#include "precompiled.h"
//
// Copyright (c) 2002-2013 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

// utilities.cpp: Conversion functions and other utility routines.

#include "libGLESv2/utilities.h"
#include "libGLESv2/mathutil.h"

namespace gl
{

int UniformComponentCount(GLenum type)
{
    switch (type)
    {
      case GL_BOOL:
      case GL_FLOAT:
      case GL_INT:
      case GL_SAMPLER_2D:
      case GL_SAMPLER_CUBE:
      case GL_UNSIGNED_INT:
          return 1;
      case GL_BOOL_VEC2:
      case GL_FLOAT_VEC2:
      case GL_INT_VEC2:
      case GL_UNSIGNED_INT_VEC2:
          return 2;
      case GL_INT_VEC3:
      case GL_FLOAT_VEC3:
      case GL_BOOL_VEC3:
      case GL_UNSIGNED_INT_VEC3:
          return 3;
      case GL_BOOL_VEC4:
      case GL_FLOAT_VEC4:
      case GL_INT_VEC4:
      case GL_UNSIGNED_INT_VEC4:
      case GL_FLOAT_MAT2:
          return 4;
      case GL_FLOAT_MAT2x3:
      case GL_FLOAT_MAT3x2:
          return 6;
      case GL_FLOAT_MAT2x4:
      case GL_FLOAT_MAT4x2:
          return 8;
      case GL_FLOAT_MAT3:
          return 9;
      case GL_FLOAT_MAT3x4:
      case GL_FLOAT_MAT4x3:
          return 12;
      case GL_FLOAT_MAT4:
          return 16;
      default:
          UNREACHABLE();
    }

    return 0;
}

GLenum UniformComponentType(GLenum type)
{
    switch(type)
    {
      case GL_BOOL:
      case GL_BOOL_VEC2:
      case GL_BOOL_VEC3:
      case GL_BOOL_VEC4:
          return GL_BOOL;
      case GL_FLOAT:
      case GL_FLOAT_VEC2:
      case GL_FLOAT_VEC3:
      case GL_FLOAT_VEC4:
      case GL_FLOAT_MAT2:
      case GL_FLOAT_MAT3:
      case GL_FLOAT_MAT4:
      case GL_FLOAT_MAT2x3:
      case GL_FLOAT_MAT3x2:
      case GL_FLOAT_MAT2x4:
      case GL_FLOAT_MAT4x2:
      case GL_FLOAT_MAT3x4:
      case GL_FLOAT_MAT4x3:
          return GL_FLOAT;
      case GL_INT:
      case GL_SAMPLER_2D:
      case GL_SAMPLER_CUBE:
      case GL_INT_VEC2:
      case GL_INT_VEC3:
      case GL_INT_VEC4:
          return GL_INT;
      case GL_UNSIGNED_INT:
      case GL_UNSIGNED_INT_VEC2:
      case GL_UNSIGNED_INT_VEC3:
      case GL_UNSIGNED_INT_VEC4:
          return GL_UNSIGNED_INT;
      default:
          UNREACHABLE();
    }

    return GL_NONE;
}

size_t UniformComponentSize(GLenum type)
{
    switch(type)
    {
      case GL_BOOL:         return sizeof(GLint);
      case GL_FLOAT:        return sizeof(GLfloat);
      case GL_INT:          return sizeof(GLint);
      case GL_UNSIGNED_INT: return sizeof(GLuint);
      default:       UNREACHABLE();
    }

    return 0;
}

size_t UniformInternalSize(GLenum type)
{
    // Expanded to 4-element vectors
    return UniformComponentSize(UniformComponentType(type)) * VariableRowCount(type) * 4;
}

size_t UniformExternalSize(GLenum type)
{
    return UniformComponentSize(UniformComponentType(type)) * UniformComponentCount(type);
}

GLenum UniformBoolVectorType(GLenum type)
{
    switch (type)
    {
      case GL_FLOAT:
      case GL_INT:
      case GL_UNSIGNED_INT:
        return GL_BOOL;
      case GL_FLOAT_VEC2:
      case GL_INT_VEC2:
      case GL_UNSIGNED_INT_VEC2:
        return GL_BOOL_VEC2;
      case GL_FLOAT_VEC3:
      case GL_INT_VEC3:
      case GL_UNSIGNED_INT_VEC3:
        return GL_BOOL_VEC3;
      case GL_FLOAT_VEC4:
      case GL_INT_VEC4:
      case GL_UNSIGNED_INT_VEC4:
        return GL_BOOL_VEC4;

      default:
        UNREACHABLE();
        return GL_NONE;
    }
}

int VariableRowCount(GLenum type)
{
    switch (type)
    {
      case GL_NONE:
        return 0;
      case GL_BOOL:
      case GL_FLOAT:
      case GL_INT:
      case GL_BOOL_VEC2:
      case GL_FLOAT_VEC2:
      case GL_INT_VEC2:
      case GL_INT_VEC3:
      case GL_FLOAT_VEC3:
      case GL_BOOL_VEC3:
      case GL_BOOL_VEC4:
      case GL_FLOAT_VEC4:
      case GL_INT_VEC4:
      case GL_SAMPLER_2D:
      case GL_SAMPLER_CUBE:
        return 1;
      case GL_FLOAT_MAT2:
      case GL_FLOAT_MAT3x2:
      case GL_FLOAT_MAT4x2:
        return 2;
      case GL_FLOAT_MAT3:
      case GL_FLOAT_MAT2x3:
      case GL_FLOAT_MAT4x3:
        return 3;
      case GL_FLOAT_MAT4:
      case GL_FLOAT_MAT2x4:
      case GL_FLOAT_MAT3x4:
        return 4;
      default:
        UNREACHABLE();
    }

    return 0;
}

int VariableColumnCount(GLenum type)
{
    switch (type)
    {
      case GL_NONE:
        return 0;
      case GL_BOOL:
      case GL_FLOAT:
      case GL_INT:
      case GL_SAMPLER_2D:
      case GL_SAMPLER_CUBE:
        return 1;
      case GL_BOOL_VEC2:
      case GL_FLOAT_VEC2:
      case GL_INT_VEC2:
      case GL_FLOAT_MAT2:
      case GL_FLOAT_MAT2x3:
      case GL_FLOAT_MAT2x4:
        return 2;
      case GL_INT_VEC3:
      case GL_FLOAT_VEC3:
      case GL_BOOL_VEC3:
      case GL_FLOAT_MAT3:
      case GL_FLOAT_MAT3x2:
      case GL_FLOAT_MAT3x4:
        return 3;
      case GL_BOOL_VEC4:
      case GL_FLOAT_VEC4:
      case GL_INT_VEC4:
      case GL_FLOAT_MAT4:
      case GL_FLOAT_MAT4x2:
      case GL_FLOAT_MAT4x3:
        return 4;
      default:
        UNREACHABLE();
    }

    return 0;
}

bool IsMatrixType(GLenum type)
{
    return VariableRowCount(type) > 1;
}

int AllocateFirstFreeBits(unsigned int *bits, unsigned int allocationSize, unsigned int bitsSize)
{
    ASSERT(allocationSize <= bitsSize);

    unsigned int mask = std::numeric_limits<unsigned int>::max() >> (std::numeric_limits<unsigned int>::digits - allocationSize);

    for (unsigned int i = 0; i < bitsSize - allocationSize + 1; i++)
    {
        if ((*bits & mask) == 0)
        {
            *bits |= mask;
            return i;
        }

        mask <<= 1;
    }

    return -1;
}

GLsizei ComputeRowPitch(GLsizei width, GLint internalformat, GLint alignment)
{
    ASSERT(alignment > 0 && isPow2(alignment));

    GLsizei rawPitch = ComputePixelSize(internalformat) * width;
    return (rawPitch + alignment - 1) & ~(alignment - 1);
}

GLsizei ComputeDepthPitch(GLsizei width, GLsizei height, GLint internalformat, GLint alignment)
{
    return ComputeRowPitch(width, internalformat, alignment) * height;
}

GLsizei ComputeCompressedRowPitch(GLsizei width, GLenum internalformat)
{
    return ComputeCompressedSize(width, 1, internalformat);
}

GLsizei ComputeCompressedDepthPitch(GLsizei width, GLsizei height, GLenum internalformat)
{
    return ComputeCompressedSize(width, height, internalformat);
}

GLsizei ComputeCompressedSize(GLsizei width, GLsizei height, GLenum internalformat)
{
    switch (internalformat)
    {
      case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
        return 8 * ((width + 3) / 4) * ((height + 3) / 4);
      case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE:
      case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE:
        return 16 * ((width + 3) / 4) * ((height + 3) / 4);
      default:
        return 0;
    }
}

bool IsCompressed(GLenum format)
{
    if(format == GL_COMPRESSED_RGB_S3TC_DXT1_EXT ||
       format == GL_COMPRESSED_RGBA_S3TC_DXT1_EXT ||
       format == GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE ||
       format == GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE)
    {
        return true;
    }
    else
    {
        return false;
    }
}

bool IsDepthTexture(GLenum format)
{
    if (format == GL_DEPTH_COMPONENT ||
        format == GL_DEPTH_STENCIL_OES ||
        format == GL_DEPTH_COMPONENT16 ||
        format == GL_DEPTH_COMPONENT32_OES ||
        format == GL_DEPTH24_STENCIL8_OES)
    {
        return true;
    }

    return false;
}

bool IsStencilTexture(GLenum format)
{
    if (format == GL_DEPTH_STENCIL_OES ||
        format == GL_DEPTH24_STENCIL8_OES)
    {
        return true;
    }

    return false;
}

void MakeValidSize(bool isImage, bool isCompressed, GLsizei *requestWidth, GLsizei *requestHeight, int *levelOffset)
{
    int upsampleCount = 0;

    if (isCompressed)
    {
        // Don't expand the size of full textures that are at least 4x4
        // already.
        if (isImage || *requestWidth < 4 || *requestHeight < 4)
        {
            while (*requestWidth % 4 != 0 || *requestHeight % 4 != 0)
            {
                *requestWidth <<= 1;
                *requestHeight <<= 1;
                upsampleCount++;
            }
        }
    }
    *levelOffset = upsampleCount;
}

// Returns the size, in bytes, of a single texel in an Image
int ComputePixelSize(GLint internalformat)
{
    switch (internalformat)
    {
      case GL_ALPHA8_EXT:                       return sizeof(unsigned char);
      case GL_LUMINANCE8_EXT:                   return sizeof(unsigned char);
      case GL_ALPHA32F_EXT:                     return sizeof(float);
      case GL_LUMINANCE32F_EXT:                 return sizeof(float);
      case GL_ALPHA16F_EXT:                     return sizeof(unsigned short);
      case GL_LUMINANCE16F_EXT:                 return sizeof(unsigned short);
      case GL_LUMINANCE8_ALPHA8_EXT:            return sizeof(unsigned char) * 2;
      case GL_LUMINANCE_ALPHA32F_EXT:           return sizeof(float) * 2;
      case GL_LUMINANCE_ALPHA16F_EXT:           return sizeof(unsigned short) * 2;
      case GL_RGB8_OES:                         return sizeof(unsigned char) * 3;
      case GL_RGB565:                           return sizeof(unsigned short);
      case GL_RGB32F_EXT:                       return sizeof(float) * 3;
      case GL_RGB16F_EXT:                       return sizeof(unsigned short) * 3;
      case GL_RGBA8_OES:                        return sizeof(unsigned char) * 4;
      case GL_RGBA4:                            return sizeof(unsigned short);
      case GL_RGB5_A1:                          return sizeof(unsigned short);
      case GL_RGBA32F_EXT:                      return sizeof(float) * 4;
      case GL_RGBA16F_EXT:                      return sizeof(unsigned short) * 4;
      case GL_BGRA8_EXT:                        return sizeof(unsigned char) * 4;
      case GL_SRGB8_ALPHA8:                     return sizeof(unsigned char) * 4;
      case GL_RGB10_A2:                         return sizeof(unsigned char) * 4;
      case GL_RG8:                              return sizeof(unsigned char) * 2;
      case GL_R8:                               return sizeof(unsigned char);
      case GL_BGRA4_ANGLEX:                     return sizeof(unsigned short);
      case GL_BGR5_A1_ANGLEX:                   return sizeof(unsigned short);
      default:
        UNIMPLEMENTED();   // TODO: Remaining ES3 formats
        UNREACHABLE();
    }

    return 0;
}

bool IsCubemapTextureTarget(GLenum target)
{
    return (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X && target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z);
}

bool IsInternalTextureTarget(GLenum target)
{
    return target == GL_TEXTURE_2D || IsCubemapTextureTarget(target);
}

GLint ConvertSizedInternalFormat(GLenum format, GLenum type)
{
    switch (format)
    {
      case GL_ALPHA:
        switch (type)
        {
          case GL_UNSIGNED_BYTE:    return GL_ALPHA8_EXT;
          case GL_FLOAT:            return GL_ALPHA32F_EXT;
          case GL_HALF_FLOAT_OES:   return GL_ALPHA16F_EXT;
          default:                  UNIMPLEMENTED();
        }
        break;
      case GL_LUMINANCE:
        switch (type)
        {
          case GL_UNSIGNED_BYTE:    return GL_LUMINANCE8_EXT;
          case GL_FLOAT:            return GL_LUMINANCE32F_EXT;
          case GL_HALF_FLOAT_OES:   return GL_LUMINANCE16F_EXT;
          default:                  UNIMPLEMENTED();
        }
        break;
      case GL_LUMINANCE_ALPHA:
        switch (type)
        {
          case GL_UNSIGNED_BYTE:    return GL_LUMINANCE8_ALPHA8_EXT;
          case GL_FLOAT:            return GL_LUMINANCE_ALPHA32F_EXT;
          case GL_HALF_FLOAT_OES:   return GL_LUMINANCE_ALPHA16F_EXT;
          default:                  UNIMPLEMENTED();
        }
        break;
      case GL_RGB:
        switch (type)
        {
          case GL_UNSIGNED_BYTE:            return GL_RGB8_OES;
          case GL_UNSIGNED_SHORT_5_6_5:     return GL_RGB565;
          case GL_FLOAT:                    return GL_RGB32F_EXT;
          case GL_HALF_FLOAT_OES:           return GL_RGB16F_EXT;
          default:                          UNIMPLEMENTED();
        }
        break;
      case GL_RGBA:
        switch (type)
        {
          case GL_UNSIGNED_BYTE:            return GL_RGBA8_OES;
          case GL_UNSIGNED_SHORT_4_4_4_4:   return GL_RGBA4;
          case GL_UNSIGNED_SHORT_5_5_5_1:   return GL_RGB5_A1;
          case GL_FLOAT:                    return GL_RGBA32F_EXT;
          case GL_HALF_FLOAT_OES:           return GL_RGBA16F_EXT;
            break;
          default:                          UNIMPLEMENTED();
        }
        break;
      case GL_BGRA_EXT:
        switch (type)
        {
          case GL_UNSIGNED_BYTE:                    return GL_BGRA8_EXT;
          case GL_UNSIGNED_SHORT_4_4_4_4_REV_EXT:   return GL_BGRA4_ANGLEX;
          case GL_UNSIGNED_SHORT_1_5_5_5_REV_EXT:   return GL_BGR5_A1_ANGLEX;
          default:                                  UNIMPLEMENTED();
        }
        break;
      case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE:
      case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE:
        return format;
      case GL_DEPTH_COMPONENT:
        switch (type)
        {
          case GL_UNSIGNED_SHORT:           return GL_DEPTH_COMPONENT16;
          case GL_UNSIGNED_INT:             return GL_DEPTH_COMPONENT32_OES;
          default:                          UNIMPLEMENTED();
        }
        break;
      case GL_DEPTH_STENCIL_OES:
        switch (type)
        {
          case GL_UNSIGNED_INT_24_8_OES:    return GL_DEPTH24_STENCIL8_OES;
          default:                          UNIMPLEMENTED();
        }
        break;
      default:
        UNIMPLEMENTED();
    }

    return GL_NONE;
}

GLenum ExtractFormat(GLenum internalformat)
{
    switch (internalformat)
    {
      case GL_RGB565:                          return GL_RGB;
      case GL_RGBA4:                           return GL_RGBA;
      case GL_RGB5_A1:                         return GL_RGBA;
      case GL_RGB8_OES:                        return GL_RGB;
      case GL_RGBA8_OES:                       return GL_RGBA;
      case GL_LUMINANCE8_ALPHA8_EXT:           return GL_LUMINANCE_ALPHA;
      case GL_LUMINANCE8_EXT:                  return GL_LUMINANCE;
      case GL_ALPHA8_EXT:                      return GL_ALPHA;
      case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:    return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
      case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:   return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
      case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE: return GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE;
      case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE: return GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE;
      case GL_RGBA32F_EXT:                     return GL_RGBA;
      case GL_RGB32F_EXT:                      return GL_RGB;
      case GL_ALPHA32F_EXT:                    return GL_ALPHA;
      case GL_LUMINANCE32F_EXT:                return GL_LUMINANCE;
      case GL_LUMINANCE_ALPHA32F_EXT:          return GL_LUMINANCE_ALPHA;
      case GL_RGBA16F_EXT:                     return GL_RGBA;
      case GL_RGB16F_EXT:                      return GL_RGB;
      case GL_ALPHA16F_EXT:                    return GL_ALPHA;
      case GL_LUMINANCE16F_EXT:                return GL_LUMINANCE;
      case GL_LUMINANCE_ALPHA16F_EXT:          return GL_LUMINANCE_ALPHA;
      case GL_BGRA8_EXT:                       return GL_BGRA_EXT;
      case GL_DEPTH_COMPONENT16:               return GL_DEPTH_COMPONENT;
      case GL_DEPTH_COMPONENT32_OES:           return GL_DEPTH_COMPONENT;
      case GL_DEPTH24_STENCIL8_OES:            return GL_DEPTH_STENCIL_OES;
      default:                                 return GL_NONE;   // Unsupported
    }
}

GLenum ExtractType(GLenum internalformat)
{
    switch (internalformat)
    {
      case GL_RGB565:                          return GL_UNSIGNED_SHORT_5_6_5;
      case GL_RGBA4:                           return GL_UNSIGNED_SHORT_4_4_4_4;
      case GL_RGB5_A1:                         return GL_UNSIGNED_SHORT_5_5_5_1;
      case GL_RGB8_OES:                        return GL_UNSIGNED_BYTE;
      case GL_RGBA8_OES:                       return GL_UNSIGNED_BYTE;
      case GL_LUMINANCE8_ALPHA8_EXT:           return GL_UNSIGNED_BYTE;
      case GL_LUMINANCE8_EXT:                  return GL_UNSIGNED_BYTE;
      case GL_ALPHA8_EXT:                      return GL_UNSIGNED_BYTE;
      case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:    return GL_UNSIGNED_BYTE;
      case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:   return GL_UNSIGNED_BYTE;
      case GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE: return GL_UNSIGNED_BYTE;
      case GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE: return GL_UNSIGNED_BYTE;
      case GL_RGBA32F_EXT:                     return GL_FLOAT;
      case GL_RGB32F_EXT:                      return GL_FLOAT;
      case GL_ALPHA32F_EXT:                    return GL_FLOAT;
      case GL_LUMINANCE32F_EXT:                return GL_FLOAT;
      case GL_LUMINANCE_ALPHA32F_EXT:          return GL_FLOAT;
      case GL_RGBA16F_EXT:                     return GL_HALF_FLOAT_OES;
      case GL_RGB16F_EXT:                      return GL_HALF_FLOAT_OES;
      case GL_ALPHA16F_EXT:                    return GL_HALF_FLOAT_OES;
      case GL_LUMINANCE16F_EXT:                return GL_HALF_FLOAT_OES;
      case GL_LUMINANCE_ALPHA16F_EXT:          return GL_HALF_FLOAT_OES;
      case GL_BGRA8_EXT:                       return GL_UNSIGNED_BYTE;
      case GL_DEPTH_COMPONENT16:               return GL_UNSIGNED_SHORT;
      case GL_DEPTH_COMPONENT32_OES:           return GL_UNSIGNED_INT;
      case GL_DEPTH24_STENCIL8_OES:            return GL_UNSIGNED_INT_24_8_OES;
      default:                                 return GL_NONE;   // Unsupported
    }
}

bool IsColorRenderable(GLenum internalformat)
{
    switch (internalformat)
    {
      case GL_RGBA4:
      case GL_RGB5_A1:
      case GL_RGB565:
      case GL_RGB8_OES:
      case GL_RGBA8_OES:
      case GL_BGRA8_EXT:
      case GL_SRGB8_ALPHA8:
      case GL_RGB10_A2:
      case GL_RG8:
      case GL_R8:
        return true;
      case GL_DEPTH_COMPONENT16:
      case GL_STENCIL_INDEX8:
      case GL_DEPTH24_STENCIL8_OES:
        return false;
      default:
        UNIMPLEMENTED();   // TODO: Remaining ES3 formats
        UNREACHABLE();
    }

    return false;
}

bool IsDepthRenderable(GLenum internalformat)
{
    switch (internalformat)
    {
      case GL_DEPTH_COMPONENT16:
      case GL_DEPTH24_STENCIL8_OES:
        return true;
      case GL_STENCIL_INDEX8:
      case GL_RGBA4:
      case GL_RGB5_A1:
      case GL_RGB565:
      case GL_RGB8_OES:
      case GL_RGBA8_OES:
        return false;
      default:
        UNIMPLEMENTED();
    }

    return false;
}

bool IsStencilRenderable(GLenum internalformat)
{
    switch (internalformat)
    {
      case GL_STENCIL_INDEX8:
      case GL_DEPTH24_STENCIL8_OES:
        return true;
      case GL_RGBA4:
      case GL_RGB5_A1:
      case GL_RGB565:
      case GL_RGB8_OES:
      case GL_RGBA8_OES:
      case GL_DEPTH_COMPONENT16:
        return false;
      default:
        UNIMPLEMENTED();
    }

    return false;
}

bool IsFloat32Format(GLint internalformat)
{
    switch (internalformat)
    {
      case GL_RGBA32F_EXT:
      case GL_RGB32F_EXT:
      case GL_ALPHA32F_EXT:
      case GL_LUMINANCE32F_EXT:
      case GL_LUMINANCE_ALPHA32F_EXT:
        return true;
      default:
        return false;
    }
}

bool IsFloat16Format(GLint internalformat)
{
    switch (internalformat)
    {
      case GL_RGBA16F_EXT:
      case GL_RGB16F_EXT:
      case GL_ALPHA16F_EXT:
      case GL_LUMINANCE16F_EXT:
      case GL_LUMINANCE_ALPHA16F_EXT:
        return true;
      default:
        return false;
    }
}

unsigned int GetAlphaSize(GLenum colorFormat)
{
    switch (colorFormat)
    {
      case GL_RGBA16F_EXT:
        return 16;
      case GL_RGBA32F_EXT:
        return 32;
      case GL_RGBA4:
        return 4;
      case GL_RGBA8_OES:
      case GL_BGRA8_EXT:
        return 8;
      case GL_RGB5_A1:
        return 1;
      case GL_RGB8_OES:
      case GL_RGB565:
      case GL_RGB32F_EXT:
      case GL_RGB16F_EXT:
        return 0;
      default:
        return 0;
    }
}

unsigned int GetRedSize(GLenum colorFormat)
{
    switch (colorFormat)
    {
      case GL_RGBA16F_EXT:
      case GL_RGB16F_EXT:
        return 16;
      case GL_RGBA32F_EXT:
      case GL_RGB32F_EXT:
        return 32;
      case GL_RGBA4:
        return 4;
      case GL_RGBA8_OES:
      case GL_BGRA8_EXT:
      case GL_RGB8_OES:
        return 8;
      case GL_RGB5_A1:
      case GL_RGB565:
        return 5;
      default:
        return 0;
    }
}

unsigned int GetGreenSize(GLenum colorFormat)
{
    switch (colorFormat)
    {
      case GL_RGBA16F_EXT:
      case GL_RGB16F_EXT:
        return 16;
      case GL_RGBA32F_EXT:
      case GL_RGB32F_EXT:
        return 32;
      case GL_RGBA4:
        return 4;
      case GL_RGBA8_OES:
      case GL_BGRA8_EXT:
      case GL_RGB8_OES:
        return 8;
      case GL_RGB5_A1:
        return 5;
      case GL_RGB565:
        return 6;
      default:
        return 0;
    }
}

unsigned int GetBlueSize(GLenum colorFormat)
{
    switch (colorFormat)
    {
      case GL_RGBA16F_EXT:
      case GL_RGB16F_EXT:
        return 16;
      case GL_RGBA32F_EXT:
      case GL_RGB32F_EXT:
        return 32;
      case GL_RGBA4:
        return 4;
      case GL_RGBA8_OES:
      case GL_BGRA8_EXT:
      case GL_RGB8_OES:
        return 8;
      case GL_RGB5_A1:
      case GL_RGB565:
        return 5;
      default:
        return 0;
    }
}

unsigned int GetDepthSize(GLenum depthFormat)
{
    switch (depthFormat)
    {
      case GL_DEPTH_COMPONENT16:        return 16;
      case GL_DEPTH_COMPONENT32_OES:    return 32;
      case GL_DEPTH24_STENCIL8_OES:     return 24;
      default:                          return 0;
    }
}

unsigned int GetStencilSize(GLenum stencilFormat)
{
    switch (stencilFormat)
    {
      case GL_DEPTH24_STENCIL8_OES:     return 8;
      default:                          return 0;
    }
}

bool IsTriangleMode(GLenum drawMode)
{
    switch (drawMode)
    {
      case GL_TRIANGLES:
      case GL_TRIANGLE_FAN:
      case GL_TRIANGLE_STRIP:
        return true;
      case GL_POINTS:
      case GL_LINES:
      case GL_LINE_LOOP:
      case GL_LINE_STRIP:
        return false;
      default: UNREACHABLE();
    }

    return false;
}

struct FormatInfo
{
    GLenum mFormat;
    GLenum mType;
    GLint mInternalformat;

    FormatInfo(GLenum format, GLenum type, GLint internalformat)
        : mFormat(format), mType(type), mInternalformat(internalformat) { }

    bool operator<(const FormatInfo& other) const
    {
        return memcmp(this, &other, sizeof(FormatInfo)) < 0;
    }
};

typedef std::set<FormatInfo> formatInfoSet;
static formatInfoSet buildValidES3FormatCombinationSet()
{
    formatInfoSet set;

    // From ES 3.0.1 spec, table 3.2
    set.insert(FormatInfo(GL_RGBA,            GL_UNSIGNED_BYTE,                   GL_RGBA8             ));
    set.insert(FormatInfo(GL_RGBA,            GL_UNSIGNED_BYTE,                   GL_RGB5_A1           ));
    set.insert(FormatInfo(GL_RGBA,            GL_UNSIGNED_BYTE,                   GL_RGBA4             ));
    set.insert(FormatInfo(GL_RGBA,            GL_UNSIGNED_BYTE,                   GL_SRGB8_ALPHA8      ));
    set.insert(FormatInfo(GL_RGBA,            GL_BYTE,                            GL_RGBA8_SNORM       ));
    set.insert(FormatInfo(GL_RGBA,            GL_UNSIGNED_SHORT_4_4_4_4,          GL_RGBA4             ));
    set.insert(FormatInfo(GL_RGBA,            GL_UNSIGNED_INT_2_10_10_10_REV,     GL_RGB10_A2          ));
    set.insert(FormatInfo(GL_RGBA,            GL_UNSIGNED_INT_2_10_10_10_REV,     GL_RGB5_A1           ));
    set.insert(FormatInfo(GL_RGBA,            GL_HALF_FLOAT,                      GL_RGBA16F           ));
    set.insert(FormatInfo(GL_RGBA,            GL_FLOAT,                           GL_RGBA32F           ));
    set.insert(FormatInfo(GL_RGBA,            GL_FLOAT,                           GL_RGBA16F           ));
    set.insert(FormatInfo(GL_RGBA_INTEGER,    GL_UNSIGNED_BYTE,                   GL_RGBA8UI           ));
    set.insert(FormatInfo(GL_RGBA_INTEGER,    GL_BYTE,                            GL_RGBA8I            ));
    set.insert(FormatInfo(GL_RGBA_INTEGER,    GL_UNSIGNED_SHORT,                  GL_RGBA16UI          ));
    set.insert(FormatInfo(GL_RGBA_INTEGER,    GL_SHORT,                           GL_RGBA16I           ));
    set.insert(FormatInfo(GL_RGBA_INTEGER,    GL_UNSIGNED_INT,                    GL_RGBA32UI          ));
    set.insert(FormatInfo(GL_RGBA_INTEGER,    GL_INT,                             GL_RGBA32I           ));
    set.insert(FormatInfo(GL_RGBA_INTEGER,    GL_UNSIGNED_INT_2_10_10_10_REV,     GL_RGB10_A2UI        ));
    set.insert(FormatInfo(GL_RGB,             GL_UNSIGNED_BYTE,                   GL_RGB8              ));
    set.insert(FormatInfo(GL_RGB,             GL_UNSIGNED_BYTE,                   GL_RGB565            ));
    set.insert(FormatInfo(GL_RGB,             GL_UNSIGNED_BYTE,                   GL_SRGB8             ));
    set.insert(FormatInfo(GL_RGB,             GL_BYTE,                            GL_RGB8_SNORM        ));
    set.insert(FormatInfo(GL_RGB,             GL_UNSIGNED_SHORT_5_6_5,            GL_RGB565            ));
    set.insert(FormatInfo(GL_RGB,             GL_UNSIGNED_INT_10F_11F_11F_REV,    GL_R11F_G11F_B10F    ));
    set.insert(FormatInfo(GL_RGB,             GL_UNSIGNED_INT_5_9_9_9_REV,        GL_RGB9_E5           ));
    set.insert(FormatInfo(GL_RGB,             GL_HALF_FLOAT,                      GL_RGB16F            ));
    set.insert(FormatInfo(GL_RGB,             GL_HALF_FLOAT,                      GL_R11F_G11F_B10F    ));
    set.insert(FormatInfo(GL_RGB,             GL_HALF_FLOAT,                      GL_RGB9_E5           ));
    set.insert(FormatInfo(GL_RGB,             GL_FLOAT,                           GL_RGB32F            ));
    set.insert(FormatInfo(GL_RGB,             GL_FLOAT,                           GL_RGB16F            ));
    set.insert(FormatInfo(GL_RGB,             GL_FLOAT,                           GL_R11F_G11F_B10F    ));
    set.insert(FormatInfo(GL_RGB,             GL_FLOAT,                           GL_RGB9_E5           ));
    set.insert(FormatInfo(GL_RGB_INTEGER,     GL_UNSIGNED_BYTE,                   GL_RGB8UI            ));
    set.insert(FormatInfo(GL_RGB_INTEGER,     GL_BYTE,                            GL_RGB8I             ));
    set.insert(FormatInfo(GL_RGB_INTEGER,     GL_UNSIGNED_SHORT,                  GL_RGB16UI           ));
    set.insert(FormatInfo(GL_RGB_INTEGER,     GL_SHORT,                           GL_RGB16I            ));
    set.insert(FormatInfo(GL_RGB_INTEGER,     GL_UNSIGNED_INT,                    GL_RGB32UI           ));
    set.insert(FormatInfo(GL_RGB_INTEGER,     GL_INT,                             GL_RGB32I            ));
    set.insert(FormatInfo(GL_RG,              GL_UNSIGNED_BYTE,                   GL_RG8               ));
    set.insert(FormatInfo(GL_RG,              GL_BYTE,                            GL_RG8_SNORM         ));
    set.insert(FormatInfo(GL_RG,              GL_HALF_FLOAT,                      GL_RG16F             ));
    set.insert(FormatInfo(GL_RG,              GL_FLOAT,                           GL_RG32F             ));
    set.insert(FormatInfo(GL_RG,              GL_FLOAT,                           GL_RG16F             ));
    set.insert(FormatInfo(GL_RG_INTEGER,      GL_UNSIGNED_BYTE,                   GL_RG8UI             ));
    set.insert(FormatInfo(GL_RG_INTEGER,      GL_BYTE,                            GL_RG8I              ));
    set.insert(FormatInfo(GL_RG_INTEGER,      GL_UNSIGNED_SHORT,                  GL_RG16UI            ));
    set.insert(FormatInfo(GL_RG_INTEGER,      GL_SHORT,                           GL_RG16I             ));
    set.insert(FormatInfo(GL_RG_INTEGER,      GL_UNSIGNED_INT,                    GL_RG32UI            ));
    set.insert(FormatInfo(GL_RG_INTEGER,      GL_INT,                             GL_RG32I             ));
    set.insert(FormatInfo(GL_RED,             GL_UNSIGNED_BYTE,                   GL_R8                ));
    set.insert(FormatInfo(GL_RED,             GL_BYTE,                            GL_R8_SNORM          ));
    set.insert(FormatInfo(GL_RED,             GL_HALF_FLOAT,                      GL_R16F              ));
    set.insert(FormatInfo(GL_RED,             GL_FLOAT,                           GL_R32F              ));
    set.insert(FormatInfo(GL_RED,             GL_FLOAT,                           GL_R16F              ));
    set.insert(FormatInfo(GL_RED_INTEGER,     GL_UNSIGNED_BYTE,                   GL_R8UI              ));
    set.insert(FormatInfo(GL_RED_INTEGER,     GL_BYTE,                            GL_R8I               ));
    set.insert(FormatInfo(GL_RED_INTEGER,     GL_UNSIGNED_SHORT,                  GL_R16UI             ));
    set.insert(FormatInfo(GL_RED_INTEGER,     GL_SHORT,                           GL_R16I              ));
    set.insert(FormatInfo(GL_RED_INTEGER,     GL_UNSIGNED_INT,                    GL_R32UI             ));
    set.insert(FormatInfo(GL_RED_INTEGER,     GL_INT,                             GL_R32I              ));
    set.insert(FormatInfo(GL_DEPTH_COMPONENT, GL_UNSIGNED_SHORT,                  GL_DEPTH_COMPONENT16 ));
    set.insert(FormatInfo(GL_DEPTH_COMPONENT, GL_UNSIGNED_INT,                    GL_DEPTH_COMPONENT24 ));
    set.insert(FormatInfo(GL_DEPTH_COMPONENT, GL_UNSIGNED_INT,                    GL_DEPTH_COMPONENT16 ));
    set.insert(FormatInfo(GL_DEPTH_COMPONENT, GL_FLOAT,                           GL_DEPTH_COMPONENT32F));
    set.insert(FormatInfo(GL_DEPTH_STENCIL,   GL_UNSIGNED_INT_24_8,               GL_DEPTH24_STENCIL8  ));
    set.insert(FormatInfo(GL_DEPTH_STENCIL,   GL_FLOAT_32_UNSIGNED_INT_24_8_REV,  GL_DEPTH32F_STENCIL8 ));

    // From ES 3.0.1 spec, table 3.3
    set.insert(FormatInfo(GL_RGBA,            GL_UNSIGNED_BYTE,                   GL_RGBA              ));
    set.insert(FormatInfo(GL_RGBA,            GL_UNSIGNED_SHORT_4_4_4_4,          GL_RGBA              ));
    set.insert(FormatInfo(GL_RGBA,            GL_UNSIGNED_SHORT_5_5_5_1,          GL_RGBA              ));
    set.insert(FormatInfo(GL_RGB,             GL_UNSIGNED_BYTE,                   GL_RGB               ));
    set.insert(FormatInfo(GL_RGB,             GL_UNSIGNED_SHORT_5_6_5,            GL_RGB               ));
    set.insert(FormatInfo(GL_LUMINANCE_ALPHA, GL_UNSIGNED_BYTE,                   GL_LUMINANCE_ALPHA   ));
    set.insert(FormatInfo(GL_LUMINANCE,       GL_UNSIGNED_BYTE,                   GL_LUMINANCE         ));
    set.insert(FormatInfo(GL_ALPHA,           GL_UNSIGNED_BYTE,                   GL_ALPHA             ));

    // From GL_OES_texture_float
    set.insert(FormatInfo(GL_LUMINANCE_ALPHA, GL_FLOAT,                           GL_LUMINANCE_ALPHA   ));
    set.insert(FormatInfo(GL_LUMINANCE,       GL_FLOAT,                           GL_LUMINANCE         ));
    set.insert(FormatInfo(GL_ALPHA,           GL_FLOAT,                           GL_ALPHA             ));

    // From GL_OES_texture_half_float
    set.insert(FormatInfo(GL_LUMINANCE_ALPHA, GL_HALF_FLOAT,                      GL_LUMINANCE_ALPHA   ));
    set.insert(FormatInfo(GL_LUMINANCE,       GL_HALF_FLOAT,                      GL_LUMINANCE         ));
    set.insert(FormatInfo(GL_ALPHA,           GL_HALF_FLOAT,                      GL_ALPHA             ));

    return set;
}

typedef std::set<GLint> internalFormatSet;
static internalFormatSet buildValidES3InternalFormatSet(const formatInfoSet& formatCombos)
{
    internalFormatSet internalFormats;
    for (formatInfoSet::const_iterator i = formatCombos.begin(); i != formatCombos.end(); i++)
    {
        internalFormats.insert(i->mInternalformat);
    }
    return internalFormats;
}

typedef std::set<GLenum> formatSet;
static formatSet buildValidES3FormatSet(const formatInfoSet& formatCombos)
{
    formatSet formats;
    for (formatInfoSet::const_iterator i = formatCombos.begin(); i != formatCombos.end(); i++)
    {
        formats.insert(i->mFormat);
    }
    return formats;
}

typedef std::set<GLenum> typeSet;
static typeSet buildValidES3TypeSet(const formatInfoSet& formatCombos)
{
    typeSet types;
    for (formatInfoSet::const_iterator i = formatCombos.begin(); i != formatCombos.end(); i++)
    {
        types.insert(i->mType);
    }
    return types;
}

bool IsValidES3FormatCombination(GLint internalformat, GLenum format, GLenum type, GLenum* err)
{
    static const formatInfoSet combinations = buildValidES3FormatCombinationSet();
    static const internalFormatSet internalFormats = buildValidES3InternalFormatSet(combinations);
    static const formatSet formats = buildValidES3FormatSet(combinations);
    static const typeSet types = buildValidES3TypeSet(combinations);

    // Invalid internal format, format or type results in an INVALID_ENUM
    if (internalFormats.find(internalformat) == internalFormats.end() ||
        formats.find(format) == formats.end() ||
        types.find(type) == types.end())
    {
        *err = GL_INVALID_ENUM;
        return false;
    }

    // Invalid internal format + format + type combination results in an INVALID_OPERATION
    if (combinations.find(FormatInfo(format, type, internalformat)) == combinations.end())
    {
        *err = GL_INVALID_OPERATION;
        return false;
    }

    return true;
}

typedef std::set<GLenum> compressedFormatSet;
static compressedFormatSet buildValidES3CompressedFormats()
{
    compressedFormatSet formats;

    // From ES 3.0.1 spec, table 3.16
    formats.insert(GL_COMPRESSED_R11_EAC                       );
    formats.insert(GL_COMPRESSED_R11_EAC                       );
    formats.insert(GL_COMPRESSED_SIGNED_R11_EAC                );
    formats.insert(GL_COMPRESSED_RG11_EAC                      );
    formats.insert(GL_COMPRESSED_SIGNED_RG11_EAC               );
    formats.insert(GL_COMPRESSED_RGB8_ETC2                     );
    formats.insert(GL_COMPRESSED_SRGB8_ETC2                    );
    formats.insert(GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2 );
    formats.insert(GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2);
    formats.insert(GL_COMPRESSED_RGBA8_ETC2_EAC                );
    formats.insert(GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC         );

    // From GL_EXT_texture_compression_dxt1
    formats.insert(GL_COMPRESSED_RGB_S3TC_DXT1_EXT             );
    formats.insert(GL_COMPRESSED_RGBA_S3TC_DXT1_EXT            );

    // From GL_ANGLE_texture_compression_dxt3
    formats.insert(GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE          );

    // From GL_ANGLE_texture_compression_dxt5
    formats.insert(GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE          );

    return formats;
}

bool IsValidES3CompressedFormat(GLenum format)
{
    static const compressedFormatSet validCompressedFormats = buildValidES3CompressedFormats();
    return validCompressedFormats.find(format) != validCompressedFormats.end();
}

struct CopyConversion
{
    GLenum mTextureFormat;
    GLenum mFramebufferFormat;

    CopyConversion(GLenum textureFormat, GLenum framebufferFormat)
        : mTextureFormat(textureFormat), mFramebufferFormat(framebufferFormat) { }

    bool operator<(const CopyConversion& other) const
    {
        return memcmp(this, &other, sizeof(CopyConversion)) < 0;
    }
};

typedef std::set<CopyConversion> copyConversionSet;
static copyConversionSet buildValidES3CopyTexImageCombinations()
{
    copyConversionSet set;

    // From ES 3.0.1 spec, table 3.15
    set.insert(CopyConversion(GL_ALPHA,           GL_RGBA));
    set.insert(CopyConversion(GL_LUMINANCE,       GL_RED));
    set.insert(CopyConversion(GL_LUMINANCE,       GL_RG));
    set.insert(CopyConversion(GL_LUMINANCE,       GL_RGB));
    set.insert(CopyConversion(GL_LUMINANCE,       GL_RGBA));
    set.insert(CopyConversion(GL_LUMINANCE_ALPHA, GL_RGBA));
    set.insert(CopyConversion(GL_RED,             GL_RED));
    set.insert(CopyConversion(GL_RED,             GL_RG));
    set.insert(CopyConversion(GL_RED,             GL_RGB));
    set.insert(CopyConversion(GL_RED,             GL_RGBA));
    set.insert(CopyConversion(GL_RG,              GL_RG));
    set.insert(CopyConversion(GL_RG,              GL_RGB));
    set.insert(CopyConversion(GL_RG,              GL_RGBA));
    set.insert(CopyConversion(GL_RGB,             GL_RGB));
    set.insert(CopyConversion(GL_RGB,             GL_RGBA));
    set.insert(CopyConversion(GL_RGBA,            GL_RGBA));

    return set;
}

bool IsValidES3CopyTexImageCombination(GLenum textureFormat, GLenum frameBufferFormat)
{
    static const copyConversionSet conversions = buildValidES3CopyTexImageCombinations();
    return conversions.find(CopyConversion(textureFormat, frameBufferFormat)) != conversions.end();
}

}

std::string getTempPath()
{
    char path[MAX_PATH];
    DWORD pathLen = GetTempPathA(sizeof(path) / sizeof(path[0]), path);
    if (pathLen == 0)
    {
        UNREACHABLE();
        return std::string();
    }

    UINT unique = GetTempFileNameA(path, "sh", 0, path);
    if (unique == 0)
    {
        UNREACHABLE();
        return std::string();
    }
    
    return path;
}

void writeFile(const char* path, const void* content, size_t size)
{
    FILE* file = fopen(path, "w");
    if (!file)
    {
        UNREACHABLE();
        return;
    }

    fwrite(content, sizeof(char), size, file);
    fclose(file);
}
