gallium: add and use generic function for querying patented format support (v2)

v2: Unsigned floats are allowed regardless of the configure switch.

2 files changed, 59 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_format.c b/src/gallium/auxiliary/util/u_format.c
index 4896faa..9cbdd0a 100644
--- a/src/gallium/auxiliary/util/u_format.c
+++ b/src/gallium/auxiliary/util/u_format.c
@@ -36,6 +36,55 @@
 #include "u_memory.h"
 #include "u_rect.h"
 #include "u_format.h"
+#include "u_format_s3tc.h"
+
+#include "pipe/p_defines.h"
+
+
+boolean
+util_format_is_float(enum pipe_format format)
+{
+   const struct util_format_description *desc = util_format_description(format);
+   unsigned i;
+
+   assert(desc);
+   if (!desc) {
+      return FALSE;
+   }
+
+   /* Find the first non-void channel. */
+   for (i = 0; i < 4; i++) {
+      if (desc->channel[i].type != UTIL_FORMAT_TYPE_VOID) {
+         break;
+      }
+   }
+
+   if (i == 4) {
+      return FALSE;
+   }
+
+   return desc->channel[i].type == UTIL_FORMAT_TYPE_FLOAT ? TRUE : FALSE;
+}
+
+
+boolean
+util_format_is_supported(enum pipe_format format, unsigned bind)
+{
+   if (util_format_is_s3tc(format) && !util_format_s3tc_enabled) {
+      return FALSE;
+   }
+
+#ifndef TEXTURE_FLOAT_ENABLED
+   if ((bind & PIPE_BIND_RENDER_TARGET) &&
+       format != PIPE_FORMAT_R9G9B9E5_FLOAT &&
+       format != PIPE_FORMAT_R11G11B10_FLOAT &&
+       util_format_is_float(format)) {
+      return FALSE;
+   }
+#endif
+
+   return TRUE;
+}
 
 
 void
diff --git a/src/gallium/auxiliary/util/u_format.h b/src/gallium/auxiliary/util/u_format.h
index 7659a80..bb3ed72 100644
--- a/src/gallium/auxiliary/util/u_format.h
+++ b/src/gallium/auxiliary/util/u_format.h
@@ -473,6 +473,10 @@ util_format_colormask(const struct util_format_description *desc)
 }
 
 
+boolean
+util_format_is_float(enum pipe_format format);
+
+
 /**
  * Whether the src format can be blitted to destation format with a simple
  * memcpy.
@@ -481,6 +485,12 @@ boolean
 util_is_format_compatible(const struct util_format_description *src_desc,
                           const struct util_format_description *dst_desc);
 
+/**
+ * Whether the format is supported by Gallium for the given bindings.
+ * This covers S3TC textures and floating-point render targets.
+ */
+boolean
+util_format_is_supported(enum pipe_format format, unsigned bind);
 
 /**
  * Whether this format is a rgab8 variant.