[Mesa-dev] [PATCH 15/15] intel: Advertise multisample DRI2 configs on gen >= 6

[Chad Versace]

This turns on window system multisampling.

No Piglit regressions on Ivybridge.

Tested with `glxgears -samples 1`.

Passes 53/70 of oglconform's winsys multisample tests. The failing tests
mostly consist of those that call glDrawPixels on the depth and stencil
buffer (which fail due to a swrast fallback) or do fancy things with the
msaa alpha enums.

CC: Eric Anholt <eric at anholt.net>
CC: Ian Romanick <idr at freedesktop.org>
Signed-off-by: Chad Versace <chad.versace at linux.intel.com>
---
 src/mesa/drivers/dri/intel/intel_screen.c | 44 +++++++++++++++++++++++++++++--
 1 file changed, 42 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/intel/intel_screen.c b/src/mesa/drivers/dri/intel/intel_screen.c
index 61daea7..420901e 100644
--- a/src/mesa/drivers/dri/intel/intel_screen.c
+++ b/src/mesa/drivers/dri/intel/intel_screen.c
@@ -866,14 +866,54 @@ intel_screen_make_configs(__DRIscreen *dri_screen)
       GLX_SWAP_UNDEFINED_OML, GLX_NONE, GLX_SWAP_COPY_OML,
    };
 
-   static const uint8_t msaa_samples[] = {0};
+   static const uint8_t msaa_samples[] = {0, 4};
+
+   struct intel_screen *screen = dri_screen->driverPrivate;
+
+   int num_msaa_modes;
+   if (screen->gen >= 6)
+      num_msaa_modes = 2;
+   else
+      num_msaa_modes = 1;
 
    /* Starting with DRI2 protocol version 1.1 we can request a depth/stencil
     * buffer that has a different number of bits per pixel than the color
     * buffer.  This isn't yet supported here.
     */
    struct config_params params[] = {
-      /* Configs without accumulation buffer. */
+      /* Multisample configs. */
+      {
+         .color_format = GL_RGB,
+         .color_type = GL_UNSIGNED_SHORT_5_6_5,
+         .depth_sizes =   {0, 16},
+         .stencil_sizes = {0,  0},
+         .num_depth_stencil_sizes = 2,
+         .num_back_buffer_modes = 1,
+         .num_msaa_modes = num_msaa_modes,
+         .enable_accum = false,
+      },
+      {
+         .color_format = GL_BGR,
+         .color_type = GL_UNSIGNED_INT_8_8_8_8_REV,
+         .depth_sizes =   {0, 24},
+         .stencil_sizes = {0,  8},
+         .num_depth_stencil_sizes = 2,
+         .num_back_buffer_modes = 1,
+         .num_msaa_modes = num_msaa_modes,
+         .enable_accum = false,
+      },
+      {
+         .color_format = GL_BGRA,
+         .color_type = GL_UNSIGNED_INT_8_8_8_8_REV,
+         .depth_sizes =   {0, 24},
+         .stencil_sizes = {0,  8},
+         .num_depth_stencil_sizes = 2,
+         .num_back_buffer_modes = 1,
+         .num_msaa_modes = num_msaa_modes,
+         .enable_accum = false,
+      },
+
+      /* Single sample configs. */
       {
          .color_format = GL_RGB,
          .color_type = GL_UNSIGNED_SHORT_5_6_5,
-- 
1.7.11.2