[Mesa-dev] [PATCH 15/15] i965/msaa: Enable 4x MSAA on Gen7.

[Paul Berry]

Basic 4x MSAA support now works on Gen7.  This patch enables it.

As with Gen6, MSAA support is still fairly preliminary.  In
particular, the following are not yet supported:
- 8x oversampling (Gen7 has hardware support for this, but we do not
  yet expose it).
- Fully general blits between MSAA and non-MSAA buffers.
- Formats other than RGBA8, DEPTH24, and STENCIL8.
- Centrold interpolation.
- Coverage parameters (glSampleCoverage, GL_SAMPLE_ALPHA_TO_COVERAGE,
  GL_SAMPLE_ALPHA_TO_ONE, GL_SAMPLE_COVERAGE, GL_SAMPLE_COVERAGE_VALUE,
  GL_SAMPLE_COVERAGE_INVERT).
---
 src/mesa/drivers/dri/i965/gen6_multisample_state.c |   12 ++++--------
 src/mesa/drivers/dri/intel/intel_fbo.c             |    6 +++++-
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/gen6_multisample_state.c b/src/mesa/drivers/dri/i965/gen6_multisample_state.c
index e01ead1..3cf94f6 100644
--- a/src/mesa/drivers/dri/i965/gen6_multisample_state.c
+++ b/src/mesa/drivers/dri/i965/gen6_multisample_state.c
@@ -36,10 +36,8 @@ gen6_emit_3dstate_multisample(struct brw_context *brw,
 {
    struct intel_context *intel = &brw->intel;
 
-   /* TODO: MSAA only implemented on Gen6 */
-   if (intel->gen != 6) {
-      assert(num_samples == 0);
-   }
+   /* TODO: 8x MSAA not implemented */
+   assert(num_samples <= 4);
 
    int len = intel->gen >= 7 ? 4 : 3;
    BEGIN_BATCH(len);
@@ -62,10 +60,8 @@ gen6_emit_3dstate_sample_mask(struct brw_context *brw,
 {
    struct intel_context *intel = &brw->intel;
 
-   /* TODO: MSAA only implemented on Gen6 */
-   if (intel->gen != 6) {
-      assert(num_samples == 0);
-   }
+   /* TODO: 8x MSAA not implemented */
+   assert(num_samples <= 4);
 
    BEGIN_BATCH(2);
    OUT_BATCH(_3DSTATE_SAMPLE_MASK << 16 | (2 - 2));
diff --git a/src/mesa/drivers/dri/intel/intel_fbo.c b/src/mesa/drivers/dri/intel/intel_fbo.c
index bbd5f66..a801bb7 100644
--- a/src/mesa/drivers/dri/intel/intel_fbo.c
+++ b/src/mesa/drivers/dri/intel/intel_fbo.c
@@ -202,7 +202,11 @@ quantize_num_samples(struct intel_context *intel, unsigned num_samples)
       else
          return 0;
    case 7:
-      /* TODO: MSAA only implemented on Gen6 */
+      /* TODO: Gen7 supports only 4x multisampling at the moment. */
+      if (num_samples > 0)
+         return 4;
+      else
+         return 0;
       return 0;
    default:
       /* MSAA unsupported */
-- 
1.7.7.6