setswapinterval.cc

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#if defined(ION_PLATFORM_MAC)
#  include <OpenGL/OpenGL.h>  // For CGLContext.
#endif

#include "ion/portgfx/setswapinterval.h"

#include "ion/portgfx/getglprocaddress.h"
#include "ion/portgfx/glheaders.h"

namespace ion {
namespace portgfx {

bool SetSwapInterval(int interval) {
  if (interval < 0)
    return false;
#if defined(ION_PLATFORM_IOS) || defined(ION_PLATFORM_ANDROID) || \
    defined(ION_PLATFORM_ASMJS) || defined(ION_PLATFORM_NACL) || \
    defined(ION_PLATFORM_GENERIC_ARM)
  return true;
#elif defined(ION_PLATFORM_LINUX)
  typedef int (ION_APIENTRY *SwapIntervalProc)(int interval);
  SwapIntervalProc vsync_func = reinterpret_cast<SwapIntervalProc>(
      GetGlProcAddress("glXSwapIntervalSGI", false));
  return vsync_func && vsync_func(interval) == 0;
#elif defined(ION_PLATFORM_MAC)
  if (CGLContextObj context = CGLGetCurrentContext()) {
    CGLSetParameter(context, kCGLCPSwapInterval, &interval);
    int new_interval = -1;
    CGLGetParameter(context, kCGLCPSwapInterval, &new_interval);
    return interval == new_interval;
  }
  return false;
#elif defined(ION_PLATFORM_WINDOWS) && !defined(ION_ANGLE)
  typedef BOOL (ION_APIENTRY *SwapIntervalProc)(int interval);
  typedef int (ION_APIENTRY *GetSwapIntervalProc)();
  SwapIntervalProc vsync_set_func = reinterpret_cast<SwapIntervalProc>(
      GetGlProcAddress("wglSwapIntervalEXT", false));
  GetSwapIntervalProc vsync_get_func = reinterpret_cast<GetSwapIntervalProc>(
      GetGlProcAddress("wglGetSwapIntervalEXT", false));
  if (vsync_get_func && vsync_set_func) {
    BOOL set_val = vsync_set_func(interval);
    int get_val = vsync_get_func();
    return set_val == TRUE && get_val == interval;
  }
  return false;
#elif defined(ION_GFX_OGLES20) || defined(ION_ANGLE)
  EGLDisplay display = eglGetCurrentDisplay();
  return display != EGL_NO_DISPLAY &&
      eglSwapInterval(display, interval) == EGL_TRUE;
#endif
}

}  // namespace portgfx
}  // namespace ion