src/video/x11/SDL_x11opengles.c
author Sam Lantinga <slouken@libsdl.org>
Sun, 08 Jan 2012 02:23:37 -0500
changeset 6188 e82023802002
parent 6138 4c64952a58fb
child 6190 519380462400
permissions -rwxr-xr-x
Fixed bug 1242 - PATCH: Improve support for OpenGL ES under X11 Scott Percival 2011-07-03 06:41:51 PDT This submission is aimed at making life easier for OpenGL ES capable devices running a X11 stack (e.g. Maemo, Meego, TrimSlice, other ARM SoC boards not running Android). SDL's Pandora support already has the neccesary GLES-to-X11 glue code, however it's all ghetto'd off in Makefile.pandora and not very flexible. The patch: - adds an awesome --enable-video-opengles option to configure - re-modifies the opengles and opengles2 SDL_renderers to use function pointers - no idea why this was removed? - for SDL_Renderers, links in libGLESv1_CM, libGLES_CM (for PowerVR fans) or libGLESv2 at runtime - links in libEGL.so at runtime - the old code made an assumption that eglFunctions could be pulled from the active GLES library, PowerVR for one doesn't let you do that with their libGLESv2 - allows you to pick which of GLES v1 or v2 to load via SDL_GL_CONTEXT_MAJOR_VERSION So far I've tested this on a Nokia N900 (OMAP 3430/SGX 530 running Maemo 5) and a Toshiba AC100 (Tegra 2 running Ubuntu 10.10). I haven't tested it on... well, everything that isn't those two, such as a Pandora, iOS or Android device. The Pandora specific code should be kept intact (fingers crossed), and nothing painfully drastic has been added to the SDL_renderers. The library loading sequence in SDL_x11opengles has been updated to accomodate both NVIDIA's propensity to let developers get away with murder and PowerVR's alternative of punishing every missed step. The test apps work okay with GLES or GLES2 as the renderer. For some reason alpha blending doesn't seem to work on the Tegra 2; last week NVIDIA pushed out a new set of X11 GLES drivers, so I'll try and investigate once I upgrade those. Also, this patch adds things to configure.in, include/SDL_config.h.in and test/configure.in. I didn't know what the policy was re. committing generated spaghetti from autotools, so ./autogen.sh has to be run again. Sorry. I think that's about everything, let me know if there's anything I've overlooked.

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_config.h"

#if SDL_VIDEO_DRIVER_X11 && SDL_VIDEO_OPENGL_ES

#include "SDL_x11video.h"
#include "SDL_x11opengles.h"

#define DEFAULT_EGL "/usr/lib/libEGL.so"
#define DEFAULT_OGL_ES2 "/usr/lib/libGLESv2.so"
#define DEFAULT_OGL_ES_PVR "/usr/lib/libGLES_CM.so"
#define DEFAULT_OGL_ES "/usr/lib/libGLESv1_CM.so"

#define LOAD_FUNC(NAME) \
	*((void**)&_this->gles_data->NAME) = dlsym(handle, #NAME); \
	if (!_this->gles_data->NAME) \
	{ \
		SDL_SetError("Could not retrieve EGL function " #NAME); \
		return -1; \
	}

/* GLES implementation of SDL OpenGL support */

void *
X11_GLES_GetProcAddress(_THIS, const char *proc)
{
    static char procname[1024];
    void *handle;
    void *retval;

    handle = _this->gles_data->egl_dll_handle;
    if (_this->gles_data->eglGetProcAddress) {
        retval = _this->gles_data->eglGetProcAddress(proc);
        if (retval) {
            return retval;
        }
    }
    
    handle = _this->gl_config.dll_handle;
#if defined(__OpenBSD__) && !defined(__ELF__)
#undef dlsym(x,y);
#endif
    retval = dlsym(handle, proc);
    if (!retval && strlen(proc) <= 1022) {
        procname[0] = '_';
        strcpy(procname + 1, proc);
        retval = dlsym(handle, procname);
    }
    return retval;
}

void
X11_GLES_UnloadLibrary(_THIS)
{
    if (_this->gl_config.driver_loaded) {
        _this->gles_data->eglTerminate(_this->gles_data->egl_display);

        dlclose(_this->gl_config.dll_handle);
        dlclose(_this->gles_data->egl_dll_handle);

        _this->gles_data->eglGetProcAddress = NULL;
        _this->gles_data->eglChooseConfig = NULL;
        _this->gles_data->eglCreateContext = NULL;
        _this->gles_data->eglCreateWindowSurface = NULL;
        _this->gles_data->eglDestroyContext = NULL;
        _this->gles_data->eglDestroySurface = NULL;
        _this->gles_data->eglMakeCurrent = NULL;
        _this->gles_data->eglSwapBuffers = NULL;
        _this->gles_data->eglGetDisplay = NULL;
        _this->gles_data->eglTerminate = NULL;

        _this->gl_config.dll_handle = NULL;
        _this->gl_config.driver_loaded = 0;
    }
}

int
X11_GLES_LoadLibrary(_THIS, const char *path)
{
    void *handle;
    int dlopen_flags;

    SDL_VideoData *data = (SDL_VideoData *) _this->driverdata;

    if (_this->gles_data->egl_active) {
        SDL_SetError("OpenGL ES context already created");
        return -1;
    }
#ifdef RTLD_GLOBAL
    dlopen_flags = RTLD_LAZY | RTLD_GLOBAL;
#else
    dlopen_flags = RTLD_LAZY;
#endif
    handle = dlopen(path, dlopen_flags);
    /* Catch the case where the application isn't linked with EGL */
    if ((dlsym(handle, "eglChooseConfig") == NULL) && (path == NULL)) {

        dlclose(handle);
        path = getenv("SDL_VIDEO_GL_DRIVER");
        if (path == NULL) {
            path = DEFAULT_EGL;
        }
        handle = dlopen(path, dlopen_flags);
    }

    if (handle == NULL) {
        SDL_SetError("Could not load OpenGL ES/EGL library");
        return -1;
    }

    /* Unload the old driver and reset the pointers */
    X11_GLES_UnloadLibrary(_this);

    /* Load new function pointers */
    LOAD_FUNC(eglGetDisplay);
    LOAD_FUNC(eglInitialize);
    LOAD_FUNC(eglTerminate);
    LOAD_FUNC(eglGetProcAddress);
    LOAD_FUNC(eglChooseConfig);
    LOAD_FUNC(eglGetConfigAttrib);
    LOAD_FUNC(eglCreateContext);
    LOAD_FUNC(eglDestroyContext);
    LOAD_FUNC(eglCreateWindowSurface);
    LOAD_FUNC(eglDestroySurface);
    LOAD_FUNC(eglMakeCurrent);
    LOAD_FUNC(eglSwapBuffers);

    _this->gles_data->egl_display =
        _this->gles_data->eglGetDisplay((NativeDisplayType) data->display);

    if (!_this->gles_data->egl_display) {
        SDL_SetError("Could not get EGL display");
        return -1;
    }

    if (_this->gles_data->
        eglInitialize(_this->gles_data->egl_display, NULL,
                      NULL) != EGL_TRUE) {
        SDL_SetError("Could not initialize EGL");
        return -1;
    }

    _this->gles_data->egl_dll_handle = handle;

    path = getenv("SDL_VIDEO_GL_DRIVER");
    handle = dlopen(path, dlopen_flags);
    if ((path == NULL) | (handle == NULL)) {
        if (_this->gl_config.major_version > 1) {
            path = DEFAULT_OGL_ES2;
            handle = dlopen(path, dlopen_flags);
        } else {
            path = DEFAULT_OGL_ES;
            handle = dlopen(path, dlopen_flags);
            if (handle == NULL) {
                path = DEFAULT_OGL_ES_PVR;
                handle = dlopen(path, dlopen_flags);
            }
        }
    }

    if (handle == NULL) {
        SDL_SetError("Could not initialize OpenGL ES library");
        return -1;
    }

    _this->gl_config.dll_handle = handle;
    _this->gl_config.driver_loaded = 1;

    if (path) {
        strncpy(_this->gl_config.driver_path, path,
                sizeof(_this->gl_config.driver_path) - 1);
    } else {
        strcpy(_this->gl_config.driver_path, "");
    }
    return 0;
}

XVisualInfo *
X11_GLES_GetVisual(_THIS, Display * display, int screen)
{
    /* 64 seems nice. */
    EGLint attribs[64];
    EGLint found_configs = 0;
    VisualID visual_id;
    int i;

    /* load the gl driver from a default path */
    if (!_this->gl_config.driver_loaded) {
        /* no driver has been loaded, use default (ourselves) */
        if (X11_GLES_LoadLibrary(_this, NULL) < 0) {
            return NULL;
        }
    }

    i = 0;
    attribs[i++] = EGL_RED_SIZE;
    attribs[i++] = _this->gl_config.red_size;
    attribs[i++] = EGL_GREEN_SIZE;
    attribs[i++] = _this->gl_config.green_size;
    attribs[i++] = EGL_BLUE_SIZE;
    attribs[i++] = _this->gl_config.blue_size;

    if (_this->gl_config.alpha_size) {
        attribs[i++] = EGL_ALPHA_SIZE;
        attribs[i++] = _this->gl_config.alpha_size;
    }

    if (_this->gl_config.buffer_size) {
        attribs[i++] = EGL_BUFFER_SIZE;
        attribs[i++] = _this->gl_config.buffer_size;
    }

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

    if (_this->gl_config.stencil_size) {
        attribs[i++] = EGL_STENCIL_SIZE;
        attribs[i++] = _this->gl_config.stencil_size;
    }

    if (_this->gl_config.multisamplebuffers) {
        attribs[i++] = EGL_SAMPLE_BUFFERS;
        attribs[i++] = _this->gl_config.multisamplebuffers;
    }

    if (_this->gl_config.multisamplesamples) {
        attribs[i++] = EGL_SAMPLES;
        attribs[i++] = _this->gl_config.multisamplesamples;
    }

    attribs[i++] = EGL_RENDERABLE_TYPE;
    if (_this->gl_config.major_version == 2) {
        attribs[i++] = EGL_OPENGL_ES2_BIT;
    } else {
        attribs[i++] = EGL_OPENGL_ES_BIT;
    }

    attribs[i++] = EGL_NONE;

    if (_this->gles_data->eglChooseConfig(_this->gles_data->egl_display,
                                          attribs,
                                          &_this->gles_data->egl_config, 1,
                                          &found_configs) == EGL_FALSE ||
        found_configs == 0) {
        SDL_SetError("Couldn't find matching EGL config");
        return NULL;
    }

    if (_this->gles_data->eglGetConfigAttrib(_this->gles_data->egl_display,
                                             _this->gles_data->egl_config,
                                             EGL_NATIVE_VISUAL_ID,
                                             (EGLint *) & visual_id) ==
        EGL_FALSE || !visual_id) {
        /* Use the default visual when all else fails */
        XVisualInfo vi_in;
        int out_count;
        vi_in.screen = screen;

        _this->gles_data->egl_visualinfo = XGetVisualInfo(display,
                                                          VisualScreenMask,
                                                          &vi_in, &out_count);
    } else {
        XVisualInfo vi_in;
        int out_count;

        vi_in.screen = screen;
        vi_in.visualid = visual_id;
        _this->gles_data->egl_visualinfo = XGetVisualInfo(display,
                                                          VisualScreenMask |
                                                          VisualIDMask,
                                                          &vi_in, &out_count);
    }

    return _this->gles_data->egl_visualinfo;
}

SDL_GLContext
X11_GLES_CreateContext(_THIS, SDL_Window * window)
{
    EGLint context_attrib_list[] = {
        EGL_CONTEXT_CLIENT_VERSION,
        1,
        EGL_NONE
    };

    SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
    Display *display = data->videodata->display;

    XSync(display, False);

    if (_this->gl_config.major_version) {
        context_attrib_list[1] = _this->gl_config.major_version;
    }

    _this->gles_data->egl_context =
        _this->gles_data->eglCreateContext(_this->gles_data->egl_display,
                                           _this->gles_data->egl_config,
                                           EGL_NO_CONTEXT, context_attrib_list);
    XSync(display, False);

    if (_this->gles_data->egl_context == EGL_NO_CONTEXT) {
        SDL_SetError("Could not create EGL context");
        return NULL;
    }

    _this->gles_data->egl_active = 1;

    if (X11_GLES_MakeCurrent(_this, window, context) < 0) {
        X11_GLES_DeleteContext(_this, context);
        return NULL;
    }

    return (SDL_GLContext)(1);
}

int
X11_GLES_MakeCurrent(_THIS, SDL_Window * window, SDL_GLContext context)
{
    int retval;

//    SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
//    Display *display = data->videodata->display;

    retval = 1;
    if (!_this->gles_data->eglMakeCurrent(_this->gles_data->egl_display,
                                          _this->gles_data->egl_surface,
                                          _this->gles_data->egl_surface,
                                          _this->gles_data->egl_context)) {
        SDL_SetError("Unable to make EGL context current");
        retval = -1;
    }
//    XSync(display, False);

    return (retval);
}

static int swapinterval = -1;
int
X11_GLES_SetSwapInterval(_THIS, int interval)
{
    return 0;
}

int
X11_GLES_GetSwapInterval(_THIS)
{
    return 0;
}

void
X11_GLES_SwapWindow(_THIS, SDL_Window * window)
{
    _this->gles_data->eglSwapBuffers(_this->gles_data->egl_display,
                                     _this->gles_data->egl_surface);
}

void
X11_GLES_DeleteContext(_THIS, SDL_GLContext context)
{
    /* Clean up GLES and EGL */
    if (_this->gles_data->egl_context != EGL_NO_CONTEXT ||
        _this->gles_data->egl_surface != EGL_NO_SURFACE) {
        _this->gles_data->eglMakeCurrent(_this->gles_data->egl_display,
                                         EGL_NO_SURFACE, EGL_NO_SURFACE,
                                         EGL_NO_CONTEXT);

        if (_this->gles_data->egl_context != EGL_NO_CONTEXT) {
            _this->gles_data->eglDestroyContext(_this->gles_data->egl_display,
                                                _this->gles_data->
                                                egl_context);
            _this->gles_data->egl_context = EGL_NO_CONTEXT;
        }

        if (_this->gles_data->egl_surface != EGL_NO_SURFACE) {
            _this->gles_data->eglDestroySurface(_this->gles_data->egl_display,
                                                _this->gles_data->
                                                egl_surface);
            _this->gles_data->egl_surface = EGL_NO_SURFACE;
        }
    }
    _this->gles_data->egl_active = 0;

/* crappy fix */
    X11_GLES_UnloadLibrary(_this);

}

#endif /* SDL_VIDEO_DRIVER_X11 && SDL_VIDEO_OPENGL_ES */

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