[Mesa-dev] [PATCH 1/8] softpipe: add depth clamping support.
Roland Scheidegger
sroland at vmware.com
Tue Jun 10 06:42:39 PDT 2014
Am 10.06.2014 07:57, schrieb Dave Airlie:
> From: Dave Airlie <airlied at redhat.com>
>
> This passes the piglit depth clamp tests.
>
> this is required for GL 3.2.
>
> Signed-off-by: Dave Airlie <airlied at redhat.com>
> ---
> src/gallium/drivers/softpipe/sp_quad_depth_test.c | 37 ++++++++++++++++++-----
> src/gallium/drivers/softpipe/sp_screen.c | 2 +-
> 2 files changed, 31 insertions(+), 8 deletions(-)
>
> diff --git a/src/gallium/drivers/softpipe/sp_quad_depth_test.c b/src/gallium/drivers/softpipe/sp_quad_depth_test.c
> index f4d7993..2a63fa0 100644
> --- a/src/gallium/drivers/softpipe/sp_quad_depth_test.c
> +++ b/src/gallium/drivers/softpipe/sp_quad_depth_test.c
> @@ -148,10 +148,11 @@ interpolate_quad_depth( struct quad_header *quad )
> * Compute the depth_data::qzzzz[] values from the float fragment Z values.
> */
> static void
> -convert_quad_depth( struct depth_data *data,
> +convert_quad_depth( struct quad_stage *qs, struct depth_data *data,
> const struct quad_header *quad )
> {
> unsigned j;
> + float dvals[TGSI_QUAD_SIZE];
>
> /* Convert quad's float depth values to int depth values (qzzzz).
> * If the Z buffer stores integer values, we _have_ to do the depth
> @@ -159,13 +160,31 @@ convert_quad_depth( struct depth_data *data,
> * conversion of Z values (which isn't an identity function) will cause
> * Z-fighting errors.
> */
> + if (!qs->softpipe->rasterizer->depth_clip) {
> + float near_val, far_val;
> + float minval, maxval;
> +
> + near_val = qs->softpipe->viewport.translate[2] - qs->softpipe->viewport.scale[2];
> + far_val = near_val + (qs->softpipe->viewport.scale[2] * 2.0);
> +
> + minval = MIN2(near_val, far_val);
> + maxval = MAX2(near_val, far_val);
I guess you could precalculate minval/maxval before running the fs. No
biggie though.
(And I'm wondering, though it's only partially related to this code, if
the depth 0/1 clamp is actually happening somewhere. This code here will
clamp to 0/1 if depth clamp is enabled (since the near/far range can't
be outside that), but not if depth clamp is disabled - clipping will
eliminate values outside that, but if depth is written by the fs it
won't of course. GL (but not d3d10) still requires you to clamp depth to
0/1 in this case, and while everybody hates that behavior for float
depth buffers at least if you have non-float depth buffers you need to
do it somewhere otherwise the values outside 0/1 will be random. But
maybe this is done elsewhere.)
> + for (j = 0; j < TGSI_QUAD_SIZE; j++) {
> + dvals[j] = CLAMP(quad->output.depth[j], minval, maxval);
> + }
> + } else {
> + for (j = 0; j < TGSI_QUAD_SIZE; j++) {
> + dvals[j] = quad->output.depth[j];
> + }
> + }
> +
> switch (data->format) {
> case PIPE_FORMAT_Z16_UNORM:
> {
> float scale = 65535.0;
>
> for (j = 0; j < TGSI_QUAD_SIZE; j++) {
> - data->qzzzz[j] = (unsigned) (quad->output.depth[j] * scale);
> + data->qzzzz[j] = (unsigned) (dvals[j] * scale);
> }
> }
> break;
> @@ -174,7 +193,7 @@ convert_quad_depth( struct depth_data *data,
> double scale = (double) (uint) ~0UL;
>
> for (j = 0; j < TGSI_QUAD_SIZE; j++) {
> - data->qzzzz[j] = (unsigned) (quad->output.depth[j] * scale);
> + data->qzzzz[j] = (unsigned) (dvals[j] * scale);
> }
> }
> break;
> @@ -184,7 +203,7 @@ convert_quad_depth( struct depth_data *data,
> float scale = (float) ((1 << 24) - 1);
>
> for (j = 0; j < TGSI_QUAD_SIZE; j++) {
> - data->qzzzz[j] = (unsigned) (quad->output.depth[j] * scale);
> + data->qzzzz[j] = (unsigned) (dvals[j] * scale);
> }
> }
> break;
> @@ -194,7 +213,7 @@ convert_quad_depth( struct depth_data *data,
> float scale = (float) ((1 << 24) - 1);
>
> for (j = 0; j < TGSI_QUAD_SIZE; j++) {
> - data->qzzzz[j] = (unsigned) (quad->output.depth[j] * scale);
> + data->qzzzz[j] = (unsigned) (dvals[j] * scale);
> }
> }
> break;
> @@ -204,7 +223,7 @@ convert_quad_depth( struct depth_data *data,
> union fi fui;
>
> for (j = 0; j < TGSI_QUAD_SIZE; j++) {
> - fui.f = quad->output.depth[j];
> + fui.f = dvals[j];
> data->qzzzz[j] = fui.ui;
> }
> }
> @@ -796,7 +815,7 @@ depth_test_quads_fallback(struct quad_stage *qs,
> if (interp_depth)
> interpolate_quad_depth(quads[i]);
>
> - convert_quad_depth(&data, quads[i]);
> + convert_quad_depth(qs, &data, quads[i]);
> }
>
> if (qs->softpipe->depth_stencil->stencil[0].enabled) {
> @@ -895,6 +914,8 @@ choose_depth_test(struct quad_stage *qs,
>
> boolean occlusion = qs->softpipe->active_query_count;
>
> + boolean clipped = qs->softpipe->rasterizer->depth_clip;
> +
> if(!qs->softpipe->framebuffer.zsbuf)
> depth = depthwrite = stencil = FALSE;
>
> @@ -905,6 +926,7 @@ choose_depth_test(struct quad_stage *qs,
> if (!alpha &&
> !depth &&
> !occlusion &&
> + !clipped &&
> !stencil) {
> qs->run = depth_noop;
> }
> @@ -913,6 +935,7 @@ choose_depth_test(struct quad_stage *qs,
> depth &&
> depthwrite &&
> !occlusion &&
> + !clipped &&
> !stencil)
> {
> if (qs->softpipe->framebuffer.zsbuf->format == PIPE_FORMAT_Z16_UNORM) {
> diff --git a/src/gallium/drivers/softpipe/sp_screen.c b/src/gallium/drivers/softpipe/sp_screen.c
> index 34dbb91..7851777 100644
> --- a/src/gallium/drivers/softpipe/sp_screen.c
> +++ b/src/gallium/drivers/softpipe/sp_screen.c
> @@ -111,7 +111,7 @@ softpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
> case PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_INTEGER:
> return 1;
> case PIPE_CAP_DEPTH_CLIP_DISABLE:
> - return 0;
> + return 1;
> case PIPE_CAP_MAX_STREAM_OUTPUT_BUFFERS:
> return PIPE_MAX_SO_BUFFERS;
> case PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_COMPONENTS:
>
Reviewed-by: Roland Scheidegger <sroland at vmware.com>
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