i965: Add an env var for forcing window system MSAA.

Sometimes it would be nice to benchmark some app with MSAA versus not, but
it doesn't offer the controls you want.  Just provide a handy knob to
force the issue.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
index 4e9a77594b36dedfc701dd40e29d4972bd913ce7..0788a1b8e5f7fa1a355c80ffcdb40bc7f1e5fc6b 100644 (file)
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -975,6 +975,11 @@ intelCreateBuffer(__DRIscreen * driScrnPriv,
 
    _mesa_initialize_window_framebuffer(fb, mesaVis);
 
+   if (screen->winsys_msaa_samples_override != -1) {
+      num_samples = screen->winsys_msaa_samples_override;
+      fb->Visual.samples = num_samples;
+   }
+
    if (mesaVis->redBits == 5)
       rgbFormat = MESA_FORMAT_B5G6R5_UNORM;
    else if (mesaVis->sRGBCapable)
@@ -1335,6 +1340,16 @@ __DRIconfig **intelInitScreen2(__DRIscreen *psp)
 
    intelScreen->hw_has_swizzling = intel_detect_swizzling(intelScreen);
 
+   const char *force_msaa = getenv("INTEL_FORCE_MSAA");
+   if (force_msaa) {
+      intelScreen->winsys_msaa_samples_override =
+         intel_quantize_num_samples(intelScreen, atoi(force_msaa));
+      printf("Forcing winsys sample count to %d\n",
+             intelScreen->winsys_msaa_samples_override);
+   } else {
+      intelScreen->winsys_msaa_samples_override = -1;
+   }
+
    set_max_gl_versions(intelScreen);
 
    /* Notification of GPU resets requires hardware contexts and a kernel new

diff --git a/src/mesa/drivers/dri/i965/intel_screen.h b/src/mesa/drivers/dri/i965/intel_screen.h
index 09690215dedc73e94c9527f17b3537ef13ce2236..945f6f5f43f01c6efc56f43c4ba5577c8914aaef 100644 (file)
--- a/src/mesa/drivers/dri/i965/intel_screen.h
+++ b/src/mesa/drivers/dri/i965/intel_screen.h
@@ -62,6 +62,8 @@ struct intel_screen
     */
    unsigned program_id;
 
+   int winsys_msaa_samples_override;
+
    struct {
       struct ra_regs *regs;