On 05/04/2017 09:51 PM, Samuel Pitoiset wrote:
On 05/04/2017 09:44 PM, Nicolai Hähnle wrote:
On 04.05.2017 20:54, Marek Olšák wrote:
On Wed, Apr 26, 2017 at 9:40 AM, Nicolai Hähnle <nhaeh...@gmail.com>
wrote:
On 24.04.2017 12:35, Samuel Pitoiset wrote:
The ARB_bindless_texture spec says:
"Interactions with GLSL 4.20"
"Without GLSL 4.20 support, sampler and image uniforms may only
be initialized through the OpenGL API. With GLSL 4.20, sampler
and image uniforms may be initialized in the shader using
layout(binding = integer-constant)
as described in section 4.4.4 "Opaque-Uniform Layout Qualifiers".
When ARB_bindless_texture is supported, these initial binding
values are always taken to mean a texture image or image unit
number, not a bindless handle."
Signed-off-by: Samuel Pitoiset <samuel.pitoi...@gmail.com>
---
src/compiler/glsl/ast_to_hir.cpp | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/src/compiler/glsl/ast_to_hir.cpp
b/src/compiler/glsl/ast_to_hir.cpp
index ae81ed95d8..943c25a224 100644
--- a/src/compiler/glsl/ast_to_hir.cpp
+++ b/src/compiler/glsl/ast_to_hir.cpp
@@ -2920,6 +2920,26 @@ apply_explicit_binding(struct
_mesa_glsl_parse_state *state,
return;
}
+ /* The ARB_bindless_texture_spec says:
+ *
+ * "Interactions with GLSL 4.20"
+ *
+ * "Without GLSL 4.20 support, sampler and image uniforms may
only be
+ * initialized through the OpenGL API. With GLSL 4.20, sampler
and
image
+ * uniforms may be initialized in the shader using
+ *
+ * layout(binding = integer-constant)
+ *
+ * as described in section 4.4.4 "Opaque-Uniform Layout
Qualifiers".
When
+ * ARB_bindless_texture is supported, these initial binding
values
are
+ * always taken to mean a texture image or image unit number,
not a
+ * bindless handle."
+ */
+ if (state->has_bindless() &&
+ (base_type->is_sampler() || base_type->is_image())) {
+ var->data.bindless = false;
+ }
I don't think this is correct. The way I understand the spec, saying
layout (bindless_sampler, binding = 5) uniform sampler2D s;
means that s is still bindless, it's just that it's *initial* value
is set
up as if the application had called
glUniform1i(index of s, 5);
You're still allowed to later on change it to a bindless handle by
calling
one of the glUniformHandleui64* functions.
I don't like this. Are you suggesting that a texture bound to unit 5
has to be somehow converted to a bindless texture and made resident
under the hood (in Mesa), so that the bindless shader code works?
I don't think we have much of a choice, unfortunately. I agree it's
very annoying.
This can only happen for default block uniforms, which st/mesa uploads
in a special way anyway. Maybe we can also treat default block
bindless uniforms in a special way?
I don't think this case has been fully implemented in the WIP branches.
Well, that's really unfortunate. The spec also says:
"For samplers and images with values specified as texture image or image
units, the GL implemenation will translate the unit number to an
internal handle as required."
If my understanding is correct, we need to a way to ask the driver and
get a handle to a bound texture?
If doing this makes sense, we can consider all uniform samplers declared
with the bindless_sampler layout qualifier to be a constant value at the
TGSI level.
And when glUniform1i() is setting a value to a bindless sampler, we do
something like: ctx->Driver.GetTextureHandleFromUnit(x) and put the
64-bit value into the uniform storage?
Yeah, that part is not implemented mainly because it's... really annoying.
Cheers,
Nicolai
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