On 10.04.2017 00:26, Dorian Apanel wrote:
Hi Nicolai,
Thanks for checking it.
Yes I can add some negative tests for it - as another patch, maybe in
this week.
Thanks.
As I understand the spec, log2(size) is not relevant here.
Example: You create texture, default filter uses mipmaps, and default
max level is 1000, base 0. You supply 5 mips (16,8,4,2,1). At this
point, even if log2(16)+1 == 5, texture is not complete. OGL expects 995
more levels of size 1.
From Spec: "required width for mipmap level i is max(1, floor(w_b / 2^i))"
See also this SO answer http://stackoverflow.com/a/3906855/1688267 and
"Creating a complete texture" paragraph
here https://www.khronos.org/opengl/wiki/Common_Mistakes
Section 8.17 (Texture Completeness) says:
"Image levels k where k < level_base or k > q are insignificant to the
definition of completeness."
... and Section 8.14.3 (Mipmapping) defines q as:
p = floor(log2 (maxsize)) + level_base
q = min{p, level_max}
Explicitly setting TEXTURE_MAX_LEVEL has *never* been a necessity in
OpenGL. You only need it if, as in this test, you don't define the
smallest levels in the mip tree.
Cheers,
Nicolai
Thanks,
Dorian
2017-04-05 15:58 GMT+02:00 Nicolai Hähnle <[email protected]
<mailto:[email protected]>>:
On 05.04.2017 09:55, Dorian Apanel wrote:
From: Dorian Apanel <[email protected]
<mailto:dorian.apanel%[email protected]>>
Textures created by image load/store tests are not complete (max
level defaults to 1000).
Load/Store on incomplete textures should return zeros/change
nothing.
This fix sets proper base and max level of textures.
Signed-off-by: Dorian Apanel <[email protected]
<mailto:[email protected]>>
Interesting. It seems you're right, but could you please also add a
corresponding negative test and check it against whatever drivers
you have? I.e., a test that creates a texture with mipmaps enabled,
defines only the first level image, and then tries to use it from a
shader to make sure that (a) reads return 0 and (b) writes are ignored?
Also, the commit message doesn't quite capture the heart of it as
far as I understand it. The textures are incomplete because
num_levels levels are created, which may be less than log2(size). So
GL_TEXTURE_MAX_LEVEL is used to restrict the required number of levels.
Thanks,
Nicolai
---
tests/spec/arb_shader_image_load_store/common.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/tests/spec/arb_shader_image_load_store/common.c
b/tests/spec/arb_shader_image_load_store/common.c
index cbeaac7..fdc2ef3 100644
--- a/tests/spec/arb_shader_image_load_store/common.c
+++ b/tests/spec/arb_shader_image_load_store/common.c
@@ -141,6 +141,11 @@ upload_image_levels(const struct image_info
img, unsigned num_levels,
glGenTextures(1, &textures[unit]);
glBindTexture(img.target->target, textures[unit]);
+ if (img.target->target != GL_TEXTURE_BUFFER) {
+ glTexParameteri(img.target->target,
GL_TEXTURE_BASE_LEVEL, 0);
+ glTexParameteri(img.target->target,
GL_TEXTURE_MAX_LEVEL, num_levels - 1);
+ }
+
switch (img.target->target) {
case GL_TEXTURE_1D:
for (l = 0; l < num_levels; ++l) {
@@ -301,6 +306,8 @@ upload_image_levels(const struct image_info
img, unsigned num_levels,
glGenTextures(1, &tmp_tex);
glBindTexture(GL_TEXTURE_2D, tmp_tex);
+ glTexParameteri(GL_TEXTURE_2D,
GL_TEXTURE_BASE_LEVEL, 0);
+ glTexParameteri(GL_TEXTURE_2D,
GL_TEXTURE_MAX_LEVEL, 0);
if (img.target->target ==
GL_TEXTURE_2D_MULTISAMPLE_ARRAY) {
glTexImage3DMultisample(GL_TEXTURE_2D_MULTISAMPLE_ARRAY,
@@ -462,6 +469,8 @@ download_image_levels(const struct
image_info img, unsigned num_levels,
glGenTextures(1, &tmp_tex);
glBindTexture(GL_TEXTURE_2D, tmp_tex);
+ glTexParameteri(GL_TEXTURE_2D,
GL_TEXTURE_BASE_LEVEL, 0);
+ glTexParameteri(GL_TEXTURE_2D,
GL_TEXTURE_MAX_LEVEL, 0);
glTexImage2D(GL_TEXTURE_2D, 0, img.format->format,
grid.size.x, grid.size.y, 0,
--
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.
--
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.
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