - fd = inv.d * 65536; + fa = (int)(inv.a *= 65536.0f); + fb = (int)(inv.b *= 65536.0f); + fc = (int)(inv.c *= 65536.0f); + fd = (int)(inv.d *= 65536.0f); + inv.e *= 65536.0f; + inv.f *= 65536.0f; /* Calculate initial texture positions. Do a half step to start. */ - u = (fa * x) + (fc * y) + inv.e * 65536 + ((fa + fc) >> 1); - v = (fb * x) + (fd * y) + inv.f * 65536 + ((fb + fd) >> 1); + /* Bug 693021: Keep calculation in float for as long as possible to + * avoid overflow. */ + u = (int)((inv.a * x) + (inv.c * y) + inv.e + ((inv.a + inv.c) * .5f)); + v = (int)((inv.b * x) + (inv.d * y) + inv.f + ((inv.b + inv.d) * .5f)); /* RJW: The following is voodoo. No idea why it works, but it gives * the best match between scaled/unscaled/interpolated/non-interpolated |