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List:       openjdk-openjfx-dev
Subject:    Re: Gradients w/o BGRA_PRE
From:       Jim Graham <james.graham () oracle ! com>
Date:       2015-02-27 22:44:14
Message-ID: 54F0F33E.1010806 () oracle ! com
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My suggestion would be to add BYTE_RGBA_PRE to the PixelFormat enums and 
that ES2 claims it supports and have the gradient code then test for 
either BYTE_BGRA_PRE or BYTE_RGBA_PRE support and use the appropriate 
indices depending on the result...

			...jim

On 2/27/15 2:29 PM, Michael Heinrichs wrote:
> Hi Jim,
> 
> after disabling the test and switching the channels in insertInterpColor(), \
> gradients are rendered correctly. It is a hack, but it works for now. :) Thanks for \
> the hint. 
> The format supported by default in ES 2.0 is actually BYTE_RGBA and not INT_RGBA. I \
> think it makes sense to use a byte array in both cases as you initially suggested. 
> - Michael
> 
> 
> 
> > On 23 Feb 2015, at 20:58, Jim Graham <james.graham@oracle.com> wrote:
> > 
> > Oh dear, it is a bit worse than that.  The texture creation code doesn't even \
> > have an enum constant to specify BYTE_RGBA_PRE.  It has BYTE_BGRA_PRE (which is \
> > used by this code with a byte array) and INT_RGBA_PRE (which would involve more \
> > than simply index twiddling to support). 
> > So, if INT_RGBA was universally supported, the code could be refactored to use \
> > that.  If we have to do it conditionally, that could be done as well as I said \
> > below, but it would involve factoring "how do we store these components and into \
> > which array?" rather than just index twiddling... 
> > 			...jim
> > 
> > On 2/23/2015 11:53 AM, Jim Graham wrote:
> > > Ah, I see.  I was looking at the code that uploaded the pixels which
> > > behaved as I described, but I didn't check the texture creation code,
> > > which does look like it will reject it as you indicate.
> > > 
> > > It looks like insertInterpColor, which computes the image data for the
> > > texture from the gradient colors, could handle either BGRA or RGBA just
> > > by changing the indices it uses.  Is RGBA universally supported on
> > > Linux/OGL2/D3D?  If so, then we could switch to that.  Otherwise we'd
> > > have to factor in conditional BGRA vs RGBA tests into the appropriate
> > > places (probably just remember which was supported by the
> > > ResourceFactory in the initGradientTextures() function and have the
> > > insert() function test and modify its indices as appropriate)...
> > > 
> > > ...jim
> > > 
> > > On 2/23/2015 1:51 AM, Michael Heinrichs wrote:
> > > > Hi Jim,
> > > > 
> > > > thanks for your reply. Right now I do not see anything.
> > > > PaintHelper.initGradientTextures() eventually calls
> > > > ES2Texture.create(), which checks if the requested pixel format is
> > > > supported. This test fails in my case, because WebGL is ES2 only and
> > > > the extension is not supported. But when I disable this test and
> > > > pretend that BGRA is RGBA, I see exactly what you describe: the red
> > > > and the blue channel are swapped.
> > > > 
> > > > Thanks,
> > > > Michael
> > > > 
> > > > 
> > > > > On 23 Feb 2015, at 00:55, Jim Graham <james.graham@oracle.com> wrote:
> > > > > 
> > > > > Hi Michael,
> > > > > 
> > > > > What error are you seeing, or is it just rendering incorrectly?
> > > > > 
> > > > > Looking at the code in ES2Texture.uploadPixels() it looks like ES2
> > > > > might support BGRA via an extension.  Perhaps we've only encountered
> > > > > platforms with that extension so far.  Otherwise, if I read the code
> > > > > correctly it looks like we will just pretend the incoming data is in
> > > > > RGBA format, which would mean that the rendering would happen, but
> > > > > the red and blue components would be swapped.  Is that what you are
> > > > > seeing?
> > > > > 
> > > > > ...jim
> > > > > 
> > > > > On 2/21/2015 5:06 AM, Michael Heinrichs wrote:
> > > > > > Hi,
> > > > > > 
> > > > > > I am experimenting with JavaFX on top of WebGL. Right now I am stuck
> > > > > > implementing gradients, but maybe somebody from this list can help.
> > > > > > 
> > > > > > WebGL usually does not support the pixel format BGRA_PRE. From my
> > > > > > understanding, the ES2 renderer should work with such a
> > > > > > configuration, too. But when I try to use a gradient, at some point
> > > > > > PaintHelper.initGradientTextures() is called, which requires the
> > > > > > pixel format BGRA_PRE  Obviously something about my configuration is
> > > > > > wrong. But I cannot figure out, where the alternative implementation
> > > > > > resides. How should the implementation of gradients work if BGRA_PRE
> > > > > > is not available?
> > > > > > 
> > > > > > Thanks,
> > > > > > Michael
> > > > > > 
> > > > 
> 


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