i965: Move brw_is_color_fast_clear_compatible to brw_meta_util

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_meta_util.c b/src/mesa/drivers/dri/i965/brw_meta_util.c
index ac4f6154dc..432321dbbb 100644
--- a/src/mesa/drivers/dri/i965/brw_meta_util.c
+++ b/src/mesa/drivers/dri/i965/brw_meta_util.c
@@ -24,6 +24,8 @@
 #include "brw_context.h"
 #include "intel_fbo.h"
 #include "brw_meta_util.h"
+#include "brw_state.h"
+#include "main/blend.h"
 #include "main/fbobject.h"
 
 /**
@@ -305,3 +307,62 @@ brw_get_rb_for_slice(struct brw_context *brw,
 
    return rb;
 }
+
+/**
+ * Determine if fast color clear supports the given clear color.
+ *
+ * Fast color clear can only clear to color values of 1.0 or 0.0.  At the
+ * moment we only support floating point, unorm, and snorm buffers.
+ */
+bool
+brw_is_color_fast_clear_compatible(struct brw_context *brw,
+                                   const struct intel_mipmap_tree *mt,
+                                   const union gl_color_union *color)
+{
+   const struct gl_context *ctx = &brw->ctx;
+
+   /* If we're mapping the render format to a different format than the
+    * format we use for texturing then it is a bit questionable whether it
+    * should be possible to use a fast clear. Although we only actually
+    * render using a renderable format, without the override workaround it
+    * wouldn't be possible to have a non-renderable surface in a fast clear
+    * state so the hardware probably legitimately doesn't need to support
+    * this case. At least on Gen9 this really does seem to cause problems.
+    */
+   if (brw->gen >= 9 &&
+       brw_format_for_mesa_format(mt->format) !=
+       brw->render_target_format[mt->format])
+      return false;
+
+   /* Gen9 doesn't support fast clear on single-sampled SRGB buffers. When
+    * GL_FRAMEBUFFER_SRGB is enabled any color renderbuffers will be
+    * resolved in intel_update_state. In that case it's pointless to do a
+    * fast clear because it's very likely to be immediately resolved.
+    */
+   if (brw->gen >= 9 &&
+       mt->num_samples <= 1 &&
+       ctx->Color.sRGBEnabled &&
+       _mesa_get_srgb_format_linear(mt->format) != mt->format)
+      return false;
+
+   const mesa_format format = _mesa_get_render_format(ctx, mt->format);
+   if (_mesa_is_format_integer_color(format)) {
+      if (brw->gen >= 8) {
+         perf_debug("Integer fast clear not enabled for (%s)",
+                    _mesa_get_format_name(format));
+      }
+      return false;
+   }
+
+   for (int i = 0; i < 4; i++) {
+      if (!_mesa_format_has_color_component(format, i)) {
+         continue;
+      }
+
+      if (brw->gen < 9 &&
+          color->f[i] != 0.0f && color->f[i] != 1.0f) {
+         return false;
+      }
+   }
+   return true;
+}