328820 - Fast path ASCII text measuring/drawing

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Stuart Parmenter]

Since the DOM can provide us with ASCII strings, we should fast path them on the various platforms where we can.

Comment 1

[Stuart Parmenter]

Attachment: windows fast pathing

With a few changes, we could probably use this function to also support non-complex scripts which would probably give us a win as well.

I also need to see if I need to support RTL here...

Comment 2

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Comment on attachment 213436 [details] [diff] [review]
windows fast pathing


>+        int dxbuf[1024];
>+        results.nGlyphs = 1020;
>+        results.lpDx = dxbuf;

...

>+        for (PRInt32 k = 0; k < numGlyphs; k++) {

What happens if I have more than 1024 glyphs?  Why is nGlyphs 1020 instead of 1024?

Comment 3

[Stuart Parmenter]

Attachment: updated patch

this should be good enough.  I'm told it isn't possible to do RTL with ascii text, but I'm skeptical so I added a warning.
This should all be good now.

Comment 4

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Comment on attachment 213500 [details] [diff] [review]
updated patch


>@@ -354,16 +365,47 @@
> void
> gfxWindowsTextRun::DrawString(gfxContext *aContext, gfxPoint pt)
> {
>+    if (mIsASCII && (MeasureOrDrawAscii(aContext, PR_TRUE, pt.x, pt.y, nsnull) != -1))
>+        return;
>+
>     MeasureOrDrawUniscribe(aContext, PR_TRUE, pt.x, pt.y, nsnull);
> }


> gfxFloat
> gfxWindowsTextRun::MeasureString(gfxContext *aContext)
> {

>+#else
>+    if (mIsASCII) {
>+        PRInt32 ret = MeasureOrDrawAscii(aContext, PR_FALSE, 0, 0, nsnull);
>+        if (ret != -1) {
>+            return ret;
>+        }
>+    }

Use the same construct as above (or change the one above to match this one, just make 'em consistent)

r=me

Comment 5

[David G King]

This patch seems to have caused the following error in my Win32/cygwin/MinGW build

e:/mozilla/source/mozilla/gfx/thebes/src/gfxWindowsFonts.cpp:557: error: invalid
 static_cast from type `NS_ConvertASCIItoUTF16' to type `nsAString_internal&'

Comment 6

[Stuart Parmenter]

so file a new bug. this one is fixed.