[Mesa-dev] [PATCH] gallium/radeon: fix Nine with its slightly shifted viewports

[Axel Davy]

Reviewed-by: Axel Davy <axel.davy at ens.fr>

On 16/04/2016 00:44, Marek Olšák wrote:
> From: Marek Olšák <marek.olsak at amd.com>
>
> just need to do the calculation in floating-point and then round things
> properly
> ---
>   src/gallium/drivers/radeon/r600_viewport.c | 36 +++++++++++++++++-------------
>   1 file changed, 21 insertions(+), 15 deletions(-)
>
> diff --git a/src/gallium/drivers/radeon/r600_viewport.c b/src/gallium/drivers/radeon/r600_viewport.c
> index 980c5ef..5c998c8 100644
> --- a/src/gallium/drivers/radeon/r600_viewport.c
> +++ b/src/gallium/drivers/radeon/r600_viewport.c
> @@ -51,32 +51,38 @@ static void r600_get_scissor_from_viewport(struct r600_common_context *rctx,
>   					   const struct pipe_viewport_state *vp,
>   					   struct r600_signed_scissor *scissor)
>   {
> -	int tmp;
> +	float tmp, minx, miny, maxx, maxy;
>   
>   	/* Convert (-1, -1) and (1, 1) from clip space into window space. */
> -	scissor->minx = -vp->scale[0] + vp->translate[0];
> -	scissor->miny = -vp->scale[1] + vp->translate[1];
> -	scissor->maxx = vp->scale[0] + vp->translate[0];
> -	scissor->maxy = vp->scale[1] + vp->translate[1];
> +	minx = -vp->scale[0] + vp->translate[0];
> +	miny = -vp->scale[1] + vp->translate[1];
> +	maxx = vp->scale[0] + vp->translate[0];
> +	maxy = vp->scale[1] + vp->translate[1];
>   
>   	/* r600_draw_rectangle sets this. Disable the scissor. */
> -	if (scissor->minx == -1 && scissor->miny == -1 &&
> -	    scissor->maxx == 1 && scissor->maxy == 1) {
> +	if (minx == -1 && miny == -1 && maxx == 1 && maxy == 1) {
>   		scissor->minx = scissor->miny = 0;
>   		scissor->maxx = scissor->maxy = GET_MAX_SCISSOR(rctx);
> +		return;
>   	}
>   
>   	/* Handle inverted viewports. */
> -	if (scissor->minx > scissor->maxx) {
> -		tmp = scissor->minx;
> -		scissor->minx = scissor->maxx;
> -		scissor->maxx = tmp;
> +	if (minx > maxx) {
> +		tmp = minx;
> +		minx = maxx;
> +		maxx = tmp;
>   	}
> -	if (scissor->miny > scissor->maxy) {
> -		tmp = scissor->miny;
> -		scissor->miny = scissor->maxy;
> -		scissor->maxy = tmp;
> +	if (miny > maxy) {
> +		tmp = miny;
> +		miny = maxy;
> +		maxy = tmp;
>   	}
> +
> +	/* Convert to integer and round up the max bounds. */
> +	scissor->minx = minx;
> +	scissor->miny = miny;
> +	scissor->maxx = ceilf(maxx);
> +	scissor->maxy = ceilf(maxy);
>   }
>   
>   static void r600_clamp_scissor(struct r600_common_context *rctx,