module Render.Unlit.TileMap.Pipeline
  ( Pipeline
  , allocate
  , allocateBlend

  , Config
  , config
  , configBlend
  ) where

import RIO
import Render.DescSets.Set0.Code

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

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.Unlit.TileMap.Model qualified as Model

type Config = Pipeline.Configure Pipeline ()
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 :: forall env renderpass.
(HasVulkan env, HasRenderPass renderpass) =>
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 spec (dsl :: [*]) vertices
       instances.
(MonadVulkan env m, MonadResource m, HasRenderPass renderpass,
 Specialization spec, HasCallStack) =>
Maybe Extent2D
-> SampleCountFlagBits
-> Config dsl vertices instances spec
-> renderpass
-> m (ReleaseKey, Pipeline dsl vertices instances)
Pipeline.allocate
    Maybe Extent2D
forall a. Maybe a
Nothing
    SampleCountFlagBits
multisample
    (Tagged Scene DsBindings -> Config
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 :: forall env renderpass.
(HasVulkan env, HasRenderPass renderpass) =>
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 spec (dsl :: [*]) vertices
       instances.
(MonadVulkan env m, MonadResource m, HasRenderPass renderpass,
 Specialization spec, HasCallStack) =>
Maybe Extent2D
-> SampleCountFlagBits
-> Config dsl vertices instances spec
-> renderpass
-> m (ReleaseKey, Pipeline dsl vertices instances)
Pipeline.allocate
    Maybe Extent2D
forall a. Maybe a
Nothing
    SampleCountFlagBits
multisample
    (Tagged Scene DsBindings -> Config
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
config (Tagged DsBindings
set0) = Config '[] Any Any ()
forall vertices instances. Config '[] vertices instances ()
Pipeline.baseConfig
  { $sel:cDescLayouts:Config :: Tagged '[Scene] [DsBindings]
Pipeline.cDescLayouts  = forall {s :: [*]} {b}. b -> Tagged s b
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
      , (VertexInputRate
Vk.VERTEX_INPUT_RATE_VERTEX,   [Format]
Model.vkVertexAttrs)
      , (VertexInputRate
Vk.VERTEX_INPUT_RATE_INSTANCE, [Format]
Model.vkInstanceTileMap)
      , (VertexInputRate, [Format])
instanceTransform
      ]

configBlend :: Tagged Scene DsBindings -> Config
configBlend :: Tagged Scene DsBindings -> Config
configBlend Tagged Scene DsBindings
tset0 = (Tagged Scene DsBindings -> Config
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;
    // tilemapParams
    layout(location = 2) in ivec4 iTextureIds; // combined: tileset, tileset sampler, map, repeat
    layout(location = 3) in vec2  iViewOffset;
    layout(location = 4) in vec2  iViewportSize;
    layout(location = 5) in vec2  iMapTextureSize;
    layout(location = 6) in vec2  iTilesetTextureSize;
    layout(location = 7) in vec2  iTileSize;

    // transformMat
    layout(location = 8) in mat4 iModel;

    layout(location = 0)      out  vec2 fTexCoord;
    layout(location = 1)      out  vec2 fPixCoord;
    layout(location = 2) flat out ivec4 fTextureIds;
    layout(location = 3) flat out  vec2 fTilesetTextureSize;
    layout(location = 4) flat out  vec2 fTileSize;

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

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

      fPixCoord = (vTexCoord * iViewportSize) + iViewOffset;
      fTexCoord = fPixCoord / iMapTextureSize / iTileSize;

      fTextureIds = iTextureIds;
      fTilesetTextureSize = iTilesetTextureSize;
      fTileSize = iTileSize;
    }
  |])

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

    ${set0binding1}
    ${set0binding2}

    layout(location = 0) in vec2 fTexCoord;
    layout(location = 1) in vec2 fPixCoord;

    // combined: tileset, tileset sampler, map, repeat
    layout(location = 2) flat in ivec4 fTextureIds;
    layout(location = 3) flat in vec2 fTilesetTextureSize;
    layout(location = 4) flat in vec2 fTileSize;

    layout(location = 0) out vec4 oColor;

    int tilesetTextureIx = fTextureIds[0];
    int tilesetSamplerIx = fTextureIds[1];
    int mapTextureIx     = fTextureIds[2];
    int repeatTiles      = fTextureIds[3];

    // TODO
    // const vec4 fTextureGamma = vec4(1.0);

    void main() {
      if (repeatTiles == 0 && (fTexCoord.x < 0.0 || fTexCoord.y < 0.0 || fTexCoord.x > 1.0 || fTexCoord.y > 1.0)) {
        discard;
      }

      vec4 map = texture(
        sampler2D(
          textures[nonuniformEXT(mapTextureIx)],
          samplers[7] // nearest
        ),
        fTexCoord
      );

      vec2 spriteOffset = floor(map.xy * 256.0) * fTileSize;
      vec2 spriteCoord = mod(fPixCoord, fTileSize);
      vec2 spriteUV = (spriteOffset + spriteCoord) / fTilesetTextureSize;

      oColor = texture(
        sampler2D(
          textures[nonuniformEXT(tilesetTextureIx)],
          samplers[nonuniformEXT(tilesetSamplerIx)]
        ),
        spriteUV
      );
    }
  |])