Re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-13 Thread Reece Dunn
2008/7/12 Michael Karcher <[EMAIL PROTECTED]>: > Am Samstag, den 12.07.2008, 16:55 -0500 schrieb James Hawkins: >> > GDI+ uses floating >> > point values for matrix elements so don't you think the result could be >> > slightly different due different calculation algorithms? > As they say: Never com

Re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-12 Thread Nikolay Sivov
Michael Karcher wrote: > Am Samstag, den 12.07.2008, 16:55 -0500 schrieb James Hawkins: > > -GdipCreateMatrix2(1.0/9.0, 2.0/9.0, 4.0/9.0, -1.0/9.0, -2.0, -1.0, > >>> Of course there's only one value of inverted matrix. >>> > Which is not representable as a finite bi

Re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-12 Thread Dan Kegel
On Sat, Jul 12, 2008 at 4:16 PM, Dan Kegel <[EMAIL PROTECTED]> wrote: > Floating point equality comparisons need an error tolerance. > See e.g. > > http://teaching.idallen.com/cst8110/97s/floating_point.html > http://docs.hp.com/en/B3906-90006/ch03s05.html > http://en.wikipedia.org/wiki/Floating_po

Re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-12 Thread Michael Karcher
Am Sonntag, den 13.07.2008, 01:14 +0200 schrieb Michael Karcher: > Am Samstag, den 12.07.2008, 23:56 +0100 schrieb Reece Dunn: > If you are brave enough to really find out what happens (might be > different depending on Windows version, instruction sets available and > things like that), also try t

re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-12 Thread Dan Kegel
James wrote: > > GDI+ uses floating point values for matrix elements so >> don't you think the result could be slightly different... > > No I don't think the results will be slightly different. > Higher-precision arithmetic doesn't mean more slop. Floating point equality comparisons need an error

Re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-12 Thread Michael Karcher
Am Samstag, den 12.07.2008, 23:56 +0100 schrieb Reece Dunn: > > Nikolay: Please write a test whether the matrix > > 1.0/131072, 2.0/131072, 4.0/131072, -1/131072, 0, 0 > > is invertible. According to your criterion, it is *not* invertible, as > > the determinant will be 9.0/17179869184, which is w

Re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-12 Thread Michael Karcher
Am Samstag, den 12.07.2008, 16:55 -0500 schrieb James Hawkins: > >>> -GdipCreateMatrix2(1.0/9.0, 2.0/9.0, 4.0/9.0, -1.0/9.0, -2.0, -1.0, > > Of course there's only one value of inverted matrix. Which is not representable as a finite binary fraction. > > GDI+ uses floating > > point values for

Re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-12 Thread Nikolay Sivov
James Hawkins wrote: > On Sat, Jul 12, 2008 at 4:35 PM, Nikolay Sivov <[EMAIL PROTECTED]> wrote: > >> James Hawkins wrote: >> >>> On Sat, Jul 12, 2008 at 4:12 PM, Nikolay Sivov <[EMAIL PROTECTED]> >>> wrote: >>> >>> Changelog: - Make GdipInvertMatrix test pass on native >

Re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-12 Thread James Hawkins
On Sat, Jul 12, 2008 at 4:35 PM, Nikolay Sivov <[EMAIL PROTECTED]> wrote: > James Hawkins wrote: >> >> On Sat, Jul 12, 2008 at 4:12 PM, Nikolay Sivov <[EMAIL PROTECTED]> >> wrote: >> >>> >>> Changelog: >>> - Make GdipInvertMatrix test pass on native >>> >>> --- >>> dlls/gdiplus/tests/matrix.c |

Re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-12 Thread Nikolay Sivov
James Hawkins wrote: > On Sat, Jul 12, 2008 at 4:12 PM, Nikolay Sivov <[EMAIL PROTECTED]> wrote: > >> Changelog: >>- Make GdipInvertMatrix test pass on native >> >> --- >> dlls/gdiplus/tests/matrix.c | 23 +-- >> 1 files changed, 17 insertions(+), 6 deletions(-) >> >>

Re: [3/3] gdiplus: Make GdipInvertMatrix test pass on native

2008-07-12 Thread James Hawkins
On Sat, Jul 12, 2008 at 4:12 PM, Nikolay Sivov <[EMAIL PROTECTED]> wrote: > Changelog: >- Make GdipInvertMatrix test pass on native > > --- > dlls/gdiplus/tests/matrix.c | 23 +-- > 1 files changed, 17 insertions(+), 6 deletions(-) > > diff --git a/dlls/gdiplus/tests/matr