vulkan-tutorial/src/Util.hs

{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE DataKinds #-}
module Util where

import Data.Bits

import qualified Data.Vector as V

import Data.Word (Word32)

import qualified Vulkan as Vk
import qualified Vulkan.CStruct.Extends as Vk
import qualified Vulkan.Zero as Vk

-- internal imports

import Types

getFrame :: EngineData -> Int -> FrameData
getFrame engineData frame =
  let frameVector = engineFrames engineData
  in
    frameVector V.! (frame `mod` V.length frameVector)

padUniformBufferSize
  :: Vk.DeviceSize
  -> Vk.PhysicalDeviceProperties
  -> Vk.DeviceSize
padUniformBufferSize origSize gpuProperties =
  let minUBOAlignment = Vk.minUniformBufferOffsetAlignment $ Vk.limits gpuProperties
  in
    if minUBOAlignment > 0
    then (origSize + minUBOAlignment - 1) .&. complement (minUBOAlignment - 1)
    else origSize

descriptorsetLayoutBinding
  :: Vk.DescriptorType
  -> Vk.ShaderStageFlags
  -> Word32
  -> Vk.DescriptorSetLayoutBinding
descriptorsetLayoutBinding type' stageFlags binding =
  Vk.zero
    { Vk.binding           = binding
    , Vk.descriptorCount   = 1
    , Vk.descriptorType    = type'
    , Vk.immutableSamplers = V.empty
    , Vk.stageFlags        = stageFlags
    }

writeDescriptorBuffer
  :: Vk.DescriptorType
  -> Vk.DescriptorSet
  -> Vk.DescriptorBufferInfo
  -> Word32
  -> Vk.SomeStruct Vk.WriteDescriptorSet
writeDescriptorBuffer type' dstSet bufferInfo binding = Vk.SomeStruct $
  Vk.zero
    { Vk.dstBinding      = binding
    , Vk.dstSet          = dstSet
    , Vk.descriptorCount = 1
    , Vk.descriptorType  = type'
    , Vk.bufferInfo      = V.singleton bufferInfo
    }