Load GLX dynamically with GLAD

This is accomplished through the addition of a GLAD GLX loader in the
`thirdparty` directory.

This is another step towards a nice Wayland/X11 interoperation.

1 files changed, 395 insertions, 0 deletions

diff --git a/thirdparty/glad/glx.c b/thirdparty/glad/glx.c
new file mode 100644
index 0000000000..6391027db2
--- /dev/null
+++ b/thirdparty/glad/glx.c
@@ -0,0 +1,395 @@
+/**
+ * SPDX-License-Identifier: (WTFPL OR CC0-1.0) AND Apache-2.0
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <glad/glx.h>
+
+#ifndef GLAD_IMPL_UTIL_C_
+#define GLAD_IMPL_UTIL_C_
+
+#ifdef _MSC_VER
+#define GLAD_IMPL_UTIL_SSCANF sscanf_s
+#else
+#define GLAD_IMPL_UTIL_SSCANF sscanf
+#endif
+
+#endif /* GLAD_IMPL_UTIL_C_ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+
+int GLAD_GLX_VERSION_1_0 = 0;
+int GLAD_GLX_VERSION_1_1 = 0;
+int GLAD_GLX_VERSION_1_2 = 0;
+int GLAD_GLX_VERSION_1_3 = 0;
+int GLAD_GLX_VERSION_1_4 = 0;
+int GLAD_GLX_ARB_create_context = 0;
+int GLAD_GLX_ARB_create_context_profile = 0;
+int GLAD_GLX_ARB_get_proc_address = 0;
+int GLAD_GLX_EXT_swap_control = 0;
+int GLAD_GLX_MESA_swap_control = 0;
+int GLAD_GLX_SGI_swap_control = 0;
+
+
+
+PFNGLXCHOOSEFBCONFIGPROC glad_glXChooseFBConfig = NULL;
+PFNGLXCHOOSEVISUALPROC glad_glXChooseVisual = NULL;
+PFNGLXCOPYCONTEXTPROC glad_glXCopyContext = NULL;
+PFNGLXCREATECONTEXTPROC glad_glXCreateContext = NULL;
+PFNGLXCREATECONTEXTATTRIBSARBPROC glad_glXCreateContextAttribsARB = NULL;
+PFNGLXCREATEGLXPIXMAPPROC glad_glXCreateGLXPixmap = NULL;
+PFNGLXCREATENEWCONTEXTPROC glad_glXCreateNewContext = NULL;
+PFNGLXCREATEPBUFFERPROC glad_glXCreatePbuffer = NULL;
+PFNGLXCREATEPIXMAPPROC glad_glXCreatePixmap = NULL;
+PFNGLXCREATEWINDOWPROC glad_glXCreateWindow = NULL;
+PFNGLXDESTROYCONTEXTPROC glad_glXDestroyContext = NULL;
+PFNGLXDESTROYGLXPIXMAPPROC glad_glXDestroyGLXPixmap = NULL;
+PFNGLXDESTROYPBUFFERPROC glad_glXDestroyPbuffer = NULL;
+PFNGLXDESTROYPIXMAPPROC glad_glXDestroyPixmap = NULL;
+PFNGLXDESTROYWINDOWPROC glad_glXDestroyWindow = NULL;
+PFNGLXGETCLIENTSTRINGPROC glad_glXGetClientString = NULL;
+PFNGLXGETCONFIGPROC glad_glXGetConfig = NULL;
+PFNGLXGETCURRENTCONTEXTPROC glad_glXGetCurrentContext = NULL;
+PFNGLXGETCURRENTDISPLAYPROC glad_glXGetCurrentDisplay = NULL;
+PFNGLXGETCURRENTDRAWABLEPROC glad_glXGetCurrentDrawable = NULL;
+PFNGLXGETCURRENTREADDRAWABLEPROC glad_glXGetCurrentReadDrawable = NULL;
+PFNGLXGETFBCONFIGATTRIBPROC glad_glXGetFBConfigAttrib = NULL;
+PFNGLXGETFBCONFIGSPROC glad_glXGetFBConfigs = NULL;
+PFNGLXGETPROCADDRESSPROC glad_glXGetProcAddress = NULL;
+PFNGLXGETPROCADDRESSARBPROC glad_glXGetProcAddressARB = NULL;
+PFNGLXGETSELECTEDEVENTPROC glad_glXGetSelectedEvent = NULL;
+PFNGLXGETSWAPINTERVALMESAPROC glad_glXGetSwapIntervalMESA = NULL;
+PFNGLXGETVISUALFROMFBCONFIGPROC glad_glXGetVisualFromFBConfig = NULL;
+PFNGLXISDIRECTPROC glad_glXIsDirect = NULL;
+PFNGLXMAKECONTEXTCURRENTPROC glad_glXMakeContextCurrent = NULL;
+PFNGLXMAKECURRENTPROC glad_glXMakeCurrent = NULL;
+PFNGLXQUERYCONTEXTPROC glad_glXQueryContext = NULL;
+PFNGLXQUERYDRAWABLEPROC glad_glXQueryDrawable = NULL;
+PFNGLXQUERYEXTENSIONPROC glad_glXQueryExtension = NULL;
+PFNGLXQUERYEXTENSIONSSTRINGPROC glad_glXQueryExtensionsString = NULL;
+PFNGLXQUERYSERVERSTRINGPROC glad_glXQueryServerString = NULL;
+PFNGLXQUERYVERSIONPROC glad_glXQueryVersion = NULL;
+PFNGLXSELECTEVENTPROC glad_glXSelectEvent = NULL;
+PFNGLXSWAPBUFFERSPROC glad_glXSwapBuffers = NULL;
+PFNGLXSWAPINTERVALEXTPROC glad_glXSwapIntervalEXT = NULL;
+PFNGLXSWAPINTERVALMESAPROC glad_glXSwapIntervalMESA = NULL;
+PFNGLXSWAPINTERVALSGIPROC glad_glXSwapIntervalSGI = NULL;
+PFNGLXUSEXFONTPROC glad_glXUseXFont = NULL;
+PFNGLXWAITGLPROC glad_glXWaitGL = NULL;
+PFNGLXWAITXPROC glad_glXWaitX = NULL;
+
+
+static void glad_glx_load_GLX_VERSION_1_0( GLADuserptrloadfunc load, void* userptr) {
+    if(!GLAD_GLX_VERSION_1_0) return;
+    glad_glXChooseVisual = (PFNGLXCHOOSEVISUALPROC) load(userptr, "glXChooseVisual");
+    glad_glXCopyContext = (PFNGLXCOPYCONTEXTPROC) load(userptr, "glXCopyContext");
+    glad_glXCreateContext = (PFNGLXCREATECONTEXTPROC) load(userptr, "glXCreateContext");
+    glad_glXCreateGLXPixmap = (PFNGLXCREATEGLXPIXMAPPROC) load(userptr, "glXCreateGLXPixmap");
+    glad_glXDestroyContext = (PFNGLXDESTROYCONTEXTPROC) load(userptr, "glXDestroyContext");
+    glad_glXDestroyGLXPixmap = (PFNGLXDESTROYGLXPIXMAPPROC) load(userptr, "glXDestroyGLXPixmap");
+    glad_glXGetConfig = (PFNGLXGETCONFIGPROC) load(userptr, "glXGetConfig");
+    glad_glXGetCurrentContext = (PFNGLXGETCURRENTCONTEXTPROC) load(userptr, "glXGetCurrentContext");
+    glad_glXGetCurrentDrawable = (PFNGLXGETCURRENTDRAWABLEPROC) load(userptr, "glXGetCurrentDrawable");
+    glad_glXIsDirect = (PFNGLXISDIRECTPROC) load(userptr, "glXIsDirect");
+    glad_glXMakeCurrent = (PFNGLXMAKECURRENTPROC) load(userptr, "glXMakeCurrent");
+    glad_glXQueryExtension = (PFNGLXQUERYEXTENSIONPROC) load(userptr, "glXQueryExtension");
+    glad_glXQueryVersion = (PFNGLXQUERYVERSIONPROC) load(userptr, "glXQueryVersion");
+    glad_glXSwapBuffers = (PFNGLXSWAPBUFFERSPROC) load(userptr, "glXSwapBuffers");
+    glad_glXUseXFont = (PFNGLXUSEXFONTPROC) load(userptr, "glXUseXFont");
+    glad_glXWaitGL = (PFNGLXWAITGLPROC) load(userptr, "glXWaitGL");
+    glad_glXWaitX = (PFNGLXWAITXPROC) load(userptr, "glXWaitX");
+}
+static void glad_glx_load_GLX_VERSION_1_1( GLADuserptrloadfunc load, void* userptr) {
+    if(!GLAD_GLX_VERSION_1_1) return;
+    glad_glXGetClientString = (PFNGLXGETCLIENTSTRINGPROC) load(userptr, "glXGetClientString");
+    glad_glXQueryExtensionsString = (PFNGLXQUERYEXTENSIONSSTRINGPROC) load(userptr, "glXQueryExtensionsString");
+    glad_glXQueryServerString = (PFNGLXQUERYSERVERSTRINGPROC) load(userptr, "glXQueryServerString");
+}
+static void glad_glx_load_GLX_VERSION_1_2( GLADuserptrloadfunc load, void* userptr) {
+    if(!GLAD_GLX_VERSION_1_2) return;
+    glad_glXGetCurrentDisplay = (PFNGLXGETCURRENTDISPLAYPROC) load(userptr, "glXGetCurrentDisplay");
+}
+static void glad_glx_load_GLX_VERSION_1_3( GLADuserptrloadfunc load, void* userptr) {
+    if(!GLAD_GLX_VERSION_1_3) return;
+    glad_glXChooseFBConfig = (PFNGLXCHOOSEFBCONFIGPROC) load(userptr, "glXChooseFBConfig");
+    glad_glXCreateNewContext = (PFNGLXCREATENEWCONTEXTPROC) load(userptr, "glXCreateNewContext");
+    glad_glXCreatePbuffer = (PFNGLXCREATEPBUFFERPROC) load(userptr, "glXCreatePbuffer");
+    glad_glXCreatePixmap = (PFNGLXCREATEPIXMAPPROC) load(userptr, "glXCreatePixmap");
+    glad_glXCreateWindow = (PFNGLXCREATEWINDOWPROC) load(userptr, "glXCreateWindow");
+    glad_glXDestroyPbuffer = (PFNGLXDESTROYPBUFFERPROC) load(userptr, "glXDestroyPbuffer");
+    glad_glXDestroyPixmap = (PFNGLXDESTROYPIXMAPPROC) load(userptr, "glXDestroyPixmap");
+    glad_glXDestroyWindow = (PFNGLXDESTROYWINDOWPROC) load(userptr, "glXDestroyWindow");
+    glad_glXGetCurrentReadDrawable = (PFNGLXGETCURRENTREADDRAWABLEPROC) load(userptr, "glXGetCurrentReadDrawable");
+    glad_glXGetFBConfigAttrib = (PFNGLXGETFBCONFIGATTRIBPROC) load(userptr, "glXGetFBConfigAttrib");
+    glad_glXGetFBConfigs = (PFNGLXGETFBCONFIGSPROC) load(userptr, "glXGetFBConfigs");
+    glad_glXGetSelectedEvent = (PFNGLXGETSELECTEDEVENTPROC) load(userptr, "glXGetSelectedEvent");
+    glad_glXGetVisualFromFBConfig = (PFNGLXGETVISUALFROMFBCONFIGPROC) load(userptr, "glXGetVisualFromFBConfig");
+    glad_glXMakeContextCurrent = (PFNGLXMAKECONTEXTCURRENTPROC) load(userptr, "glXMakeContextCurrent");
+    glad_glXQueryContext = (PFNGLXQUERYCONTEXTPROC) load(userptr, "glXQueryContext");
+    glad_glXQueryDrawable = (PFNGLXQUERYDRAWABLEPROC) load(userptr, "glXQueryDrawable");
+    glad_glXSelectEvent = (PFNGLXSELECTEVENTPROC) load(userptr, "glXSelectEvent");
+}
+static void glad_glx_load_GLX_VERSION_1_4( GLADuserptrloadfunc load, void* userptr) {
+    if(!GLAD_GLX_VERSION_1_4) return;
+    glad_glXGetProcAddress = (PFNGLXGETPROCADDRESSPROC) load(userptr, "glXGetProcAddress");
+}
+static void glad_glx_load_GLX_ARB_create_context( GLADuserptrloadfunc load, void* userptr) {
+    if(!GLAD_GLX_ARB_create_context) return;
+    glad_glXCreateContextAttribsARB = (PFNGLXCREATECONTEXTATTRIBSARBPROC) load(userptr, "glXCreateContextAttribsARB");
+}
+static void glad_glx_load_GLX_ARB_get_proc_address( GLADuserptrloadfunc load, void* userptr) {
+    if(!GLAD_GLX_ARB_get_proc_address) return;
+    glad_glXGetProcAddressARB = (PFNGLXGETPROCADDRESSARBPROC) load(userptr, "glXGetProcAddressARB");
+}
+static void glad_glx_load_GLX_EXT_swap_control( GLADuserptrloadfunc load, void* userptr) {
+    if(!GLAD_GLX_EXT_swap_control) return;
+    glad_glXSwapIntervalEXT = (PFNGLXSWAPINTERVALEXTPROC) load(userptr, "glXSwapIntervalEXT");
+}
+static void glad_glx_load_GLX_MESA_swap_control( GLADuserptrloadfunc load, void* userptr) {
+    if(!GLAD_GLX_MESA_swap_control) return;
+    glad_glXGetSwapIntervalMESA = (PFNGLXGETSWAPINTERVALMESAPROC) load(userptr, "glXGetSwapIntervalMESA");
+    glad_glXSwapIntervalMESA = (PFNGLXSWAPINTERVALMESAPROC) load(userptr, "glXSwapIntervalMESA");
+}
+static void glad_glx_load_GLX_SGI_swap_control( GLADuserptrloadfunc load, void* userptr) {
+    if(!GLAD_GLX_SGI_swap_control) return;
+    glad_glXSwapIntervalSGI = (PFNGLXSWAPINTERVALSGIPROC) load(userptr, "glXSwapIntervalSGI");
+}
+
+
+
+static int glad_glx_has_extension(Display *display, int screen, const char *ext) {
+#ifndef GLX_VERSION_1_1
+    GLAD_UNUSED(display);
+    GLAD_UNUSED(screen);
+    GLAD_UNUSED(ext);
+#else
+    const char *terminator;
+    const char *loc;
+    const char *extensions;
+
+    if (glXQueryExtensionsString == NULL) {
+        return 0;
+    }
+
+    extensions = glXQueryExtensionsString(display, screen);
+
+    if(extensions == NULL || ext == NULL) {
+        return 0;
+    }
+
+    while(1) {
+        loc = strstr(extensions, ext);
+        if(loc == NULL)
+            break;
+
+        terminator = loc + strlen(ext);
+        if((loc == extensions || *(loc - 1) == ' ') &&
+            (*terminator == ' ' || *terminator == '\0')) {
+            return 1;
+        }
+        extensions = terminator;
+    }
+#endif
+
+    return 0;
+}
+
+static GLADapiproc glad_glx_get_proc_from_userptr(void *userptr, const char* name) {
+    return (GLAD_GNUC_EXTENSION (GLADapiproc (*)(const char *name)) userptr)(name);
+}
+
+static int glad_glx_find_extensions(Display *display, int screen) {
+    GLAD_GLX_ARB_create_context = glad_glx_has_extension(display, screen, "GLX_ARB_create_context");
+    GLAD_GLX_ARB_create_context_profile = glad_glx_has_extension(display, screen, "GLX_ARB_create_context_profile");
+    GLAD_GLX_ARB_get_proc_address = glad_glx_has_extension(display, screen, "GLX_ARB_get_proc_address");
+    GLAD_GLX_EXT_swap_control = glad_glx_has_extension(display, screen, "GLX_EXT_swap_control");
+    GLAD_GLX_MESA_swap_control = glad_glx_has_extension(display, screen, "GLX_MESA_swap_control");
+    GLAD_GLX_SGI_swap_control = glad_glx_has_extension(display, screen, "GLX_SGI_swap_control");
+    return 1;
+}
+
+static int glad_glx_find_core_glx(Display **display, int *screen) {
+    int major = 0, minor = 0;
+    if(*display == NULL) {
+#ifdef GLAD_GLX_NO_X11
+        GLAD_UNUSED(screen);
+        return 0;
+#else
+        *display = XOpenDisplay(0);
+        if (*display == NULL) {
+            return 0;
+        }
+        *screen = XScreenNumberOfScreen(XDefaultScreenOfDisplay(*display));
+#endif
+    }
+    glXQueryVersion(*display, &major, &minor);
+    GLAD_GLX_VERSION_1_0 = (major == 1 && minor >= 0) || major > 1;
+    GLAD_GLX_VERSION_1_1 = (major == 1 && minor >= 1) || major > 1;
+    GLAD_GLX_VERSION_1_2 = (major == 1 && minor >= 2) || major > 1;
+    GLAD_GLX_VERSION_1_3 = (major == 1 && minor >= 3) || major > 1;
+    GLAD_GLX_VERSION_1_4 = (major == 1 && minor >= 4) || major > 1;
+    return GLAD_MAKE_VERSION(major, minor);
+}
+
+int gladLoadGLXUserPtr(Display *display, int screen, GLADuserptrloadfunc load, void *userptr) {
+    int version;
+    glXQueryVersion = (PFNGLXQUERYVERSIONPROC) load(userptr, "glXQueryVersion");
+    if(glXQueryVersion == NULL) return 0;
+    version = glad_glx_find_core_glx(&display, &screen);
+
+    glad_glx_load_GLX_VERSION_1_0(load, userptr);
+    glad_glx_load_GLX_VERSION_1_1(load, userptr);
+    glad_glx_load_GLX_VERSION_1_2(load, userptr);
+    glad_glx_load_GLX_VERSION_1_3(load, userptr);
+    glad_glx_load_GLX_VERSION_1_4(load, userptr);
+
+    if (!glad_glx_find_extensions(display, screen)) return 0;
+    glad_glx_load_GLX_ARB_create_context(load, userptr);
+    glad_glx_load_GLX_ARB_get_proc_address(load, userptr);
+    glad_glx_load_GLX_EXT_swap_control(load, userptr);
+    glad_glx_load_GLX_MESA_swap_control(load, userptr);
+    glad_glx_load_GLX_SGI_swap_control(load, userptr);
+
+
+    return version;
+}
+
+int gladLoadGLX(Display *display, int screen, GLADloadfunc load) {
+    return gladLoadGLXUserPtr(display, screen, glad_glx_get_proc_from_userptr, GLAD_GNUC_EXTENSION (void*) load);
+}
+
+ 
+
+#ifdef GLAD_GLX
+
+#ifndef GLAD_LOADER_LIBRARY_C_
+#define GLAD_LOADER_LIBRARY_C_
+
+#include <stddef.h>
+#include <stdlib.h>
+
+#if GLAD_PLATFORM_WIN32
+#include <windows.h>
+#else
+#include <dlfcn.h>
+#endif
+
+
+static void* glad_get_dlopen_handle(const char *lib_names[], int length) {
+    void *handle = NULL;
+    int i;
+
+    for (i = 0; i < length; ++i) {
+#if GLAD_PLATFORM_WIN32
+  #if GLAD_PLATFORM_UWP
+        size_t buffer_size = (strlen(lib_names[i]) + 1) * sizeof(WCHAR);
+        LPWSTR buffer = (LPWSTR) malloc(buffer_size);
+        if (buffer != NULL) {
+            int ret = MultiByteToWideChar(CP_ACP, 0, lib_names[i], -1, buffer, buffer_size);
+            if (ret != 0) {
+                handle = (void*) LoadPackagedLibrary(buffer, 0);
+            }
+            free((void*) buffer);
+        }
+  #else
+        handle = (void*) LoadLibraryA(lib_names[i]);
+  #endif
+#else
+        handle = dlopen(lib_names[i], RTLD_LAZY | RTLD_LOCAL);
+#endif
+        if (handle != NULL) {
+            return handle;
+        }
+    }
+
+    return NULL;
+}
+
+static void glad_close_dlopen_handle(void* handle) {
+    if (handle != NULL) {
+#if GLAD_PLATFORM_WIN32
+        FreeLibrary((HMODULE) handle);
+#else
+        dlclose(handle);
+#endif
+    }
+}
+
+static GLADapiproc glad_dlsym_handle(void* handle, const char *name) {
+    if (handle == NULL) {
+        return NULL;
+    }
+
+#if GLAD_PLATFORM_WIN32
+    return (GLADapiproc) GetProcAddress((HMODULE) handle, name);
+#else
+    return GLAD_GNUC_EXTENSION (GLADapiproc) dlsym(handle, name);
+#endif
+}
+
+#endif /* GLAD_LOADER_LIBRARY_C_ */
+
+typedef void* (GLAD_API_PTR *GLADglxprocaddrfunc)(const char*);
+
+static GLADapiproc glad_glx_get_proc(void *userptr, const char *name) {
+    return GLAD_GNUC_EXTENSION ((GLADapiproc (*)(const char *name)) userptr)(name);
+}
+
+static void* _glx_handle;
+
+static void* glad_glx_dlopen_handle(void) {
+    static const char *NAMES[] = {
+#if defined __CYGWIN__
+        "libGL-1.so",
+#endif
+        "libGL.so.1",
+        "libGL.so"
+    };
+
+    if (_glx_handle == NULL) {
+        _glx_handle = glad_get_dlopen_handle(NAMES, sizeof(NAMES) / sizeof(NAMES[0]));
+    }
+
+    return _glx_handle;
+}
+
+int gladLoaderLoadGLX(Display *display, int screen) {
+    int version = 0;
+    void *handle = NULL;
+    int did_load = 0;
+    GLADglxprocaddrfunc loader;
+
+    did_load = _glx_handle == NULL;
+    handle = glad_glx_dlopen_handle();
+    if (handle != NULL) {
+        loader = (GLADglxprocaddrfunc) glad_dlsym_handle(handle, "glXGetProcAddressARB");
+        if (loader != NULL) {
+            version = gladLoadGLXUserPtr(display, screen, glad_glx_get_proc, GLAD_GNUC_EXTENSION (void*) loader);
+        }
+
+        if (!version && did_load) {
+            gladLoaderUnloadGLX();
+        }
+    }
+
+    return version;
+}
+
+
+void gladLoaderUnloadGLX() {
+    if (_glx_handle != NULL) {
+        glad_close_dlopen_handle(_glx_handle);
+        _glx_handle = NULL;
+    }
+}
+
+#endif /* GLAD_GLX */
+
+#ifdef __cplusplus
+}
+#endif