DescriptorSetLayout testing breaks existing code

[rolandhill]

Hi Robert,

I just upgrade to the latest master and found that commit 6a76d54 breaks my application. A textured surface that was rendered prior to this commit is no longer rendered.

The commit implements the check below, which fails in my case, so the graph doesn't get compiled.

        if (setLayout->bindings.size() != descriptors.size())
        {
            throw Exception{make_string("Error: invalid DescriptorSet as setLayout bindings size (", setLayout->bindings.size(), ") and descriptors size ", descriptors.size(), ") not equal."), VK_INCOMPLETE};
        }

I may be doing this wrong so I don't know if this is a bug in VSG, but what worked before was (MAX_TEXTURES = 8)

...
    tileDescriptorBindings.push_back(VkDescriptorSetLayoutBinding{2, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1, VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT, nullptr}); 

    tileDescriptorBindings.push_back(VkDescriptorSetLayoutBinding{7, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, MAX_TEXTURES, VK_SHADER_STAGE_FRAGMENT_BIT, nullptr});

...
    tileDescriptors.push_back(vsg::DescriptorBuffer::create(sdTileValue::create(), 2));
   
 for(uint32_t i = 0; i < MAX_TEXTURES; i++)
    {
        auto texture = vsg::DescriptorImage::create(surface->_imageSampler, texData, 7, i, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER);
        tileDescriptors.push_back(texture);
    }

The question is, should the test in DescriptorSet::compile() take account of the descriptorCount value in the descriptor bindings before it compares it to the number of descriptors?

Thanks,
Roland

[robertosfield]

You need to have the same number of bindings as descriptors as it's the binding that tell the GPU what each of the descriptors are. Compile is called after the scene graph has been set up and should be in a valid state.

I suspect you've created an invalid scene graph state that is now being picked up. It was probably just working before because of luck rather than valid setup.

If you can't figure out the problem then could you provide a model or test program that I can use to reproduce the issue.