module Render.Debug.Code
  ( vert
  , frag
  ) where

import RIO

import Render.Code (Code, glsl)
import Render.DescSets.Set0.Code (set0binding0, set0binding1, set0binding2, set0binding3, set0binding5color)

vert :: Code
vert = fromString
  [glsl|
    #version 450

    ${set0binding0}

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

    // transformMat
    layout(location = 5) in mat4 iModel;

    layout(location = 0)      out  vec2 fTexCoord;
    layout(location = 1) flat out  vec4 fTextureGamma;
    layout(location = 2) flat out ivec2 fTextureIds;

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

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

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

frag :: Code
frag = fromString
  [glsl|
    #version 450
    #extension GL_EXT_nonuniform_qualifier : enable

    ${set0binding1}
    ${set0binding2}
    ${set0binding3}
    ${set0binding5color}

    layout(location = 0)      in  vec2 fTexCoord;
    layout(location = 1) flat in  vec4 fTextureGamma;
    layout(location = 2) flat in ivec2 fTextureIds;

    layout(location = 0) out vec4 oColor;

    layout(constant_id=0) const uint mode = 0;
    layout(constant_id=1) const uint shadow_mask = 0;

    void main() {
      vec4 texel = vec4(0);

      switch(mode) {
        case 0:
          texel = vec4(fTexCoord, 0, 1);
          break;

        case 1:
          if ((fTextureIds.t < 0) || (fTextureIds.s < 0)) break;

          texel = texture(
            sampler2D(
              textures[nonuniformEXT(fTextureIds.t)],
              samplers[nonuniformEXT(fTextureIds.s)]
            ),
            fTexCoord
          );
          break;

        case 2:
          float d0 = 1.0;
          if ((shadow_mask & 1) == 1)
            d0 = texture(
              shadowmaps,
              vec3(fTexCoord, 0.0)
            ).x;

          float d1 = 1.0;
          if ((shadow_mask & 2) == 2)
            d1 = texture(
              shadowmaps,
              vec3(fTexCoord, 1.0)
            ).x;

          float d2 = 1.0;
          if ((shadow_mask & 4) == 4)
            d2 = texture(
              shadowmaps,
              vec3(fTexCoord, 2.0)
            ).x;

          texel = vec4(1-d0, 1-d1, 1-d2, 1.0);
          break;

        default:
          break;
      }

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

      // XXX: premultiply alpha due to additive blending
      oColor = vec4(color * combinedAlpha, combinedAlpha);
    }
  |]