src/mesa/state_tracker/st_cb_readpixels.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 #include "main/image.h"
  29 #include "main/pbo.h"
  30 #include "main/imports.h"
  31 #include "main/readpix.h"
  32 #include "main/enums.h"
  33 #include "main/framebuffer.h"
  34 #include "util/u_inlines.h"
  35 #include "util/u_format.h"
  36
  37 #include "st_cb_fbo.h"
  38 #include "st_atom.h"
  39 #include "st_context.h"
  40 #include "st_cb_bitmap.h"
  41 #include "st_cb_readpixels.h"
  42 #include "state_tracker/st_cb_texture.h"
  43 #include "state_tracker/st_format.h"
  44 #include "state_tracker/st_texture.h"
  45
  46 static boolean
  47 needs_integer_signed_unsigned_conversion(const struct gl_context *ctx,
  48                                          GLenum format, GLenum type)
  49 {
  50    struct gl_renderbuffer *rb =
  51       _mesa_get_read_renderbuffer_for_format(ctx, format);
  52
  53    assert(rb);
  54
  55    GLenum srcType = _mesa_get_format_datatype(rb->Format);
  56
  57     if ((srcType == GL_INT &&
  58         (type == GL_UNSIGNED_INT ||
  59          type == GL_UNSIGNED_SHORT ||
  60          type == GL_UNSIGNED_BYTE)) ||
  61        (srcType == GL_UNSIGNED_INT &&
  62         (type == GL_INT ||
  63          type == GL_SHORT ||
  64          type == GL_BYTE))) {
  65       return TRUE;
  66    }
  67
  68    return FALSE;
  69 }
  70
  71 /**
  72  * This uses a blit to copy the read buffer to a texture format which matches
  73  * the format and type combo and then a fast read-back is done using memcpy.
  74  * We can do arbitrary X/Y/Z/W/0/1 swizzling here as long as there is
  75  * a format which matches the swizzling.
  76  *
  77  * If such a format isn't available, we fall back to _mesa_readpixels.
  78  *
  79  * NOTE: Some drivers use a blit to convert between tiled and linear
  80  *       texture layouts during texture uploads/downloads, so the blit
  81  *       we do here should be free in such cases.
  82  */
  83 static void
  84 st_readpixels(struct gl_context *ctx, GLint x, GLint y,
  85               GLsizei width, GLsizei height,
  86               GLenum format, GLenum type,
  87               const struct gl_pixelstore_attrib *pack,
  88               GLvoid *pixels)
  89 {
  90    struct st_context *st = st_context(ctx);
  91    struct gl_renderbuffer *rb =
  92          _mesa_get_read_renderbuffer_for_format(ctx, format);
  93    struct st_renderbuffer *strb = st_renderbuffer(rb);
  94    struct pipe_context *pipe = st->pipe;
  95    struct pipe_screen *screen = pipe->screen;
  96    struct pipe_resource *src;
  97    struct pipe_resource *dst = NULL;
  98    struct pipe_resource dst_templ;
  99    enum pipe_format dst_format, src_format;
 100    struct pipe_blit_info blit;
 101    unsigned bind = PIPE_BIND_TRANSFER_READ;
 102    struct pipe_transfer *tex_xfer;
 103    ubyte *map = NULL;
 104
 105    /* Validate state (to be sure we have up-to-date framebuffer surfaces)
 106     * and flush the bitmap cache prior to reading. */
 107    st_validate_state(st);
 108    st_flush_bitmap_cache(st);
 109
 110    if (!st->prefer_blit_based_texture_transfer) {
 111       goto fallback;
 112    }
 113
 114    /* This must be done after state validation. */
 115    src = strb->texture;
 116
 117    /* XXX Fallback for depth-stencil formats due to an incomplete
 118     * stencil blit implementation in some drivers. */
 119    if (format == GL_DEPTH_STENCIL) {
 120       goto fallback;
 121    }
 122
 123    /* We are creating a texture of the size of the region being read back.
 124     * Need to check for NPOT texture support. */
 125    if (!screen->get_param(screen, PIPE_CAP_NPOT_TEXTURES) &&
 126        (!util_is_power_of_two(width) ||
 127         !util_is_power_of_two(height))) {
 128       goto fallback;
 129    }
 130
 131    /* If the base internal format and the texture format don't match, we have
 132     * to use the slow path. */
 133    if (rb->_BaseFormat !=
 134        _mesa_get_format_base_format(rb->Format)) {
 135       goto fallback;
 136    }
 137
 138    /* See if the texture format already matches the format and type,
 139     * in which case the memcpy-based fast path will likely be used and
 140     * we don't have to blit. */
 141    if (_mesa_format_matches_format_and_type(rb->Format, format,
 142                                             type, pack->SwapBytes, NULL)) {
 143       goto fallback;
 144    }
 145
 146    if (_mesa_readpixels_needs_slow_path(ctx, format, type, GL_TRUE)) {
 147       goto fallback;
 148    }
 149
 150    if (needs_integer_signed_unsigned_conversion(ctx, format, type)) {
 151       goto fallback;
 152    }
 153
 154    /* Convert the source format to what is expected by ReadPixels
 155     * and see if it's supported. */
 156    src_format = util_format_linear(src->format);
 157    src_format = util_format_luminance_to_red(src_format);
 158    src_format = util_format_intensity_to_red(src_format);
 159
 160    if (!src_format ||
 161        !screen->is_format_supported(screen, src_format, src->target,
 162                                     src->nr_samples,
 163                                     PIPE_BIND_SAMPLER_VIEW)) {
 164       goto fallback;
 165    }
 166
 167    if (format == GL_DEPTH_COMPONENT || format == GL_DEPTH_STENCIL)
 168       bind |= PIPE_BIND_DEPTH_STENCIL;
 169    else
 170       bind |= PIPE_BIND_RENDER_TARGET;
 171
 172    /* Choose the destination format by finding the best match
 173     * for the format+type combo. */
 174    dst_format = st_choose_matching_format(st, bind, format, type,
 175                                           pack->SwapBytes);
 176    if (dst_format == PIPE_FORMAT_NONE) {
 177       goto fallback;
 178    }
 179
 180    /* create the destination texture */
 181    memset(&dst_templ, 0, sizeof(dst_templ));
 182    dst_templ.target = PIPE_TEXTURE_2D;
 183    dst_templ.format = dst_format;
 184    dst_templ.bind = bind;
 185    dst_templ.usage = PIPE_USAGE_STAGING;
 186
 187    st_gl_texture_dims_to_pipe_dims(GL_TEXTURE_2D, width, height, 1,
 188                                    &dst_templ.width0, &dst_templ.height0,
 189                                    &dst_templ.depth0, &dst_templ.array_size);
 190
 191    dst = screen->resource_create(screen, &dst_templ);
 192    if (!dst) {
 193       goto fallback;
 194    }
 195
 196    memset(&blit, 0, sizeof(blit));
 197    blit.src.resource = src;
 198    blit.src.level = strb->surface->u.tex.level;
 199    blit.src.format = src_format;
 200    blit.dst.resource = dst;
 201    blit.dst.level = 0;
 202    blit.dst.format = dst->format;
 203    blit.src.box.x = x;
 204    blit.dst.box.x = 0;
 205    blit.src.box.y = y;
 206    blit.dst.box.y = 0;
 207    blit.src.box.z = strb->surface->u.tex.first_layer;
 208    blit.dst.box.z = 0;
 209    blit.src.box.width = blit.dst.box.width = width;
 210    blit.src.box.height = blit.dst.box.height = height;
 211    blit.src.box.depth = blit.dst.box.depth = 1;
 212    blit.mask = st_get_blit_mask(rb->_BaseFormat, format);
 213    blit.filter = PIPE_TEX_FILTER_NEAREST;
 214    blit.scissor_enable = FALSE;
 215
 216    if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 217       blit.src.box.y = rb->Height - blit.src.box.y;
 218       blit.src.box.height = -blit.src.box.height;
 219    }
 220
 221    /* blit */
 222    st->pipe->blit(st->pipe, &blit);
 223
 224    /* map resources */
 225    pixels = _mesa_map_pbo_dest(ctx, pack, pixels);
 226
 227    map = pipe_transfer_map_3d(pipe, dst, 0, PIPE_TRANSFER_READ,
 228                               0, 0, 0, width, height, 1, &tex_xfer);
 229    if (!map) {
 230       _mesa_unmap_pbo_dest(ctx, pack);
 231       pipe_resource_reference(&dst, NULL);
 232       goto fallback;
 233    }
 234
 235    /* memcpy data into a user buffer */
 236    {
 237       const uint bytesPerRow = width * util_format_get_blocksize(dst_format);
 238       GLuint row;
 239
 240       for (row = 0; row < (unsigned) height; row++) {
 241          GLvoid *dest = _mesa_image_address3d(pack, pixels,
 242                                               width, height, format,
 243                                               type, 0, row, 0);
 244          memcpy(dest, map, bytesPerRow);
 245          map += tex_xfer->stride;
 246       }
 247    }
 248
 249    pipe_transfer_unmap(pipe, tex_xfer);
 250    _mesa_unmap_pbo_dest(ctx, pack);
 251    pipe_resource_reference(&dst, NULL);
 252    return;
 253
 254 fallback:
 255    _mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels);
 256 }
 257
 258 void st_init_readpixels_functions(struct dd_function_table *functions)
 259 {
 260    functions->ReadPixels = st_readpixels;
 261 }