OCCT

// Copyright (c) 2025 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

// clang-format off
// This file has been automatically generated from resource file resources/Shaders/LightShadow.glsl

static const char Shaders_LightShadow_glsl[] =
  "#if (__VERSION__ >= 120)\n"
  "//! Coefficients for gathering close samples for antialiasing.\n"
  "//! Use only with decent OpenGL (array constants cannot be initialized with GLSL 1.1 / GLSL ES 1.1)\n"
  "const vec2 occPoissonDisk16[16] = vec2[](\n"
  " vec2(-0.94201624,-0.39906216), vec2( 0.94558609,-0.76890725), vec2(-0.09418410,-0.92938870), vec2( 0.34495938, 0.29387760),\n"
  " vec2(-0.91588581, 0.45771432), vec2(-0.81544232,-0.87912464), vec2(-0.38277543, 0.27676845), vec2( 0.97484398, 0.75648379),\n"
  " vec2( 0.44323325,-0.97511554), vec2( 0.53742981,-0.47373420), vec2(-0.26496911,-0.41893023), vec2( 0.79197514, 0.19090188),\n"
  " vec2(-0.24188840, 0.99706507), vec2(-0.81409955, 0.91437590), vec2( 0.19984126, 0.78641367), vec2( 0.14383161,-0.14100790)\n"
  ");\n"
  "#endif\n"
  "\n"
  "//! Function computes directional and spot light shadow attenuation (1.0 means no shadow).\n"
  "float occLightShadow (in sampler2D theShadow,\n"
  "                      in int  theId,\n"
  "                      in vec3 theNormal)\n"
  "{\n"
  "  vec4 aPosLightSpace = PosLightSpace[occLight_Index(theId)];\n"
  "  vec3 aLightDir = occLight_Position (theId);\n"
  "  vec3 aProjCoords = (aPosLightSpace.xyz / aPosLightSpace.w);\n"
  "#ifdef THE_ZERO_TO_ONE_DEPTH\n"
  "  aProjCoords.xy = aProjCoords.xy * 0.5 + vec2 (0.5);\n"
  "#else\n"
  "  aProjCoords = aProjCoords * 0.5 + vec3 (0.5);\n"
  "#endif\n"
  "  float aCurrentDepth = aProjCoords.z;\n"
  "  if (aProjCoords.x < 0.0 || aProjCoords.x > 1.0\n"
  "   || aProjCoords.y < 0.0 || aProjCoords.y > 1.0\n"
  "   || aCurrentDepth > 1.0)\n"
  "  {\n"
  "    return 1.0;\n"
  "  }\n"
  "\n"
  "  vec2 aTexelSize = vec2 (occShadowMapSizeBias.x);\n"
  "  float aBias = max (occShadowMapSizeBias.y * (1.0 - dot (theNormal, aLightDir)), occShadowMapSizeBias.y * 0.1);\n"
  "#if (__VERSION__ >= 120)\n"
  "  float aShadow = 0.0;\n"
  "  for (int aPosIter = 0; aPosIter < 16; ++aPosIter)\n"
  "  {\n"
  "    float aClosestDepth = occTexture2D (theShadow, aProjCoords.xy + occPoissonDisk16[aPosIter] * aTexelSize).r;\n"
  "    aShadow += (aCurrentDepth - aBias) > aClosestDepth ? 1.0 : 0.0;\n"
  "  }\n"
  "  return 1.0 - aShadow / 16.0;\n"
  "#else\n"
  "  float aClosestDepth = occTexture2D (theShadow, aProjCoords.xy).r;\n"
  "  float aShadow = (aCurrentDepth - aBias) > aClosestDepth ? 1.0 : 0.0;\n"
  "  return 1.0 - aShadow;\n"
  "#endif\n"
  "}\n";

// clang-format on