On Sun, Feb 17, 2013 at 03:29:03PM -0600, Paul Archer wrote:
> I tried adding in a 'cairo_scale', which works. It does seem to slow things
> down a little, but not horribly. That is, it's pretty slow to begin with,
> when the overlay is on, so it doesn't make it much worse.
> My big problem is I can't figure out how to find the right scale. I can
> hard-code numbers, but that will only work with my particular model.
> cairo_t *cr = cairo_create(priv->pixmap);
> while (tmp) {
> image = ENTANGLE_IMAGE(tmp->data);
> pixbuf = entangle_image_get_pixbuf(image);
>
> gdk_cairo_set_source_pixbuf(cr, pixbuf, 0, 0);
> if (tmp == priv->images) {
> cairo_scale(cr,5,5);
> cairo_paint(cr);
> } else {
> cairo_paint_with_alpha(cr, 0.5); }
>
> tmp = tmp->next;
> }
> cairo_destroy(cr);
You need to get the first pixbuf on the stack and call gdk_pixbuf_get_width
and gdk_pixbuf_get_height. Then for adjust subsequent images to match.
You're also scaling up the low res image - I'd suggest scaling down
the high res images instead.
So perhaps something like this:
cairo_t *cr = cairo_create(priv->pixmap);
int basex, basey;
while (tmp) {
image = ENTANGLE_IMAGE(tmp->data);
pixbuf = entangle_image_get_pixbuf(image);
gdk_cairo_set_source_pixbuf(cr, pixbuf, 0, 0);
if (tmp == priv->images) {
basex = gdk_pixbuf_image_get_width(pixbuf);
basey = gdk_pixbuf_image_get_height(pixbuf);
cairo_paint(cr);
} else {
int thisx, thisy;
double scalex, scaley;
thisx = gdk_pixbuf_image_get_width(pixbuf);
thisy = gdk_pixbuf_image_get_height(pixbuf);
scalex = (double)basex / (double)thisx;
scaley = (double)basey / (double)thisy;
cairo_scale(cr, scalex, scaley);
cairo_paint_with_alpha(cr, 0.5);
}
tmp = tmp->next;
}
cairo_destroy(cr);
This is untested, so I may well have screwed up the math there,
but that's the general approach that ought to work
Daniel
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