On 06/26/2012 05:22 PM, Jordan Justen wrote:
On Tue, Jun 26, 2012 at 2:34 PM, Brian Paul<bri...@vmware.com> wrote:
On 06/25/2012 06:34 PM, Jordan Justen wrote:
Previously if a format of GL_RGBA was used, then float data would
be returned, even if the type was an integer type.
Signed-off-by: Jordan Justen<jordan.l.jus...@intel.com>
---
src/mesa/main/readpix.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/mesa/main/readpix.c b/src/mesa/main/readpix.c
index 4058019..e3c4611 100644
--- a/src/mesa/main/readpix.c
+++ b/src/mesa/main/readpix.c
@@ -337,7 +337,7 @@ slow_read_rgba_pixels( struct gl_context *ctx,
goto done;
for (j = 0; j< height; j++) {
- if (_mesa_is_enum_format_integer(format)) {
+ if (_mesa_is_integer_format_or_type(format, type)) {
_mesa_unpack_uint_rgba_row(rbFormat, width, map, (GLuint (*)[4])
rgba);
_mesa_rebase_rgba_uint(width, (GLuint (*)[4]) rgba,
rb->_BaseFormat);
I'm not quite sure I follow this.
If we call glReadPixels(format=GL_RGBA, type=GL_UNSIGNED_BYTE) it looks like
_mesa_is_integer_format_or_type(format, type) will evaluate to true and
we'll errantly take the integer path, rather than the float path.
If one wants to read integer-valued colors, you need to pass
format=GL_RGBA_INTEGER.
This fixed an issue with CopyTexImage and integer clamping.
In meta, we use ReadPixels, and get the base format for the texture,
which for rgb10_a2ui is GL_RGBA.
Should rgb10_a2ui use GL_RGBA_INTEGER for it's base format?
In the glReadPixels call, yes, format=GL_RGBA_INTEGER.
It doesn't look like any gl_format uses an integer base format.
That's intentional. The base format basically indicates which color
channels are present, not whether they're int, float, non-normalized, etc.
Does
this mean that CopyTexImage will always do a int to float conversion
and then a float to int conversion if the src/dest is int based?
CopyTexImage should avoid that.
Hmm, maybe the issue is that the float path is not clamping integers
properly when re-packing.
The float path in what? For glReadPixels, glTexImage, glCopyTexImage,
etc., if the source and dest data are integer, the data should not be
converted to float during the transfer.
I'll investigate further, but any advise would be appreciated.
Thanks for your time,
-Jordan
-Brian
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