/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997-2009 Sam Lantinga

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with _this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Sam Lantinga

slouken@libsdl.org

*/

#include "SDL_config.h"

#include "SDL_x11video.h"

/* GLX implementation of SDL OpenGL support */

#if SDL_VIDEO_OPENGL_GLX

#include "SDL_loadso.h"

#if defined(__IRIX__)

/* IRIX doesn't have a GL library versioning system */

#define DEFAULT_OPENGL "libGL.so"

#elif defined(__MACOSX__)

#define DEFAULT_OPENGL "/usr/X11R6/lib/libGL.1.dylib"

#elif defined(__QNXNTO__)

#define DEFAULT_OPENGL "libGL.so.3"

#else

#define DEFAULT_OPENGL "libGL.so.1"

#endif

#ifndef GLX_ARB_multisample

#define GLX_ARB_multisample

#define GLX_SAMPLE_BUFFERS_ARB 100000

#define GLX_SAMPLES_ARB 100001

#endif

#ifndef GLX_EXT_visual_rating

#define GLX_EXT_visual_rating

#define GLX_VISUAL_CAVEAT_EXT 0x20

#define GLX_NONE_EXT 0x8000

#define GLX_SLOW_VISUAL_EXT 0x8001

#define GLX_NON_CONFORMANT_VISUAL_EXT 0x800D

#endif

#define OPENGL_REQUIRS_DLOPEN

#if defined(OPENGL_REQUIRS_DLOPEN) && defined(SDL_LOADSO_DLOPEN)

#include <dlfcn.h>

#define GL_LoadObject(X) dlopen(X, (RTLD_NOW|RTLD_GLOBAL))

#define GL_LoadFunction dlsym

#define GL_UnloadObject dlclose

#else

#define GL_LoadObject SDL_LoadObject

#define GL_LoadFunction SDL_LoadFunction

#define GL_UnloadObject SDL_UnloadObject

#endif

static void X11_GL_InitExtensions(_THIS);

int

X11_GL_LoadLibrary(_THIS, const char *path)

{

void *handle;

/* Load the OpenGL library */

if (path == NULL) {

path = SDL_getenv("SDL_OPENGL_LIBRARY");

}

if (path == NULL) {

path = DEFAULT_OPENGL;

}

_this->gl_config.dll_handle = SDL_LoadObject(path);

if (!_this->gl_config.dll_handle) {

return -1;

}

SDL_strlcpy(_this->gl_config.driver_path, path,

SDL_arraysize(_this->gl_config.driver_path));

/* Allocate OpenGL memory */

_this->gl_data =

(struct SDL_GLDriverData *) SDL_calloc(1,

sizeof(struct

SDL_GLDriverData));

if (!_this->gl_data) {

SDL_OutOfMemory();

return -1;

}

/* Load function pointers */

handle = _this->gl_config.dll_handle;

_this->gl_data->glXGetProcAddress =

(void *(*)(const GLubyte *)) GL_LoadFunction(handle,

"glXGetProcAddressARB");

_this->gl_data->glXChooseVisual =

(XVisualInfo * (*)(Display *, int, int *)) GL_LoadFunction(handle,

"glXChooseVisual");

_this->gl_data->glXCreateContext =

(GLXContext(*)(Display *, XVisualInfo *, GLXContext, int))

GL_LoadFunction(handle, "glXCreateContext");

_this->gl_data->glXDestroyContext =

(void (*)(Display *, GLXContext)) GL_LoadFunction(handle,

"glXDestroyContext");

_this->gl_data->glXMakeCurrent =

(int (*)(Display *, GLXDrawable, GLXContext)) GL_LoadFunction(handle,

"glXMakeCurrent");

_this->gl_data->glXSwapBuffers =

(void (*)(Display *, GLXDrawable)) GL_LoadFunction(handle,

"glXSwapBuffers");

if (!_this->gl_data->glXChooseVisual ||

!_this->gl_data->glXCreateContext ||

!_this->gl_data->glXDestroyContext ||

!_this->gl_data->glXMakeCurrent || !_this->gl_data->glXSwapBuffers) {

SDL_SetError("Could not retrieve OpenGL functions");

return -1;

}

/* Initialize extensions */

X11_GL_InitExtensions(_this);

return 0;

}

void *

X11_GL_GetProcAddress(_THIS, const char *proc)

{

void *handle;

handle = _this->gl_config.dll_handle;

if (_this->gl_data->glXGetProcAddress) {

return _this->gl_data->glXGetProcAddress((const GLubyte *) proc);

}

return GL_LoadFunction(handle, proc);

}

void

X11_GL_UnloadLibrary(_THIS)

{

/* Don't actually unload the library, since it may have registered

* X11 shutdown hooks, per the notes at:

* http://dri.sourceforge.net/doc/DRIuserguide.html

*/

#if 0

GL_UnloadObject(_this->gl_config.dll_handle);

_this->gl_config.dll_handle = NULL;

#endif

/* Free OpenGL memory */

SDL_free(_this->gl_data);

_this->gl_data = NULL;

}

static SDL_bool

HasExtension(const char *extension, const char *extensions)

{

const char *start;

const char *where, *terminator;

/* Extension names should not have spaces. */

where = SDL_strchr(extension, ' ');

if (where || *extension == '\0')

return SDL_FALSE;

if (!extensions)

return SDL_FALSE;

/* It takes a bit of care to be fool-proof about parsing the

* OpenGL extensions string. Don't be fooled by sub-strings,

* etc. */

start = extensions;

for (;;) {

where = SDL_strstr(start, extension);

if (!where)

break;

terminator = where + SDL_strlen(extension);

if (where == start || *(where - 1) == ' ')

if (*terminator == ' ' || *terminator == '\0')

return SDL_TRUE;

start = terminator;

}

return SDL_FALSE;

}

static void

X11_GL_InitExtensions(_THIS)

{

Display *display = ((SDL_VideoData *) _this->driverdata)->display;

int screen = ((SDL_DisplayData *) SDL_CurrentDisplay.driverdata)->screen;

XVisualInfo *vinfo;

XSetWindowAttributes xattr;

Window w;

GLXContext context;

const char *(*glXQueryExtensionsStringFunc) (Display *, int);

const char *extensions;

vinfo = X11_GL_GetVisual(_this, display, screen);

if (!vinfo) {

return;

}

xattr.background_pixel = 0;

xattr.border_pixel = 0;

xattr.colormap =

XCreateColormap(display, RootWindow(display, screen), vinfo->visual,

AllocNone);

w = XCreateWindow(display, RootWindow(display, screen), 0, 0, 32, 32, 0,

vinfo->depth, InputOutput, vinfo->visual,

(CWBackPixel | CWBorderPixel | CWColormap), &xattr);

context = _this->gl_data->glXCreateContext(display, vinfo, NULL, True);

if (context) {

_this->gl_data->glXMakeCurrent(display, w, context);

}

XFree(vinfo);

glXQueryExtensionsStringFunc =

(const char *(*)(Display *, int)) X11_GL_GetProcAddress(_this,

"glXQueryExtensionsString");

if (glXQueryExtensionsStringFunc) {

extensions = glXQueryExtensionsStringFunc(display, screen);

} else {

extensions = NULL;

}

/* Check for SGI_swap_control */

if (HasExtension("GLX_SGI_swap_control", extensions)) {

_this->gl_data->glXSwapIntervalSGI =

(int (*)(int)) X11_GL_GetProcAddress(_this, "glXSwapIntervalSGI");

}

/* Check for GLX_MESA_swap_control */

if (HasExtension("GLX_MESA_swap_control", extensions)) {

_this->gl_data->glXSwapIntervalMESA =

(GLint(*)(unsigned)) X11_GL_GetProcAddress(_this,

"glXSwapIntervalMESA");

_this->gl_data->glXGetSwapIntervalMESA =

(GLint(*)(void)) X11_GL_GetProcAddress(_this,

"glXGetSwapIntervalMESA");

}

/* Check for GLX_EXT_visual_rating */

if (HasExtension("GLX_EXT_visual_rating", extensions)) {

_this->gl_data->HAS_GLX_EXT_visual_rating = SDL_TRUE;

}

if (context) {

_this->gl_data->glXMakeCurrent(display, None, NULL);

_this->gl_data->glXDestroyContext(display, context);

}

XDestroyWindow(display, w);

X11_PumpEvents(_this);

}

XVisualInfo *

X11_GL_GetVisual(_THIS, Display * display, int screen)

{

XVisualInfo *vinfo;

/* 64 seems nice. */

int attribs[64];

int i;

/* Setup our GLX attributes according to the gl_config. */

i = 0;

attribs[i++] = GLX_RGBA;

attribs[i++] = GLX_RED_SIZE;

attribs[i++] = _this->gl_config.red_size;

attribs[i++] = GLX_GREEN_SIZE;

attribs[i++] = _this->gl_config.green_size;

attribs[i++] = GLX_BLUE_SIZE;

attribs[i++] = _this->gl_config.blue_size;

if (_this->gl_config.alpha_size) {

attribs[i++] = GLX_ALPHA_SIZE;

attribs[i++] = _this->gl_config.alpha_size;

}

if (_this->gl_config.buffer_size) {

attribs[i++] = GLX_BUFFER_SIZE;

attribs[i++] = _this->gl_config.buffer_size;

}

if (_this->gl_config.double_buffer) {

attribs[i++] = GLX_DOUBLEBUFFER;

}

attribs[i++] = GLX_DEPTH_SIZE;

attribs[i++] = _this->gl_config.depth_size;

if (_this->gl_config.stencil_size) {

attribs[i++] = GLX_STENCIL_SIZE;

attribs[i++] = _this->gl_config.stencil_size;

}

if (_this->gl_config.accum_red_size) {

attribs[i++] = GLX_ACCUM_RED_SIZE;

attribs[i++] = _this->gl_config.accum_red_size;

}

if (_this->gl_config.accum_green_size) {

attribs[i++] = GLX_ACCUM_GREEN_SIZE;

attribs[i++] = _this->gl_config.accum_green_size;

}

if (_this->gl_config.accum_blue_size) {

attribs[i++] = GLX_ACCUM_BLUE_SIZE;

attribs[i++] = _this->gl_config.accum_blue_size;

}

if (_this->gl_config.accum_alpha_size) {

attribs[i++] = GLX_ACCUM_ALPHA_SIZE;

attribs[i++] = _this->gl_config.accum_alpha_size;

}

if (_this->gl_config.stereo) {

attribs[i++] = GLX_STEREO;

}

if (_this->gl_config.multisamplebuffers) {

attribs[i++] = GLX_SAMPLE_BUFFERS_ARB;

attribs[i++] = _this->gl_config.multisamplebuffers;

}

if (_this->gl_config.multisamplesamples) {

attribs[i++] = GLX_SAMPLES_ARB;

attribs[i++] = _this->gl_config.multisamplesamples;

}

if (_this->gl_config.accelerated >= 0

&& _this->gl_data->HAS_GLX_EXT_visual_rating) {

attribs[i++] = GLX_VISUAL_CAVEAT_EXT;

attribs[i++] = GLX_NONE_EXT;

}

#ifdef GLX_DIRECT_COLOR /* Try for a DirectColor visual for gamma support */

if (X11_UseDirectColorVisuals()) {

attribs[i++] = GLX_X_VISUAL_TYPE;

attribs[i++] = GLX_DIRECT_COLOR;

}

#endif

attribs[i++] = None;

vinfo = _this->gl_data->glXChooseVisual(display, screen, attribs);

#ifdef GLX_DIRECT_COLOR

if (!vinfo && X11_UseDirectColorVisuals()) { /* No DirectColor visual? Try again.. */

attribs[i - 3] = None;

vinfo = _this->gl_data->glXChooseVisual(display, screen, attribs);

}

#endif

if (!vinfo) {

SDL_SetError("Couldn't find matching GLX visual");

}

return vinfo;

}

SDL_GLContext

X11_GL_CreateContext(_THIS, SDL_Window * window)

{

SDL_WindowData *data = (SDL_WindowData *) window->driverdata;

Display *display = data->videodata->display;

int screen =

((SDL_DisplayData *) SDL_GetDisplayFromWindow(window)->

driverdata)->screen;

XWindowAttributes xattr;

XVisualInfo v, *vinfo;

int n;

GLXContext context = NULL;

/* We do this to create a clean separation between X and GLX errors. */

XSync(display, False);

XGetWindowAttributes(display, data->window, &xattr);

v.screen = screen;

v.visualid = XVisualIDFromVisual(xattr.visual);

vinfo = XGetVisualInfo(display, VisualScreenMask | VisualIDMask, &v, &n);

if (vinfo) {

context =

_this->gl_data->glXCreateContext(display, vinfo, NULL, True);

XFree(vinfo);

}

XSync(display, False);

if (!context) {

SDL_SetError("Could not create GL context");

return NULL;

}

if (X11_GL_MakeCurrent(_this, window, context) < 0) {

X11_GL_DeleteContext(_this, context);

return NULL;

}

return context;

}

int

X11_GL_MakeCurrent(_THIS, SDL_Window * window, SDL_GLContext context)

{

Display *display = ((SDL_VideoData *) _this->driverdata)->display;

Window drawable =

(window ? ((SDL_WindowData *) window->driverdata)->window : None);

GLXContext glx_context = (GLXContext) context;

int status;

status = 0;

if (!_this->gl_data->glXMakeCurrent(display, drawable, glx_context)) {

SDL_SetError("Unable to make GL context current");

status = -1;

}

XSync(display, False);

return (status);

}

/*

0 is a valid argument to glxSwapIntervalMESA and setting it to 0

with the MESA version of the extension will undo the effect of a

previous call with a value that is greater than zero (or at least

that is what the FM says. OTOH, 0 is an invalid argument to

glxSwapIntervalSGI and it returns an error if you call it with 0 as

an argument.

*/

static int swapinterval = -1;

int

X11_GL_SetSwapInterval(_THIS, int interval)

{

int status;

if (_this->gl_data->glXSwapIntervalMESA) {

status = _this->gl_data->glXSwapIntervalMESA(interval);

if (status != 0) {

SDL_SetError("glxSwapIntervalMESA failed");

status = -1;

} else {

swapinterval = interval;

}

} else if (_this->gl_data->glXSwapIntervalSGI) {

status = _this->gl_data->glXSwapIntervalSGI(interval);

if (status != 0) {

SDL_SetError("glxSwapIntervalSGI failed");

status = -1;

} else {

swapinterval = interval;

}

} else {

SDL_Unsupported();

status = -1;

}

return status;

}

int

X11_GL_GetSwapInterval(_THIS)

{

if (_this->gl_data->glXGetSwapIntervalMESA) {

return _this->gl_data->glXGetSwapIntervalMESA();

} else {

return swapinterval;

}

}

void

X11_GL_SwapWindow(_THIS, SDL_Window * window)

{

SDL_WindowData *data = (SDL_WindowData *) window->driverdata;

Display *display = data->videodata->display;

_this->gl_data->glXSwapBuffers(display, data->window);

}

void

X11_GL_DeleteContext(_THIS, SDL_GLContext context)

{

Display *display = ((SDL_VideoData *) _this->driverdata)->display;

GLXContext glx_context = (GLXContext) context;

_this->gl_data->glXDestroyContext(display, glx_context);

XSync(display, False);

}

#endif /* SDL_VIDEO_OPENGL_GLX */

/* vi: set ts=4 sw=4 expandtab: */