--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/semicongine/vulkan/buffer.nim	Sat Dec 02 22:23:29 2023 +0700
@@ -0,0 +1,146 @@
+import std/strformat
+import std/typetraits
+import std/sequtils
+import std/tables
+import std/logging
+
+import ../core
+import ./device
+import ./memory
+import ./physicaldevice
+import ./commandbuffer
+
+type
+  Buffer* = object
+    device*: Device
+    vk*: VkBuffer
+    size*: int
+    usage*: seq[VkBufferUsageFlagBits]
+    case memoryAllocated*: bool
+      of false: discard
+      of true:
+        memory*: DeviceMemory
+
+
+proc `==`*(a, b: Buffer): bool =
+  a.vk == b.vk
+
+func `$`*(buffer: Buffer): string =
+  &"Buffer(vk: {buffer.vk}, size: {buffer.size}, usage: {buffer.usage})"
+
+proc requirements(buffer: Buffer): MemoryRequirements =
+  assert buffer.vk.valid
+  assert buffer.device.vk.valid
+  var req: VkMemoryRequirements
+  buffer.device.vk.vkGetBufferMemoryRequirements(buffer.vk, addr req)
+  result.size = req.size
+  result.alignment = req.alignment
+  let memorytypes = buffer.device.physicaldevice.vk.getMemoryProperties().types
+  for i in 0 ..< sizeof(req.memoryTypeBits) * 8:
+    if ((req.memoryTypeBits shr i) and 1) == 1:
+      result.memoryTypes.add memorytypes[i]
+
+proc allocateMemory(buffer: var Buffer, requireMappable: bool, preferVRAM: bool, preferAutoFlush: bool) =
+  assert buffer.device.vk.valid
+  assert buffer.memoryAllocated == false
+
+  let requirements = buffer.requirements()
+  let memoryType = requirements.memoryTypes.selectBestMemoryType(
+    requireMappable=requireMappable,
+    preferVRAM=preferVRAM,
+    preferAutoFlush=preferAutoFlush
+  )
+
+  debug "Allocating memory for buffer: ", buffer.size, " bytes of type ", memoryType
+  # need to replace the whole buffer object, due to case statement
+  buffer = Buffer(
+    device: buffer.device,
+    vk: buffer.vk,
+    size: buffer.size,
+    usage: buffer.usage,
+    memoryAllocated: true,
+    memory: buffer.device.allocate(requirements.size, memoryType)
+  )
+  checkVkResult buffer.device.vk.vkBindBufferMemory(buffer.vk, buffer.memory.vk, VkDeviceSize(0))
+
+# currently no support for extended structure and concurrent/shared use
+# (shardingMode = VK_SHARING_MODE_CONCURRENT not supported)
+proc createBuffer*(
+  device: Device,
+  size: int,
+  usage: openArray[VkBufferUsageFlagBits],
+  requireMappable: bool,
+  preferVRAM: bool,
+  preferAutoFlush=true,
+): Buffer =
+  assert device.vk.valid
+  assert size > 0
+
+  result.device = device
+  result.size = size
+  result.usage = usage.toSeq
+  if not requireMappable:
+    result.usage.add VK_BUFFER_USAGE_TRANSFER_DST_BIT
+  var createInfo = VkBufferCreateInfo(
+    sType: VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO,
+    flags: VkBufferCreateFlags(0),
+    size: uint64(size),
+    usage: toBits(result.usage),
+    sharingMode: VK_SHARING_MODE_EXCLUSIVE,
+  )
+
+  checkVkResult vkCreateBuffer(
+    device=device.vk,
+    pCreateInfo=addr createInfo,
+    pAllocator=nil,
+    pBuffer=addr result.vk
+  )
+  result.allocateMemory(requireMappable=requireMappable, preferVRAM=preferVRAM, preferAutoFlush=preferAutoFlush)
+
+
+proc copy*(src, dst: Buffer, dstOffset=0) =
+  assert src.device.vk.valid
+  assert dst.device.vk.valid
+  assert src.device == dst.device
+  assert src.size <= dst.size - dstOffset
+  assert VK_BUFFER_USAGE_TRANSFER_SRC_BIT in src.usage
+  assert VK_BUFFER_USAGE_TRANSFER_DST_BIT in dst.usage
+
+  var copyRegion = VkBufferCopy(size: VkDeviceSize(src.size), dstOffset: VkDeviceSize(dstOffset))
+  withSingleUseCommandBuffer(src.device, true, commandBuffer):
+    commandBuffer.vkCmdCopyBuffer(src.vk, dst.vk, 1, addr(copyRegion))
+
+proc destroy*(buffer: var Buffer) =
+  assert buffer.device.vk.valid
+  assert buffer.vk.valid
+  buffer.device.vk.vkDestroyBuffer(buffer.vk, nil)
+  if buffer.memoryAllocated:
+    assert buffer.memory.vk.valid
+    buffer.memory.free
+    buffer = Buffer(
+      device: buffer.device,
+      vk: buffer.vk,
+      size: buffer.size,
+      usage: buffer.usage,
+      memoryAllocated: false,
+    )
+  buffer.vk.reset
+
+proc setData*(dst: Buffer, src: pointer, size: int, bufferOffset=0) =
+  assert bufferOffset + size <= dst.size
+  if dst.memory.canMap:
+    copyMem(cast[pointer](cast[int](dst.memory.data) + bufferOffset), src, size)
+    if dst.memory.needsFlushing:
+      dst.memory.flush()
+  else: # use staging buffer, slower but required if memory is not host visible
+    var stagingBuffer = dst.device.createBuffer(size, [VK_BUFFER_USAGE_TRANSFER_SRC_BIT], requireMappable=true, preferVRAM=false, preferAutoFlush=true)
+    setData(stagingBuffer, src, size, 0)
+    stagingBuffer.copy(dst, bufferOffset)
+    stagingBuffer.destroy()
+
+proc setData*[T: seq](dst: Buffer, src: ptr T, offset=0'u64) =
+  dst.setData(src, sizeof(get(genericParams(T), 0)) * src[].len, offset=offset)
+
+proc setData*[T](dst: Buffer, src: ptr T, offset=0'u64) =
+  dst.setData(src, sizeof(T), offset=offset)
+