summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorEdward Welbourne <edward.welbourne@qt.io>2017-02-24 14:49:29 (GMT)
committerEdward Welbourne <edward.welbourne@qt.io>2017-07-06 14:02:48 (GMT)
commit368b24bfa00a5ef8fe14cd5e4690333675d7704a (patch)
tree712feb4dc1589d229438f27e291ecfdc8bd72703
parent92ae0d2e5df16096893d03de3f5602d7d5d70e7d (diff)
downloadqtsensors-368b24bfa00a5ef8fe14cd5e4690333675d7704a.tar.gz
Be consistent about values related to pi (radian / degree ratio)
Use JavaScript's Math.PI to compute 180 / pi (the number of degrees in one radian), rather than a hand-coded value for this constant. Store the result in a readonly property double to avoid repeating the computation. Tweak the pitch and roll calculations to use more apt Math methods: use hypot rather than sqrt of a sum of squares, and use atan2 instead of a tan of a ratio (whose denominator is always positive, so this doesn't change which angle we get). Task-number: QTBUG-58083 Change-Id: Ic3f865dfcbd9b02a0b93f065995d850386aef18c Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io> Reviewed-by: Lorn Potter <lorn.potter@gmail.com>
-rw-r--r--examples/sensors/accelbubble/accelbubble.qml6
-rw-r--r--examples/sensors/maze/Mouse.qml4
2 files changed, 5 insertions, 5 deletions
diff --git a/examples/sensors/accelbubble/accelbubble.qml b/examples/sensors/accelbubble/accelbubble.qml
index 37bf427..8bd036f 100644
--- a/examples/sensors/accelbubble/accelbubble.qml
+++ b/examples/sensors/accelbubble/accelbubble.qml
@@ -63,7 +63,7 @@ ApplicationWindow {
width: 320
height: 480
visible: true
-
+ readonly property double radians_to_degrees: 180 / Math.PI
//! [1]
Accelerometer {
@@ -101,10 +101,10 @@ ApplicationWindow {
}
function calcPitch(x,y,z) {
- return -(Math.atan(y / Math.sqrt(x * x + z * z)) * 57.2957795);
+ return -Math.atan2(y, Math.hypot(x, z)) * mainWindow.radians_to_degrees;
}
function calcRoll(x,y,z) {
- return -(Math.atan(x / Math.sqrt(y * y + z * z)) * 57.2957795);
+ return -Math.atan2(x, Math.hypot(y, z)) * mainWindow.radians_to_degrees;
}
Image {
diff --git a/examples/sensors/maze/Mouse.qml b/examples/sensors/maze/Mouse.qml
index 7f8ea27..cf83991 100644
--- a/examples/sensors/maze/Mouse.qml
+++ b/examples/sensors/maze/Mouse.qml
@@ -62,6 +62,7 @@ Item {
width: Lib.cellDimension
height: Lib.cellDimension
property int angle
+ readonly property double radians_to_degrees: 180 / Math.PI
AnimatedImage {
id: img
@@ -79,8 +80,7 @@ Item {
//! [0]
var a = newy - mouse.y
var b = newx - mouse.x
- var radians_to_degrees = 57.2957795
- angle = Math.atan2(-b, a) * radians_to_degrees
+ angle = Math.atan2(-b, a) * mouse.radians_to_degrees
if (angle < 0)
angle = 360 + angle