src/gallium/frontends/xa/xa_composite.c

   1 /**********************************************************
   2  * Copyright 2009-2011 VMware, Inc. All rights reserved.
   3  *
   4  * Permission is hereby granted, free of charge, to any person
   5  * obtaining a copy of this software and associated documentation
   6  * files (the "Software"), to deal in the Software without
   7  * restriction, including without limitation the rights to use, copy,
   8  * modify, merge, publish, distribute, sublicense, and/or sell copies
   9  * of the Software, and to permit persons to whom the Software is
  10  * furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  *
  24  *********************************************************
  25  * Authors:
  26  * Zack Rusin <zackr-at-vmware-dot-com>
  27  * Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  28  */
  29
  30 #include "xa_composite.h"
  31 #include "xa_context.h"
  32 #include "xa_priv.h"
  33 #include "cso_cache/cso_context.h"
  34 #include "util/u_sampler.h"
  35 #include "util/u_inlines.h"
  36
  37
  38 /*XXX also in Xrender.h but the including it here breaks compilition */
  39 #define XFixedToDouble(f)    (((double) (f)) / 65536.)
  40
  41 struct xa_composite_blend {
  42     unsigned op : 8;
  43
  44     unsigned alpha_dst : 4;
  45     unsigned alpha_src : 4;
  46
  47     unsigned rgb_src : 8;    /**< PIPE_BLENDFACTOR_x */
  48     unsigned rgb_dst : 8;    /**< PIPE_BLENDFACTOR_x */
  49 };
  50
  51 #define XA_BLEND_OP_OVER 3
  52 static const struct xa_composite_blend xa_blends[] = {
  53     { xa_op_clear,
  54       0, 0, PIPE_BLENDFACTOR_ZERO, PIPE_BLENDFACTOR_ZERO},
  55     { xa_op_src,
  56       0, 0, PIPE_BLENDFACTOR_ONE, PIPE_BLENDFACTOR_ZERO},
  57     { xa_op_dst,
  58       0, 0, PIPE_BLENDFACTOR_ZERO, PIPE_BLENDFACTOR_ONE},
  59     { xa_op_over,
  60       0, 1, PIPE_BLENDFACTOR_ONE, PIPE_BLENDFACTOR_INV_SRC_ALPHA},
  61     { xa_op_over_reverse,
  62       1, 0, PIPE_BLENDFACTOR_INV_DST_ALPHA, PIPE_BLENDFACTOR_ONE},
  63     { xa_op_in,
  64       1, 0, PIPE_BLENDFACTOR_DST_ALPHA, PIPE_BLENDFACTOR_ZERO},
  65     { xa_op_in_reverse,
  66       0, 1, PIPE_BLENDFACTOR_ZERO, PIPE_BLENDFACTOR_SRC_ALPHA},
  67     { xa_op_out,
  68       1, 0, PIPE_BLENDFACTOR_INV_DST_ALPHA, PIPE_BLENDFACTOR_ZERO},
  69     { xa_op_out_reverse,
  70       0, 1, PIPE_BLENDFACTOR_ZERO, PIPE_BLENDFACTOR_INV_SRC_ALPHA},
  71     { xa_op_atop,
  72       1, 1, PIPE_BLENDFACTOR_DST_ALPHA, PIPE_BLENDFACTOR_INV_SRC_ALPHA},
  73     { xa_op_atop_reverse,
  74       1, 1, PIPE_BLENDFACTOR_INV_DST_ALPHA, PIPE_BLENDFACTOR_SRC_ALPHA},
  75     { xa_op_xor,
  76       1, 1, PIPE_BLENDFACTOR_INV_DST_ALPHA, PIPE_BLENDFACTOR_INV_SRC_ALPHA},
  77     { xa_op_add,
  78       0, 0, PIPE_BLENDFACTOR_ONE, PIPE_BLENDFACTOR_ONE},
  79 };
  80
  81 /*
  82  * The alpha value stored in a L8 texture is read by the
  83  * hardware as color, and R8 is read as red. The source alpha value
  84  * at the end of the fragment shader is stored in all color channels,
  85  * so the correct approach is to blend using DST_COLOR instead of
  86  * DST_ALPHA and then output any color channel (L8) or the red channel (R8).
  87  */
  88 static unsigned
  89 xa_convert_blend_for_luminance(unsigned factor)
  90 {
  91     switch(factor) {
  92     case PIPE_BLENDFACTOR_DST_ALPHA:
  93         return PIPE_BLENDFACTOR_DST_COLOR;
  94     case PIPE_BLENDFACTOR_INV_DST_ALPHA:
  95         return PIPE_BLENDFACTOR_INV_DST_COLOR;
  96     default:
  97         break;
  98     }
  99     return factor;
 100 }
 101
 102 static boolean
 103 blend_for_op(struct xa_composite_blend *blend,
 104              enum xa_composite_op op,
 105              struct xa_picture *src_pic,
 106              struct xa_picture *mask_pic,
 107              struct xa_picture *dst_pic)
 108 {
 109     const int num_blends =
 110         sizeof(xa_blends)/sizeof(struct xa_composite_blend);
 111     int i;
 112     boolean supported = FALSE;
 113
 114     /*
 115      * our default in case something goes wrong
 116      */
 117     *blend = xa_blends[XA_BLEND_OP_OVER];
 118
 119     for (i = 0; i < num_blends; ++i) {
 120         if (xa_blends[i].op == op) {
 121             *blend = xa_blends[i];
 122             supported = TRUE;
 123             break;
 124         }
 125     }
 126
 127     /*
 128      * No component alpha yet.
 129      */
 130     if (mask_pic && mask_pic->component_alpha && blend->alpha_src)
 131         return FALSE;
 132
 133     if (!dst_pic->srf)
 134         return supported;
 135
 136     if ((dst_pic->srf->tex->format == PIPE_FORMAT_L8_UNORM ||
 137          dst_pic->srf->tex->format == PIPE_FORMAT_R8_UNORM)) {
 138         blend->rgb_src = xa_convert_blend_for_luminance(blend->rgb_src);
 139         blend->rgb_dst = xa_convert_blend_for_luminance(blend->rgb_dst);
 140     }
 141
 142     /*
 143      * If there's no dst alpha channel, adjust the blend op so that we'll treat
 144      * it as always 1.
 145      */
 146
 147     if (xa_format_a(dst_pic->pict_format) == 0 && blend->alpha_dst) {
 148         if (blend->rgb_src == PIPE_BLENDFACTOR_DST_ALPHA)
 149             blend->rgb_src = PIPE_BLENDFACTOR_ONE;
 150         else if (blend->rgb_src == PIPE_BLENDFACTOR_INV_DST_ALPHA)
 151             blend->rgb_src = PIPE_BLENDFACTOR_ZERO;
 152     }
 153
 154     return supported;
 155 }
 156
 157
 158 static inline int
 159 xa_repeat_to_gallium(int mode)
 160 {
 161     switch(mode) {
 162     case xa_wrap_clamp_to_border:
 163         return PIPE_TEX_WRAP_CLAMP_TO_BORDER;
 164     case xa_wrap_repeat:
 165         return PIPE_TEX_WRAP_REPEAT;
 166     case xa_wrap_mirror_repeat:
 167         return PIPE_TEX_WRAP_MIRROR_REPEAT;
 168     case xa_wrap_clamp_to_edge:
 169         return PIPE_TEX_WRAP_CLAMP_TO_EDGE;
 170     default:
 171         break;
 172     }
 173     return PIPE_TEX_WRAP_REPEAT;
 174 }
 175
 176 static inline boolean
 177 xa_filter_to_gallium(int xrender_filter, int *out_filter)
 178 {
 179
 180     switch (xrender_filter) {
 181     case xa_filter_nearest:
 182         *out_filter = PIPE_TEX_FILTER_NEAREST;
 183         break;
 184     case xa_filter_linear:
 185         *out_filter = PIPE_TEX_FILTER_LINEAR;
 186         break;
 187     default:
 188         *out_filter = PIPE_TEX_FILTER_NEAREST;
 189         return FALSE;
 190     }
 191     return TRUE;
 192 }
 193
 194 static int
 195 xa_is_filter_accelerated(struct xa_picture *pic)
 196 {
 197     int filter;
 198     if (pic && !xa_filter_to_gallium(pic->filter, &filter))
 199         return 0;
 200     return 1;
 201 }
 202
 203 /**
 204  * xa_src_pict_is_accelerated - Check whether we support acceleration
 205  * of the given src_pict type
 206  *
 207  * \param src_pic[in]: Pointer to a union xa_source_pict to check.
 208  *
 209  * \returns TRUE if accelerated, FALSE otherwise.
 210  */
 211 static boolean
 212 xa_src_pict_is_accelerated(const union xa_source_pict *src_pic)
 213 {
 214     if (!src_pic)
 215         return TRUE;
 216
 217     if (src_pic->type == xa_src_pict_solid_fill ||
 218         src_pic->type == xa_src_pict_float_solid_fill)
 219         return TRUE;
 220
 221     return FALSE;
 222 }
 223
 224 XA_EXPORT int
 225 xa_composite_check_accelerated(const struct xa_composite *comp)
 226 {
 227     struct xa_picture *src_pic = comp->src;
 228     struct xa_picture *mask_pic = comp->mask;
 229     struct xa_composite_blend blend;
 230
 231     if (!xa_is_filter_accelerated(src_pic) ||
 232         !xa_is_filter_accelerated(comp->mask)) {
 233         return -XA_ERR_INVAL;
 234     }
 235
 236     if (!xa_src_pict_is_accelerated(src_pic->src_pict) ||
 237         (mask_pic && !xa_src_pict_is_accelerated(mask_pic->src_pict)))
 238         return -XA_ERR_INVAL;
 239
 240     if (!blend_for_op(&blend, comp->op, comp->src, comp->mask, comp->dst))
 241         return -XA_ERR_INVAL;
 242
 243     /*
 244      * No component alpha yet.
 245      */
 246     if (mask_pic && mask_pic->component_alpha && blend.alpha_src)
 247         return -XA_ERR_INVAL;
 248
 249     return XA_ERR_NONE;
 250 }
 251
 252 static int
 253 bind_composite_blend_state(struct xa_context *ctx,
 254                            const struct xa_composite *comp)
 255 {
 256     struct xa_composite_blend blend_opt;
 257     struct pipe_blend_state blend;
 258
 259     if (!blend_for_op(&blend_opt, comp->op, comp->src, comp->mask, comp->dst))
 260         return -XA_ERR_INVAL;
 261
 262     memset(&blend, 0, sizeof(struct pipe_blend_state));
 263     blend.rt[0].blend_enable = 1;
 264     blend.rt[0].colormask = PIPE_MASK_RGBA;
 265
 266     blend.rt[0].rgb_src_factor   = blend_opt.rgb_src;
 267     blend.rt[0].alpha_src_factor = blend_opt.rgb_src;
 268     blend.rt[0].rgb_dst_factor   = blend_opt.rgb_dst;
 269     blend.rt[0].alpha_dst_factor = blend_opt.rgb_dst;
 270
 271     cso_set_blend(ctx->cso, &blend);
 272     return XA_ERR_NONE;
 273 }
 274
 275 static unsigned int
 276 picture_format_fixups(struct xa_picture *src_pic,
 277                       int mask)
 278 {
 279     boolean set_alpha = FALSE;
 280     boolean swizzle = FALSE;
 281     unsigned ret = 0;
 282     struct xa_surface *src = src_pic->srf;
 283     enum xa_formats src_hw_format, src_pic_format;
 284     enum xa_surface_type src_hw_type, src_pic_type;
 285
 286     if (!src)
 287         return 0;
 288
 289     src_hw_format = xa_surface_format(src);
 290     src_pic_format = src_pic->pict_format;
 291
 292     set_alpha = (xa_format_type_is_color(src_hw_format) &&
 293                  xa_format_a(src_pic_format) == 0);
 294
 295     if (set_alpha)
 296         ret |= mask ? FS_MASK_SET_ALPHA : FS_SRC_SET_ALPHA;
 297
 298     if (src_hw_format == src_pic_format) {
 299         if (src->tex->format == PIPE_FORMAT_L8_UNORM ||
 300             src->tex->format == PIPE_FORMAT_R8_UNORM)
 301             return ((mask) ? FS_MASK_LUMINANCE : FS_SRC_LUMINANCE);
 302
 303         return ret;
 304     }
 305
 306     src_hw_type = xa_format_type(src_hw_format);
 307     src_pic_type = xa_format_type(src_pic_format);
 308
 309     swizzle = ((src_hw_type == xa_type_argb &&
 310                 src_pic_type == xa_type_abgr) ||
 311                ((src_hw_type == xa_type_abgr &&
 312                  src_pic_type == xa_type_argb)));
 313
 314     if (!swizzle && (src_hw_type != src_pic_type))
 315       return ret;
 316
 317     if (swizzle)
 318         ret |= mask ? FS_MASK_SWIZZLE_RGB : FS_SRC_SWIZZLE_RGB;
 319
 320     return ret;
 321 }
 322
 323 static void
 324 xa_src_in_mask(float src[4], const float mask[4])
 325 {
 326         src[0] *= mask[3];
 327         src[1] *= mask[3];
 328         src[2] *= mask[3];
 329         src[3] *= mask[3];
 330 }
 331
 332 /**
 333  * xa_handle_src_pict - Set up xa_context state and fragment shader
 334  * input based on scr_pict type
 335  *
 336  * \param ctx[in, out]: Pointer to the xa context.
 337  * \param src_pict[in]: Pointer to the union xa_source_pict to consider.
 338  * \param is_mask[in]: Whether we're considering a mask picture.
 339  *
 340  * \returns TRUE if succesful, FALSE otherwise.
 341  *
 342  * This function computes some xa_context state used to determine whether
 343  * to upload the solid color and also the solid color itself used as an input
 344  * to the fragment shader.
 345  */
 346 static boolean
 347 xa_handle_src_pict(struct xa_context *ctx,
 348                    const union xa_source_pict *src_pict,
 349                    boolean is_mask)
 350 {
 351     float solid_color[4];
 352
 353     switch(src_pict->type) {
 354     case xa_src_pict_solid_fill:
 355         xa_pixel_to_float4(src_pict->solid_fill.color, solid_color);
 356         break;
 357     case xa_src_pict_float_solid_fill:
 358         memcpy(solid_color, src_pict->float_solid_fill.color,
 359                sizeof(solid_color));
 360         break;
 361     default:
 362         return FALSE;
 363     }
 364
 365     if (is_mask && ctx->has_solid_src)
 366         xa_src_in_mask(ctx->solid_color, solid_color);
 367     else
 368         memcpy(ctx->solid_color, solid_color, sizeof(solid_color));
 369
 370     if (is_mask)
 371         ctx->has_solid_mask = TRUE;
 372     else
 373         ctx->has_solid_src = TRUE;
 374
 375     return TRUE;
 376 }
 377
 378 static int
 379 bind_shaders(struct xa_context *ctx, const struct xa_composite *comp)
 380 {
 381     unsigned vs_traits = 0, fs_traits = 0;
 382     struct xa_shader shader;
 383     struct xa_picture *src_pic = comp->src;
 384     struct xa_picture *mask_pic = comp->mask;
 385     struct xa_picture *dst_pic = comp->dst;
 386
 387     ctx->has_solid_src = FALSE;
 388     ctx->has_solid_mask = FALSE;
 389
 390     if (dst_pic && xa_format_type(dst_pic->pict_format) !=
 391         xa_format_type(xa_surface_format(dst_pic->srf)))
 392        return -XA_ERR_INVAL;
 393
 394     if (src_pic) {
 395         if (src_pic->wrap == xa_wrap_clamp_to_border && src_pic->has_transform)
 396             fs_traits |= FS_SRC_REPEAT_NONE;
 397
 398         fs_traits |= FS_COMPOSITE;
 399         vs_traits |= VS_COMPOSITE;
 400
 401         if (src_pic->src_pict) {
 402             if (!xa_handle_src_pict(ctx, src_pic->src_pict, false))
 403                 return -XA_ERR_INVAL;
 404             fs_traits |= FS_SRC_SRC;
 405             vs_traits |= VS_SRC_SRC;
 406         } else
 407            fs_traits |= picture_format_fixups(src_pic, 0);
 408     }
 409
 410     if (mask_pic) {
 411         vs_traits |= VS_MASK;
 412         fs_traits |= FS_MASK;
 413         if (mask_pic->component_alpha)
 414            fs_traits |= FS_CA;
 415         if (mask_pic->src_pict) {
 416             if (!xa_handle_src_pict(ctx, mask_pic->src_pict, true))
 417                 return -XA_ERR_INVAL;
 418
 419             if (ctx->has_solid_src) {
 420                 vs_traits &= ~VS_MASK;
 421                 fs_traits &= ~FS_MASK;
 422             } else {
 423                 vs_traits |= VS_MASK_SRC;
 424                 fs_traits |= FS_MASK_SRC;
 425             }
 426         } else {
 427             if (mask_pic->wrap == xa_wrap_clamp_to_border &&
 428                 mask_pic->has_transform)
 429                 fs_traits |= FS_MASK_REPEAT_NONE;
 430
 431             fs_traits |= picture_format_fixups(mask_pic, 1);
 432         }
 433     }
 434
 435     if (ctx->srf->format == PIPE_FORMAT_L8_UNORM ||
 436         ctx->srf->format == PIPE_FORMAT_R8_UNORM)
 437         fs_traits |= FS_DST_LUMINANCE;
 438
 439     shader = xa_shaders_get(ctx->shaders, vs_traits, fs_traits);
 440     cso_set_vertex_shader_handle(ctx->cso, shader.vs);
 441     cso_set_fragment_shader_handle(ctx->cso, shader.fs);
 442     return XA_ERR_NONE;
 443 }
 444
 445 static void
 446 bind_samplers(struct xa_context *ctx,
 447               const struct xa_composite *comp)
 448 {
 449     struct pipe_sampler_state *samplers[PIPE_MAX_SAMPLERS];
 450     struct pipe_sampler_state src_sampler, mask_sampler;
 451     struct pipe_sampler_view view_templ;
 452     struct pipe_sampler_view *src_view;
 453     struct pipe_context *pipe = ctx->pipe;
 454     struct xa_picture *src_pic = comp->src;
 455     struct xa_picture *mask_pic = comp->mask;
 456     int num_samplers = 0;
 457
 458     xa_ctx_sampler_views_destroy(ctx);
 459     memset(&src_sampler, 0, sizeof(struct pipe_sampler_state));
 460     memset(&mask_sampler, 0, sizeof(struct pipe_sampler_state));
 461
 462     if (src_pic && !ctx->has_solid_src) {
 463         unsigned src_wrap = xa_repeat_to_gallium(src_pic->wrap);
 464         int filter;
 465
 466         (void) xa_filter_to_gallium(src_pic->filter, &filter);
 467
 468         src_sampler.wrap_s = src_wrap;
 469         src_sampler.wrap_t = src_wrap;
 470         src_sampler.min_img_filter = filter;
 471         src_sampler.mag_img_filter = filter;
 472         src_sampler.min_mip_filter = PIPE_TEX_MIPFILTER_NEAREST;
 473         src_sampler.normalized_coords = 1;
 474         samplers[0] = &src_sampler;
 475         u_sampler_view_default_template(&view_templ,
 476                                         src_pic->srf->tex,+                                     src_pic->srf->tex->format);
 477         src_view = pipe->create_sampler_view(pipe, src_pic->srf->tex,
 478                                              &view_templ);
 479         ctx->bound_sampler_views[0] = src_view;
 480         num_samplers++;
 481     }
 482
 483     if (mask_pic && !ctx->has_solid_mask) {
 484         unsigned mask_wrap = xa_repeat_to_gallium(mask_pic->wrap);
 485         int filter;
 486
 487         (void) xa_filter_to_gallium(mask_pic->filter, &filter);
 488
 489         mask_sampler.wrap_s = mask_wrap;
 490         mask_sampler.wrap_t = mask_wrap;
 491         mask_sampler.min_img_filter = filter;
 492         mask_sampler.mag_img_filter = filter;
 493         src_sampler.min_mip_filter = PIPE_TEX_MIPFILTER_NEAREST;
 494         mask_sampler.normalized_coords = 1;
 495         samplers[num_samplers] = &mask_sampler;
 496         u_sampler_view_default_template(&view_templ,
 497                                         mask_pic->srf->tex,
 498                                         mask_pic->srf->tex->format);
 499         src_view = pipe->create_sampler_view(pipe, mask_pic->srf->tex,
 500                                              &view_templ);
 501         ctx->bound_sampler_views[num_samplers] = src_view;
 502         num_samplers++;
 503     }
 504
 505     cso_set_samplers(ctx->cso, PIPE_SHADER_FRAGMENT, num_samplers,
 506                      (const struct pipe_sampler_state **)samplers);
 507     cso_set_sampler_views(ctx->cso, PIPE_SHADER_FRAGMENT, num_samplers,
 508                                    ctx->bound_sampler_views);
 509     ctx->num_bound_samplers = num_samplers;
 510 }
 511
 512 XA_EXPORT int
 513 xa_composite_prepare(struct xa_context *ctx,
 514                      const struct xa_composite *comp)
 515 {
 516     struct xa_surface *dst_srf = comp->dst->srf;
 517     int ret;
 518
 519     ret = xa_ctx_srf_create(ctx, dst_srf);
 520     if (ret != XA_ERR_NONE)
 521         return ret;
 522
 523     ctx->dst = dst_srf;
 524     renderer_bind_destination(ctx, ctx->srf);
 525
 526     ret = bind_composite_blend_state(ctx, comp);
 527     if (ret != XA_ERR_NONE)
 528         return ret;
 529     ret = bind_shaders(ctx, comp);
 530     if (ret != XA_ERR_NONE)
 531         return ret;
 532     bind_samplers(ctx, comp);
 533
 534     if (ctx->num_bound_samplers == 0 ) { /* solid fill */
 535         renderer_begin_solid(ctx);
 536     } else {
 537         renderer_begin_textures(ctx);
 538         ctx->comp = comp;
 539     }
 540
 541     xa_ctx_srf_destroy(ctx);
 542     return XA_ERR_NONE;
 543 }
 544
 545 XA_EXPORT void
 546 xa_composite_rect(struct xa_context *ctx,
 547                   int srcX, int srcY, int maskX, int maskY,
 548                   int dstX, int dstY, int width, int height)
 549 {
 550     if (ctx->num_bound_samplers == 0 ) { /* solid fill */
 551         xa_scissor_update(ctx, dstX, dstY, dstX + width, dstY + height);
 552         renderer_solid(ctx, dstX, dstY, dstX + width, dstY + height);
 553     } else {
 554         const struct xa_composite *comp = ctx->comp;
 555         int pos[6] = {srcX, srcY, maskX, maskY, dstX, dstY};
 556         const float *src_matrix = NULL;
 557         const float *mask_matrix = NULL;
 558
 559         xa_scissor_update(ctx, dstX, dstY, dstX + width, dstY + height);
 560
 561         if (comp->src->has_transform)
 562             src_matrix = comp->src->transform;
 563         if (comp->mask && comp->mask->has_transform)
 564             mask_matrix = comp->mask->transform;
 565
 566         renderer_texture(ctx, pos, width, height,
 567                          src_matrix, mask_matrix);
 568     }
 569 }
 570
 571 XA_EXPORT void
 572 xa_composite_done(struct xa_context *ctx)
 573 {
 574     renderer_draw_flush(ctx);
 575
 576     ctx->comp = NULL;
 577     ctx->has_solid_src = FALSE;
 578     ctx->has_solid_mask = FALSE;
 579     xa_ctx_sampler_views_destroy(ctx);
 580 }
 581
 582 static const struct xa_composite_allocation a = {
 583     .xa_composite_size = sizeof(struct xa_composite),
 584     .xa_picture_size = sizeof(struct xa_picture),
 585     .xa_source_pict_size = sizeof(union xa_source_pict),
 586 };
 587
 588 XA_EXPORT const struct xa_composite_allocation *
 589 xa_composite_allocation(void)
 590 {
 591     return &a;
 592 }