module Render.Lit.Textured.Pipeline
  ( Pipeline
  , allocate
  , allocateBlend
  ) where

import RIO

import Control.Monad.Trans.Resource (ResourceT)
import Data.Tagged (Tagged(..))
import Vulkan.Core10 qualified as Vk
import Vulkan.Zero (zero)

import Engine.Vulkan.Pipeline qualified as Pipeline
import Engine.Vulkan.Types (HasVulkan, HasRenderPass(..), DsBindings)
import Render.Code (compileVert, compileFrag, glsl)
import Render.DescSets.Set0 (Scene, vertexPos, instanceTransform)
import Render.DescSets.Set0.Code (set0binding0, set0binding1, set0binding2, set0binding3, set0binding4, set0binding5)
import Render.Code.Lit (litMain, shadowFuns, structLight, brdfSpecular)
import Render.Lit.Textured.Model qualified as Model

type Config = Pipeline.Config '[Scene] Model.VertexAttrs Model.InstanceAttrs
type Pipeline = Pipeline.Pipeline '[Scene] Model.VertexAttrs Model.InstanceAttrs

allocate
  :: ( HasVulkan env
     , HasRenderPass renderpass
     )
  => Vk.SampleCountFlagBits
  -> Tagged Scene DsBindings
  -> renderpass
  -> ResourceT (RIO env) Pipeline
allocate :: SampleCountFlagBits
-> Tagged Scene DsBindings
-> renderpass
-> ResourceT (RIO env) Pipeline
allocate SampleCountFlagBits
multisample Tagged Scene DsBindings
tset0 renderpass
rp = do
  (ReleaseKey
_, Pipeline
p) <- Maybe Extent2D
-> SampleCountFlagBits
-> Config '[Scene] VertexAttrs InstanceAttrs
-> renderpass
-> ResourceT (RIO env) (ReleaseKey, Pipeline)
forall env (m :: * -> *) renderpass (dsl :: [*]) vertices
       instances.
(MonadVulkan env m, MonadResource m, HasRenderPass renderpass,
 HasCallStack) =>
Maybe Extent2D
-> SampleCountFlagBits
-> Config dsl vertices instances
-> renderpass
-> m (ReleaseKey, Pipeline dsl vertices instances)
Pipeline.allocate
    Maybe Extent2D
forall a. Maybe a
Nothing
    SampleCountFlagBits
multisample
    (Tagged Scene DsBindings
-> Config '[Scene] VertexAttrs InstanceAttrs
config Tagged Scene DsBindings
tset0)
    renderpass
rp
  Pipeline -> ResourceT (RIO env) Pipeline
forall (f :: * -> *) a. Applicative f => a -> f a
pure Pipeline
p

allocateBlend
  :: ( HasVulkan env
     , HasRenderPass renderpass
     )
  => Vk.SampleCountFlagBits
  -> Tagged Scene DsBindings
  -> renderpass
  -> ResourceT (RIO env) Pipeline
allocateBlend :: SampleCountFlagBits
-> Tagged Scene DsBindings
-> renderpass
-> ResourceT (RIO env) Pipeline
allocateBlend SampleCountFlagBits
multisample Tagged Scene DsBindings
tset0 renderpass
rp = do
  (ReleaseKey
_, Pipeline
p) <- Maybe Extent2D
-> SampleCountFlagBits
-> Config '[Scene] VertexAttrs InstanceAttrs
-> renderpass
-> ResourceT (RIO env) (ReleaseKey, Pipeline)
forall env (m :: * -> *) renderpass (dsl :: [*]) vertices
       instances.
(MonadVulkan env m, MonadResource m, HasRenderPass renderpass,
 HasCallStack) =>
Maybe Extent2D
-> SampleCountFlagBits
-> Config dsl vertices instances
-> renderpass
-> m (ReleaseKey, Pipeline dsl vertices instances)
Pipeline.allocate
    Maybe Extent2D
forall a. Maybe a
Nothing
    SampleCountFlagBits
multisample
    (Tagged Scene DsBindings
-> Config '[Scene] VertexAttrs InstanceAttrs
configBlend Tagged Scene DsBindings
tset0)
    renderpass
rp
  Pipeline -> ResourceT (RIO env) Pipeline
forall (f :: * -> *) a. Applicative f => a -> f a
pure Pipeline
p

config :: Tagged Scene DsBindings -> Config
config :: Tagged Scene DsBindings
-> Config '[Scene] VertexAttrs InstanceAttrs
config (Tagged DsBindings
set0) = Config Any Any Any
forall a. Zero a => a
zero
  { $sel:cDescLayouts:Config :: Tagged '[Scene] [DsBindings]
Pipeline.cDescLayouts  = [DsBindings] -> Tagged '[Scene] [DsBindings]
forall k (s :: k) b. b -> Tagged s b
Tagged @'[Scene] [DsBindings
set0]
  , $sel:cVertexCode:Config :: Maybe ByteString
Pipeline.cVertexCode   = ByteString -> Maybe ByteString
forall a. a -> Maybe a
Just ByteString
vertCode
  , $sel:cVertexInput:Config :: SomeStruct PipelineVertexInputStateCreateInfo
Pipeline.cVertexInput  = SomeStruct PipelineVertexInputStateCreateInfo
vertexInput
  , $sel:cFragmentCode:Config :: Maybe ByteString
Pipeline.cFragmentCode = ByteString -> Maybe ByteString
forall a. a -> Maybe a
Just ByteString
fragCode
  }
  where
    vertexInput :: SomeStruct PipelineVertexInputStateCreateInfo
vertexInput = [(VertexInputRate, [Format])]
-> SomeStruct PipelineVertexInputStateCreateInfo
Pipeline.vertexInput
      [ (VertexInputRate, [Format])
vertexPos -- vPosition
      , (VertexInputRate
Vk.VERTEX_INPUT_RATE_VERTEX,   [Format]
Model.vkVertexAttrs)
      , (VertexInputRate
Vk.VERTEX_INPUT_RATE_INSTANCE, [Format]
Model.vkInstanceTexture)
      , (VertexInputRate, [Format])
instanceTransform
      ]

configBlend :: Tagged Scene DsBindings -> Config
configBlend :: Tagged Scene DsBindings
-> Config '[Scene] VertexAttrs InstanceAttrs
configBlend Tagged Scene DsBindings
tset0 = (Tagged Scene DsBindings
-> Config '[Scene] VertexAttrs InstanceAttrs
config Tagged Scene DsBindings
tset0)
  { $sel:cBlend:Config :: Bool
Pipeline.cBlend      = Bool
True
  , $sel:cDepthWrite:Config :: Bool
Pipeline.cDepthWrite = Bool
False
  }

vertCode :: ByteString
vertCode :: ByteString
vertCode =
  $(compileVert [glsl|
    #version 450
    #extension GL_ARB_separate_shader_objects : enable

    ${set0binding0}

    // vertexPos
    layout(location = 0) in vec3 vPosition;
    // vertexAttrs
    layout(location = 1) in vec2 vTexCoord;
    layout(location = 2) in vec3 vNormal;
    // textureParams
    layout(location = 3) in  vec4 iTextureScaleOffset;
    layout(location = 4) in  vec4 iTextureGamma;
    layout(location = 5) in ivec2 iTextureIds;

    // transformMat
    layout(location = 6) in mat4 iModel;

    layout(location = 0)      out  vec4 fPosition;
    layout(location = 1)      out  vec3 fNormal;
    layout(location = 2)      out  vec2 fTexCoord;
    layout(location = 3) flat out  vec4 fTextureGamma;
    layout(location = 4) flat out ivec2 fTextureIds;

    void main() {
      fPosition = iModel * vec4(vPosition, 1.0);

      gl_Position
        = scene.projection
        * scene.view
        * fPosition;

      fNormal = transpose(mat3(inverse(iModel))) * vNormal; // TODO: use modelInv

      fTexCoord     = vTexCoord * iTextureScaleOffset.st + iTextureScaleOffset.pq;
      fTextureGamma = iTextureGamma;
      fTextureIds   = iTextureIds;
    }
  |])

fragCode :: ByteString
fragCode :: ByteString
fragCode =
  $(compileFrag [glsl|
    #version 450
    #extension GL_ARB_separate_shader_objects : enable
    #extension GL_EXT_nonuniform_qualifier : enable

    // XXX: copypasta from Lit.Colored
    // TODO: move to spec constant
    const uint MAX_LIGHTS = 255;
    const float PCF_STEP = 1.5 / 4096;

    // TODO: move to material
    const float reflectivity = 1.0/256.0;

    ${structLight}

    ${set0binding0}
    ${set0binding1}
    ${set0binding2}
    ${set0binding3}
    ${set0binding4}
    ${set0binding5}

    layout(location = 0)      in  vec4 fPosition;
    layout(location = 1)      in  vec3 fNormal;
    layout(location = 2)      in  vec2 fTexCoord;
    layout(location = 3) flat in  vec4 fTextureGamma;
    layout(location = 4) flat in ivec2 fTextureIds;

    layout(location = 0) out vec4 oColor;

    ${shadowFuns}
    ${brdfSpecular}

    void main() {
      // XXX: fall back to solid color
      vec4 baseColor = fTextureGamma;
      if ((fTextureIds.t > -1) && (fTextureIds.s > -1)) {
        vec4 texel = texture(
          sampler2D(
            textures[nonuniformEXT(fTextureIds.t)],
            samplers[nonuniformEXT(fTextureIds.s)]
          ),
          fTexCoord
        );

        if (texel.a < 0.5) discard;

        vec3 color = pow(texel.rgb, fTextureGamma.rgb);
        float combinedAlpha = texel.a * fTextureGamma.a;
        baseColor = vec4(color * combinedAlpha, combinedAlpha);
      }

      // TODO: get from textures
      float metallic = 0.0;
      float roughness = 0.6;
      float nonOcclusion = 1.0;

      vec3 normal = normalize(fNormal);

      ${litMain}
    }
  |])