On Mon, Jan 21, 2013 at 9:02 PM, Jeremy White <jwh...@codeweavers.com>wrote:
> Hi Vincent,
>
> > +function flip_image_data(img)
> > +{
> > + var w = img.width;
> > + var h = img.height;
> > + var temp_w = w;
> > + var temp_h = h;
> > + var buff = new Uint8Array(img.width * img.height * 4);
> > + while (temp_h--)
> > + {
> > + while (temp_w--)
> > + {
> > + buff[(temp_h * w + temp_w) * 4] = img.data[((h - temp_h -
> > 1) * w + temp_w) * 4];
> > + buff[(temp_h * w + temp_w) * 4 + 1] = img.data[((h - temp_h
> > - 1) * w + temp_w) * 4 + 1];
> > + buff[(temp_h * w + temp_w) * 4 + 2] = img.data[((h - temp_h
> > - 1) * w + temp_w) * 4 + 2];
> > + buff[(temp_h * w + temp_w) * 4 + 3] = img.data[((h - temp_h
> > - 1) * w + temp_w) * 4 + 3];
> > + }
> > + temp_w = w;
> > + }
> > + img.data.set(buff);
>
> Couldn't this be done more simply by swapping line by line, rather than
> pixel by pixel? If I'm not mistaken, the Uint8Array set() method will
> take an array and offset as a parameter, and you can get a subarray
> fairly easily. I have no idea if that will provide a performance boost,
> but it will least enable the Javascript engines to try.
>
Well I didn't know about this function but I saw that generally built-in
array functions aren’t so efficient compared to raw loops. Anyway I
made as you said and I didn’t notice any significant performance
gain or loss.
>
> Either way, if you could resubmit this as a discrete git-format-patch
> entry (probably with signed-off-by while you're at it), I'd appreciate it.
>
> Cheers,
>
> Jeremy
> _______________________________________________
> Spice-devel mailing list
> Spice-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/spice-devel
>
Signed-off-by: Vincent Desprez <vincent.desp...@apwise.com>
---
display.js | 3 ---
lz.js | 16 ++++++++++++++++
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/display.js b/display.js
index 15d43d3..e4ae64b 100644
--- a/display.js
+++ b/display.js
@@ -243,9 +243,6 @@ SpiceDisplayConn.prototype.process_channel_message =
function(msg)
return false;
}
- if (draw_copy.data.src_bitmap.lz_rgb.top_down != 1)
- this.log_warn("FIXME: Implement non top down support
for lz_rgb");
-
var source_img =
convert_spice_lz_rgb_to_web(canvas.context,
draw_copy.data.src_bitmap.lz_rgb);
if (! source_img)
diff --git a/lz.js b/lz.js
index 2914c37..5c3452f 100644
--- a/lz.js
+++ b/lz.js
@@ -141,6 +141,19 @@ function lz_rgb32_decompress(in_buf, at, out_buf,
type, default_alpha)
return encoder - 1;
}
+function flip_image_data(img)
+{
+ var wb = img.width * 4;
+ var h = img.height;
+ var temp_h = h;
+ var buff = new Uint8Array(img.width * img.height * 4);
+ while (temp_h--)
+ {
+ buff.set(img.data.subarray(temp_h * wb, (temp_h + 1) * wb),
(h - temp_h - 1) * wb);
+ }
+ img.data.set(buff);
+}
+
function convert_spice_lz_rgb_to_web(context, lz_rgb)
{
var u8 = new Uint8Array(lz_rgb.data);
@@ -151,6 +164,9 @@ function convert_spice_lz_rgb_to_web(context, lz_rgb)
var ret = context.createImageData(lz_rgb.width, lz_rgb.height);
at = lz_rgb32_decompress(u8, 0, ret.data, LZ_IMAGE_TYPE_RGB32,
lz_rgb.type != LZ_IMAGE_TYPE_RGBA);
+ if (!lz_rgb.top_down)
+ flip_image_data(ret);
+
if (lz_rgb.type == LZ_IMAGE_TYPE_RGBA)
lz_rgb32_decompress(u8, at, ret.data, LZ_IMAGE_TYPE_RGBA, false);
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