From d9b7c48953a9af18237cbf47d78fad9dd0b4174f Mon Sep 17 00:00:00 2001
From: nek0 <nek0@nek0.eu>
Date: Sun, 11 Jun 2023 08:08:29 +0200
Subject: [PATCH] using indirect draw, not working yet

---
 src/CommandBuffer.hs | 72 ++++++++++++++++++++++++++++++++++++++++++++
 src/Types.hs         |  1 +
 2 files changed, 73 insertions(+)

diff --git a/src/CommandBuffer.hs b/src/CommandBuffer.hs
index 687697b..188d568 100644
--- a/src/CommandBuffer.hs
+++ b/src/CommandBuffer.hs
@@ -101,6 +101,12 @@ createFrames
         Vk.BUFFER_USAGE_STORAGE_BUFFER_BIT
         VMA.MEMORY_USAGE_CPU_TO_GPU
 
+      indirectBuffer <- createAllocatedBuffer
+        allocator
+        (sizeOf maxObjects)
+        Vk.BUFFER_USAGE_STORAGE_BUFFER_BIT
+        VMA.MEMORY_USAGE_CPU_TO_GPU
+
       let allocationInfo = Vk.zero
             { Vk.descriptorPool = descriptorPool
             , Vk.setLayouts     = V.singleton setLayout
@@ -162,6 +168,7 @@ createFrames
         , frameCameraBuffer      = cameraBuffer
         , frameSceneBuffer       = sceneBuffer
         , frameObjectBuffer      = objectBuffer
+        , frameIndirectBuffer    = indirectBuffer
         , frameGlobalDescriptor  = V.head globalDescriptor
         , frameObjectDescriptor  = V.head objectDescriptor
         }
@@ -226,6 +233,71 @@ recordCommandBuffer
 
         let draws = compactDraws meshMap materialMap renderObjects
 
+        let drawCommands = V.map
+              (\(i, RenderObject mesh matrix material) ->
+                Vk.DrawIndirectCommand
+                  { vertexCount   = fromIntegral (V.length $ meshVertices $ meshMap M.! mesh)
+                  , firstVertex   = 0
+                  , instanceCount = 1
+                  , firstInstance = i
+                  }
+                )
+              (V.zip
+                (V.fromList [0..])
+                renderObjects
+                )
+
+        V.mapM_
+          (\(IndirectBatch mesh material first count) -> do
+
+            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)
+
+            Vk.cmdBindDescriptorSets
+              commandBuffer
+              Vk.PIPELINE_BIND_POINT_GRAPHICS
+              (materialPipelineLayout material)
+              0
+              (V.singleton $ frameGlobalDescriptor frame)
+              V.empty
+
+            Vk.cmdBindDescriptorSets
+              commandBuffer
+              Vk.PIPELINE_BIND_POINT_GRAPHICS
+              (materialPipelineLayout material)
+              1
+              (V.singleton $ frameObjectDescriptor frame)
+              V.empty
+
+            Vk.cmdBindVertexBuffers
+              commandBuffer
+              0
+              (V.fromList [ allocatedBuffer $ meshBuffer mesh ])
+              (V.fromList [ 0 ])
+
+            let indirectOffset = fromIntegral $ 
+                  first * fromIntegral ( sizeOf (undefined :: Vk.DrawIndirectCommand))
+                drawStride = fromIntegral $ sizeOf (undefined :: Vk.DrawIndirectCommand)
+
+            Vk.cmdDrawIndirect
+              commandBuffer
+              (allocatedBuffer $ frameIndirectBuffer frame)
+              indirectOffset
+              (fromIntegral $ V.length draws)
+              drawStride
+            )
+          draws
+
         V.mapM_
           (\(IndirectBatch mesh material first count) -> do
 
diff --git a/src/Types.hs b/src/Types.hs
index abeb025..a33590c 100644
--- a/src/Types.hs
+++ b/src/Types.hs
@@ -227,6 +227,7 @@ data FrameData = FrameData
   , frameCameraBuffer      :: AllocatedBuffer
   , frameSceneBuffer       :: AllocatedBuffer
   , frameObjectBuffer      :: AllocatedBuffer
+  , frameIndirectBuffer    :: AllocatedBuffer
   , frameGlobalDescriptor  :: Vk.DescriptorSet
   , frameObjectDescriptor  :: Vk.DescriptorSet
   }