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| author | Edward Welbourne <edward.welbourne@qt.io> | 2017-03-22 13:18:52 +0100 |
|---|---|---|
| committer | Edward Welbourne <edward.welbourne@qt.io> | 2017-06-20 09:53:46 +0000 |
| commit | 02b7ec05d5713aec67577cebc18e5906b5a98598 (patch) | |
| tree | a8b7fe65eb276c50b5617e808ec26ddfdf065ab8 /examples/widgets/painting/painterpaths | |
| parent | 82deb0ad160459c16c77cbbea69b56387723c3a4 (diff) | |
| download | qtbase-02b7ec05d5713aec67577cebc18e5906b5a98598.tar.gz | |
Be (somewhat more) consistent about the value of pi
Use M_PI (and friends), where possible, in favor of hand-coded
approximations of various (in)accuracies. Where that's not available
(e.g. fragment shaders), use the same value that qmath.h uses for
M_PI, for consistency. Replaced math.h with qmath.h in places that
defined a fall-back in case math.h omits it (it's not in the C++
standard, although M_PI is in POSIX); or removed this entirely where
it wasn't used.
Reworked some code to reduce the amount of arithmetic needed, in the
process; e.g. pulling common factors out of loops. Revised an
example's doc to not waste time talking about using a six-sig-fig
value for pi (which we no longer do) - it really wasn't relevant, or
anything to be proud of; nor did the doc mention its later use.
Task-number: QTBUG-58083
Change-Id: I5a31e3a2b6a823b97a43209bed61a37b9aa6c05f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'examples/widgets/painting/painterpaths')
| -rw-r--r-- | examples/widgets/painting/painterpaths/window.cpp | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/examples/widgets/painting/painterpaths/window.cpp b/examples/widgets/painting/painterpaths/window.cpp index 7122411a6c..a987937b39 100644 --- a/examples/widgets/painting/painterpaths/window.cpp +++ b/examples/widgets/painting/painterpaths/window.cpp @@ -53,11 +53,7 @@ #include <QtWidgets> -#include <cmath> - -//! [0] -const float Pi = 3.14159f; -//! [0] +#include <qmath.h> //! [1] Window::Window() @@ -133,8 +129,8 @@ Window::Window() QPainterPath starPath; starPath.moveTo(90, 50); for (int i = 1; i < 5; ++i) { - starPath.lineTo(50 + 40 * std::cos(0.8 * i * Pi), - 50 + 40 * std::sin(0.8 * i * Pi)); + starPath.lineTo(50 + 40 * std::cos(0.8 * i * M_PI), + 50 + 40 * std::sin(0.8 * i * M_PI)); } starPath.closeSubpath(); //! [9] |