Commit 8907b6a8 authored by Kenneth Graunke's avatar Kenneth Graunke Committed by Ian Romanick

mesa: Fix default value of BUFFER_ACCESS_FLAGS.

According to both the GL 3.0 and ES 3.0 specifications (table 2.7 for GL
and table 2.8 for ES), the default value of BUFFER_ACCESS_FLAGS is
supposed to be zero.

Note that there are two related quantities: the obsolete BUFFER_ACCESS
enum and the new BUFFER_ACCESS_FLAGS bitfield.

BUFFER_ACCESS can only be GL_READ_ONLY, GL_WRITE_ONLY, or GL_READ_WRITE;
BUFFER_ACCESS_FLAGS can easily represent all three via GL_MAP_WRITE_BIT,
GL_MAP_READ_BIT, and their logical or.  It also supports more flags.

Thus, Mesa only stores the bitfield, and simply computes the old enum
when queried, via simplified_access_mode(bufObj->AccessFlags).

The tricky part is that, while BUFFER_ACCESS_FLAGS defaults to 0,
BUFFER_ACCESS defaults to GL_READ_WRITE for desktop [GL 3.0, table 2.8]
and GL_WRITE_ONLY_OES for ES [the GL_EXT_map_buffer_range extension].

Mesa tried to implement this by setting the default AccessFlags to
GL_MAP_READ_BIT | GL_MAP_WRITE_BIT on desktop, and GL_MAP_WRITE_BIT on
ES.  But in all specifications, it needs to be 0.

This patch moves that logic into simplified_access_mode(): when
AccessFlags == 0, it now returns GL_READ_WRITE for desktop and
GL_WRITE_ONLY for ES 1/2.  (BUFFER_ACCESS doesn't exist on ES 3.0,
so it's irrelevant there.)

With that in place, it changes the AccessFlags default to 0.

Fixes three es3conform tsets:
- copy_buffer_defaults
- map_buffer_range_modify_indices
- pixel_buffer_object_default_parameters
Reviewed-by: Jordan Justen's avatarJordan Justen <jordan.l.justen@intel.com>
Reviewed-by: default avatarIan Romanick <ian.d.romanick@intel.com>
parent f3db20da
......@@ -136,10 +136,24 @@ get_buffer(struct gl_context *ctx, const char *func, GLenum target)
}
static inline GLbitfield
default_access_mode(const struct gl_context *ctx)
/**
* Convert a GLbitfield describing the mapped buffer access flags
* into one of GL_READ_WRITE, GL_READ_ONLY, or GL_WRITE_ONLY.
*/
static GLenum
simplified_access_mode(struct gl_context *ctx, GLbitfield access)
{
/* Table 2.6 on page 31 (page 44 of the PDF) of the OpenGL 1.5 spec says:
const GLbitfield rwFlags = GL_MAP_READ_BIT | GL_MAP_WRITE_BIT;
if ((access & rwFlags) == rwFlags)
return GL_READ_WRITE;
if ((access & GL_MAP_READ_BIT) == GL_MAP_READ_BIT)
return GL_READ_ONLY;
if ((access & GL_MAP_WRITE_BIT) == GL_MAP_WRITE_BIT)
return GL_WRITE_ONLY;
/* Otherwise, AccessFlags is zero (the default state).
*
* Table 2.6 on page 31 (page 44 of the PDF) of the OpenGL 1.5 spec says:
*
* Name Type Initial Value Legal Values
* ... ... ... ...
......@@ -155,26 +169,9 @@ default_access_mode(const struct gl_context *ctx)
* The difference is because GL_OES_mapbuffer only supports mapping buffers
* write-only.
*/
return _mesa_is_gles(ctx)
? GL_MAP_WRITE_BIT : (GL_MAP_READ_BIT | GL_MAP_WRITE_BIT);
}
assert(access == 0);
/**
* Convert a GLbitfield describing the mapped buffer access flags
* into one of GL_READ_WRITE, GL_READ_ONLY, or GL_WRITE_ONLY.
*/
static GLenum
simplified_access_mode(GLbitfield access)
{
const GLbitfield rwFlags = GL_MAP_READ_BIT | GL_MAP_WRITE_BIT;
if ((access & rwFlags) == rwFlags)
return GL_READ_WRITE;
if ((access & GL_MAP_READ_BIT) == GL_MAP_READ_BIT)
return GL_READ_ONLY;
if ((access & GL_MAP_WRITE_BIT) == GL_MAP_WRITE_BIT)
return GL_WRITE_ONLY;
return GL_READ_WRITE; /* this should never happen, but no big deal */
return _mesa_is_gles(ctx) ? GL_WRITE_ONLY : GL_READ_WRITE;
}
......@@ -354,7 +351,7 @@ _mesa_initialize_buffer_object( struct gl_context *ctx,
obj->RefCount = 1;
obj->Name = name;
obj->Usage = GL_STATIC_DRAW_ARB;
obj->AccessFlags = default_access_mode(ctx);
obj->AccessFlags = 0;
}
......@@ -864,7 +861,7 @@ _mesa_DeleteBuffers(GLsizei n, const GLuint *ids)
if (_mesa_bufferobj_mapped(bufObj)) {
/* if mapped, unmap it now */
ctx->Driver.UnmapBuffer(ctx, bufObj);
bufObj->AccessFlags = default_access_mode(ctx);
bufObj->AccessFlags = 0;
bufObj->Pointer = NULL;
}
......@@ -1064,7 +1061,7 @@ _mesa_BufferData(GLenum target, GLsizeiptrARB size,
if (_mesa_bufferobj_mapped(bufObj)) {
/* Unmap the existing buffer. We'll replace it now. Not an error. */
ctx->Driver.UnmapBuffer(ctx, bufObj);
bufObj->AccessFlags = default_access_mode(ctx);
bufObj->AccessFlags = 0;
ASSERT(bufObj->Pointer == NULL);
}
......@@ -1282,7 +1279,7 @@ _mesa_UnmapBuffer(GLenum target)
#endif
status = ctx->Driver.UnmapBuffer( ctx, bufObj );
bufObj->AccessFlags = default_access_mode(ctx);
bufObj->AccessFlags = 0;
ASSERT(bufObj->Pointer == NULL);
ASSERT(bufObj->Offset == 0);
ASSERT(bufObj->Length == 0);
......@@ -1310,7 +1307,7 @@ _mesa_GetBufferParameteriv(GLenum target, GLenum pname, GLint *params)
*params = bufObj->Usage;
return;
case GL_BUFFER_ACCESS_ARB:
*params = simplified_access_mode(bufObj->AccessFlags);
*params = simplified_access_mode(ctx, bufObj->AccessFlags);
return;
case GL_BUFFER_MAPPED_ARB:
*params = _mesa_bufferobj_mapped(bufObj);
......@@ -1364,7 +1361,7 @@ _mesa_GetBufferParameteri64v(GLenum target, GLenum pname, GLint64 *params)
*params = bufObj->Usage;
return;
case GL_BUFFER_ACCESS_ARB:
*params = simplified_access_mode(bufObj->AccessFlags);
*params = simplified_access_mode(ctx, bufObj->AccessFlags);
return;
case GL_BUFFER_ACCESS_FLAGS:
if (!ctx->Extensions.ARB_map_buffer_range)
......
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