kc3-lang/angle/src/common/mathutil.cpp

• Show log

  Commit

• Hash : 78048112
  Author :
  Date : 2025-01-15T15:13:14
  

  Fix IndexRange::vertexIndexCount calculation
  
  Use only one loop.
  Avoid redundant primitive restart index parameter.
  Avoid calling GetPrimitiveRestartIndexFromType() because the algorithm
  relies on the value being numeric_limits<T>::max().
  
  Fixes a bug where primitive restart case would process the value
  after first primitive restart twice, once in both for loops. This would
  result in incorrect vertexIndexCount.
  
  Fix by removing IndexRange::vertexIndexCount, and instead using
  IndexRange::mCount == 0 to signify empty range.
  
  Bug: angleproject:401284933
  Change-Id: Ifaeb9949f2e852fb7c5ef80bc47f72bfabba21a6
  Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6333541
  Reviewed-by: Geoff Lang <geofflang@chromium.org>
  Auto-Submit: Kimmo Kinnunen <kkinnunen@apple.com>
  Commit-Queue: Kimmo Kinnunen <kkinnunen@apple.com>
  

Download

• src/common/mathutil.cpp

• //
  // Copyright 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.
  //
  
  // mathutil.cpp: Math and bit manipulation functions.
  
  #include "common/mathutil.h"
  
  #include <math.h>
  #include <algorithm>
  
  namespace gl
  {
  
  namespace
  {
  
  struct RGB9E5Data
  {
      unsigned int R : 9;
      unsigned int G : 9;
      unsigned int B : 9;
      unsigned int E : 5;
  };
  
  // B is the exponent bias (15)
  constexpr int g_sharedexp_bias = 15;
  
  // N is the number of mantissa bits per component (9)
  constexpr int g_sharedexp_mantissabits = 9;
  
  // number of mantissa bits per component pre-biased
  constexpr int g_sharedexp_biased_mantissabits = g_sharedexp_bias + g_sharedexp_mantissabits;
  
  // Emax is the maximum allowed biased exponent value (31)
  constexpr int g_sharedexp_maxexponent = 31;
  
  constexpr float g_sharedexp_max =
      ((static_cast<float>(1 << g_sharedexp_mantissabits) - 1) /
       static_cast<float>(1 << g_sharedexp_mantissabits)) *
      static_cast<float>(1 << (g_sharedexp_maxexponent - g_sharedexp_bias));
  
  }  // anonymous namespace
  
  unsigned int convertRGBFloatsTo999E5(float red, float green, float blue)
  {
      const float red_c   = std::max<float>(0, std::min(g_sharedexp_max, red));
      const float green_c = std::max<float>(0, std::min(g_sharedexp_max, green));
      const float blue_c  = std::max<float>(0, std::min(g_sharedexp_max, blue));
  
      const float max_c = std::max<float>({red_c, green_c, blue_c});
      const float exp_p =
          std::max<float>(-g_sharedexp_bias - 1, floor(log(max_c))) + 1 + g_sharedexp_bias;
      const int max_s = static_cast<int>(
          floor((max_c / (pow(2.0f, exp_p - g_sharedexp_biased_mantissabits))) + 0.5f));
      const int exp_s =
          static_cast<int>((max_s < pow(2.0f, g_sharedexp_mantissabits)) ? exp_p : exp_p + 1);
      const float pow2_exp = pow(2.0f, static_cast<float>(exp_s) - g_sharedexp_biased_mantissabits);
  
      RGB9E5Data output;
      output.R = static_cast<unsigned int>(floor((red_c / pow2_exp) + 0.5f));
      output.G = static_cast<unsigned int>(floor((green_c / pow2_exp) + 0.5f));
      output.B = static_cast<unsigned int>(floor((blue_c / pow2_exp) + 0.5f));
      output.E = exp_s;
  
      return bitCast<unsigned int>(output);
  }
  
  void convert999E5toRGBFloats(unsigned int input, float *red, float *green, float *blue)
  {
      const RGB9E5Data *inputData = reinterpret_cast<const RGB9E5Data *>(&input);
  
      const float pow2_exp =
          pow(2.0f, static_cast<float>(inputData->E) - g_sharedexp_biased_mantissabits);
  
      *red   = inputData->R * pow2_exp;
      *green = inputData->G * pow2_exp;
      *blue  = inputData->B * pow2_exp;
  }
  
  std::ostream &operator<<(std::ostream &s, const IndexRange &a)
  {
      if (a.isEmpty())
      {
          s << "[]";
      }
      else
      {
          s << "[" << a.start() << ", " << a.end() << "]";
      }
      return s;
  }
  
  }  // namespace gl
  

Download