[Mesa-dev] [PATCH 1/8] i965: Pull format conversion logic out of brw_depthbuffer_format.

[Kenneth Graunke]

brw_depthbuffer_format is not very reusable at the moment, since it
uses global state (ctx->DrawBuffer) to access a particular depth buffer.

For HiZ on Broadwell, I need a function which simply converts the
formats.  However, at least one existing user of brw_depthbuffer_format
really wants the existing interface.  So, I've created a new function.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/mesa/drivers/dri/i965/brw_context.h         |  1 +
 src/mesa/drivers/dri/i965/brw_misc_state.c      | 33 +-------------------
 src/mesa/drivers/dri/i965/brw_surface_formats.c | 41 +++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 32 deletions(-)

This patch depends on one I sent out a little bit earlier:
"mesa: Fix MESA_FORMAT_Z24_UNORM_S8_UINT vs. X8_UINT mix-up."

You can also view it in context on the origin/broadwell branch.

diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
index 98e90e2..cf0fe98 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -1666,6 +1666,7 @@ void brw_upload_abo_surfaces(struct brw_context *brw,
 bool brw_is_hiz_depth_format(struct brw_context *ctx, mesa_format format);
 bool brw_render_target_supported(struct brw_context *brw,
                                  struct gl_renderbuffer *rb);
+uint32_t brw_depth_format(struct brw_context *brw, mesa_format format);
 
 /* brw_performance_monitor.c */
 void brw_init_performance_monitors(struct brw_context *brw);
diff --git a/src/mesa/drivers/dri/i965/brw_misc_state.c b/src/mesa/drivers/dri/i965/brw_misc_state.c
index ca88b94..b984d47 100644
--- a/src/mesa/drivers/dri/i965/brw_misc_state.c
+++ b/src/mesa/drivers/dri/i965/brw_misc_state.c
@@ -150,38 +150,7 @@ brw_depthbuffer_format(struct brw_context *brw)
    if (!drb)
       return BRW_DEPTHFORMAT_D32_FLOAT;
 
-   switch (drb->mt->format) {
-   case MESA_FORMAT_Z_UNORM16:
-      return BRW_DEPTHFORMAT_D16_UNORM;
-   case MESA_FORMAT_Z_FLOAT32:
-      return BRW_DEPTHFORMAT_D32_FLOAT;
-   case MESA_FORMAT_Z24_UNORM_X8_UINT:
-      if (brw->gen >= 6) {
-	 return BRW_DEPTHFORMAT_D24_UNORM_X8_UINT;
-      } else {
-	 /* Use D24_UNORM_S8, not D24_UNORM_X8.
-	  *
-	  * D24_UNORM_X8 was not introduced until Gen5. (See the Ironlake PRM,
-	  * Volume 2, Part 1, Section 8.4.6 "Depth/Stencil Buffer State", Bits
-	  * 3DSTATE_DEPTH_BUFFER.Surface_Format).
-	  *
-	  * However, on Gen5, D24_UNORM_X8 may be used only if separate
-	  * stencil is enabled, and we never enable it. From the Ironlake PRM,
-	  * same section as above, Bit 3DSTATE_DEPTH_BUFFER.Separate_Stencil_Buffer_Enable:
-	  *     If this field is disabled, the Surface Format of the depth
-	  *     buffer cannot be D24_UNORM_X8_UINT.
-	  */
-	 return BRW_DEPTHFORMAT_D24_UNORM_S8_UINT;
-      }
-   case MESA_FORMAT_Z24_UNORM_S8_UINT:
-      return BRW_DEPTHFORMAT_D24_UNORM_S8_UINT;
-   case MESA_FORMAT_Z32_FLOAT_S8X24_UINT:
-      return BRW_DEPTHFORMAT_D32_FLOAT_S8X24_UINT;
-   default:
-      _mesa_problem(ctx, "Unexpected depth format %s\n",
-		    _mesa_get_format_name(intel_rb_format(drb)));
-      return BRW_DEPTHFORMAT_D16_UNORM;
-   }
+   return brw_depth_format(brw, drb->mt->format);
 }
 
 /**
diff --git a/src/mesa/drivers/dri/i965/brw_surface_formats.c b/src/mesa/drivers/dri/i965/brw_surface_formats.c
index 6a7e00a..b2c36d9 100644
--- a/src/mesa/drivers/dri/i965/brw_surface_formats.c
+++ b/src/mesa/drivers/dri/i965/brw_surface_formats.c
@@ -730,6 +730,47 @@ translate_tex_format(struct brw_context *brw,
    }
 }
 
+/**
+ * Convert a MESA_FORMAT to the corresponding BRW_DEPTHFORMAT enum.
+ */
+uint32_t
+brw_depth_format(struct brw_context *brw, mesa_format format)
+{
+   switch (format) {
+   case MESA_FORMAT_Z_UNORM16:
+      return BRW_DEPTHFORMAT_D16_UNORM;
+   case MESA_FORMAT_Z_FLOAT32:
+      return BRW_DEPTHFORMAT_D32_FLOAT;
+   case MESA_FORMAT_Z24_UNORM_S8_UINT:
+      if (brw->gen >= 6) {
+         return BRW_DEPTHFORMAT_D24_UNORM_X8_UINT;
+      } else {
+         /* Use D24_UNORM_S8, not D24_UNORM_X8.
+          *
+          * D24_UNORM_X8 was not introduced until Gen5. (See the Ironlake PRM,
+          * Volume 2, Part 1, Section 8.4.6 "Depth/Stencil Buffer State", Bits
+          * 3DSTATE_DEPTH_BUFFER.Surface_Format).
+          *
+          * However, on Gen5, D24_UNORM_X8 may be used only if separate
+          * stencil is enabled, and we never enable it. From the Ironlake PRM,
+          * same section as above, 3DSTATE_DEPTH_BUFFER's
+          * "Separate Stencil Buffer Enable" bit:
+          *
+          * "If this field is disabled, the Surface Format of the depth
+          *  buffer cannot be D24_UNORM_X8_UINT."
+          */
+         return BRW_DEPTHFORMAT_D24_UNORM_S8_UINT;
+      }
+   case MESA_FORMAT_Z24_UNORM_X8_UINT:
+      return BRW_DEPTHFORMAT_D24_UNORM_X8_UINT;
+   case MESA_FORMAT_Z32_FLOAT_S8X24_UINT:
+      return BRW_DEPTHFORMAT_D32_FLOAT_S8X24_UINT;
+   default:
+      assert(!"Unexpected depth format.");
+      return BRW_DEPTHFORMAT_D32_FLOAT;
+   }
+}
+
 /** Can HiZ be enabled on a depthbuffer of the given format? */
 bool
 brw_is_hiz_depth_format(struct brw_context *brw, mesa_format format)
-- 
1.8.4.2