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.
CC: Paul Berry <stereotype...@gmail.com>
CC: Eric Anholt <e...@anholt.net>
CC: Kenneth Graunke <kenn...@whitecape.org>
Signed-off-by: Chad Versace <chad.vers...@linux.intel.com>
---
This patch lives on my driconf-clamp-max-samples branch.
src/mesa/drivers/dri/i965/brw_context.c | 70 ++++++++++++++++++++++++++++----
src/mesa/drivers/dri/i965/intel_screen.c | 8 +++-
2 files changed, 69 insertions(+), 9 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_context.c
b/src/mesa/drivers/dri/i965/brw_context.c
index 38147e9..f405629 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -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)
{
@@ -333,16 +380,17 @@ brw_initialize_context_constants(struct brw_context *brw)
ctx->Const.AlwaysUseGetTransformFeedbackVertexCount = true;
+ const int max_samples = brw_supported_msaa_modes(brw)[0];
if (brw->gen == 6) {
- ctx->Const.MaxSamples = 4;
- ctx->Const.MaxColorTextureSamples = 4;
- ctx->Const.MaxDepthTextureSamples = 4;
- ctx->Const.MaxIntegerSamples = 4;
+ ctx->Const.MaxSamples = max_samples;
+ ctx->Const.MaxColorTextureSamples = max_samples;
+ ctx->Const.MaxDepthTextureSamples = max_samples;
+ ctx->Const.MaxIntegerSamples = max_samples;
} else if (brw->gen >= 7) {
- ctx->Const.MaxSamples = 8;
- ctx->Const.MaxColorTextureSamples = 8;
- ctx->Const.MaxDepthTextureSamples = 8;
- ctx->Const.MaxIntegerSamples = 8;
+ ctx->Const.MaxSamples = max_samples;
+ ctx->Const.MaxColorTextureSamples = max_samples;
+ ctx->Const.MaxDepthTextureSamples = max_samples;
+ ctx->Const.MaxIntegerSamples = max_samples;
ctx->Const.MaxProgramTextureGatherComponents = 4;
}
@@ -696,6 +744,12 @@ 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);
diff --git a/src/mesa/drivers/dri/i965/intel_screen.c
b/src/mesa/drivers/dri/i965/intel_screen.c
index eafafa2..ce8124b 100644
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -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")
--
1.8.3.1
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/mesa-dev
