Commit 8cb5a194 authored by Gert Wollny's avatar Gert Wollny
Browse files

virgl: Add support for glGetMultisample



Use caps to obtain the multisample sample positions for up to 16
positions and implement the according Gallium interface.

This implemenation (plus its counterpart in virglrenderer) assume that
the fixed sample position are always the same for a given number of samples
over the whole live time of a qemu session. It also assumes that sample
series are only given for 2, 4, 8, and 16 samples, and for intermediate
numbers N of samples the next higher supported set from above list is picked
and the sample positions for the first N samples are returned accordingly.

Fixes (when run on GL host):
  dEQP-GLES31.functional.texture.multisample.samples_1.sample_position
  dEQP-GLES31.functional.texture.multisample.samples_2.sample_position
  dEQP-GLES31.functional.texture.multisample.samples_3.sample_position
  dEQP-GLES31.functional.texture.multisample.samples_4.sample_position
  dEQP-GLES31.functional.texture.multisample.samples_8.sample_position
  dEQP-GLES31.functional.texture.multisample.samples_10.sample_position
  dEQP-GLES31.functional.texture.multisample.samples_12.sample_position
  dEQP-GLES31.functional.texture.multisample.samples_13.sample_position
  dEQP-GLES31.functional.texture.multisample.samples_16.sample_position

  v2: remove unrelated chunk (thanks Ilia Mirkin)
  v3: - also return positions for intermediate sample counts
      - fix unused varible warning
      - update description
  v4: explain better what this patch assumes and how it handles sample numbers
      that are not directly advertised (thanks go to Erik Faye-Lund for making
      me aware that this should be documented)
Signed-off-by: default avatarGert Wollny <gert.wollny@collabora.com>
Reviewed-by: Erik Faye-Lund's avatarErik Faye-Lund <erik.faye-lund@collabora.com>
parent be82fb58
......@@ -1035,6 +1035,42 @@ virgl_context_destroy( struct pipe_context *ctx )
FREE(vctx);
}
static void virgl_get_sample_position(struct pipe_context *ctx,
unsigned sample_count,
unsigned index,
float *out_value)
{
struct virgl_context *vctx = virgl_context(ctx);
struct virgl_screen *vs = virgl_screen(vctx->base.screen);
if (sample_count > vs->caps.caps.v1.max_samples) {
debug_printf("VIRGL: requested %d MSAA samples, but only %d supported\n",
sample_count, vs->caps.caps.v1.max_samples);
return;
}
/* The following is basically copied from dri/i965gen6_get_sample_position
* The only addition is that we hold the msaa positions for all sample
* counts in a flat array. */
uint32_t bits = 0;
if (sample_count == 1) {
out_value[0] = out_value[1] = 0.5f;
return;
} else if (sample_count == 2) {
bits = vs->caps.caps.v2.msaa_sample_positions[0] >> (8 * index);
} else if (sample_count < 4) {
bits = vs->caps.caps.v2.msaa_sample_positions[1] >> (8 * index);
} else if (sample_count < 8) {
bits = vs->caps.caps.v2.msaa_sample_positions[2 + (index >> 2)] >> (8 * (index & 3));
} else if (sample_count < 8) {
bits = vs->caps.caps.v2.msaa_sample_positions[4 + (index >> 2)] >> (8 * (index & 3));
}
out_value[0] = ((bits >> 4) & 0xf) / 16.0f;
out_value[1] = (bits & 0xf) / 16.0f;
debug_printf("VIRGL: sample postion [%2d/%2d] = (%f, %f)\n",
index, sample_count, out_value[0], out_value[1]);
}
struct pipe_context *virgl_context_create(struct pipe_screen *pscreen,
void *priv,
unsigned flags)
......@@ -1115,6 +1151,8 @@ struct pipe_context *virgl_context_create(struct pipe_screen *pscreen,
vctx->base.set_blend_color = virgl_set_blend_color;
vctx->base.get_sample_position = virgl_get_sample_position;
vctx->base.resource_copy_region = virgl_resource_copy_region;
vctx->base.flush_resource = virgl_flush_resource;
vctx->base.blit = virgl_blit;
......
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