GL_UTILS Class Reference

#include <gl_utils.h>

Static Public Member Functions
static int	SetSwapInterval (int aVal)
	Attempts to set the OpenGL swap interval. More...

Detailed Description

Definition at line 33 of file gl_utils.h.

Member Function Documentation

SetSwapInterval()

static int GL_UTILS::SetSwapInterval ( int  aVal )

inlinestatic

Attempts to set the OpenGL swap interval.

Parameters

aVal	if -1 = try to set adaptive swapping, 0 = sync off, 1 = sync with VSYNC rate.

Returns

actual value set

This routine is written for Linux using X11 only. The equivalent functions under Windows would include <wglext.h> and call wglSwapIntervalEXT

Definition at line 42 of file gl_utils.h.

 {
#if defined( __linux__ ) && !defined( KICAD_USE_EGL )

 Display *dpy = glXGetCurrentDisplay();
 GLXDrawable drawable = glXGetCurrentDrawable();
 std::string vendor( reinterpret_cast<const char*>( glGetString( GL_VENDOR ) ) );
 bool is_mesa = ( vendor.find( "Mesa" ) != std::string::npos );

 if( !is_mesa && glXSwapIntervalEXT && glXQueryDrawable && dpy && drawable )
 {
 std::string exts( glXQueryExtensionsString( dpy, DefaultScreen( dpy ) ) );

 if( aVal < 0 )
 {
 if( exts.find( "GLX_EXT_swap_control_tear" ) == std::string::npos )
 {
 aVal = 0;
 }
 else
 {
 // Even though the extensions might be available,
 // we need to be sure that late/adaptive swaps are
 // enabled on the drawable.

 unsigned lateSwapsEnabled = 0;
 glXQueryDrawable( dpy, drawable, GLX_LATE_SWAPS_TEAR_EXT, &lateSwapsEnabled );

 if( !lateSwapsEnabled )
 {
 aVal = 0;
 }
 }
 }

 unsigned clampedInterval;
 glXSwapIntervalEXT( dpy, drawable, aVal );
 glXQueryDrawable( dpy, drawable, GLX_SWAP_INTERVAL_EXT, &clampedInterval );

 return clampedInterval;
 }

 if( glXSwapIntervalMESA &&glXGetSwapIntervalMESA )
 {
 if( aVal < 0 )
 aVal = 0;

 glXSwapIntervalMESA( aVal );
 return glXGetSwapIntervalMESA();
 }

 if( glXSwapIntervalSGI )
 {
 if( aVal < 1 )
 aVal = 1;

 if( glXSwapIntervalSGI( aVal ) )
 glXSwapIntervalSGI( 1 );

 return 1;
 }

 return std::numeric_limits<int>::max();
#else
 return 0;
#endif
 }

Referenced by KIGFX::OPENGL_GAL::init(), and EDA_3D_CANVAS::initializeOpenGL().

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The documentation for this class was generated from the following file:

• gl_utils.h