Bug 573953. Ensure that zoom factors are chosen in reftests so appunits-per-dev-pixel is an integer. r=dbaron

2010-07-16 09:04:16 +12:00 · 2010-07-16 09:04:16 +12:00 · 0587a61cc8
--- a/gfx/src/thebes/nsThebesDeviceContext.cpp
+++ b/gfx/src/thebes/nsThebesDeviceContext.cpp
@ -1224,7 +1224,8 @@ nsThebesDeviceContext::SetPixelScale(float aScale)
 void
 nsThebesDeviceContext::UpdateScaledAppUnits()
 {
-    mAppUnitsPerDevPixel = PR_MAX(1, PRInt32(float(mAppUnitsPerDevNotScaledPixel) / mPixelScale));
+    mAppUnitsPerDevPixel =
+        PR_MAX(1, NSToIntRound(float(mAppUnitsPerDevNotScaledPixel) / mPixelScale));
 }

 #if defined(XP_WIN) || defined(XP_OS2)
--- a/layout/reftests/bugs/446100-1a.html
+++ b/layout/reftests/bugs/446100-1a.html
@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<html reftest-zoom="1.1">
+<html reftest-zoom="1.2">
 <head>
 <style>
 div { margin:1em; }
--- a/layout/reftests/bugs/446100-1c.html
+++ b/layout/reftests/bugs/446100-1c.html
@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<html reftest-zoom="1.7">
+<html reftest-zoom="1.8">
 <head>
 <style>
 div { margin:1em; }
--- a/layout/reftests/bugs/446100-1f.html
+++ b/layout/reftests/bugs/446100-1f.html
@ -1,5 +1,5 @@
 <!DOCTYPE HTML>
-<html reftest-zoom="0.67">
+<html reftest-zoom="0.6666666">
 <head>
 <style>
 div { margin:1em; }
--- a/layout/reftests/image-rect/background-zoom-1-ref.html
+++ b/layout/reftests/image-rect/background-zoom-1-ref.html
@ -10,7 +10,7 @@
    This file is identical to background-common-usage-pixel.html except the
    zoom factor.
 -->
-<html reftest-zoom="1.3">
+<html reftest-zoom="1.304348">
  <head>
    <title>Testcases: -moz-image-rect() [bug 113577]</title>
    <style>
--- a/layout/reftests/image-rect/background-zoom-1.html
+++ b/layout/reftests/image-rect/background-zoom-1.html
@ -10,7 +10,7 @@
    This file is identical to background-common-usage-pixel.html except the
    zoom factor.
 -->
-<html reftest-zoom="1.3">
+<html reftest-zoom="1.304348">
  <head>
    <title>Testcases: -moz-image-rect() [bug 113577]</title>
    <style>
--- a/layout/reftests/image-rect/background-zoom-2-ref.html
+++ b/layout/reftests/image-rect/background-zoom-2-ref.html
@ -10,7 +10,7 @@
    This file is identical to background-common-usage-pixel.html except the
    zoom factor.
 -->
-<html reftest-zoom="1.3">
+<html reftest-zoom="1.304348">
  <head>
    <title>Testcases: -moz-image-rect() [bug 113577]</title>
    <style>
--- a/layout/reftests/image-rect/background-zoom-2.html
+++ b/layout/reftests/image-rect/background-zoom-2.html
@ -10,7 +10,7 @@
    This file is identical to background-common-usage-pixel.html except the
    zoom factor.
 -->
-<html reftest-zoom="1.3">
+<html reftest-zoom="1.304348">
  <head>
    <title>Testcases: -moz-image-rect() [bug 113577]</title>
    <style>
--- a/layout/reftests/image-rect/background-zoom-3-ref.html
+++ b/layout/reftests/image-rect/background-zoom-3-ref.html
@ -10,7 +10,7 @@
    This file is identical to background-common-usage-pixel.html except the
    zoom factor.
 -->
-<html reftest-zoom="1.3">
+<html reftest-zoom="1.304348">
  <head>
    <title>Testcases: -moz-image-rect() [bug 113577]</title>
    <style>
--- a/layout/reftests/image-rect/background-zoom-3.html
+++ b/layout/reftests/image-rect/background-zoom-3.html
@ -10,7 +10,7 @@
    This file is identical to background-common-usage-pixel.html except the
    zoom factor.
 -->
-<html reftest-zoom="1.3">
+<html reftest-zoom="1.304348">
  <head>
    <title>Testcases: -moz-image-rect() [bug 113577]</title>
    <style>
--- a/layout/reftests/image-rect/background-zoom-4-ref.html
+++ b/layout/reftests/image-rect/background-zoom-4-ref.html
@ -10,7 +10,7 @@
    This file is identical to background-common-usage-pixel.html except the
    zoom factor.
 -->
-<html reftest-zoom="1.3">
+<html reftest-zoom="1.304348">
  <head>
    <title>Testcases: -moz-image-rect() [bug 113577]</title>
    <style>
--- a/layout/reftests/image-rect/background-zoom-4.html
+++ b/layout/reftests/image-rect/background-zoom-4.html
@ -10,7 +10,7 @@
    This file is identical to background-common-usage-pixel.html except the
    zoom factor.
 -->
-<html reftest-zoom="1.3">
+<html reftest-zoom="1.304348">
  <head>
    <title>Testcases: -moz-image-rect() [bug 113577]</title>
    <style>
--- a/layout/tools/reftest/README.txt
+++ b/layout/tools/reftest/README.txt
@ -351,6 +351,17 @@ function doTest() {
 }
 document.addEventListener("MozReftestInvalidate", doTest, false);

+Zoom Tests
+==========
+
+When the root element of a test has a "reftest-zoom" attribute, that zoom
+factor is applied when rendering the test. The reftest document will be
+800 device pixels wide by 1000 device pixels high. The reftest harness assumes
+that the CSS pixel dimensions are 800/zoom and 1000/zoom. For best results
+therefore, choose zoom factors that do not require rounding when we calculate
+the number of appunits per device pixel; i.e. the zoom factor should divide 60,
+so 60/zoom is an integer.
+
 Printing Tests
 ==============
 Now that the patch for bug 374050 has landed