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authorMarek Olšák <marek.olsak@amd.com>2014-02-03 03:21:29 +0100
committerMarek Olšák <marek.olsak@amd.com>2014-02-06 17:30:00 +0100
commiteeb5a4a50e1317a7f8d9e168c962ce3b1d7b36f9 (patch)
tree8678a3a93a4b3595c1aadf391c7e9d48789c3928 /src
parented84fb3167aa3a048dedaf7cbd865e306b971d50 (diff)
gallium: define the behavior of PIPE_USAGE_* flags properly
STATIC will be removed in the following commit. v2: changed the definition of IMMUTABLE Reviewed-by: Brian Paul <brianp@vmware.com>
Diffstat (limited to 'src')
-rw-r--r--src/gallium/docs/source/screen.rst18
-rw-r--r--src/gallium/include/pipe/p_defines.h13
2 files changed, 19 insertions, 12 deletions
diff --git a/src/gallium/docs/source/screen.rst b/src/gallium/docs/source/screen.rst
index ed8e8322e8f..0c9c2749dfe 100644
--- a/src/gallium/docs/source/screen.rst
+++ b/src/gallium/docs/source/screen.rst
@@ -340,12 +340,18 @@ PIPE_USAGE_*
^^^^^^^^^^^^
The PIPE_USAGE enums are hints about the expected usage pattern of a resource.
-
-* ``PIPE_USAGE_DEFAULT``: Expect many uploads to the resource, intermixed with draws.
-* ``PIPE_USAGE_DYNAMIC``: Expect many uploads to the resource, intermixed with draws.
-* ``PIPE_USAGE_STATIC``: Same as immutable (?)
-* ``PIPE_USAGE_IMMUTABLE``: Resource will not be changed after first upload.
-* ``PIPE_USAGE_STREAM``: Upload will be followed by draw, followed by upload, ...
+Note that drivers must always support read and write CPU access at any time
+no matter which hint they got.
+
+* ``PIPE_USAGE_DEFAULT``: Optimized for fast GPU access.
+* ``PIPE_USAGE_IMMUTABLE``: Optimized for fast GPU access and the resource is
+ not expected to be mapped or changed (even by the GPU) after the first upload.
+* ``PIPE_USAGE_DYNAMIC``: Expect frequent write-only CPU access. What is
+ uploaded is expected to be used at least several times by the GPU.
+* ``PIPE_USAGE_STATIC``: Same as PIPE_USAGE_DEFAULT.
+* ``PIPE_USAGE_STREAM``: Expect frequent write-only CPU access. What is
+ uploaded is expected to be used only once by the GPU.
+* ``PIPE_USAGE_STAGING``: Optimized for fast CPU access.
Methods
diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index 183726c0666..85385380970 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -356,13 +356,14 @@ enum pipe_flush_flags {
#define PIPE_RESOURCE_FLAG_ST_PRIV (1 << 24) /* state-tracker/winsys private */
/* Hint about the expected lifecycle of a resource.
+ * Sorted according to GPU vs CPU access.
*/
-#define PIPE_USAGE_DEFAULT 0 /* many uploads, draws intermixed */
-#define PIPE_USAGE_DYNAMIC 1 /* many uploads, draws intermixed */
-#define PIPE_USAGE_STATIC 2 /* same as immutable?? */
-#define PIPE_USAGE_IMMUTABLE 3 /* no change after first upload */
-#define PIPE_USAGE_STREAM 4 /* upload, draw, upload, draw */
-#define PIPE_USAGE_STAGING 5 /* supports data transfers from the GPU to the CPU */
+#define PIPE_USAGE_DEFAULT 0 /* fast GPU access */
+#define PIPE_USAGE_IMMUTABLE 1 /* fast GPU access, immutable */
+#define PIPE_USAGE_DYNAMIC 2 /* uploaded data is used multiple times */
+#define PIPE_USAGE_STREAM 3 /* uploaded data is used once */
+#define PIPE_USAGE_STAGING 4 /* fast CPU access */
+#define PIPE_USAGE_STATIC 5 /* same as DEFAULT, will be removed */
/**