#include "shader_CFluidPlaneShader.hpp"
#include <fmt/ostream.h>
#include <sstream>

#define FOG_STRUCT_METAL                                                                                               \
  "struct Fog\n"                                                                                                       \
  "{\n"                                                                                                                \
  "    float4 color;\n"                                                                                                \
  "    float A;\n"                                                                                                     \
  "    float B;\n"                                                                                                     \
  "    float C;\n"                                                                                                     \
  "    int mode;\n"                                                                                                    \
  "    float indScale;\n"                                                                                              \
"};\n"

#define FOG_ALGORITHM_METAL                                                                                            \
  "static float4 MainPostFunc(thread VertToFrag& vtf, constant LightingUniform& lu, float4 colorIn)\n"                 \
  "{\n"                                                                                                                \
  "    float fogZ;\n"                                                                                                  \
  "    float fogF = saturate((lu.fog.A / (lu.fog.B - (1.0 - vtf.pos.z))) - lu.fog.C);\n"                               \
  "    switch (lu.fog.mode)\n"                                                                                         \
  "    {\n"                                                                                                            \
  "    case 2:\n"                                                                                                      \
  "        fogZ = fogF;\n"                                                                                             \
  "        break;\n"                                                                                                   \
  "    case 4:\n"                                                                                                      \
  "        fogZ = 1.0 - exp2(-8.0 * fogF);\n"                                                                          \
  "        break;\n"                                                                                                   \
  "    case 5:\n"                                                                                                      \
  "        fogZ = 1.0 - exp2(-8.0 * fogF * fogF);\n"                                                                   \
  "        break;\n"                                                                                                   \
  "    case 6:\n"                                                                                                      \
  "        fogZ = exp2(-8.0 * (1.0 - fogF));\n"                                                                        \
  "        break;\n"                                                                                                   \
  "    case 7:\n"                                                                                                      \
  "        fogF = 1.0 - fogF;\n"                                                                                       \
  "        fogZ = exp2(-8.0 * fogF * fogF);\n"                                                                         \
  "        break;\n"                                                                                                   \
  "    default:\n"                                                                                                     \
  "        fogZ = 0.0;\n"                                                                                              \
  "        break;\n"                                                                                                   \
  "    }\n"                                                                                                            \
  "#if IS_ADDITIVE\n"                                                                                                  \
  "    return float4(mix(colorIn, float4(0.0), saturate(fogZ)).rgb, colorIn.a);\n"                                     \
  "#else\n"                                                                                                            \
  "    return float4(mix(colorIn, lu.fog.color, saturate(fogZ)).rgb, colorIn.a);\n"                                    \
  "#endif\n"                                                                                                           \
  "}\n"

static const char* VS =
    "struct VertData\n"
    "{\n"
    "    float4 posIn [[ attribute(0) ]];\n"
    "    float4 normalIn [[ attribute(1) ]];\n"
    "    float4 binormalIn [[ attribute(2) ]];\n"
    "    float4 tangentIn [[ attribute(3) ]];\n"
    "    float4 colorIn [[ attribute(4) ]];\n"
    "};\n"
    "\n"
    "struct FluidPlaneUniform\n"
    "{\n"
    "    float4x4 mv;\n"
    "    float4x4 mvNorm;\n"
    "    float4x4 proj;\n"
    "    float4x4 texMtxs[6];\n"
    "};\n"
    "\n"
    "struct VertToFrag\n"
    "{\n"
    "    float4 pos [[ position ]];\n"
    "    float4 mvPos;\n"
    "    float4 mvNorm;\n"
    "    float4 mvBinorm;\n"
    "    float4 mvTangent;\n"
    "    float4 color;\n"
    "    float2 uv0;\n"
    "    float2 uv1;\n"
    "    float2 uv2;\n"
    "    float2 uv3;\n"
    "    float2 uv4;\n"
    "    float2 uv5;\n"
    "    float2 uv6;\n"
    "};\n"
    "\n"
    "vertex VertToFrag vmain(VertData v [[ stage_in ]],\n"
    "                        constant FluidPlaneUniform& fu [[ buffer(2) ]])\n"
    "{\n"
    "    VertToFrag vtf;\n"
    "    float4 pos = float4(v.posIn.xyz, 1.0);\n"
    "    float4 normalIn = v.normalIn;\n"
    "    vtf.mvPos = fu.mv * pos;\n"
    "    vtf.pos = fu.proj * vtf.mvPos;\n"
    "    vtf.mvNorm = fu.mvNorm * v.normalIn;\n"
    "    vtf.mvBinorm = fu.mvNorm * v.binormalIn;\n"
    "    vtf.mvTangent = fu.mvNorm * v.tangentIn;\n"
    "    vtf.color = v.colorIn;\n"
    "    vtf.uv0 = (fu.texMtxs[0] * pos).xy;\n"
    "    vtf.uv1 = (fu.texMtxs[1] * pos).xy;\n"
    "    vtf.uv2 = (fu.texMtxs[2] * pos).xy;\n"
    "    ADDITIONAL_TCGS\n" // Additional TCGs here
    "    return vtf;\n"
    "}\n";

static const char* TessCS =
    "struct VertData\n"
    "{\n"
    "    float4 minMaxPos [[ attribute(0) ]];\n"
    "    float4 outerLevelsIn [[ attribute(1) ]];\n"
    "    float2 innerLevelsIn [[ attribute(2) ]];\n"
    "};\n"
    "\n"
    "struct KernelPatchInfo {\n"
    "    uint numPatches; // total number of patches to process.\n"
    "                     // we need this because this value may\n"
    "                     // not be a multiple of threadgroup size.\n"
    "    ushort numPatchesInThreadGroup; // number of patches processed by a\n"
    "                                    // thread-group\n"
    "    ushort numControlPointsPerPatch;\n"
    "};\n"
    "\n"
    "kernel void\n"
    "cmain(VertData v [[ stage_in ]],\n"
    "      constant KernelPatchInfo& patchInfo [[ buffer(2) ]],\n"
    "      device MTLQuadTessellationFactorsHalf* tessellationFactorBuffer [[ buffer(3) ]],\n"
    "      ushort lID [[ thread_position_in_threadgroup ]],\n"
    "      ushort groupID [[ threadgroup_position_in_grid ]])\n"
    "{\n"
    "    uint patchGroupID = groupID * patchInfo.numPatchesInThreadGroup;\n"
    "\n"
    "    // execute the per-patch hull function\n"
    "    if (lID < patchInfo.numPatchesInThreadGroup)\n"
    "    {\n"
    "        uint patchID = patchGroupID + lID;\n"
    "        device MTLQuadTessellationFactorsHalf& patchOut = tessellationFactorBuffer[patchID];\n"
    "        for (int i=0 ; i<4 ; ++i)\n"
    "            patchOut.edgeTessellationFactor[i] = v.outerLevelsIn[i];\n"
    "        for (int i=0 ; i<2 ; ++i)\n"
    "            patchOut.insideTessellationFactor[i] = v.innerLevelsIn[i];\n"
    "    }\n"
    "}\n";

static const char* TessES =
    "struct Ripple\n"
    "{\n"
    "    float4 center; // time, distFalloff\n"
    "    float4 params; // amplitude, lookupPhase, lookupTime\n"
    "};\n"
    "\n"
    "struct FluidPlaneUniform\n"
    "{\n"
    "    float4x4 mv;\n"
    "    float4x4 mvNorm;\n"
    "    float4x4 proj;\n"
    "    float4x4 texMtxs[6];\n"
    "    Ripple ripples[20];\n"
    "    float4 colorMul;\n"
    "    float rippleNormResolution;\n"
    "};\n"
    "\n"
    "struct VertToFrag\n"
    "{\n"
    "    float4 pos [[ position ]];\n"
    "    float4 mvPos;\n"
    "    float4 mvNorm;\n"
    "    float4 mvBinorm;\n"
    "    float4 mvTangent;\n"
    "    float4 color;\n"
    "    float2 uv0;\n"
    "    float2 uv1;\n"
    "    float2 uv2;\n"
    "    float2 uv3;\n"
    "    float2 uv4;\n"
    "    float2 uv5;\n"
    "    float2 uv6;\n"
    "};\n"
    "\n"
    "struct VertData\n"
    "{\n"
    "    float4 minMaxPos [[ attribute(0) ]];\n"
    "    float4 outerLevelsIn [[ attribute(1) ]];\n"
    "    float2 innerLevelsIn [[ attribute(2) ]];\n"
    "};\n"
    "\n"
    "#define PI_X2 6.283185307179586\n"
    "\n"
    "static void ApplyRipple(constant Ripple& ripple, float2 pos, thread float& height,\n"
    "                        sampler samp, texture2d<float> RippleMap)\n"
    "{\n"
    "    float dist = length(ripple.center.xy - pos);\n"
    "    float rippleV = RippleMap.sample(samp, float2(dist * ripple.center.w, ripple.center.z), level(0.0)).r;\n"
    "    height += rippleV * ripple.params.x * sin((dist * ripple.params.y + ripple.params.z) * PI_X2);\n"
    "}\n"
    "\n"
    "[[ patch(quad, 1) ]]\n"
    "vertex VertToFrag emain(VertData v [[ stage_in ]], float2 TessCoord [[ position_in_patch ]],\n"
    "                        constant FluidPlaneUniform& fu [[ buffer(2) ]],\n"
    "                        sampler samp [[ sampler(2) ]],\n"
    "                        texture2d<float> RippleMap [[ texture(RIPPLE_TEXTURE_IDX) ]])\n"
    "{\n"
    "    float2 posIn = float2(mix(v.minMaxPos.x, v.minMaxPos.z, TessCoord.x),\n"
    "                          mix(v.minMaxPos.y, v.minMaxPos.w, TessCoord.y));\n"
    "    float height = 0.0;\n"
    "    float upHeight = 0.0;\n"
    "    float downHeight = 0.0;\n"
    "    float rightHeight = 0.0;\n"
    "    float leftHeight = 0.0;\n"
    "    for (int i=0 ; i<20 ; ++i)\n"
    "    {\n"
    "        ApplyRipple(fu.ripples[i], posIn, height, samp, RippleMap);\n"
    "        ApplyRipple(fu.ripples[i], posIn + float2(0.0, fu.rippleNormResolution), upHeight, samp, RippleMap);\n"
    "        ApplyRipple(fu.ripples[i], posIn - float2(0.0, fu.rippleNormResolution), downHeight, samp, RippleMap);\n"
    "        ApplyRipple(fu.ripples[i], posIn + float2(fu.rippleNormResolution, 0.0), rightHeight, samp, RippleMap);\n"
    "        ApplyRipple(fu.ripples[i], posIn - float2(fu.rippleNormResolution, 0.0), leftHeight, samp, RippleMap);\n"
    "    }\n"
    "    float4 normalIn = float4(normalize(float3((leftHeight - rightHeight),\n"
    "                                              (downHeight - upHeight),\n"
    "                                              fu.rippleNormResolution)), 1.0);\n"
    "    float4 binormalIn = float4(normalIn.x, normalIn.z, -normalIn.y, 1.0);\n"
    "    float4 tangentIn = float4(normalIn.z, normalIn.y, -normalIn.x, 1.0);\n"
    "    float4 pos = float4(posIn, height, 1.0);\n"
    "    VertToFrag vtf;\n"
    "    vtf.mvPos = (fu.mv * pos);\n"
    "    vtf.pos = (fu.proj * vtf.mvPos);\n"
    "    vtf.mvNorm = (fu.mvNorm * normalIn);\n"
    "    vtf.mvBinorm = (fu.mvNorm * binormalIn);\n"
    "    vtf.mvTangent = (fu.mvNorm * tangentIn);\n"
    "    vtf.color = max(height, 0.0) * fu.colorMul;\n"
    "    vtf.color.a = 1.0;\n"
    "    vtf.uv0 = (fu.texMtxs[0] * pos).xy;\n"
    "    vtf.uv1 = (fu.texMtxs[1] * pos).xy;\n"
    "    vtf.uv2 = (fu.texMtxs[2] * pos).xy;\n"
    "    ADDITIONAL_TCGS\n" // Additional TCGs here
    "    return vtf;\n"
    "}\n";

static const char* FS =
"struct Light\n"
"{\n"
"    float4 pos;\n"
"    float4 dir;\n"
"    float4 color;\n"
"    float4 linAtt;\n"
"    float4 angAtt;\n"
"};\n"
FOG_STRUCT_METAL
"\n"
"struct LightingUniform\n"
"{\n"
"    Light lights[" _XSTR(URDE_MAX_LIGHTS) "];\n"
"    float4 ambient;\n"
"    float4 kColor0;\n"
"    float4 kColor1;\n"
"    float4 kColor2;\n"
"    float4 kColor3;\n"
"    float4 addColor;\n"
"    Fog fog;\n"
"};\n"
"\n"
"static float4 LightingFunc(constant LightingUniform& lu, float3 mvPosIn, float3 mvNormIn)\n"
"{\n"
"    float4 ret = lu.ambient;\n"
"    \n"
"    for (int i=0 ; i<" _XSTR(URDE_MAX_LIGHTS) " ; ++i)\n"
"    {\n"
"        float3 delta = mvPosIn - lu.lights[i].pos.xyz;\n"
"        float dist = length(delta);\n"
"        float angDot = clamp(dot(normalize(delta), lu.lights[i].dir.xyz), 0.0, 1.0);\n"
"        float att = 1.0 / (lu.lights[i].linAtt[2] * dist * dist +\n"
"                           lu.lights[i].linAtt[1] * dist +\n"
"                           lu.lights[i].linAtt[0]);\n"
"        float angAtt = lu.lights[i].angAtt[2] * angDot * angDot +\n"
"                       lu.lights[i].angAtt[1] * angDot +\n"
"                       lu.lights[i].angAtt[0];\n"
"        ret += lu.lights[i].color * angAtt * att * saturate(dot(normalize(-delta), mvNormIn));\n"
"    }\n"
"    \n"
"    return saturate(ret);\n"
"}\n"
"\n"
"struct VertToFrag\n"
"{\n"
"    float4 pos [[ position ]];\n"
"    float4 mvPos;\n"
"    float4 mvNorm;\n"
"    float4 mvBinorm;\n"
"    float4 mvTangent;\n"
"    float4 color;\n"
"    float2 uv0;\n"
"    float2 uv1;\n"
"    float2 uv2;\n"
"    float2 uv3;\n"
"    float2 uv4;\n"
"    float2 uv5;\n"
"    float2 uv6;\n"
"};\n"
"\n"
FOG_ALGORITHM_METAL
"\n"
"fragment float4 fmain(VertToFrag vtf [[ stage_in ]],\n"
"                      sampler samp [[ sampler(0) ]],\n"
"                      constant LightingUniform& lu [[ buffer(4) ]]"
"                      TEXTURE_PARAMS)\n" // Textures here
"{\n"
"    float4 lighting = LightingFunc(lu, vtf.mvPos.xyz, normalize(vtf.mvNorm.xyz));\n"
"    float4 colorOut;\n"
"    COMBINER_EXPRS\n" // Combiner expression here
"    return MainPostFunc(vtf, lu, colorOut);\n"
"}\n";

static const char* FSDoor =
"struct Light\n"
"{\n"
"    float4 pos;\n"
"    float4 dir;\n"
"    float4 color;\n"
"    float4 linAtt;\n"
"    float4 angAtt;\n"
"};\n"
FOG_STRUCT_METAL
"\n"
"struct LightingUniform\n"
"{\n"
"    Light lights[" _XSTR(URDE_MAX_LIGHTS) "];\n"
"    float4 ambient;\n"
"    float4 kColor0;\n"
"    float4 kColor1;\n"
"    float4 kColor2;\n"
"    float4 kColor3;\n"
"    float4 addColor;\n"
"    Fog fog;\n"
"};\n"
"\n"
"struct VertToFrag\n"
"{\n"
"    float4 pos [[ position ]];\n"
"    float4 mvPos;\n"
"    float4 mvNorm;\n"
"    float4 mvBinorm;\n"
"    float4 mvTangent;\n"
"    float4 color;\n"
"    float2 uv0;\n"
"    float2 uv1;\n"
"    float2 uv2;\n"
"    float2 uv3;\n"
"    float2 uv4;\n"
"    float2 uv5;\n"
"    float2 uv6;\n"
"};\n"
FOG_ALGORITHM_METAL
"\n"
"fragment float4 fmain(VertToFrag vtf [[ stage_in ]],\n"
"                      sampler samp [[ sampler(0) ]],\n"
"                      constant LightingUniform& lu [[ buffer(4) ]]"
"                      TEXTURE_PARAMS)\n" // Textures here
"{\n"
"    float4 colorOut;\n"
"    COMBINER_EXPRS\n" // Combiner expression here
"    return MainPostFunc(vtf, lu, colorOut);\n"
"}\n";

static std::string _BuildFS(const SFluidPlaneShaderInfo& info) {
  std::stringstream out;
  int nextTex = 0;
  int nextTCG = 3;
  int bumpMapUv, envBumpMapUv, envMapUv, lightmapUv;

  out << "#define TEXTURE_PARAMS ";
  if (info.m_hasPatternTex1)
    fmt::print(out, FMT_STRING(",texture2d<float> patternTex1 [[ texture({}) ]]"), nextTex++);
  if (info.m_hasPatternTex2)
    fmt::print(out, FMT_STRING(",texture2d<float> patternTex2 [[ texture({}) ]]"), nextTex++);
  if (info.m_hasColorTex)
    fmt::print(out, FMT_STRING(",texture2d<float> colorTex [[ texture({}) ]]"), nextTex++);
  if (info.m_hasBumpMap)
    fmt::print(out, FMT_STRING(",texture2d<float> bumpMap [[ texture({}) ]]"), nextTex++);
  if (info.m_hasEnvMap)
    fmt::print(out, FMT_STRING(",texture2d<float> envMap [[ texture({}) ]]"), nextTex++);
  if (info.m_hasEnvBumpMap)
    fmt::print(out, FMT_STRING(",texture2d<float> envBumpMap [[ texture({}) ]]"), nextTex++);
  if (info.m_hasLightmap)
    fmt::print(out, FMT_STRING(",texture2d<float> lightMap [[ texture({}) ]]"), nextTex++);
  out << '\n';

  if (info.m_hasBumpMap) {
    bumpMapUv = nextTCG;
  }
  if (info.m_hasEnvBumpMap) {
    envBumpMapUv = nextTCG;
  }
  if (info.m_hasEnvMap) {
    envMapUv = nextTCG;
  }
  if (info.m_hasLightmap) {
    lightmapUv = nextTCG;
  }

  out << "#define COMBINER_EXPRS ";
  switch (info.m_type) {
  case EFluidType::NormalWater:
  case EFluidType::PhazonFluid:
  case EFluidType::Four:
    if (info.m_hasLightmap) {
      fmt::print(out, FMT_STRING("float4 lightMapTexel = lightMap.sample(samp, vtf.uv{});"), lightmapUv);
      // 0: Tex4TCG, Tex4, doubleLightmapBlend ? NULL : GX_COLOR1A1
      // ZERO, TEX, KONST, doubleLightmapBlend ? ZERO : RAS
      // Output reg 2
      // KColor 2
      if (info.m_doubleLightmapBlend) {
        // 1: Tex4TCG2, Tex4, GX_COLOR1A1
        // C2, TEX, KONST, RAS
        // Output reg 2
        // KColor 3
        // Tex * K2 + Lighting
        out << "lighting += mix(lightMapTexel * lu.kColor2, lightMapTexel, lu.kColor3);";
      } else {
        // mix(Tex * K2, Tex, K3) + Lighting
        out << "lighting += lightMapTexel * lu.kColor2;";
      }
    }

    // Next: Tex0TCG, Tex0, GX_COLOR1A1
    // ZERO, TEX, KONST, RAS
    // Output reg prev
    // KColor 0

    // Next: Tex1TCG, Tex1, GX_COLOR0A0
    // ZERO, TEX, PREV, RAS
    // Output reg prev

    // Next: Tex2TCG, Tex2, GX_COLOR1A1
    // ZERO, TEX, hasTex4 ? C2 : RAS, PREV
    // Output reg prev

    // (Tex0 * kColor0 + Lighting) * Tex1 + VertColor + Tex2 * Lighting
    if (info.m_hasPatternTex2) {
      if (info.m_hasPatternTex1)
        out <<
            "colorOut = (patternTex1.sample(samp, vtf.uv0) * lu.kColor0 + lighting) * "
            "patternTex2.sample(samp, vtf.uv1) + vtf.color;";
      else
        out << "colorOut = lighting * patternTex2.sample(samp, vtf.uv1) + vtf.color;";
    } else {
      out << "colorOut = vtf.color;";
    }

    if (info.m_hasColorTex && !info.m_hasEnvMap && info.m_hasEnvBumpMap) {
      // Make previous stage indirect, mtx0
      fmt::print(out, FMT_STRING(
          "float2 indUvs = (envBumpMap.sample(samp, vtf.uv{}).ra - float2(0.5, 0.5)) * "
          "float2(lu.fog.indScale, -lu.fog.indScale);"),
          envBumpMapUv);
      out << "colorOut += colorTex.sample(samp, indUvs + vtf.uv2) * lighting;";
    } else if (info.m_hasEnvMap) {
      // Next: envTCG, envTex, NULL
      // PREV, TEX, KONST, ZERO
      // Output reg prev
      // KColor 1

      // Make previous stage indirect, mtx0
      if (info.m_hasColorTex)
        out << "colorOut += colorTex.sample(samp, vtf.uv2) * lighting;";
      fmt::print(out, FMT_STRING(
          "float2 indUvs = (envBumpMap.sample(samp, vtf.uv{}).ra - float2(0.5, 0.5)) * "
          "float2(lu.fog.indScale, -lu.fog.indScale);"),
          envBumpMapUv);
      fmt::print(out, FMT_STRING(
          "colorOut = mix(colorOut, envMap.sample(samp, indUvs + vtf.uv{}), lu.kColor1);"), envMapUv);
    } else if (info.m_hasColorTex) {
      out << "colorOut += colorTex.sample(samp, vtf.uv2) * lighting;";
    }

    break;

  case EFluidType::PoisonWater:
    if (info.m_hasLightmap) {
      fmt::print(out, FMT_STRING("float4 lightMapTexel = lightMap.sample(samp, vtf.uv{});"), lightmapUv);
      // 0: Tex4TCG, Tex4, doubleLightmapBlend ? NULL : GX_COLOR1A1
      // ZERO, TEX, KONST, doubleLightmapBlend ? ZERO : RAS
      // Output reg 2
      // KColor 2
      if (info.m_doubleLightmapBlend) {
        // 1: Tex4TCG2, Tex4, GX_COLOR1A1
        // C2, TEX, KONST, RAS
        // Output reg 2
        // KColor 3
        // Tex * K2 + Lighting
        out << "lighting += mix(lightMapTexel * lu.kColor2, lightMapTexel, lu.kColor3);";
      } else {
        // mix(Tex * K2, Tex, K3) + Lighting
        out << "lighting += lightMapTexel * lu.kColor2;";
      }
    }

    // Next: Tex0TCG, Tex0, GX_COLOR1A1
    // ZERO, TEX, KONST, RAS
    // Output reg prev
    // KColor 0

    // Next: Tex1TCG, Tex1, GX_COLOR0A0
    // ZERO, TEX, PREV, RAS
    // Output reg prev

    // Next: Tex2TCG, Tex2, GX_COLOR1A1
    // ZERO, TEX, hasTex4 ? C2 : RAS, PREV
    // Output reg prev

    // (Tex0 * kColor0 + Lighting) * Tex1 + VertColor + Tex2 * Lighting
    if (info.m_hasPatternTex2) {
      if (info.m_hasPatternTex1)
        out <<
            "colorOut = (patternTex1.sample(samp, vtf.uv0) * lu.kColor0 + lighting) * "
            "patternTex2.sample(samp, vtf.uv1) + vtf.color;";
      else
        out << "colorOut = lighting * patternTex2.sample(samp, vtf.uv1) + vtf.color;";
    } else {
      out << "colorOut = vtf.color;";
    }

    if (info.m_hasColorTex) {
      if (info.m_hasEnvBumpMap) {
        // Make previous stage indirect, mtx0
        fmt::print(out, FMT_STRING(
            "float2 indUvs = (envBumpMap.sample(samp, vtf.uv{}).ra - float2(0.5, 0.5)) * "
            "float2(lu.fog.indScale, -lu.fog.indScale);"),
            envBumpMapUv);
        out << "colorOut += colorTex.sample(samp, indUvs + vtf.uv2) * lighting;";
      } else {
        out << "colorOut += colorTex.sample(samp, vtf.uv2) * lighting;";
      }
    }

    break;

  case EFluidType::Lava:
    // 0: Tex0TCG, Tex0, GX_COLOR0A0
    // ZERO, TEX, KONST, RAS
    // Output reg prev
    // KColor 0

    // 1: Tex1TCG, Tex1, GX_COLOR0A0
    // ZERO, TEX, PREV, RAS
    // Output reg prev

    // 2: Tex2TCG, Tex2, NULL
    // ZERO, TEX, ONE, PREV
    // Output reg prev

    // (Tex0 * kColor0 + VertColor) * Tex1 + VertColor + Tex2
    if (info.m_hasPatternTex2) {
      if (info.m_hasPatternTex1)
        out <<
            "colorOut = (patternTex1.sample(samp, vtf.uv0) * lu.kColor0 + vtf.color) * "
            "patternTex2.sample(samp, vtf.uv1) + vtf.color;";
      else
        out << "colorOut = vtf.color * patternTex2.sample(samp, vtf.uv1) + vtf.color;";
    } else {
      out << "colorOut = vtf.color;";
    }

    if (info.m_hasColorTex)
      out << "colorOut += colorTex.sample(samp, vtf.uv2);";

    if (info.m_hasBumpMap) {
      // 3: bumpMapTCG, bumpMap, NULL
      // ZERO, TEX, ONE, HALF
      // Output reg 0, no clamp, no bias

      // 4: bumpMapTCG2, bumpMap, NULL
      // ZERO, TEX, ONE, C0
      // Output reg 0, subtract, clamp, no bias

      out <<
          "float3 lightVec = lu.lights[3].pos.xyz - vtf.mvPos.xyz;"
          "float lx = dot(vtf.mvTangent.xyz, lightVec);"
          "float ly = dot(vtf.mvBinorm.xyz, lightVec);";
      fmt::print(out, FMT_STRING(
          "float4 emboss1 = bumpMap.sample(samp, vtf.uv{}) + float4(0.5);"
          "float4 emboss2 = bumpMap.sample(samp, vtf.uv{} + float2(lx, ly));"),
          bumpMapUv, bumpMapUv);

      // 5: NULL, NULL, NULL
      // ZERO, PREV, C0, ZERO
      // Output reg prev, scale 2, clamp

      // colorOut * clamp(emboss1 + 0.5 - emboss2, 0.0, 1.0) * 2.0
      out << "colorOut *= clamp((emboss1 + float4(0.5) - emboss2) * float4(2.0), float4(0.0), float4(1.0));";
    }

    break;

  case EFluidType::ThickLava:
    // 0: Tex0TCG, Tex0, GX_COLOR0A0
    // ZERO, TEX, KONST, RAS
    // Output reg prev
    // KColor 0

    // 1: Tex1TCG, Tex1, GX_COLOR0A0
    // ZERO, TEX, PREV, RAS
    // Output reg prev

    // 2: Tex2TCG, Tex2, NULL
    // ZERO, TEX, ONE, PREV
    // Output reg prev

    // (Tex0 * kColor0 + VertColor) * Tex1 + VertColor + Tex2
    if (info.m_hasPatternTex2) {
      if (info.m_hasPatternTex1)
        out <<
            "colorOut = (patternTex1.sample(samp, vtf.uv0) * lu.kColor0 + vtf.color) * "
            "patternTex2.sample(samp, vtf.uv1) + vtf.color;";
      else
        out << "colorOut = vtf.color * patternTex2.sample(samp, vtf.uv1) + vtf.color;";
    } else {
      out << "colorOut = vtf.color;";
    }

    if (info.m_hasColorTex)
      out << "colorOut += colorTex.sample(samp, vtf.uv2);";

    if (info.m_hasBumpMap) {
      // 3: bumpMapTCG, bumpMap, NULL
      // ZERO, TEX, PREV, ZERO
      // Output reg prev, scale 2
      fmt::print(out, FMT_STRING("float4 emboss1 = bumpMap.sample(samp, vtf.uv{}) + float4(0.5);"), bumpMapUv);
      out << "colorOut *= emboss1 * float4(2.0);";
    }

    break;
  }

  out << "colorOut.a = lu.kColor0.a;\n";

  out << "#define IS_ADDITIVE " << int(info.m_additive) << '\n';
  out << FS;
  return out.str();
}

static void _BuildAdditionalTCGs(std::stringstream& out, const SFluidPlaneShaderInfo& info) {
  int nextTCG = 3;
  int nextMtx = 4;

  out << "#define ADDITIONAL_TCGS ";
  if (info.m_hasBumpMap)
    fmt::print(out, FMT_STRING("vtf.uv{} = (fu.texMtxs[0] * pos).xy;"), nextTCG++);
  if (info.m_hasEnvBumpMap)
    fmt::print(out, FMT_STRING("vtf.uv{} = (fu.texMtxs[3] * float4(normalIn.xyz, 1.0)).xy;"), nextTCG++);
  if (info.m_hasEnvMap)
    fmt::print(out, FMT_STRING("vtf.uv{} = (fu.texMtxs[{}] * pos).xy;"), nextTCG++, nextMtx++);
  if (info.m_hasLightmap)
    fmt::print(out, FMT_STRING("vtf.uv{} = (fu.texMtxs[{}] * pos).xy;"), nextTCG++, nextMtx++);
  out << '\n';
}

static std::string _BuildVS(const SFluidPlaneShaderInfo& info, bool tessellation) {
  std::stringstream out;
  _BuildAdditionalTCGs(out, info);
  out << VS;
  return out.str();
}
template <>
std::string StageObject_CFluidPlaneShader<hecl::PlatformType::Metal, hecl::PipelineStage::Vertex>::BuildShader(
    const SFluidPlaneShaderInfo& in, bool tessellation) {
  return _BuildVS(in, tessellation);
}

template <>
std::string StageObject_CFluidPlaneShader<hecl::PlatformType::Metal, hecl::PipelineStage::Fragment>::BuildShader(
    const SFluidPlaneShaderInfo& in, bool tessellation) {
  return _BuildFS(in);
}

template <>
std::string StageObject_CFluidPlaneShader<hecl::PlatformType::Metal, hecl::PipelineStage::Control>::BuildShader(
    const SFluidPlaneShaderInfo& in, bool tessellation) {
  return TessCS;
}

static std::string BuildES(const SFluidPlaneShaderInfo& info) {
  int nextTex = 0;
  if (info.m_hasPatternTex1)
    nextTex++;
  if (info.m_hasPatternTex2)
    nextTex++;
  if (info.m_hasColorTex)
    nextTex++;
  if (info.m_hasBumpMap)
    nextTex++;
  if (info.m_hasEnvMap)
    nextTex++;
  if (info.m_hasEnvBumpMap)
    nextTex++;
  if (info.m_hasLightmap)
    nextTex++;

  std::stringstream out;
  _BuildAdditionalTCGs(out, info);
  out << "#define RIPPLE_TEXTURE_IDX " << nextTex << '\n';
  out << TessES;
  return out.str();
}

template <>
std::string StageObject_CFluidPlaneShader<hecl::PlatformType::Metal, hecl::PipelineStage::Evaluation>::BuildShader(
    const SFluidPlaneShaderInfo& in, bool tessellation) {
  return BuildES(in);
}

static std::string _BuildVS(const SFluidPlaneDoorShaderInfo& info) {
  std::stringstream out;
  out << "#define ADDITIONAL_TCGS\n";
  out << VS;
  return out.str();
}

static std::string _BuildFS(const SFluidPlaneDoorShaderInfo& info) {
  int nextTex = 0;
  std::stringstream out;

  out << "#define TEXTURE_PARAMS ";
  if (info.m_hasPatternTex1)
    fmt::print(out, FMT_STRING(",texture2d<float> patternTex1 [[ texture({}) ]]"), nextTex++);
  if (info.m_hasPatternTex2)
    fmt::print(out, FMT_STRING(",texture2d<float> patternTex2 [[ texture({}) ]]"), nextTex++);
  if (info.m_hasColorTex)
    fmt::print(out, FMT_STRING(",texture2d<float> colorTex [[ texture({}) ]]"), nextTex++);
  out << '\n';

  // Tex0 * kColor0 * Tex1 + Tex2
  out << "#define COMBINER_EXPRS ";
  if (info.m_hasPatternTex1 && info.m_hasPatternTex2) {
    out <<
        "colorOut = patternTex1.sample(samp, vtf.uv0) * lu.kColor0 * "
        "patternTex2.sample(samp, vtf.uv1);";
  } else {
    out << "colorOut = float4(0.0);";
  }

  if (info.m_hasColorTex) {
    out << "colorOut += colorTex.sample(samp, vtf.uv2);";
  }

  out << "colorOut.a = lu.kColor0.a;\n";

  out << "#define IS_ADDITIVE 0\n";
  out << FSDoor;
  return out.str();
}

template <>
std::string StageObject_CFluidPlaneDoorShader<hecl::PlatformType::Metal, hecl::PipelineStage::Vertex>::BuildShader(
    const SFluidPlaneDoorShaderInfo& in) {
  return _BuildVS(in);
}

template <>
std::string StageObject_CFluidPlaneDoorShader<hecl::PlatformType::Metal, hecl::PipelineStage::Fragment>::BuildShader(
    const SFluidPlaneDoorShaderInfo& in) {
  return _BuildFS(in);
}