src/gallium/drivers/cell/ppu/cell_texture.c - fp2-dev/platform/external/mesa3d - Gitiles

 /**************************************************************************
  *
  * Copyright 2006 Tungsten Graphics, Inc., Cedar Park, Texas.
  * All Rights Reserved.
  *
  * 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 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 TUNGSTEN GRAPHICS AND/OR ITS 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.
  *
  **************************************************************************/
  /*
   * Authors:
   *   Keith Whitwell <keith@tungstengraphics.com>
   *   Michel Dänzer <michel@tungstengraphics.com>
   *   Brian Paul
   */

 #include "pipe/p_context.h"
 #include "pipe/p_defines.h"
 #include "pipe/p_inlines.h"
 #include "pipe/internal/p_winsys_screen.h"

 #include "util/u_format.h"
 #include "util/u_math.h"
 #include "util/u_memory.h"

 #include "cell_context.h"
 #include "cell_state.h"
 #include "cell_texture.h"


 static void
 cell_texture_layout(struct cell_texture *ct)
 {
    struct pipe_texture *pt = &ct->base;
    unsigned level;
    unsigned width = pt->width0;
    unsigned height = pt->height0;
    unsigned depth = pt->depth0;

    ct->buffer_size = 0;

    for (level = 0; level <= pt->last_level; level++) {
       unsigned size;
       unsigned w_tile, h_tile;

       assert(level < CELL_MAX_TEXTURE_LEVELS);

       /* width, height, rounded up to tile size */
       w_tile = align(width, TILE_SIZE);
       h_tile = align(height, TILE_SIZE);

       ct->stride[level] = util_format_get_stride(pt->format, w_tile);

       ct->level_offset[level] = ct->buffer_size;

       size = ct->stride[level] * util_format_get_nblocksy(pt->format, h_tile);
       if (pt->target == PIPE_TEXTURE_CUBE)
          size *= 6;
       else
          size *= depth;

       ct->buffer_size += size;

       width = u_minify(width, 1);
       height = u_minify(height, 1);
       depth = u_minify(depth, 1);
    }
 }


 static struct pipe_texture *
 cell_texture_create(struct pipe_screen *screen,
                     const struct pipe_texture *templat)
 {
    struct cell_texture *ct = CALLOC_STRUCT(cell_texture);
    if (!ct)
       return NULL;

    ct->base = *templat;
    pipe_reference_init(&ct->base.reference, 1);
    ct->base.screen = screen;

    cell_texture_layout(ct);

    ct->buffer = screen->buffer_create(screen, 32, PIPE_BUFFER_USAGE_PIXEL,
                                    ct->buffer_size);

    if (!ct->buffer) {
       FREE(ct);
       return NULL;
    }

    return &ct->base;
 }


 static void
 cell_texture_destroy(struct pipe_texture *pt)
 {
    struct cell_texture *ct = cell_texture(pt);

    if (ct->mapped) {
       pipe_buffer_unmap(ct->buffer->screen, ct->buffer);
       ct->mapped = NULL;
    }

    pipe_buffer_reference(&ct->buffer, NULL);

    FREE(ct);
 }


 /**
  * Convert image from linear layout to tiled layout.  4-byte pixels.
  */
 static void
 twiddle_image_uint(uint w, uint h, uint tile_size, uint *dst,
                    uint src_stride, const uint *src)
 {
    const uint tile_size2 = tile_size * tile_size;
    const uint h_t = (h + tile_size - 1) / tile_size;
    const uint w_t = (w + tile_size - 1) / tile_size;

    uint it, jt;  /* tile counters */
    uint i, j;    /* intra-tile counters */

    src_stride /= 4; /* convert from bytes to pixels */

    /* loop over dest tiles */
    for (it = 0; it < h_t; it++) {
       for (jt = 0; jt < w_t; jt++) {
          /* start of dest tile: */
          uint *tdst = dst + (it * w_t + jt) * tile_size2;

          /* compute size of this tile (may be smaller than tile_size) */
          /* XXX note: a compiler bug was found here. That's why the code
           * looks as it does.
           */
          uint tile_width = w - jt * tile_size;
          tile_width = MIN2(tile_width, tile_size);
          uint tile_height = h - it * tile_size;
          tile_height = MIN2(tile_height, tile_size);

          /* loop over texels in the tile */
          for (i = 0; i < tile_height; i++) {
             for (j = 0; j < tile_width; j++) {
                const uint srci = it * tile_size + i;
                const uint srcj = jt * tile_size + j;
                ASSERT(srci < h);
                ASSERT(srcj < w);
                tdst[i * tile_size + j] = src[srci * src_stride + srcj];
             }
          }
       }
    }
 }


 /**
  * For Cell.  Basically, rearrange the pixels/quads from this layout:
  *  +--+--+--+--+
  *  |p0|p1|p2|p3|....
  *  +--+--+--+--+
  *
  * to this layout:
  *  +--+--+
  *  |p0|p1|....
  *  +--+--+
  *  |p2|p3|
  *  +--+--+
  */
 static void
 twiddle_tile(const uint *tileIn, uint *tileOut)
 {
    int y, x;

    for (y = 0; y < TILE_SIZE; y+=2) {
       for (x = 0; x < TILE_SIZE; x+=2) {
          int k = 4 * (y/2 * TILE_SIZE/2 + x/2);
          tileOut[y * TILE_SIZE + (x + 0)] = tileIn[k];
          tileOut[y * TILE_SIZE + (x + 1)] = tileIn[k+1];
          tileOut[(y + 1) * TILE_SIZE + (x + 0)] = tileIn[k+2];
          tileOut[(y + 1) * TILE_SIZE + (x + 1)] = tileIn[k+3];
       }
    }
 }


 /**
  * Convert image from tiled layout to linear layout.  4-byte pixels.
  */
 static void
 untwiddle_image_uint(uint w, uint h, uint tile_size, uint *dst,
                      uint dst_stride, const uint *src)
 {
    const uint tile_size2 = tile_size * tile_size;
    const uint h_t = (h + tile_size - 1) / tile_size;
    const uint w_t = (w + tile_size - 1) / tile_size;
    uint *tile_buf;
    uint it, jt;  /* tile counters */
    uint i, j;    /* intra-tile counters */

    dst_stride /= 4; /* convert from bytes to pixels */

    tile_buf = align_malloc(tile_size * tile_size * 4, 16);

    /* loop over src tiles */
    for (it = 0; it < h_t; it++) {
       for (jt = 0; jt < w_t; jt++) {
          /* start of src tile: */
          const uint *tsrc = src + (it * w_t + jt) * tile_size2;

          twiddle_tile(tsrc, tile_buf);
          tsrc = tile_buf;

          /* compute size of this tile (may be smaller than tile_size) */
          /* XXX note: a compiler bug was found here. That's why the code
           * looks as it does.
           */
          uint tile_width = w - jt * tile_size;
          tile_width = MIN2(tile_width, tile_size);
          uint tile_height = h - it * tile_size;
          tile_height = MIN2(tile_height, tile_size);

          /* loop over texels in the tile */
          for (i = 0; i < tile_height; i++) {
             for (j = 0; j < tile_width; j++) {
                uint dsti = it * tile_size + i;
                uint dstj = jt * tile_size + j;
                ASSERT(dsti < h);
                ASSERT(dstj < w);
                dst[dsti * dst_stride + dstj] = tsrc[i * tile_size + j];
             }
          }
       }
    }

    align_free(tile_buf);
 }


 static struct pipe_surface *
 cell_get_tex_surface(struct pipe_screen *screen,
                      struct pipe_texture *pt,
                      unsigned face, unsigned level, unsigned zslice,
                      unsigned usage)
 {
    struct cell_texture *ct = cell_texture(pt);
    struct pipe_surface *ps;

    ps = CALLOC_STRUCT(pipe_surface);
    if (ps) {
       pipe_reference_init(&ps->reference, 1);
       pipe_texture_reference(&ps->texture, pt);
       ps->format = pt->format;
       ps->width = u_minify(pt->width0, level);
       ps->height = u_minify(pt->height0, level);
       ps->offset = ct->level_offset[level];
       /* XXX may need to override usage flags (see sp_texture.c) */
       ps->usage = usage;
       ps->face = face;
       ps->level = level;
       ps->zslice = zslice;

       if (pt->target == PIPE_TEXTURE_CUBE) {
          unsigned h_tile = align(ps->height, TILE_SIZE);
          ps->offset += face * util_format_get_nblocksy(ps->format, h_tile) * ct->stride[level];
       }
       else if (pt->target == PIPE_TEXTURE_3D) {
          unsigned h_tile = align(ps->height, TILE_SIZE);
          ps->offset += zslice * util_format_get_nblocksy(ps->format, h_tile) * ct->stride[level];
       }
       else {
          assert(face == 0);
          assert(zslice == 0);
       }
    }
    return ps;
 }


 static void
 cell_tex_surface_destroy(struct pipe_surface *surf)
 {
    pipe_texture_reference(&surf->texture, NULL);
    FREE(surf);
 }


 /**
  * Create new pipe_transfer object.
  * This is used by the user to put tex data into a texture (and get it
  * back out for glGetTexImage).
  */
 static struct pipe_transfer *
 cell_get_tex_transfer(struct pipe_screen *screen,
                       struct pipe_texture *texture,
                       unsigned face, unsigned level, unsigned zslice,
                       enum pipe_transfer_usage usage,
                       unsigned x, unsigned y, unsigned w, unsigned h)
 {
    struct cell_texture *ct = cell_texture(texture);
    struct cell_transfer *ctrans;

    assert(texture);
    assert(level <= texture->last_level);

    ctrans = CALLOC_STRUCT(cell_transfer);
    if (ctrans) {
       struct pipe_transfer *pt = &ctrans->base;
       pipe_texture_reference(&pt->texture, texture);
       pt->x = x;
       pt->y = y;
       pt->width = w;
       pt->height = h;
       pt->stride = ct->stride[level];
       pt->usage = usage;
       pt->face = face;
       pt->level = level;
       pt->zslice = zslice;

       ctrans->offset = ct->level_offset[level];

       if (texture->target == PIPE_TEXTURE_CUBE) {
          unsigned h_tile = align(u_minify(texture->height0, level), TILE_SIZE);
          ctrans->offset += face * util_format_get_nblocksy(texture->format, h_tile) * pt->stride;
       }
       else if (texture->target == PIPE_TEXTURE_3D) {
          unsigned h_tile = align(u_minify(texture->height0, level), TILE_SIZE);
          ctrans->offset += zslice * util_format_get_nblocksy(texture->format, h_tile) * pt->stride;
       }
       else {
          assert(face == 0);
          assert(zslice == 0);
       }
       return pt;
    }
    return NULL;
 }


 static void
 cell_tex_transfer_destroy(struct pipe_transfer *t)
 {
    struct cell_transfer *transfer = cell_transfer(t);
    /* Effectively do the texture_update work here - if texture images
     * needed post-processing to put them into hardware layout, this is
     * where it would happen.  For cell, nothing to do.
     */
    assert (transfer->base.texture);
    pipe_texture_reference(&transfer->base.texture, NULL);
    FREE(transfer);
 }


 /**
  * Return pointer to texture image data in linear layout.
  */
 static void *
 cell_transfer_map(struct pipe_screen *screen, struct pipe_transfer *transfer)
 {
    struct cell_transfer *ctrans = cell_transfer(transfer);
    struct pipe_texture *pt = transfer->texture;
    struct cell_texture *ct = cell_texture(pt);
    const uint level = ctrans->base.level;
    const uint texWidth = u_minify(pt->width0, level);
    const uint texHeight = u_minify(pt->height0, level);
    const uint stride = ct->stride[level];
    unsigned size;

    assert(transfer->texture);

    if (!ct->mapped) {
       /* map now */
       ct->mapped = pipe_buffer_map(screen, ct->buffer,
                                    pipe_transfer_buffer_flags(transfer));
    }

    /*
     * Create a buffer of ordinary memory for the linear texture.
     * This is the memory that the user will read/write.
     */
    size = util_format_get_stride(pt->format, align(texWidth, TILE_SIZE)) *
           util_format_get_nblocksy(pt->format, align(texHeight, TILE_SIZE));

    ctrans->map = align_malloc(size, 16);
    if (!ctrans->map)
       return NULL; /* out of memory */

    if (transfer->usage & PIPE_TRANSFER_READ) {
       /* need to untwiddle the texture to make a linear version */
       const uint bpp = util_format_get_blocksize(ct->base.format);
       if (bpp == 4) {
          const uint *src = (uint *) (ct->mapped + ctrans->offset);
          uint *dst = ctrans->map;
          untwiddle_image_uint(texWidth, texHeight, TILE_SIZE,
                               dst, stride, src);
       }
       else {
          // xxx fix
       }
    }

    return ctrans->map;
 }


 /**
  * Called when user is done reading/writing texture data.
  * If new data was written, this is where we convert the linear data
  * to tiled data.
  */
 static void
 cell_transfer_unmap(struct pipe_screen *screen,
                     struct pipe_transfer *transfer)
 {
    struct cell_transfer *ctrans = cell_transfer(transfer);
    struct pipe_texture *pt = transfer->texture;
    struct cell_texture *ct = cell_texture(pt);
    const uint level = ctrans->base.level;
    const uint texWidth = u_minify(pt->width0, level);
    const uint texHeight = u_minify(pt->height0, level);
    const uint stride = ct->stride[level];

    if (!ct->mapped) {
       /* map now */
       ct->mapped = pipe_buffer_map(screen, ct->buffer,
                                    PIPE_BUFFER_USAGE_CPU_READ);
    }

    if (transfer->usage & PIPE_TRANSFER_WRITE) {
       /* The user wrote new texture data into the mapped buffer.
        * We need to convert the new linear data into the twiddled/tiled format.
        */
       const uint bpp = util_format_get_blocksize(ct->base.format);
       if (bpp == 4) {
          const uint *src = ctrans->map;
          uint *dst = (uint *) (ct->mapped + ctrans->offset);
          twiddle_image_uint(texWidth, texHeight, TILE_SIZE, dst, stride, src);
       }
       else {
          // xxx fix
       }
    }

    align_free(ctrans->map);
    ctrans->map = NULL;
 }


 void
 cell_init_screen_texture_funcs(struct pipe_screen *screen)
 {
    screen->texture_create = cell_texture_create;
    screen->texture_destroy = cell_texture_destroy;

    screen->get_tex_surface = cell_get_tex_surface;
    screen->tex_surface_destroy = cell_tex_surface_destroy;

    screen->get_tex_transfer = cell_get_tex_transfer;
    screen->tex_transfer_destroy = cell_tex_transfer_destroy;

    screen->transfer_map = cell_transfer_map;
    screen->transfer_unmap = cell_transfer_unmap;
 }
	/**************************************************************************
	*
	* Copyright 2006 Tungsten Graphics, Inc., Cedar Park, Texas.
	* All Rights Reserved.
	*
	* 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 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 TUNGSTEN GRAPHICS AND/OR ITS 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.
	*
	**************************************************************************/
	/*
	* Authors:
	* Keith Whitwell <keith@tungstengraphics.com>
	* Michel Dänzer <michel@tungstengraphics.com>
	* Brian Paul
	*/

	#include "pipe/p_context.h"
	#include "pipe/p_defines.h"
	#include "pipe/p_inlines.h"
	#include "pipe/internal/p_winsys_screen.h"

	#include "util/u_format.h"
	#include "util/u_math.h"
	#include "util/u_memory.h"

	#include "cell_context.h"
	#include "cell_state.h"
	#include "cell_texture.h"



	static void
	cell_texture_layout(struct cell_texture *ct)
	{
	struct pipe_texture *pt = &ct->base;
	unsigned level;
	unsigned width = pt->width0;
	unsigned height = pt->height0;
	unsigned depth = pt->depth0;

	ct->buffer_size = 0;

	for (level = 0; level <= pt->last_level; level++) {
	unsigned size;
	unsigned w_tile, h_tile;

	assert(level < CELL_MAX_TEXTURE_LEVELS);

	/* width, height, rounded up to tile size */
	w_tile = align(width, TILE_SIZE);
	h_tile = align(height, TILE_SIZE);

	ct->stride[level] = util_format_get_stride(pt->format, w_tile);

	ct->level_offset[level] = ct->buffer_size;

	size = ct->stride[level] * util_format_get_nblocksy(pt->format, h_tile);
	if (pt->target == PIPE_TEXTURE_CUBE)
	size *= 6;
	else
	size *= depth;

	ct->buffer_size += size;

	width = u_minify(width, 1);
	height = u_minify(height, 1);
	depth = u_minify(depth, 1);
	}
	}


	static struct pipe_texture *
	cell_texture_create(struct pipe_screen *screen,
	const struct pipe_texture *templat)
	{
	struct cell_texture *ct = CALLOC_STRUCT(cell_texture);
	if (!ct)
	return NULL;

	ct->base = *templat;
	pipe_reference_init(&ct->base.reference, 1);
	ct->base.screen = screen;

	cell_texture_layout(ct);

	ct->buffer = screen->buffer_create(screen, 32, PIPE_BUFFER_USAGE_PIXEL,
	ct->buffer_size);

	if (!ct->buffer) {
	FREE(ct);
	return NULL;
	}

	return &ct->base;
	}


	static void
	cell_texture_destroy(struct pipe_texture *pt)
	{
	struct cell_texture *ct = cell_texture(pt);

	if (ct->mapped) {
	pipe_buffer_unmap(ct->buffer->screen, ct->buffer);
	ct->mapped = NULL;
	}

	pipe_buffer_reference(&ct->buffer, NULL);

	FREE(ct);
	}



	/**
	* Convert image from linear layout to tiled layout. 4-byte pixels.
	*/
	static void
	twiddle_image_uint(uint w, uint h, uint tile_size, uint *dst,
	uint src_stride, const uint *src)
	{
	const uint tile_size2 = tile_size * tile_size;
	const uint h_t = (h + tile_size - 1) / tile_size;
	const uint w_t = (w + tile_size - 1) / tile_size;

	uint it, jt; /* tile counters */
	uint i, j; /* intra-tile counters */

	src_stride /= 4; /* convert from bytes to pixels */

	/* loop over dest tiles */
	for (it = 0; it < h_t; it++) {
	for (jt = 0; jt < w_t; jt++) {
	/* start of dest tile: */
	uint tdst = dst + (it w_t + jt) * tile_size2;

	/* compute size of this tile (may be smaller than tile_size) */
	/* XXX note: a compiler bug was found here. That's why the code
	* looks as it does.
	*/
	uint tile_width = w - jt * tile_size;
	tile_width = MIN2(tile_width, tile_size);
	uint tile_height = h - it * tile_size;
	tile_height = MIN2(tile_height, tile_size);

	/* loop over texels in the tile */
	for (i = 0; i < tile_height; i++) {
	for (j = 0; j < tile_width; j++) {
	const uint srci = it * tile_size + i;
	const uint srcj = jt * tile_size + j;
	ASSERT(srci < h);
	ASSERT(srcj < w);
	tdst[i * tile_size + j] = src[srci * src_stride + srcj];
	}
	}
	}
	}
	}


	/**
	* For Cell. Basically, rearrange the pixels/quads from this layout:
	* +--+--+--+--+
	* \|p0\|p1\|p2\|p3\|....
	* +--+--+--+--+
	*
	* to this layout:
	* +--+--+
	* \|p0\|p1\|....
	* +--+--+
	* \|p2\|p3\|
	* +--+--+
	*/
	static void
	twiddle_tile(const uint tileIn, uint tileOut)
	{
	int y, x;

	for (y = 0; y < TILE_SIZE; y+=2) {
	for (x = 0; x < TILE_SIZE; x+=2) {
	int k = 4 * (y/2 * TILE_SIZE/2 + x/2);
	tileOut[y * TILE_SIZE + (x + 0)] = tileIn[k];
	tileOut[y * TILE_SIZE + (x + 1)] = tileIn[k+1];
	tileOut[(y + 1) * TILE_SIZE + (x + 0)] = tileIn[k+2];
	tileOut[(y + 1) * TILE_SIZE + (x + 1)] = tileIn[k+3];
	}
	}
	}


	/**
	* Convert image from tiled layout to linear layout. 4-byte pixels.
	*/
	static void
	untwiddle_image_uint(uint w, uint h, uint tile_size, uint *dst,
	uint dst_stride, const uint *src)
	{
	const uint tile_size2 = tile_size * tile_size;
	const uint h_t = (h + tile_size - 1) / tile_size;
	const uint w_t = (w + tile_size - 1) / tile_size;
	uint *tile_buf;
	uint it, jt; /* tile counters */
	uint i, j; /* intra-tile counters */

	dst_stride /= 4; /* convert from bytes to pixels */

	tile_buf = align_malloc(tile_size * tile_size * 4, 16);

	/* loop over src tiles */
	for (it = 0; it < h_t; it++) {
	for (jt = 0; jt < w_t; jt++) {
	/* start of src tile: */
	const uint tsrc = src + (it w_t + jt) * tile_size2;

	twiddle_tile(tsrc, tile_buf);
	tsrc = tile_buf;

	/* compute size of this tile (may be smaller than tile_size) */
	/* XXX note: a compiler bug was found here. That's why the code
	* looks as it does.
	*/
	uint tile_width = w - jt * tile_size;
	tile_width = MIN2(tile_width, tile_size);
	uint tile_height = h - it * tile_size;
	tile_height = MIN2(tile_height, tile_size);

	/* loop over texels in the tile */
	for (i = 0; i < tile_height; i++) {
	for (j = 0; j < tile_width; j++) {
	uint dsti = it * tile_size + i;
	uint dstj = jt * tile_size + j;
	ASSERT(dsti < h);
	ASSERT(dstj < w);
	dst[dsti * dst_stride + dstj] = tsrc[i * tile_size + j];
	}
	}
	}
	}

	align_free(tile_buf);
	}


	static struct pipe_surface *
	cell_get_tex_surface(struct pipe_screen *screen,
	struct pipe_texture *pt,
	unsigned face, unsigned level, unsigned zslice,
	unsigned usage)
	{
	struct cell_texture *ct = cell_texture(pt);
	struct pipe_surface *ps;

	ps = CALLOC_STRUCT(pipe_surface);
	if (ps) {
	pipe_reference_init(&ps->reference, 1);
	pipe_texture_reference(&ps->texture, pt);
	ps->format = pt->format;
	ps->width = u_minify(pt->width0, level);
	ps->height = u_minify(pt->height0, level);
	ps->offset = ct->level_offset[level];
	/* XXX may need to override usage flags (see sp_texture.c) */
	ps->usage = usage;
	ps->face = face;
	ps->level = level;
	ps->zslice = zslice;

	if (pt->target == PIPE_TEXTURE_CUBE) {
	unsigned h_tile = align(ps->height, TILE_SIZE);
	ps->offset += face * util_format_get_nblocksy(ps->format, h_tile) * ct->stride[level];
	}
	else if (pt->target == PIPE_TEXTURE_3D) {
	unsigned h_tile = align(ps->height, TILE_SIZE);
	ps->offset += zslice * util_format_get_nblocksy(ps->format, h_tile) * ct->stride[level];
	}
	else {
	assert(face == 0);
	assert(zslice == 0);
	}
	}
	return ps;
	}


	static void
	cell_tex_surface_destroy(struct pipe_surface *surf)
	{
	pipe_texture_reference(&surf->texture, NULL);
	FREE(surf);
	}


	/**
	* Create new pipe_transfer object.
	* This is used by the user to put tex data into a texture (and get it
	* back out for glGetTexImage).
	*/
	static struct pipe_transfer *
	cell_get_tex_transfer(struct pipe_screen *screen,
	struct pipe_texture *texture,
	unsigned face, unsigned level, unsigned zslice,
	enum pipe_transfer_usage usage,
	unsigned x, unsigned y, unsigned w, unsigned h)
	{
	struct cell_texture *ct = cell_texture(texture);
	struct cell_transfer *ctrans;

	assert(texture);
	assert(level <= texture->last_level);

	ctrans = CALLOC_STRUCT(cell_transfer);
	if (ctrans) {
	struct pipe_transfer *pt = &ctrans->base;
	pipe_texture_reference(&pt->texture, texture);
	pt->x = x;
	pt->y = y;
	pt->width = w;
	pt->height = h;
	pt->stride = ct->stride[level];
	pt->usage = usage;
	pt->face = face;
	pt->level = level;
	pt->zslice = zslice;

	ctrans->offset = ct->level_offset[level];

	if (texture->target == PIPE_TEXTURE_CUBE) {
	unsigned h_tile = align(u_minify(texture->height0, level), TILE_SIZE);
	ctrans->offset += face * util_format_get_nblocksy(texture->format, h_tile) * pt->stride;
	}
	else if (texture->target == PIPE_TEXTURE_3D) {
	unsigned h_tile = align(u_minify(texture->height0, level), TILE_SIZE);
	ctrans->offset += zslice * util_format_get_nblocksy(texture->format, h_tile) * pt->stride;
	}
	else {
	assert(face == 0);
	assert(zslice == 0);
	}
	return pt;
	}
	return NULL;
	}


	static void
	cell_tex_transfer_destroy(struct pipe_transfer *t)
	{
	struct cell_transfer *transfer = cell_transfer(t);
	/* Effectively do the texture_update work here - if texture images
	* needed post-processing to put them into hardware layout, this is
	* where it would happen. For cell, nothing to do.
	*/
	assert (transfer->base.texture);
	pipe_texture_reference(&transfer->base.texture, NULL);
	FREE(transfer);
	}


	/**
	* Return pointer to texture image data in linear layout.
	*/
	static void *
	cell_transfer_map(struct pipe_screen screen, struct pipe_transfer transfer)
	{
	struct cell_transfer *ctrans = cell_transfer(transfer);
	struct pipe_texture *pt = transfer->texture;
	struct cell_texture *ct = cell_texture(pt);
	const uint level = ctrans->base.level;
	const uint texWidth = u_minify(pt->width0, level);
	const uint texHeight = u_minify(pt->height0, level);
	const uint stride = ct->stride[level];
	unsigned size;

	assert(transfer->texture);

	if (!ct->mapped) {
	/* map now */
	ct->mapped = pipe_buffer_map(screen, ct->buffer,
	pipe_transfer_buffer_flags(transfer));
	}

	/*
	* Create a buffer of ordinary memory for the linear texture.
	* This is the memory that the user will read/write.
	*/
	size = util_format_get_stride(pt->format, align(texWidth, TILE_SIZE)) *
	util_format_get_nblocksy(pt->format, align(texHeight, TILE_SIZE));

	ctrans->map = align_malloc(size, 16);
	if (!ctrans->map)
	return NULL; /* out of memory */

	if (transfer->usage & PIPE_TRANSFER_READ) {
	/* need to untwiddle the texture to make a linear version */
	const uint bpp = util_format_get_blocksize(ct->base.format);
	if (bpp == 4) {
	const uint src = (uint ) (ct->mapped + ctrans->offset);
	uint *dst = ctrans->map;
	untwiddle_image_uint(texWidth, texHeight, TILE_SIZE,
	dst, stride, src);
	}
	else {
	// xxx fix
	}
	}

	return ctrans->map;
	}


	/**
	* Called when user is done reading/writing texture data.
	* If new data was written, this is where we convert the linear data
	* to tiled data.
	*/
	static void
	cell_transfer_unmap(struct pipe_screen *screen,
	struct pipe_transfer *transfer)
	{
	struct cell_transfer *ctrans = cell_transfer(transfer);
	struct pipe_texture *pt = transfer->texture;
	struct cell_texture *ct = cell_texture(pt);
	const uint level = ctrans->base.level;
	const uint texWidth = u_minify(pt->width0, level);
	const uint texHeight = u_minify(pt->height0, level);
	const uint stride = ct->stride[level];

	if (!ct->mapped) {
	/* map now */
	ct->mapped = pipe_buffer_map(screen, ct->buffer,
	PIPE_BUFFER_USAGE_CPU_READ);
	}

	if (transfer->usage & PIPE_TRANSFER_WRITE) {
	/* The user wrote new texture data into the mapped buffer.
	* We need to convert the new linear data into the twiddled/tiled format.
	*/
	const uint bpp = util_format_get_blocksize(ct->base.format);
	if (bpp == 4) {
	const uint *src = ctrans->map;
	uint dst = (uint ) (ct->mapped + ctrans->offset);
	twiddle_image_uint(texWidth, texHeight, TILE_SIZE, dst, stride, src);
	}
	else {
	// xxx fix
	}
	}

	align_free(ctrans->map);
	ctrans->map = NULL;
	}


	void
	cell_init_screen_texture_funcs(struct pipe_screen *screen)
	{
	screen->texture_create = cell_texture_create;
	screen->texture_destroy = cell_texture_destroy;

	screen->get_tex_surface = cell_get_tex_surface;
	screen->tex_surface_destroy = cell_tex_surface_destroy;

	screen->get_tex_transfer = cell_get_tex_transfer;
	screen->tex_transfer_destroy = cell_tex_transfer_destroy;

	screen->transfer_map = cell_transfer_map;
	screen->transfer_unmap = cell_transfer_unmap;
	}