Examples: Vulkan: Fixed Vulkan descriptor pools. (#6642)

Only use required no. of types and sets
ocornut · Jul 29, 2023 · fa2f1bf · fa2f1bf
1 parent 7c5b0e8
commit fa2f1bf
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diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
@@ -95,6 +95,7 @@ Other changes:
 - Backends: GLFW: Revert ignoring mouse data on GLFW_CURSOR_DISABLED as it can be used
   differently. User may set ImGuiConfigFLags_NoMouse if desired. (#5625, #6609) [@scorpion-26]
 - Backends: WebGPU: Update for changes in Dawn. (#6602, #6188) [@williamhCode]
+- Examples: Vulkan: Creating minimal descriptor pools to fit only what is needed by example. (#6642) [@SaschaWillem]
 
 
 -----------------------------------------------------------------------

diff --git a/examples/example_glfw_vulkan/main.cpp b/examples/example_glfw_vulkan/main.cpp
@@ -215,25 +215,17 @@ static void SetupVulkan(ImVector<const char*> instance_extensions)
     }
 
     // Create Descriptor Pool
+    // The example only requires a single combined image sampler descriptor for the font image and only uses one descriptor set (for that)
+    // If you wish to load e.g. additional textures you may need to alter pools sizes.
     {
         VkDescriptorPoolSize pool_sizes[] =
         {
-            { VK_DESCRIPTOR_TYPE_SAMPLER, 1000 },
-            { VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1000 },
-            { VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, 1000 },
-            { VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, 1000 },
-            { VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, 1000 }
+            { VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1 },
         };
         VkDescriptorPoolCreateInfo pool_info = {};
         pool_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
         pool_info.flags = VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT;
-        pool_info.maxSets = 1000 * IM_ARRAYSIZE(pool_sizes);
+        pool_info.maxSets = 1;
         pool_info.poolSizeCount = (uint32_t)IM_ARRAYSIZE(pool_sizes);
         pool_info.pPoolSizes = pool_sizes;
         err = vkCreateDescriptorPool(g_Device, &pool_info, g_Allocator, &g_DescriptorPool);

diff --git a/examples/example_sdl2_vulkan/main.cpp b/examples/example_sdl2_vulkan/main.cpp
@@ -203,25 +203,17 @@ static void SetupVulkan(ImVector<const char*> instance_extensions)
     }
 
     // Create Descriptor Pool
+    // The example only requires a single combined image sampler descriptor for the font image and only uses one descriptor set (for that)
+    // If you wish to load e.g. additional textures you may need to alter pools sizes.
     {
         VkDescriptorPoolSize pool_sizes[] =
         {
-            { VK_DESCRIPTOR_TYPE_SAMPLER, 1000 },
-            { VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1000 },
-            { VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, 1000 },
-            { VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1000 },
-            { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, 1000 },
-            { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, 1000 },
-            { VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, 1000 }
+            { VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1 },
         };
         VkDescriptorPoolCreateInfo pool_info = {};
         pool_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
         pool_info.flags = VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT;
-        pool_info.maxSets = 1000 * IM_ARRAYSIZE(pool_sizes);
+        pool_info.maxSets = 1;
         pool_info.poolSizeCount = (uint32_t)IM_ARRAYSIZE(pool_sizes);
         pool_info.pPoolSizes = pool_sizes;
         err = vkCreateDescriptorPool(g_Device, &pool_info, g_Allocator, &g_DescriptorPool);