[Mesa-dev] [PATCH] mesa: fix incorrect viewport position when GL_CLIP_ORIGIN = GL_LOWER_LEFT

[Roland Scheidegger]

Am 09.02.2016 um 18:03 schrieb Brian Paul:
> Ilia Mirkin found/fixed the mistake.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93813
> Cc: "11.1" <mesa-stable at lists.freedesktop.org>
> ---
>  src/mesa/main/viewport.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/src/mesa/main/viewport.c b/src/mesa/main/viewport.c
> index 7d891429..681e46b 100644
> --- a/src/mesa/main/viewport.c
> +++ b/src/mesa/main/viewport.c
> @@ -456,11 +456,11 @@ _mesa_get_viewport_xform(struct gl_context *ctx, unsigned i,
>     translate[0] = half_width + x;
>     if (ctx->Transform.ClipOrigin == GL_UPPER_LEFT) {
>        scale[1] = -half_height;
> -      translate[1] = half_height - y;
>     } else {
>        scale[1] = half_height;
> -      translate[1] = half_height + y;
>     }
> +   translate[1] = half_height + y;
> +
>     if (ctx->Transform.ClipDepthMode == GL_NEGATIVE_ONE_TO_ONE) {
>        scale[2] = 0.5 * (f - n);
>        translate[2] = 0.5 * (n + f);
> 

With the caveat that I always get confused by the top/bottom flip stuff,
this looks right to me...

Reviewed-by: Roland Scheidegger <sroland at vmware.com>