diff options
author | Carl Worth <cworth@cworth.org> | 2008-02-28 15:45:11 -0800 |
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committer | Carl Worth <cworth@cworth.org> | 2008-02-28 15:45:11 -0800 |
commit | bf99e355d9d24a4820dc93b49321b15318501b61 (patch) | |
tree | 30d3cc261ee12d33ea4a0cdea8a32e00a3b7fa83 | |
parent | 4cc174f72f635e885b5f5fdc3d67789d3952cd2e (diff) |
Clarify that 16-bit limit still exists in pixman
-rw-r--r-- | NEWS | 21 |
1 files changed, 11 insertions, 10 deletions
@@ -23,21 +23,22 @@ that extends beyond the surface bounds and expect it to fill the surface completely, (rather than overflowing and triggering random behavior). -Meanwhile, nobody has ever really needed 16 bits of sub-pixel precision. +Meanwhile, nobody has ever really needed 16 bits of sub-pixel +precision. With this snapshot, the fixed-point system is still in place and is still using a 32-bit representation, (future versions of cairo might move entirely to floating-point when targeting PDF output for example). But the representation now provides 24 bits of pixel -addressing and only 8 bits of sub-pixel positioning. It is hoped that -this larger space is adequate to avoid pain for many application -developers. - -Note that the 24-bit limitation is only on the range of the allowable -device space. It is still legitimate to arrange a transformation -matrix that provides an arbitrarily large user-space, (the space in -which floating-point values are provided to cairo), as long as the -post-transformed values fit within the 24.8 representation. +addressing and only 8 bits of sub-pixel positioning. This should give +a much less stifling space to many applications. + +However, the underlying pixman library still has 16-bit limitations in +many places, (it has its roots in the X server as well). Until those +are also fixed, applications targeting cairo image surfaces, or +hitting software fallbacks when targeting other surfaces will still +encounter problems with device-space values needing more than 16 +integer bits. generic fixes ------------- |