draw textured object

assets/models/jaeger.mtl

@@ -0,0 +1,13 @@
+# Blender MTL File: 'jaeger.blend'
+# Material Count: 1
+
+newmtl Material_jaeger.texture.tga
+Ns 92.156863
+Ka 1.000000 1.000000 1.000000
+Kd 0.512000 0.512000 0.512000
+Ks 0.500000 0.500000 0.500000
+Ke 0.000000 0.000000 0.000000
+Ni 1.000000
+d 1.000000
+illum 2
+map_Kd jaeger.texture.tga

shadersrc/textured_lit.frag

@@ -0,0 +1,24 @@
+//glsl version 4.5
+#version 450
+
+//shader input
+layout (location = 0) in vec4 inColor;
+layout (location = 1) in vec2 texCoord;
+//output write
+layout (location = 0) out vec4 outFragColor;
+
+layout(set = 0, binding = 1) uniform  SceneData{
+	vec4 fogColor; // w is for exponent
+	vec4 fogDistances; //x for min, y for max, zw unused.
+	vec4 ambientColor;
+	vec4 sunlightDirection; //w for sun power
+	vec4 sunlightColor;
+} sceneData;
+
+layout(set = 2, binding = 0) uniform sampler2D tex1;
+
+void main()
+{
+  vec3 color = texture(tex1,texCoord).xyz;
+	outFragColor = vec4(color, inColor.w);
+}

shadersrc/tri_mesh.vert

@@ -2,8 +2,10 @@
 layout (location = 0) in vec3 vPosition;
 layout (location = 1) in vec3 vNormal;
 layout (location = 2) in vec4 vColor;
+layout (location = 3) in vec2 vTexCoord;
 
 layout (location = 0) out vec4 outColor;
+layout (location = 1) out vec2 texCoord;
 
 layout(set = 0, binding = 0) uniform  CameraBuffer{
 	mat4 view;
@@ -34,4 +36,5 @@ void main()
 	mat4 transformMatrix = (cameraData.viewproj * modelMatrix);
 	gl_Position = transformMatrix * vec4(vPosition, 1.0f);
 	outColor = vColor;
+  texCoord = vTexCoord;
 }

src/CommandBuffer.hs

@@ -23,6 +23,7 @@ import qualified VulkanMemoryAllocator as VMA
 import Types
 import Memory
 import Util
+import Data.Maybe (fromMaybe)
 
 frameOverlap :: Int
 frameOverlap = 2
@@ -230,8 +231,23 @@ recordCommandBuffer
                   { meshPushData     = V4 0 0 0 0
                   , meshRenderMatrix = modelMatrix
                   }
-                mesh = meshMap M.! meshID
-                material = materialMap M.! materialID
+                mesh = fromMaybe
+                  (error $ "no mesh called " <> meshID <> " present")
+                  (meshMap M.!? meshID)
+                material = fromMaybe
+                  (error $ "no material called " <> materialID <> " present")
+                  (materialMap M.!? materialID)
+
+            when
+              (materialTextureSet material /= Vk.NULL_HANDLE)
+              (Vk.cmdBindDescriptorSets
+                commandBuffer
+                Vk.PIPELINE_BIND_POINT_GRAPHICS
+                (materialPipelineLayout material)
+                2
+                (V.singleton $ materialTextureSet material)
+                V.empty
+                )
 
             Vk.cmdBindPipeline commandBuffer Vk.PIPELINE_BIND_POINT_GRAPHICS (materialPipeline material)
 

src/GraphicsPipeline.hs

@@ -194,6 +194,7 @@ createGraphicsPipelines
   -> V2 CInt
   -> Vk.PipelineLayout
   -> Maybe Vk.PipelineDepthStencilStateCreateInfo
+  -> String
   -> m ()
 createGraphicsPipelines
   logicalDevice
@@ -202,6 +203,7 @@ createGraphicsPipelines
   (V2 width height)
   pipelineLayout
   depthState
+  materialName
   = do
     meshLib <- (liftIO . STM.atomically . STM.readTMVar) =<< asks meshLibrary
     let pipelineStagesCreateInfos =
@@ -304,10 +306,10 @@ createGraphicsPipelines
           error "createGraphicsPipelines: Failed creating pipelines"
         return pipelines
         )
-    let material = Material (V.head pipeline) pipelineLayout
+    let material = Material Vk.NULL_HANDLE (V.head pipeline) pipelineLayout
     matLibraryTMVar <- asks materialLibrary
     matLibrary <- liftIO $ STM.atomically $ STM.readTMVar matLibraryTMVar
-    let newMatLibrary = M.insert "defaultMesh" material matLibrary
+    let newMatLibrary = M.insert materialName material matLibrary
     void $ liftIO $ STM.atomically $ STM.swapTMVar matLibraryTMVar newMatLibrary
 
 createMeshPipelineLayout

src/Init.hs

@@ -10,12 +10,15 @@ import Control.Monad
 import Control.Monad.IO.Class
 import Control.Monad.Reader
 import Control.Monad.Trans.Resource
+import qualified Data.Map.Strict as M
+import Data.Maybe
 import qualified Data.Vector as V
 import qualified SDL hiding (V2)
 import qualified SDL.Video.Vulkan as SDL
 import Foreign.Ptr
 import Linear as L
-import qualified Vulkan.Core10 as Vk
+import qualified Vulkan as Vk
+import qualified Vulkan.CStruct.Extends as Vk
 import qualified Vulkan.Extensions.VK_KHR_swapchain as Khr
 import qualified Vulkan.Extensions.VK_KHR_surface as Khr
 import qualified Vulkan.Zero as Vk
@@ -94,7 +97,8 @@ initVulkan window = do
 
   uploadContext <- initSyncStructures vulkanLogicalDevice queueIndex
 
-  (descriptorSetLayout1, descriptorSetLayout2, descriptorPool) <- initDescriptors vulkanLogicalDevice
+  (descriptorSetLayout1, descriptorSetLayout2, textureDescriptorSetLayout, descriptorPool) <-
+    initDescriptors vulkanLogicalDevice
 
   allocator <- initAllocator vulkanPhysicalDevice vulkanLogicalDevice vulkanInstance
 
@@ -104,15 +108,26 @@ initVulkan window = do
   imageViews <- getImageViewHandles swapchain surfaceFormat vulkanLogicalDevice
   meshVertexShader <- loadShader vulkanLogicalDevice "shadersrc/tri_mesh.vert" "vert"
   meshFragmentShader <- loadShader vulkanLogicalDevice "shadersrc/rainbow_lit.frag" "frag"
+  textureFragmentShader <- loadShader vulkanLogicalDevice "shadersrc/textured_lit.frag" "frag"
   renderPass <- createRenderPass vulkanLogicalDevice (Khr.format surfaceFormat) Vk.FORMAT_D32_SFLOAT
   meshLayout <- createMeshPipelineLayout
     vulkanLogicalDevice
     (V.fromList
       [ descriptorSetLayout1
       , descriptorSetLayout2
+      , textureDescriptorSetLayout
+      ]
+      )
+  textureLayout <- createMeshPipelineLayout
+    vulkanLogicalDevice
+    (V.fromList
+      [ descriptorSetLayout1
+      , descriptorSetLayout2
+      , textureDescriptorSetLayout
       ]
       )
   let meshContainer = ShaderContainer (Just meshVertexShader) (Just meshFragmentShader)
+      textureContainer = ShaderContainer (Just meshVertexShader) (Just textureFragmentShader)
   createGraphicsPipelines
     vulkanLogicalDevice
     renderPass
@@ -120,6 +135,15 @@ initVulkan window = do
     dimensions
     meshLayout
     (Just (createDepthStencilStateCreateInfo True True Vk.COMPARE_OP_LESS_OR_EQUAL))
+    "defaultMesh"
+  createGraphicsPipelines
+    vulkanLogicalDevice
+    renderPass
+    textureContainer
+    dimensions
+    textureLayout
+    (Just (createDepthStencilStateCreateInfo True True Vk.COMPARE_OP_LESS_OR_EQUAL))
+    "texturedMesh"
 
   frameBuffers <- createFramebuffer vulkanLogicalDevice renderPass imageViews depthImageView dimensions
 
@@ -136,7 +160,7 @@ initVulkan window = do
 
   loadImages allocator uploadContext queue vulkanLogicalDevice
 
-  initScene
+  initScene vulkanLogicalDevice descriptorPool textureDescriptorSetLayout
 
   return $ EngineData
     window
@@ -155,6 +179,7 @@ initVulkan window = do
     frames
     descriptorSetLayout1
     descriptorSetLayout2
+    textureDescriptorSetLayout
     descriptorPool
     (GPUSceneData
       (V4 0 0 0 0)
@@ -166,11 +191,16 @@ initVulkan window = do
     uploadContext
 
 
-initScene :: (MonadReader ReadState m, MonadIO m) => m ()
-initScene = do
+initScene
+  :: (MonadReader ReadState m, MonadIO m, MonadResource m)
+  => Vk.Device
+  -> Vk.DescriptorPool
+  -> Vk.DescriptorSetLayout
+  -> m ()
+initScene device descriptorPool texturedSetLayout = do
   let catMask = RenderObject
         { objectMesh     = "mask"
-        , objectMaterial = "defaultMesh"
+        , objectMaterial = "texturedMesh"
         , objectMatrix   = identity
         }
       triangles = V.concatMap
@@ -197,10 +227,51 @@ initScene = do
   void $ liftIO $ STM.atomically $ STM.swapTMVar renderableContainer $
     (renderableVector `V.snoc` catMask) V.++ triangles
 
+  let samplerInfo = samplerCreateInfo Vk.FILTER_NEAREST Vk.SAMPLER_ADDRESS_MODE_REPEAT
+  blockySampler <- snd <$> Vk.withSampler device samplerInfo Nothing allocate
+
+  matLibraryContainer <- asks materialLibrary
+  texturedMaterial <- do
+    matLibrary <- liftIO $ STM.atomically $ STM.readTMVar matLibraryContainer
+    return (fromMaybe (error "not texturedMesh") $ matLibrary M.!? "texturedMesh")
+
+  let allocInfo = Vk.zero
+        { Vk.descriptorPool = descriptorPool
+        , Vk.setLayouts     = V.singleton texturedSetLayout
+        }
+
+  texturedDescriptorSet <- V.head . snd <$> Vk.withDescriptorSets device allocInfo allocate
+
+  liftIO $ do
+    matLibrary <- STM.atomically $ STM.readTMVar matLibraryContainer
+    let material = texturedMaterial
+          { materialTextureSet = texturedDescriptorSet
+          }
+        newMatLibrary = M.insert "texturedMesh" material matLibrary
+    void $ STM.atomically $ STM.swapTMVar matLibraryContainer newMatLibrary
+
+  textureContainer <- asks textureLibrary
+  texture <- do
+    texLibrary <- liftIO $ STM.atomically $ STM.readTMVar textureContainer
+    return $ fromMaybe (error "no marksman texture found") $ texLibrary M.!? "marksman"
+
+  let imageBufferInfo = Vk.zero
+        { Vk.sampler = blockySampler
+        , Vk.imageView = textureImageView texture
+        , Vk.imageLayout = Vk.IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL
+        }
+      texture1 = V.singleton $ Vk.SomeStruct $ writeDescriptorImage
+        Vk.DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER
+        texturedDescriptorSet
+        imageBufferInfo
+        0
+
+  Vk.updateDescriptorSets device texture1 V.empty
+
 initDescriptors
   :: (MonadResource m)
   => Vk.Device
-  -> m (Vk.DescriptorSetLayout, Vk.DescriptorSetLayout, Vk.DescriptorPool)
+  -> m (Vk.DescriptorSetLayout, Vk.DescriptorSetLayout, Vk.DescriptorSetLayout, Vk.DescriptorPool)
 initDescriptors device = do
   let cameraBind = descriptorsetLayoutBinding
         Vk.DESCRIPTOR_TYPE_UNIFORM_BUFFER
@@ -214,6 +285,10 @@ initDescriptors device = do
         Vk.DESCRIPTOR_TYPE_STORAGE_BUFFER
         Vk.SHADER_STAGE_VERTEX_BIT
         0
+      textureBind = descriptorsetLayoutBinding
+        Vk.DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER
+        Vk.SHADER_STAGE_FRAGMENT_BIT
+        0
       setInfo = Vk.zero
         { Vk.flags = Vk.DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT
         , Vk.bindings = V.fromList
@@ -225,6 +300,10 @@ initDescriptors device = do
         { Vk.flags = Vk.DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT
         , Vk.bindings = V.singleton objectBind
         }
+      setInfo3 = Vk.zero
+        { Vk.flags = Vk.DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT
+        , Vk.bindings = V.singleton textureBind
+        }
       poolInfo = Vk.zero
         { Vk.flags     = Vk.DESCRIPTOR_POOL_CREATE_UPDATE_AFTER_BIND_BIT
         , Vk.maxSets   = 10
@@ -241,6 +320,10 @@ initDescriptors device = do
             { Vk.type'           = Vk.DESCRIPTOR_TYPE_STORAGE_BUFFER
             , Vk.descriptorCount = 10
             }
+          , Vk.zero
+            { Vk.type'           = Vk.DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER
+            , Vk.descriptorCount = 10
+            }
           ]
         }
 
@@ -253,4 +336,7 @@ initDescriptors device = do
   (_, descriptorPool) <-
     Vk.withDescriptorPool device poolInfo Nothing allocate
 
-  return (descriptorSetLayout1, descriptorSetLayout2, descriptorPool)
+  (_, textureDescriptorSetLayout) <-
+    Vk.withDescriptorSetLayout device setInfo3 Nothing allocate
+
+  return (descriptorSetLayout1, descriptorSetLayout2, textureDescriptorSetLayout, descriptorPool)

src/Mesh.hs

@@ -13,11 +13,14 @@ import Control.Monad.Reader
 import Control.Monad.Trans.Resource
 
 import qualified Data.Map.Strict as M
+import Data.Maybe (fromMaybe)
 import qualified Data.Vector as V
 
+import Debug.Trace
+
 import Foreign
 
-import Linear (V3(..), V4(..))
+import Linear (V2(..), V3(..), V4(..))
 
 import qualified VulkanMemoryAllocator as VMA
 import qualified Vulkan.Core10 as Vk
@@ -37,14 +40,14 @@ loadMeshes
   -> m ()
 loadMeshes allocator uploadContext queue device = do
   let triangle = V.fromList
-        [ Vertex (V3 0.5 0.5 0)    (V3 0 0 0) (V4 0 1 0 1)
-        , Vertex (V3 (-0.5) 0.5 0) (V3 0 0 0) (V4 0 1 0 1)
-        , Vertex (V3 0 (-0.5) 0)   (V3 0 0 0) (V4 0 1 0 1)
+        [ Vertex (V3 0.5 0.5 0)    (V3 0 0 0) (V4 0 1 0 1) (V2 0 0)
+        , Vertex (V3 (-0.5) 0.5 0) (V3 0 0 0) (V4 0 1 0 1) (V2 0 0)
+        , Vertex (V3 0 (-0.5) 0)   (V3 0 0 0) (V4 0 1 0 1) (V2 0 0)
         ]
 
   triMesh <- uploadMesh triangle allocator uploadContext queue device
   maskMesh <- loadFromObj
-    "./assets/models/cat_mask_cyberpunk.obj"
+    "./assets/models/jaeger.obj"
     allocator
     uploadContext
     queue
@@ -149,11 +152,12 @@ loadFromObj filepath vma uploadContext queue device = do
     Left err ->
       error ("loadFromObj:  loading mesh data: " <> err)
     Right obj -> do
-      let vertices = digestFaces (objFaces obj) (objLocations obj)
+      let vertices = digestFaces (objFaces obj) (objLocations obj) (objTexCoords obj)
       uploadMesh vertices vma uploadContext queue device
   where
-    digestFaces :: V.Vector (Element Face) -> V.Vector Location -> V.Vector Vertex
-    digestFaces faces locations =
+    digestFaces
+      :: V.Vector (Element Face) -> V.Vector Location -> V.Vector TexCoord -> V.Vector Vertex
+    digestFaces faces locations texCoords =
       V.foldl
         (\acc (Element _ _ _ _ (Face fa fb fc others)) ->
           if not (null others)
@@ -165,8 +169,9 @@ loadFromObj filepath vma uploadContext queue device = do
                     let position = faceIndexToPosition faceIndex locations
                         normal   = V3 0 0 0
                         color    = V4 1 1 0 1
+                        uv       = faceIndexToUV faceIndex texCoords
                     in
-                      Vertex position normal color
+                      Vertex position normal color uv
                     )
                   (V.fromList [ fa, fb, fc ])
             in
@@ -179,3 +184,10 @@ loadFromObj filepath vma uploadContext queue device = do
       let Location x y z _ = locations V.! (faceLocIndex index - 1)
       in
         V3 x y z
+    faceIndexToUV :: FaceIndex -> V.Vector TexCoord -> V2 Float
+    faceIndexToUV index texCoords =
+      let TexCoord r s _ =
+            texCoords V.!
+              (fromMaybe (error "no UV coordinates present") (faceTexCoordIndex index) - 1)
+      in
+        V2 r s

src/Textures.hs

@@ -152,7 +152,7 @@ loadImages
   -> m ()
 loadImages allocator uploadContext queue device = do
 
-  loadedImage <- loadImageFromFile allocator uploadContext queue device "assets/textures/bricks.png"
+  loadedImage <- loadImageFromFile allocator uploadContext queue device "assets/textures/jaeger.texture.tga"
 
   let imageInfo = imageviewCreate (image loadedImage) Vk.FORMAT_R8G8B8A8_SRGB Vk.IMAGE_ASPECT_COLOR_BIT
 
@@ -168,6 +168,6 @@ loadImages allocator uploadContext queue device = do
   void $ liftIO $ STM.atomically $ do
     texMap <- STM.readTMVar textureLib
 
-    let newMap = M.insert "bricks" texture texMap
+    let newMap = M.insert "marksman" texture texMap
 
     STM.swapTMVar textureLib newMap

src/Types.hs

@@ -24,25 +24,26 @@ data ShaderContainer = ShaderContainer
   deriving (Show)
 
 data EngineData = EngineData
-  { engineWindow           :: SDL.Window
-  , engineWindowDimensions :: V2 CInt
-  , enginePhysicalDevice   :: Vk.PhysicalDevice
-  , engineLogicalDevice    :: Vk.Device
-  , engineInstance         :: Vk.Instance
-  , engineSwapchain        :: Vk.SwapchainKHR
-  , engineQueue            :: Vk.Queue
-  , engineFramebuffers     :: V.Vector Vk.Framebuffer
-  , engineRenderPass       :: Vk.RenderPass
-  , engineAllocator        :: VMA.Allocator
-  , engineDepthImageView   :: Vk.ImageView
-  , engineDepthImage       :: AllocatedImage
-  , engineDepthFormat      :: Vk.Format
-  , engineFrames           :: V.Vector FrameData
-  , engineGlobalSetLayout  :: Vk.DescriptorSetLayout
-  , engineObjectSetLayout  :: Vk.DescriptorSetLayout
-  , engineDescriptorPool   :: Vk.DescriptorPool
-  , engineSceneParameters  :: GPUSceneData
-  , engineUploadContext    :: UploadContext
+  { engineWindow                 :: SDL.Window
+  , engineWindowDimensions       :: V2 CInt
+  , enginePhysicalDevice         :: Vk.PhysicalDevice
+  , engineLogicalDevice          :: Vk.Device
+  , engineInstance               :: Vk.Instance
+  , engineSwapchain              :: Vk.SwapchainKHR
+  , engineQueue                  :: Vk.Queue
+  , engineFramebuffers           :: V.Vector Vk.Framebuffer
+  , engineRenderPass             :: Vk.RenderPass
+  , engineAllocator              :: VMA.Allocator
+  , engineDepthImageView         :: Vk.ImageView
+  , engineDepthImage             :: AllocatedImage
+  , engineDepthFormat            :: Vk.Format
+  , engineFrames                 :: V.Vector FrameData
+  , engineGlobalSetLayout        :: Vk.DescriptorSetLayout
+  , engineObjectSetLayout        :: Vk.DescriptorSetLayout
+  , engineSingleTextureSetLayout :: Vk.DescriptorSetLayout
+  , engineDescriptorPool         :: Vk.DescriptorPool
+  , engineSceneParameters        :: GPUSceneData
+  , engineUploadContext          :: UploadContext
   } 
   deriving (Show)
 
@@ -57,24 +58,30 @@ data Vertex = Vertex
   { vertexPosition :: V3 Float
   , vertexNormal   :: V3 Float
   , vertexColor    :: V4 Float
+  , vertexUV       :: V2 Float
   }
   deriving (Show)
 
 instance Storable Vertex where
 
-  sizeOf _ = sizeOf (undefined :: V3 Float) * 2 + sizeOf (undefined :: V4 Float)
+  sizeOf _ =
+    sizeOf (undefined :: V3 Float) * 2 +
+    sizeOf (undefined :: V4 Float) +
+    sizeOf (undefined :: V2 Float)
 
   peek ptr = do
     pos <- peek (castPtr ptr)
     nor <- peek (castPtr ptr `plusPtr` sizeOf pos)
     col <- peek (castPtr ptr `plusPtr` sizeOf pos `plusPtr` sizeOf nor)
-    return $ Vertex pos nor col
+    uv <- peek (castPtr ptr `plusPtr` sizeOf pos `plusPtr` sizeOf nor `plusPtr` sizeOf col)
+    return $ Vertex pos nor col uv
 
-  poke ptr (Vertex position normal color) = do
+  poke ptr (Vertex position normal color uv) = do
     let castedV3Ptr = castPtr ptr
     pokeElemOff castedV3Ptr 0 position
     pokeElemOff castedV3Ptr 1 normal
     poke (castPtr (ptr `plusPtr` sizeOf position `plusPtr` sizeOf normal)) color
+    poke (castPtr (ptr `plusPtr` sizeOf position `plusPtr` sizeOf normal `plusPtr` sizeOf color)) uv
 
   alignment _ = 0
 
@@ -108,6 +115,13 @@ instance VertexInputDescribable Vertex where
           , Vk.format   = Vk.FORMAT_R32G32B32A32_SFLOAT
           , Vk.offset   = fromIntegral (sizeOf (vertexPosition v) + sizeOf (vertexNormal v))
           } :: Vk.VertexInputAttributeDescription
+        uvAttribute = Vk.zero
+          { Vk.binding  = 0
+          , Vk.location = 3
+          , Vk.format   = Vk.FORMAT_R32G32_SFLOAT
+          , Vk.offset   = fromIntegral $
+            sizeOf (vertexPosition v) + sizeOf (vertexNormal v) + sizeOf (vertexColor v)
+          } :: Vk.VertexInputAttributeDescription
     in
       VertexInputDescription
         { vidBindings   = V.fromList [ mainBinding ]
@@ -115,6 +129,7 @@ instance VertexInputDescribable Vertex where
           [ positionAttribute
           , normalAttribute
           , colorAttribute
+          , uvAttribute
           ]
         }
 
@@ -161,7 +176,8 @@ data AllocatedImage = AllocatedImage
   deriving (Show)
 
 data Material = Material
-  { materialPipeline       :: Vk.Pipeline
+  { materialTextureSet     :: Vk.DescriptorSet
+  , materialPipeline       :: Vk.Pipeline
   , materialPipelineLayout :: Vk.PipelineLayout
   }
   deriving (Show)

src/Util.hs

@@ -80,3 +80,31 @@ createSubmitInfo cmd = V.singleton $ Vk.SomeStruct $
   Vk.zero
     { Vk.commandBuffers = V.singleton (Vk.commandBufferHandle cmd)
     }
+
+samplerCreateInfo
+  :: Vk.Filter
+  -> Vk.SamplerAddressMode
+  -> Vk.SamplerCreateInfo '[]
+samplerCreateInfo filters addressMode =
+  Vk.zero
+    { Vk.magFilter = filters
+    , Vk.minFilter = filters
+    , Vk.addressModeU = addressMode
+    , Vk.addressModeV = addressMode
+    , Vk.addressModeW = addressMode
+    }
+
+writeDescriptorImage
+  :: Vk.DescriptorType
+  -> Vk.DescriptorSet
+  -> Vk.DescriptorImageInfo
+  -> Word32
+  -> Vk.WriteDescriptorSet '[]
+writeDescriptorImage type' set imageInfo binding =
+  Vk.zero
+    { Vk.dstBinding = binding
+    , Vk.dstSet     = set
+    , Vk.descriptorCount = 1
+    , Vk.descriptorType  = type'
+    , Vk.imageInfo       = V.singleton imageInfo
+    }