i965: Add driconf option clamp_max_samples

The new option clamps GL_MAX_SAMPLES to a hardware-supported MSAA mode.
If negative, then no clamping occurs.

v2: (for Paul)
  - Add option to i965 only, not to all DRI drivers.
  - Do not realy on int->uint cast to convert negative
    values to large positive values. Explicitly check for
    clamp_max_samples < 0.
v3: (for Ken)
   - Don't allow clamp_max_samples to alter context version.
   - Use clearer for-loop and correct comment.
   - Rename variables.
v4: (for Ken)
   - Merge identical if-branches.

Reviewed-and-tested-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
This commit is contained in:
Chad Versace
2013-11-03 13:14:50 -08:00
parent 68f1b274b0
commit 2f89662717
2 changed files with 67 additions and 12 deletions

View File

@@ -268,6 +268,53 @@ brw_init_driver_functions(struct brw_context *brw,
functions->GetSamplePosition = gen6_get_sample_position;
}
/**
* Return array of MSAA modes supported by the hardware. The array is
* zero-terminated and sorted in decreasing order.
*/
static const int*
brw_supported_msaa_modes(const struct brw_context *brw)
{
if (brw->gen >= 7) {
return (int[]){8, 4, 0};
} else if (brw->gen == 6) {
return (int[]){4, 0};
} else {
return (int[]){0};
}
}
/**
* Override GL_MAX_SAMPLES and related constants according to value of driconf
* option 'clamp_max_samples'.
*/
static void
brw_override_max_samples(struct brw_context *brw)
{
const int clamp_max_samples = driQueryOptioni(&brw->optionCache,
"clamp_max_samples");
if (clamp_max_samples < 0)
return;
const int *supported_msaa_modes = brw_supported_msaa_modes(brw);
int max_samples = 0;
/* Select the largest supported MSAA mode that does not exceed
* clamp_max_samples.
*/
for (int i = 0; supported_msaa_modes[i] != 0; ++i) {
if (supported_msaa_modes[i] <= clamp_max_samples) {
max_samples = supported_msaa_modes[i];
break;
}
}
brw->ctx.Const.MaxSamples = max_samples;
brw->ctx.Const.MaxColorTextureSamples = max_samples;
brw->ctx.Const.MaxDepthTextureSamples = max_samples;
brw->ctx.Const.MaxIntegerSamples = max_samples;
}
static void
brw_initialize_context_constants(struct brw_context *brw)
{
@@ -333,18 +380,14 @@ brw_initialize_context_constants(struct brw_context *brw)
ctx->Const.AlwaysUseGetTransformFeedbackVertexCount = true;
if (brw->gen == 6) {
ctx->Const.MaxSamples = 4;
ctx->Const.MaxColorTextureSamples = 4;
ctx->Const.MaxDepthTextureSamples = 4;
ctx->Const.MaxIntegerSamples = 4;
} else if (brw->gen >= 7) {
ctx->Const.MaxSamples = 8;
ctx->Const.MaxColorTextureSamples = 8;
ctx->Const.MaxDepthTextureSamples = 8;
ctx->Const.MaxIntegerSamples = 8;
const int max_samples = brw_supported_msaa_modes(brw)[0];
ctx->Const.MaxSamples = max_samples;
ctx->Const.MaxColorTextureSamples = max_samples;
ctx->Const.MaxDepthTextureSamples = max_samples;
ctx->Const.MaxIntegerSamples = max_samples;
if (brw->gen >= 7)
ctx->Const.MaxProgramTextureGatherComponents = 4;
}
ctx->Const.MinLineWidth = 1.0;
ctx->Const.MinLineWidthAA = 1.0;
@@ -696,6 +739,12 @@ brwCreateContext(gl_api api,
_mesa_compute_version(ctx);
/* Here we override context constants. We apply the overrides after
* calculation of the context version because we do not want the overridden
* constants to change the version.
*/
brw_override_max_samples(brw);
_mesa_initialize_dispatch_tables(ctx);
_mesa_initialize_vbo_vtxfmt(ctx);

View File

@@ -63,11 +63,17 @@ DRI_CONF_BEGIN
DRI_CONF_OPT_BEGIN_B(disable_derivative_optimization, "false")
DRI_CONF_DESC(en, "Derivatives with finer granularity by default")
DRI_CONF_OPT_END
DRI_CONF_SECTION_END
DRI_CONF_SECTION_QUALITY
DRI_CONF_FORCE_S3TC_ENABLE("false")
DRI_CONF_OPT_BEGIN(clamp_max_samples, int, -1)
DRI_CONF_DESC(en, "Clamp the value of GL_MAX_SAMPLES to the "
"given integer. If negative, then do not clamp.")
DRI_CONF_OPT_END
DRI_CONF_SECTION_END
DRI_CONF_SECTION_DEBUG
DRI_CONF_NO_RAST("false")
DRI_CONF_ALWAYS_FLUSH_BATCH("false")