Move resolving glxSwapIntervalMesa into platform plugin

Summary:
No need to resolve glx methods through the shared lib. At the moment
this duplicates some code, but will be cleaned up with a follow up
change.

Reviewers: #kwin, #plasma_on_wayland

Subscribers: plasma-devel, kwin

Tags: #plasma_on_wayland, #kwin

Differential Revision: https://phabricator.kde.org/D3335

libkwineffects/kwinglutils.cpp

@@ -45,10 +45,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <math.h>
 
-#if HAVE_EPOXY_GLX
-#include <epoxy/glx.h>
-#endif
-
 #define DEBUG_GLRENDERTARGET 0
 
 #define MAKE_GL_VERSION(major, minor, release)  ( ((major) << 16) | ((minor) << 8) | (release) )
@@ -68,22 +64,12 @@ namespace KWin
 static int eglVersion;
 // List of all supported GL, EGL and GLX extensions
 static QList<QByteArray> glExtensions;
-static QList<QByteArray> s_glxExtensions;
 static QList<QByteArray> s_eglExtensions;
 
 int glTextureUnitsCount;
 
 
 // Functions
-void initGLX()
-{
-#if HAVE_EPOXY_GLX
-    // Get list of supported GLX extensions
-    const QByteArray string = (const char *) glXQueryExtensionsString(display(), QX11Info::appScreen());
-    s_glxExtensions = string.split(' ');
-    glxResolveFunctions();
-#endif
-}
 
 void initEGL()
 {
@@ -129,7 +115,6 @@ void cleanupGL()
     GLPlatform::cleanup();
 
     glExtensions.clear();
-    s_glxExtensions.clear();
     s_eglExtensions.clear();
 
     eglVersion = 0;
@@ -148,7 +133,7 @@ bool hasEGLVersion(int major, int minor, int release)
 
 bool hasGLExtension(const QByteArray &extension)
 {
-    return glExtensions.contains(extension) || s_glxExtensions.contains(extension) || s_eglExtensions.contains(extension);
+    return glExtensions.contains(extension) || s_eglExtensions.contains(extension);
 }
 
 QList<QByteArray> eglExtensions()

libkwineffects/kwinglutils.h

@@ -48,9 +48,6 @@ namespace KWin
 class GLVertexBuffer;
 class GLVertexBufferPrivate;
 
-
-// Initializes GLX function pointers
-void KWINGLUTILS_EXPORT initGLX();
 // Initializes OpenGL stuff. This includes resolving function pointers as
 //  well as checking for GL version and extensions
 //  Note that GL context has to be created by the time this function is called

libkwineffects/kwinglutils_funcs.cpp

@@ -50,9 +50,6 @@ static void ReadnPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum
                         GLenum type, GLsizei bufSize, GLvoid *data);
 static void GetnUniformfv(GLuint program, GLint location, GLsizei bufSize, GLfloat *params);
 
-// GL_MESA_swap_control
-glXSwapIntervalMESA_func glXSwapIntervalMESA;
-
 // GL_ARB_robustness / GL_EXT_robustness
 glGetGraphicsResetStatus_func glGetGraphicsResetStatus;
 glReadnPixels_func            glReadnPixels;
@@ -71,14 +68,6 @@ static glXFuncPtr getProcAddress(const char* name)
     return ret;
 }
 
-void glxResolveFunctions()
-{
-    if (hasGLExtension(QByteArrayLiteral("GLX_MESA_swap_control")))
-        glXSwapIntervalMESA = (glXSwapIntervalMESA_func) getProcAddress("glXSwapIntervalMESA");
-    else
-        glXSwapIntervalMESA = nullptr;
-}
-
 void eglResolveFunctions()
 {
 }

libkwineffects/kwinglutils_funcs.h

@@ -47,16 +47,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 namespace KWin
 {
 
-void KWINGLUTILS_EXPORT glxResolveFunctions();
-
 void KWINGLUTILS_EXPORT eglResolveFunctions();
 
 void KWINGLUTILS_EXPORT glResolveFunctions(OpenGLPlatformInterface platformInterface);
 
-// GLX_MESA_swap_interval
-using glXSwapIntervalMESA_func = int (*)(unsigned int interval);
-extern KWINGLUTILS_EXPORT glXSwapIntervalMESA_func glXSwapIntervalMESA;
-
 // GL_ARB_robustness / GL_EXT_robustness
 using glGetGraphicsResetStatus_func = GLenum (*)();
 using glReadnPixels_func = void (*)(GLint x, GLint y, GLsizei width, GLsizei height,

plugins/platforms/x11/standalone/glxbackend.cpp

@@ -42,6 +42,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <deque>
 #include <algorithm>
+#include <dlfcn.h>
 
 #ifndef XCB_GLX_BUFFER_SWAP_COMPLETE
 #define XCB_GLX_BUFFER_SWAP_COMPLETE 1
@@ -148,10 +149,22 @@ GlxBackend::~GlxBackend()
     delete m_overlayWindow;
 }
 
+typedef void (*glXFuncPtr)();
+
+static glXFuncPtr getProcAddress(const char* name)
+{
+    glXFuncPtr ret = nullptr;
+#if HAVE_EPOXY_GLX
+    ret = glXGetProcAddress((const GLubyte*) name);
+#endif
+    if (ret == nullptr)
+        ret = (glXFuncPtr) dlsym(RTLD_DEFAULT, name);
+    return ret;
+}
+glXSwapIntervalMESA_func glXSwapIntervalMESA;
+
 void GlxBackend::init()
 {
-    initGLX();
-
     // Require at least GLX 1.3
     if (!checkVersion()) {
         setFailed(QStringLiteral("Requires at least GLX 1.3"));
@@ -160,6 +173,13 @@ void GlxBackend::init()
 
     initExtensions();
 
+    // resolve glXSwapIntervalMESA if available
+    if (hasExtension(QByteArrayLiteral("GLX_MESA_swap_control"))) {
+        glXSwapIntervalMESA = (glXSwapIntervalMESA_func) getProcAddress("glXSwapIntervalMESA");
+    } else {
+        glXSwapIntervalMESA = nullptr;
+    }
+
     initVisualDepthHashTable();
 
     if (!initBuffer()) {

plugins/platforms/x11/standalone/glxbackend.h

@@ -29,6 +29,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 namespace KWin
 {
 
+// GLX_MESA_swap_interval
+using glXSwapIntervalMESA_func = int (*)(unsigned int interval);
+extern glXSwapIntervalMESA_func glXSwapIntervalMESA;
+
 class FBConfigInfo
 {
 public: