/*
* Copyright 2008 Corbin Simpson <MostAwesomeDude@gmail.com>
* Copyright 2010 Marek Olšák <maraeo@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* on the rights to use, copy, modify, merge, publish, distribute, sub
* license, and/or sell copies of the Software, and to permit persons to whom
* the Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE. */
#include "r300_texture_desc.h"
#include "r300_context.h"
#include "util/u_format.h"
#include <inttypes.h>
/* Returns the number of pixels that the texture should be aligned to
* in the given dimension. */
unsigned r300_get_pixel_alignment(enum pipe_format format,
unsigned num_samples,
enum radeon_bo_layout microtile,
enum radeon_bo_layout macrotile,
enum r300_dim dim, boolean is_rs690)
{
static const unsigned table[2][5][3][2] =
{
{
/* Macro: linear linear linear
Micro: linear tiled square-tiled */
{{ 32, 1}, { 8, 4}, { 0, 0}}, /* 8 bits per pixel */
{{ 16, 1}, { 8, 2}, { 4, 4}}, /* 16 bits per pixel */
{{ 8, 1}, { 4, 2}, { 0, 0}}, /* 32 bits per pixel */
{{ 4, 1}, { 2, 2}, { 0, 0}}, /* 64 bits per pixel */
{{ 2, 1}, { 0, 0}, { 0, 0}} /* 128 bits per pixel */
},
{
/* Macro: tiled tiled tiled
Micro: linear tiled square-tiled */
{{256, 8}, {64, 32}, { 0, 0}}, /* 8 bits per pixel */
{{128, 8}, {64, 16}, {32, 32}}, /* 16 bits per pixel */
{{ 64, 8}, {32, 16}, { 0, 0}}, /* 32 bits per pixel */
{{ 32, 8}, {16, 16}, { 0, 0}}, /* 64 bits per pixel */
{{ 16, 8}, { 0, 0}, { 0, 0}} /* 128 bits per pixel */
}
};
unsigned tile = 0;
unsigned pixsize = util_format_get_blocksize(format);
assert(macrotile <= RADEON_LAYOUT_TILED);
assert(microtile <= RADEON_LAYOUT_SQUARETILED);
assert(pixsize <= 16);
assert(dim <= DIM_HEIGHT);
tile = table[macrotile][util_logbase2(pixsize)][microtile][dim];
if (macrotile == 0 && is_rs690 && dim == DIM_WIDTH) {
int align;
int h_tile;
h_tile = table[macrotile][util_logbase2(pixsize)][microtile][DIM_HEIGHT];
align = 64 / (pixsize * h_tile);
if (tile < align)
tile = align;
}
assert(tile);
return tile;
}
/* Return true if macrotiling should be enabled on the miplevel. */
static boolean r300_texture_macro_switch(struct r300_resource *tex,
unsigned level,
boolean rv350_mode,
enum r300_dim dim)
{
unsigned tile, texdim;
if (tex->b.b.nr_samples > 1) {
return TRUE;
}
tile = r300_get_pixel_alignment(tex->b.b.format, tex->b.b.nr_samples,
tex->tex.microtile, RADEON_LAYOUT_TILED, dim, 0);
if (dim == DIM_WIDTH) {
texdim = u_minify(tex->tex.width0, level);
} else {
texdim = u_minify(tex->tex.height0, level);
}
/* See TX_FILTER1_n.MACRO_SWITCH. */
if (rv350_mode) {
return texdim >= tile;
} else {
return texdim > tile;
}
}
/**
* Return the stride, in bytes, of the texture image of the given texture
* at the given level.
*/
static unsigned r300_texture_get_stride(struct r300_screen *screen,
struct r300_resource *tex,
unsigned level)
{
unsigned tile_width, width, stride;
boolean is_rs690 = (screen->caps.family == CHIP_RS600 ||
screen->caps.family == CHIP_RS690 ||
screen->caps.family == CHIP_RS740);
if (tex->tex.stride_in_bytes_override)
return tex->tex.stride_in_bytes_override;
/* Check the level. */
if (level > tex->b.b.last_level) {
SCREEN_DBG(screen, DBG_TEX, "%s: level (%u) > last_level (%u)\n",
__FUNCTION__, level, tex->b.b.last_level);
return 0;
}
width = u_minify(tex->tex.width0, level);
if (util_format_is_plain(tex->b.b.format)) {
tile_width = r300_get_pixel_alignment(tex->b.b.format,
tex->b.b.nr_samples,
tex->tex.microtile,
tex->tex.macrotile[level],
DIM_WIDTH, is_rs690);
width = align(width, tile_width);
stride = util_format_get_stride(tex->b.b.format, width);
/* The alignment to 32 bytes is sort of implied by the layout... */
return stride;
} else {
return align(util_format_get_stride(tex->b.b.format, width), is_rs690 ? 64 : 32);
}
}
static unsigned r300_texture_get_nblocksy(struct r300_resource *tex,
unsigned level,
boolean *out_aligned_for_cbzb)
{
unsigned height, tile_height;
height = u_minify(tex->tex.height0, level);
/* Mipmapped and 3D textures must have their height aligned to POT. */
if ((tex->b.b.target != PIPE_TEXTURE_1D &&
tex->b.b.target != PIPE_TEXTURE_2D &&
tex->b.b.target != PIPE_TEXTURE_RECT) ||
tex->b.b.last_level != 0) {
height = util_next_power_of_two(height);
}
if (util_format_is_plain(tex->b.b.format)) {
tile_height = r300_get_pixel_alignment(tex->b.b.format,
tex->b.b.nr_samples,
tex->tex.microtile,
tex->tex.macrotile[level],
DIM_HEIGHT, 0);
height = align(height, tile_height);
/* See if the CBZB clear can be used on the buffer,
* taking the texture size into account. */
if (out_aligned_for_cbzb) {
if (tex->tex.macrotile[level]) {
/* When clearing, the layer (width*height) is horizontally split
* into two, and the upper and lower halves are cleared by the CB
* and ZB units, respectively. Therefore, the number of macrotiles
* in the Y direction must be even. */
/* Align the height so that there is an even number of macrotiles.
* Do so for 3 or more macrotiles in the Y direction. */
if (level == 0 && tex->b.b.last_level == 0 &&
(tex->b.b.target == PIPE_TEXTURE_1D ||
tex->b.b.target == PIPE_TEXTURE_2D ||
tex->b.b.target == PIPE_TEXTURE_RECT) &&
height >= tile_height * 3) {
height = align(height, tile_height * 2);
}
*out_aligned_for_cbzb = height % (tile_height * 2) == 0;
} else {
*out_aligned_for_cbzb = FALSE;
}
}
}
return util_format_get_nblocksy(tex->b.b.format, height);
}
/* Get a width in pixels from a stride in bytes. */
unsigned r300_stride_to_width(enum pipe_format format,
unsigned stride_in_bytes)
{
return (stride_in_bytes / util_format_get_blocksize(format)) *
util_format_get_blockwidth(format);
}
static void r300_setup_miptree(struct r300_screen *screen,
struct r300_resource *tex,
boolean align_for_cbzb)
{
struct pipe_resource *base = &tex->b.b;
unsigned stride, size, layer_size, nblocksy, i;
boolean rv350_mode = screen->caps.family >= CHIP_R350;
boolean aligned_for_cbzb;
tex->tex.size_in_bytes = 0;
SCREEN_DBG(screen, DBG_TEXALLOC,
"r300: Making miptree for texture, format %s\n",
util_format_short_name(base->format));
for (i = 0; i <= base->last_level; i++) {
/* Let's see if this miplevel can be macrotiled. */
tex->tex.macrotile[i] =
(tex->tex.macrotile[0] == RADEON_LAYOUT_TILED &&
r300_texture_macro_switch(tex, i, rv350_mode, DIM_WIDTH) &&
r300_texture_macro_switch(tex, i, rv350_mode, DIM_HEIGHT)) ?
RADEON_LAYOUT_TILED : RADEON_LAYOUT_LINEAR;
stride = r300_texture_get_stride(screen, tex, i);
/* Compute the number of blocks in Y, see if the CBZB clear can be
* used on the texture. */
aligned_for_cbzb = FALSE;
if (align_for_cbzb && tex->tex.cbzb_allowed[i])
nblocksy = r300_texture_get_nblocksy(tex, i, &aligned_for_cbzb);
else
nblocksy = r300_texture_get_nblocksy(tex, i, NULL);
layer_size = stride * nblocksy;
if (base->nr_samples > 1) {
layer_size *= base->nr_samples;
}
if (base->target == PIPE_TEXTURE_CUBE)
size = layer_size * 6;
else
size = layer_size * u_minify(tex->tex.depth0, i);
tex->tex.offset_in_bytes[i] = tex->tex.size_in_bytes;
tex->tex.size_in_bytes = tex->tex.offset_in_bytes[i] + size;
tex->tex.layer_size_in_bytes[i] = layer_size;
tex->tex.stride_in_bytes[i] = stride;
tex->tex.cbzb_allowed[i] = tex->tex.cbzb_allowed[i] && aligned_for_cbzb;
SCREEN_DBG(screen, DBG_TEXALLOC, "r300: Texture miptree: Level %d "
"(%dx%dx%d px, pitch %d bytes) %d bytes total, macrotiled %s\n",
i, u_minify(tex->tex.width0, i), u_minify(tex->tex.height0, i),
u_minify(tex->tex.depth0, i), stride, tex->tex.size_in_bytes,
tex->tex.macrotile[i] ? "TRUE" : "FALSE");
}
}
static void r300_setup_flags(struct r300_resource *tex)
{
tex->tex.uses_stride_addressing =
!util_is_power_of_two(tex->b.b.width0) ||
(tex->tex.stride_in_bytes_override &&
r300_stride_to_width(tex->b.b.format,
tex->tex.stride_in_bytes_override) != tex->b.b.width0);
tex->tex.is_npot =
tex->tex.uses_stride_addressing ||
!util_is_power_of_two(tex->b.b.height0) ||
!util_is_power_of_two(tex->b.b.depth0);
}
static void r300_setup_cbzb_flags(struct r300_screen *rscreen,
struct r300_resource *tex)
{
unsigned i, bpp;
boolean first_level_valid;
bpp = util_format_get_blocksizebits(tex->b.b.format);
/* 1) The texture must be point-sampled,
* 2) The depth must be 16 or 32 bits.
* 3) If the midpoint ZB offset is not aligned to 2048, it returns garbage
* with certain texture sizes. Macrotiling ensures the alignment. */
first_level_valid = tex->b.b.nr_samples <= 1 &&
(bpp == 16 || bpp == 32) &&
tex->tex.macrotile[0];
if (SCREEN_DBG_ON(rscreen, DBG_NO_CBZB))
first_level_valid = FALSE;
for (i = 0; i <= tex->b.b.last_level; i++)
tex->tex.cbzb_allowed[i] = first_level_valid && tex->tex.macrotile[i];
}
static unsigned r300_pixels_to_dwords(unsigned stride,
unsigned height,
unsigned xblock, unsigned yblock)
{
return (util_align_npot(stride, xblock) * align(height, yblock)) / (xblock * yblock);
}
static void r300_setup_hyperz_properties(struct r300_screen *screen,
struct r300_resource *tex)
{
/* The tile size of 1 DWORD in ZMASK RAM is:
*
* GPU Pipes 4x4 mode 8x8 mode
* ------------------------------------------
* R580 4P/1Z 32x32 64x64
* RV570 3P/1Z 48x16 96x32
* RV530 1P/2Z 32x16 64x32
* 1P/1Z 16x16 32x32
*/
static unsigned zmask_blocks_x_per_dw[4] = {4, 8, 12, 8};
static unsigned zmask_blocks_y_per_dw[4] = {4, 4, 4, 8};
/* In HIZ RAM, one dword is always 8x8 pixels (each byte is 4x4 pixels),
* but the blocks have very weird ordering.
*
* With 2 pipes and an image of size 8xY, where Y >= 1,
* clearing 4 dwords clears blocks like this:
*
* 01012323
*
* where numbers correspond to dword indices. The blocks are interleaved
* in the X direction, so the alignment must be 4x1 blocks (32x8 pixels).
*
* With 4 pipes and an image of size 8xY, where Y >= 4,
* clearing 8 dwords clears blocks like this:
* 01012323
* 45456767
* 01012323
* 45456767
* where numbers correspond to dword indices. The blocks are interleaved
* in both directions, so the alignment must be 4x4 blocks (32x32 pixels)
*/
static unsigned hiz_align_x[4] = {8, 32, 48, 32};
static unsigned hiz_align_y[4] = {8, 8, 8, 32};
if (util_format_is_depth_or_stencil(tex->b.b.format) &&
util_format_get_blocksizebits(tex->b.b.format) == 32 &&
tex->tex.microtile) {
unsigned i, pipes;
if (screen->caps.family == CHIP_RV530) {
pipes = screen->info.r300_num_z_pipes;
} else {
pipes = screen->info.r300_num_gb_pipes;
}
for (i = 0; i <= tex->b.b.last_level; i++) {
unsigned zcomp_numdw, zcompsize, hiz_numdw, stride, height;
stride = r300_stride_to_width(tex->b.b.format,
tex->tex.stride_in_bytes[i]);
stride = align(stride, 16);
height = u_minify(tex->b.b.height0, i);
/* The 8x8 compression mode needs macrotiling. */
zcompsize = screen->caps.z_compress == R300_ZCOMP_8X8 &&
tex->tex.macrotile[i] &&
tex->b.b.nr_samples <= 1 ? 8 : 4;
/* Get the ZMASK buffer size in dwords. */
zcomp_numdw = r300_pixels_to_dwords(stride, height,
zmask_blocks_x_per_dw[pipes-1] * zcompsize,
zmask_blocks_y_per_dw[pipes-1] * zcompsize);
/* Check whether we have enough ZMASK memory. */
if (util_format_get_blocksizebits(tex->b.b.format) == 32 &&
zcomp_numdw <= screen->caps.zmask_ram * pipes) {
tex->tex.zmask_dwords[i] = zcomp_numdw;
tex->tex.zcomp8x8[i] = zcompsize == 8;
tex->tex.zmask_stride_in_pixels[i] =
util_align_npot(stride, zmask_blocks_x_per_dw[pipes-1] * zcompsize);
} else {
tex->tex.zmask_dwords[i] = 0;
tex->tex.zcomp8x8[i] = FALSE;
tex->tex.zmask_stride_in_pixels[i] = 0;
}
/* Now setup HIZ. */
stride = util_align_npot(stride, hiz_align_x[pipes-1]);
height = align(height, hiz_align_y[pipes-1]);
/* Get the HIZ buffer size in dwords. */
hiz_numdw = (stride * height) / (8*8 * pipes);
/* Check whether we have enough HIZ memory. */
if (hiz_numdw <= screen->caps.hiz_ram * pipes) {
tex->tex.hiz_dwords[i] = hiz_numdw;
tex->tex.hiz_stride_in_pixels[i] = stride;
} else {
tex->tex.hiz_dwords[i] = 0;
tex->tex.hiz_stride_in_pixels[i] = 0;
}
}
}
}
static void r300_setup_cmask_properties(struct r300_screen *screen,
struct r300_resource *tex)
{
static unsigned cmask_align_x[4] = {16, 32, 48, 32};
static unsigned cmask_align_y[4] = {16, 16, 16, 32};
unsigned pipes, stride, cmask_num_dw, cmask_max_size;
if (!screen->caps.has_cmask) {
return;
}
/* We need an AA colorbuffer, no mipmaps. */
if (tex->b.b.nr_samples <= 1 ||
tex->b.b.last_level > 0 ||
util_format_is_depth_or_stencil(tex->b.b.format)) {
return;
}
/* FP16 AA needs R500 and a fairly new DRM. */
if ((tex->b.b.format == PIPE_FORMAT_R16G16B16A16_FLOAT ||
tex->b.b.format == PIPE_FORMAT_R16G16B16X16_FLOAT) &&
(!screen->caps.is_r500 || screen->info.drm_minor < 29)) {
return;
}
if (SCREEN_DBG_ON(screen, DBG_NO_CMASK)) {
return;
}
/* CMASK is part of raster pipes. The number of Z pipes doesn't matter. */
pipes = screen->info.r300_num_gb_pipes;
/* The single-pipe cards have 5120 dwords of CMASK RAM,
* the other cards have 4096 dwords of CMASK RAM per pipe. */
cmask_max_size = pipes == 1 ? 5120 : pipes * 4096;
stride = r300_stride_to_width(tex->b.b.format,
tex->tex.stride_in_bytes[0]);
stride = align(stride, 16);
/* Get the CMASK size in dwords. */
cmask_num_dw = r300_pixels_to_dwords(stride, tex->b.b.height0,
cmask_align_x[pipes-1],
cmask_align_y[pipes-1]);
/* Check the CMASK size against the CMASK memory limit. */
if (cmask_num_dw <= cmask_max_size) {
tex->tex.cmask_dwords = cmask_num_dw;
tex->tex.cmask_stride_in_pixels =
util_align_npot(stride, cmask_align_x[pipes-1]);
}
}
static void r300_setup_tiling(struct r300_screen *screen,
struct r300_resource *tex)
{
enum pipe_format format = tex->b.b.format;
boolean rv350_mode = screen->caps.family >= CHIP_R350;
boolean is_zb = util_format_is_depth_or_stencil(format);
boolean dbg_no_tiling = SCREEN_DBG_ON(screen, DBG_NO_TILING);
boolean force_microtiling =
(tex->b.b.flags & R300_RESOURCE_FORCE_MICROTILING) != 0;
if (tex->b.b.nr_samples > 1) {
tex->tex.microtile = RADEON_LAYOUT_TILED;
tex->tex.macrotile[0] = RADEON_LAYOUT_TILED;
return;
}
tex->tex.microtile = RADEON_LAYOUT_LINEAR;
tex->tex.macrotile[0] = RADEON_LAYOUT_LINEAR;
if (tex->b.b.usage == PIPE_USAGE_STAGING) {
return;
}
if (!util_format_is_plain(format)) {
return;
}
/* If height == 1, disable microtiling except for zbuffer. */
if (!force_microtiling && !is_zb &&
(tex->b.b.height0 == 1 || dbg_no_tiling)) {
return;
}
/* Set microtiling. */
switch (util_format_get_blocksize(format)) {
case 1:
case 4:
case 8:
tex->tex.microtile = RADEON_LAYOUT_TILED;
break;
case 2:
tex->tex.microtile = RADEON_LAYOUT_SQUARETILED;
break;
}
if (dbg_no_tiling) {
return;
}
/* Set macrotiling. */
if (r300_texture_macro_switch(tex, 0, rv350_mode, DIM_WIDTH) &&
r300_texture_macro_switch(tex, 0, rv350_mode, DIM_HEIGHT)) {
tex->tex.macrotile[0] = RADEON_LAYOUT_TILED;
}
}
static void r300_tex_print_info(struct r300_resource *tex,
const char *func)
{
fprintf(stderr,
"r300: %s: Macro: %s, Micro: %s, Pitch: %i, Dim: %ix%ix%i, "
"LastLevel: %i, Size: %i, Format: %s, Samples: %i\n",
func,
tex->tex.macrotile[0] ? "YES" : " NO",
tex->tex.microtile ? "YES" : " NO",
r300_stride_to_width(tex->b.b.format, tex->tex.stride_in_bytes[0]),
tex->b.b.width0, tex->b.b.height0, tex->b.b.depth0,
tex->b.b.last_level, tex->tex.size_in_bytes,
util_format_short_name(tex->b.b.format),
tex->b.b.nr_samples);
}
void r300_texture_desc_init(struct r300_screen *rscreen,
struct r300_resource *tex,
const struct pipe_resource *base)
{
tex->b.b.target = base->target;
tex->b.b.format = base->format;
tex->b.b.width0 = base->width0;
tex->b.b.height0 = base->height0;
tex->b.b.depth0 = base->depth0;
tex->b.b.array_size = base->array_size;
tex->b.b.last_level = base->last_level;
tex->b.b.nr_samples = base->nr_samples;
tex->tex.width0 = base->width0;
tex->tex.height0 = base->height0;
tex->tex.depth0 = base->depth0;
/* There is a CB memory addressing hardware bug that limits the width
* of the MSAA buffer in some cases in R520. In order to get around it,
* the following code lowers the sample count depending on the format and
* the width.
*
* The only catch is that all MSAA colorbuffers and a zbuffer which are
* supposed to be used together should always be bound together. Only
* then the correct minimum sample count of all bound buffers is used
* for rendering. */
if (rscreen->caps.is_r500) {
/* FP16 6x MSAA buffers are limited to a width of 1360 pixels. */
if ((tex->b.b.format == PIPE_FORMAT_R16G16B16A16_FLOAT ||
tex->b.b.format == PIPE_FORMAT_R16G16B16X16_FLOAT) &&
tex->b.b.nr_samples == 6 && tex->b.b.width0 > 1360) {
tex->b.b.nr_samples = 4;
}
/* FP16 4x MSAA buffers are limited to a width of 2048 pixels. */
if ((tex->b.b.format == PIPE_FORMAT_R16G16B16A16_FLOAT ||
tex->b.b.format == PIPE_FORMAT_R16G16B16X16_FLOAT) &&
tex->b.b.nr_samples == 4 && tex->b.b.width0 > 2048) {
tex->b.b.nr_samples = 2;
}
}
/* 32-bit 6x MSAA buffers are limited to a width of 2720 pixels.
* This applies to all R300-R500 cards. */
if (util_format_get_blocksizebits(tex->b.b.format) == 32 &&
!util_format_is_depth_or_stencil(tex->b.b.format) &&
tex->b.b.nr_samples == 6 && tex->b.b.width0 > 2720) {
tex->b.b.nr_samples = 4;
}
r300_setup_flags(tex);
/* Align a 3D NPOT texture to POT. */
if (base->target == PIPE_TEXTURE_3D && tex->tex.is_npot) {
tex->tex.width0 = util_next_power_of_two(tex->tex.width0);
tex->tex.height0 = util_next_power_of_two(tex->tex.height0);
tex->tex.depth0 = util_next_power_of_two(tex->tex.depth0);
}
/* Setup tiling. */
if (tex->tex.microtile == RADEON_LAYOUT_UNKNOWN) {
r300_setup_tiling(rscreen, tex);
}
r300_setup_cbzb_flags(rscreen, tex);
/* Setup the miptree description. */
r300_setup_miptree(rscreen, tex, TRUE);
/* If the required buffer size is larger than the given max size,
* try again without the alignment for the CBZB clear. */
if (tex->buf && tex->tex.size_in_bytes > tex->buf->size) {
r300_setup_miptree(rscreen, tex, FALSE);
/* Make sure the buffer we got is large enough. */
if (tex->tex.size_in_bytes > tex->buf->size) {
fprintf(stderr,
"r300: I got a pre-allocated buffer to use it as a texture "
"storage, but the buffer is too small. I'll use the buffer "
"anyway, because I can't crash here, but it's dangerous. "
"This can be a DDX bug. Got: %"PRIu64"B, Need: %uB, Info:\n",
tex->buf->size, tex->tex.size_in_bytes);
r300_tex_print_info(tex, "texture_desc_init");
/* Ooops, what now. Apps will break if we fail this,
* so just pretend everything's okay. */
}
}
r300_setup_hyperz_properties(rscreen, tex);
r300_setup_cmask_properties(rscreen, tex);
if (SCREEN_DBG_ON(rscreen, DBG_TEX))
r300_tex_print_info(tex, "texture_desc_init");
}
unsigned r300_texture_get_offset(struct r300_resource *tex,
unsigned level, unsigned layer)
{
unsigned offset = tex->tex.offset_in_bytes[level];
switch (tex->b.b.target) {
case PIPE_TEXTURE_3D:
case PIPE_TEXTURE_CUBE:
return offset + layer * tex->tex.layer_size_in_bytes[level];
default:
assert(layer == 0);
return offset;
}
}