ui/gl/gl_version_info.cc

// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/gl/gl_version_info.h"

#include "base/strings/string_number_conversions.h"
#include "base/strings/string_tokenizer.h"
#include "base/strings/string_util.h"

namespace {

bool DesktopCoreCommonCheck(
    bool is_es, unsigned major_version, unsigned minor_version) {
  return (!is_es &&
          ((major_version == 3 && minor_version >= 2) ||
           major_version > 3));
}

}


namespace gfx {

GLVersionInfo::GLVersionInfo(const char* version_str, const char* renderer_str,
                             const char* extensions_str)
    : GLVersionInfo(version_str, renderer_str) {
  is_desktop_core_profile =
      DesktopCoreCommonCheck(is_es, major_version, minor_version) &&
      !strstr(extensions_str, "GL_ARB_compatibility");
}

GLVersionInfo::GLVersionInfo(const char* version_str, const char* renderer_str,
                             const std::set<std::string>& extensions)
    : GLVersionInfo(version_str, renderer_str) {
  is_desktop_core_profile =
      DesktopCoreCommonCheck(is_es, major_version, minor_version) &&
      extensions.find("GL_ARB_compatibility") == extensions.end();
}

GLVersionInfo::GLVersionInfo(const char* version_str, const char* renderer_str)
    : is_es(false),
      is_angle(false),
      major_version(0),
      minor_version(0),
      is_es3(false),
      is_desktop_core_profile(false) {
  if (version_str) {
    ParseVersionString(version_str, &major_version, &minor_version,
                       &is_es, &is_es3);
  }
  if (renderer_str) {
    is_angle = base::StartsWithASCII(renderer_str, "ANGLE", true);
  }
}

void GLVersionInfo::ParseVersionString(const char* version_str,
                                       unsigned* major_version,
                                       unsigned* minor_version,
                                       bool* is_es,
                                       bool* is_es3) {
  // Make sure the outputs are always initialized.
  *major_version = 0;
  *minor_version = 0;
  *is_es = false;
  *is_es3 = false;
  if (!version_str)
    return;
  std::string lstr(base::StringToLowerASCII(std::string(version_str)));
  *is_es = (lstr.length() > 12) && (lstr.substr(0, 9) == "opengl es");
  if (*is_es)
    lstr = lstr.substr(10, 3);
  base::StringTokenizer tokenizer(lstr.begin(), lstr.end(), ".");
  unsigned major, minor;
  if (tokenizer.GetNext() &&
      base::StringToUint(tokenizer.token_piece(), &major)) {
    *major_version = major;
    if (tokenizer.GetNext() &&
        base::StringToUint(tokenizer.token_piece(), &minor)) {
      *minor_version = minor;
    }
  }
  if (*is_es && *major_version == 3)
    *is_es3 = true;
}

}  // namespace gfx