src/cairo-gl-dispatch.c

   1 /* cairo - a vector graphics library with display and print output
   2  *
   3  * Copyright © 2010 Linaro Limited
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it either under the terms of the GNU Lesser General Public
   7  * License version 2.1 as published by the Free Software Foundation
   8  * (the "LGPL") or, at your option, under the terms of the Mozilla
   9  * Public License Version 1.1 (the "MPL"). If you do not alter this
  10  * notice, a recipient may use your version of this file under either
  11  * the MPL or the LGPL.
  12  *
  13  * You should have received a copy of the LGPL along with this library
  14  * in the file COPYING-LGPL-2.1; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
  16  * You should have received a copy of the MPL along with this library
  17  * in the file COPYING-MPL-1.1
  18  *
  19  * The contents of this file are subject to the Mozilla Public License
  20  * Version 1.1 (the "License"); you may not use this file except in
  21  * compliance with the License. You may obtain a copy of the License at
  22  * http://www.mozilla.org/MPL/
  23  *
  24  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
  25  * OF ANY KIND, either express or implied. See the LGPL or the MPL for
  26  * the specific language governing rights and limitations.
  27  *
  28  * Contributor(s):
  29  *      Alexandros Frantzis <alexandros.frantzis@linaro.org>
  30  */
  31
  32 #include "cairoint.h"
  33 #include "cairo-gl-private.h"
  34 #include "cairo-gl-dispatch-private.h"
  35 #if CAIRO_HAS_DLSYM
  36 #include <dlfcn.h>
  37 #endif
  38
  39 #if CAIRO_HAS_DLSYM
  40 static void *
  41 _cairo_gl_dispatch_open_lib (void)
  42 {
  43     return dlopen (NULL, RTLD_LAZY);
  44 }
  45
  46 static void
  47 _cairo_gl_dispatch_close_lib (void *handle)
  48 {
  49     dlclose (handle);
  50 }
  51
  52 static cairo_gl_generic_func_t
  53 _cairo_gl_dispatch_get_proc_addr (void *handle, const char *name)
  54 {
  55     return (cairo_gl_generic_func_t) dlsym (handle, name);
  56 }
  57 #else
  58 static void *
  59 _cairo_gl_dispatch_open_lib (void)
  60 {
  61     return NULL;
  62 }
  63
  64 static void
  65 _cairo_gl_dispatch_close_lib (void *handle)
  66 {
  67     return;
  68 }
  69
  70 static cairo_gl_generic_func_t
  71 _cairo_gl_dispatch_get_proc_addr (void *handle, const char *name)
  72 {
  73     return NULL;
  74 }
  75 #endif /* CAIRO_HAS_DLSYM */
  76
  77
  78 static void
  79 _cairo_gl_dispatch_init_entries (cairo_gl_dispatch_t *dispatch,
  80                                  cairo_gl_get_proc_addr_func_t get_proc_addr,
  81                                  cairo_gl_dispatch_entry_t *entries,
  82                                  cairo_gl_dispatch_name_t dispatch_name)
  83 {
  84     cairo_gl_dispatch_entry_t *entry = entries;
  85     void *handle = _cairo_gl_dispatch_open_lib ();
  86
  87     while (entry->name[CAIRO_GL_DISPATCH_NAME_CORE] != NULL) {
  88         void *dispatch_ptr = &((char *) dispatch)[entry->offset];
  89         const char *name = entry->name[dispatch_name];
  90
  91         /*
  92          * In strictly conforming EGL implementations, eglGetProcAddress() can
  93          * be used only to get extension functions, but some of the functions
  94          * we want belong to core GL(ES). If the *GetProcAddress function
  95          * provided by the context fails, try to get the address of the wanted
  96          * GL function using standard system facilities (eg dlsym() in *nix
  97          * systems).
  98          */
  99         cairo_gl_generic_func_t func = get_proc_addr (name);
 100         if (func == NULL)
 101             func = _cairo_gl_dispatch_get_proc_addr (handle, name);
 102
 103         *((cairo_gl_generic_func_t *) dispatch_ptr) = func;
 104
 105         ++entry;
 106     }
 107
 108     _cairo_gl_dispatch_close_lib (handle);
 109 }
 110
 111 static cairo_status_t
 112 _cairo_gl_dispatch_init_buffers (cairo_gl_dispatch_t *dispatch,
 113                                  cairo_gl_get_proc_addr_func_t get_proc_addr,
 114                                  int gl_version, cairo_gl_flavor_t gl_flavor)
 115 {
 116     cairo_gl_dispatch_name_t dispatch_name;
 117
 118     if (gl_flavor == CAIRO_GL_FLAVOR_DESKTOP)
 119     {
 120         if (gl_version >= CAIRO_GL_VERSION_ENCODE (1, 5))
 121             dispatch_name = CAIRO_GL_DISPATCH_NAME_CORE;
 122         else if (_cairo_gl_has_extension ("GL_ARB_vertex_buffer_object"))
 123             dispatch_name = CAIRO_GL_DISPATCH_NAME_EXT;
 124         else
 125             return CAIRO_STATUS_DEVICE_ERROR;
 126     }
 127     else if (gl_flavor == CAIRO_GL_FLAVOR_ES &&
 128              gl_version >= CAIRO_GL_VERSION_ENCODE (2, 0))
 129     {
 130         dispatch_name = CAIRO_GL_DISPATCH_NAME_ES;
 131     }
 132     else
 133     {
 134         return CAIRO_STATUS_DEVICE_ERROR;
 135     }
 136
 137     _cairo_gl_dispatch_init_entries (dispatch, get_proc_addr,
 138                                      dispatch_buffers_entries, dispatch_name);
 139
 140     return CAIRO_STATUS_SUCCESS;
 141 }
 142
 143 static cairo_status_t
 144 _cairo_gl_dispatch_init_shaders (cairo_gl_dispatch_t *dispatch,
 145                                  cairo_gl_get_proc_addr_func_t get_proc_addr,
 146                                  int gl_version, cairo_gl_flavor_t gl_flavor)
 147 {
 148     cairo_gl_dispatch_name_t dispatch_name;
 149
 150     if (gl_flavor == CAIRO_GL_FLAVOR_DESKTOP)
 151     {
 152         if (gl_version >= CAIRO_GL_VERSION_ENCODE (2, 0))
 153             dispatch_name = CAIRO_GL_DISPATCH_NAME_CORE;
 154         else if (_cairo_gl_has_extension ("GL_ARB_shader_objects"))
 155             dispatch_name = CAIRO_GL_DISPATCH_NAME_EXT;
 156         else
 157             return CAIRO_STATUS_DEVICE_ERROR;
 158     }
 159     else if (gl_flavor == CAIRO_GL_FLAVOR_ES &&
 160              gl_version >= CAIRO_GL_VERSION_ENCODE (2, 0))
 161     {
 162         dispatch_name = CAIRO_GL_DISPATCH_NAME_ES;
 163     }
 164     else
 165     {
 166         return CAIRO_STATUS_DEVICE_ERROR;
 167     }
 168
 169     _cairo_gl_dispatch_init_entries (dispatch, get_proc_addr,
 170                                      dispatch_shaders_entries, dispatch_name);
 171
 172     return CAIRO_STATUS_SUCCESS;
 173 }
 174
 175 static cairo_status_t
 176 _cairo_gl_dispatch_init_fbo (cairo_gl_dispatch_t *dispatch,
 177                              cairo_gl_get_proc_addr_func_t get_proc_addr,
 178                              int gl_version, cairo_gl_flavor_t gl_flavor)
 179 {
 180     cairo_gl_dispatch_name_t dispatch_name;
 181
 182     if (gl_flavor == CAIRO_GL_FLAVOR_DESKTOP)
 183     {
 184         if (gl_version >= CAIRO_GL_VERSION_ENCODE (3, 0) ||
 185             _cairo_gl_has_extension ("GL_ARB_framebuffer_object"))
 186             dispatch_name = CAIRO_GL_DISPATCH_NAME_CORE;
 187         else if (_cairo_gl_has_extension ("GL_EXT_framebuffer_object"))
 188             dispatch_name = CAIRO_GL_DISPATCH_NAME_EXT;
 189         else
 190             return CAIRO_STATUS_DEVICE_ERROR;
 191     }
 192     else if (gl_flavor == CAIRO_GL_FLAVOR_ES &&
 193              gl_version >= CAIRO_GL_VERSION_ENCODE (2, 0))
 194     {
 195         dispatch_name = CAIRO_GL_DISPATCH_NAME_ES;
 196     }
 197     else
 198     {
 199         return CAIRO_STATUS_DEVICE_ERROR;
 200     }
 201
 202     _cairo_gl_dispatch_init_entries (dispatch, get_proc_addr,
 203                                      dispatch_fbo_entries, dispatch_name);
 204
 205     return CAIRO_STATUS_SUCCESS;
 206 }
 207
 208 static cairo_status_t
 209 _cairo_gl_dispatch_init_multisampling (cairo_gl_dispatch_t *dispatch,
 210                                        cairo_gl_get_proc_addr_func_t get_proc_addr,
 211                                        int gl_version,
 212                                        cairo_gl_flavor_t gl_flavor)
 213 {
 214     /* For the multisampling table, the there are two GLES versions
 215      * of the extension, so we put one in the EXT slot and one in
 216      * the real ES slot.*/
 217     cairo_gl_dispatch_name_t dispatch_name = CAIRO_GL_DISPATCH_NAME_CORE;
 218     if (gl_flavor == CAIRO_GL_FLAVOR_ES) {
 219         if (_cairo_gl_has_extension ("GL_EXT_multisampled_render_to_texture"))
 220             dispatch_name = CAIRO_GL_DISPATCH_NAME_EXT;
 221         else if (_cairo_gl_has_extension ("GL_IMG_multisampled_render_to_texture"))
 222             dispatch_name = CAIRO_GL_DISPATCH_NAME_ES;
 223     }
 224     _cairo_gl_dispatch_init_entries (dispatch, get_proc_addr,
 225                                      dispatch_multisampling_entries,
 226                                      dispatch_name);
 227     return CAIRO_STATUS_SUCCESS;
 228 }
 229
 230 cairo_status_t
 231 _cairo_gl_dispatch_init (cairo_gl_dispatch_t *dispatch,
 232                          cairo_gl_get_proc_addr_func_t get_proc_addr)
 233 {
 234     cairo_status_t status;
 235     int gl_version;
 236     cairo_gl_flavor_t gl_flavor;
 237
 238     gl_version = _cairo_gl_get_version ();
 239     gl_flavor = _cairo_gl_get_flavor ();
 240
 241     status = _cairo_gl_dispatch_init_buffers (dispatch, get_proc_addr,
 242                                               gl_version, gl_flavor);
 243     if (status != CAIRO_STATUS_SUCCESS)
 244         return status;
 245
 246     status = _cairo_gl_dispatch_init_shaders (dispatch, get_proc_addr,
 247                                               gl_version, gl_flavor);
 248     if (status != CAIRO_STATUS_SUCCESS)
 249         return status;
 250
 251     status = _cairo_gl_dispatch_init_fbo (dispatch, get_proc_addr,
 252                                           gl_version, gl_flavor);
 253     if (status != CAIRO_STATUS_SUCCESS)
 254         return status;
 255
 256     status = _cairo_gl_dispatch_init_multisampling (dispatch, get_proc_addr,
 257                                                     gl_version, gl_flavor);
 258     if (status != CAIRO_STATUS_SUCCESS)
 259         return status;
 260
 261     return CAIRO_STATUS_SUCCESS;
 262 }