src/mesa/state_tracker/st_cb_readpixels.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   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 TUNGSTEN GRAPHICS 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
  47 /**
  48  * This uses a blit to copy the read buffer to a texture format which matches
  49  * the format and type combo and then a fast read-back is done using memcpy.
  50  * We can do arbitrary X/Y/Z/W/0/1 swizzling here as long as there is
  51  * a format which matches the swizzling.
  52  *
  53  * If such a format isn't available, we fall back to _mesa_readpixels.
  54  *
  55  * NOTE: Some drivers use a blit to convert between tiled and linear
  56  *       texture layouts during texture uploads/downloads, so the blit
  57  *       we do here should be free in such cases.
  58  */
  59 static void
  60 st_readpixels(struct gl_context *ctx, GLint x, GLint y,
  61               GLsizei width, GLsizei height,
  62               GLenum format, GLenum type,
  63               const struct gl_pixelstore_attrib *pack,
  64               GLvoid *pixels)
  65 {
  66    struct st_context *st = st_context(ctx);
  67    struct gl_renderbuffer *rb =
  68          _mesa_get_read_renderbuffer_for_format(ctx, format);
  69    struct st_renderbuffer *strb = st_renderbuffer(rb);
  70    struct pipe_context *pipe = st->pipe;
  71    struct pipe_screen *screen = pipe->screen;
  72    struct pipe_resource *src;
  73    struct pipe_resource *dst = NULL;
  74    struct pipe_resource dst_templ;
  75    enum pipe_format dst_format, src_format;
  76    struct pipe_blit_info blit;
  77    unsigned bind = PIPE_BIND_TRANSFER_READ;
  78    struct pipe_transfer *tex_xfer;
  79    ubyte *map = NULL;
  80
  81    /* Validate state (to be sure we have up-to-date framebuffer surfaces)
  82     * and flush the bitmap cache prior to reading. */
  83    st_validate_state(st);
  84    st_flush_bitmap_cache(st);
  85
  86    if (!st->prefer_blit_based_texture_transfer) {
  87       goto fallback;
  88    }
  89
  90    /* This must be done after state validation. */
  91    src = strb->texture;
  92
  93    /* XXX Fallback for depth-stencil formats due to an incomplete
  94     * stencil blit implementation in some drivers. */
  95    if (format == GL_DEPTH_STENCIL) {
  96       goto fallback;
  97    }
  98
  99    /* We are creating a texture of the size of the region being read back.
 100     * Need to check for NPOT texture support. */
 101    if (!screen->get_param(screen, PIPE_CAP_NPOT_TEXTURES) &&
 102        (!util_is_power_of_two(width) ||
 103         !util_is_power_of_two(height))) {
 104       goto fallback;
 105    }
 106
 107    /* If the base internal format and the texture format don't match, we have
 108     * to use the slow path. */
 109    if (rb->_BaseFormat !=
 110        _mesa_get_format_base_format(rb->Format)) {
 111       goto fallback;
 112    }
 113
 114    /* See if the texture format already matches the format and type,
 115     * in which case the memcpy-based fast path will likely be used and
 116     * we don't have to blit. */
 117    if (_mesa_format_matches_format_and_type(rb->Format, format,
 118                                             type, pack->SwapBytes)) {
 119       goto fallback;
 120    }
 121
 122    if (_mesa_readpixels_needs_slow_path(ctx, format, type, GL_TRUE)) {
 123       goto fallback;
 124    }
 125
 126    /* Convert the source format to what is expected by ReadPixels
 127     * and see if it's supported. */
 128    src_format = util_format_linear(src->format);
 129    src_format = util_format_luminance_to_red(src_format);
 130    src_format = util_format_intensity_to_red(src_format);
 131
 132    if (!src_format ||
 133        !screen->is_format_supported(screen, src_format, src->target,
 134                                     src->nr_samples,
 135                                     PIPE_BIND_SAMPLER_VIEW)) {
 136       goto fallback;
 137    }
 138
 139    if (format == GL_DEPTH_COMPONENT || format == GL_DEPTH_STENCIL)
 140       bind |= PIPE_BIND_DEPTH_STENCIL;
 141    else
 142       bind |= PIPE_BIND_RENDER_TARGET;
 143
 144    /* Choose the destination format by finding the best match
 145     * for the format+type combo. */
 146    dst_format = st_choose_matching_format(screen, bind, format, type,
 147                                           pack->SwapBytes);
 148    if (dst_format == PIPE_FORMAT_NONE) {
 149       goto fallback;
 150    }
 151
 152    /* create the destination texture */
 153    memset(&dst_templ, 0, sizeof(dst_templ));
 154    dst_templ.target = PIPE_TEXTURE_2D;
 155    dst_templ.format = dst_format;
 156    dst_templ.bind = bind;
 157    dst_templ.usage = PIPE_USAGE_STAGING;
 158
 159    st_gl_texture_dims_to_pipe_dims(GL_TEXTURE_2D, width, height, 1,
 160                                    &dst_templ.width0, &dst_templ.height0,
 161                                    &dst_templ.depth0, &dst_templ.array_size);
 162
 163    dst = screen->resource_create(screen, &dst_templ);
 164    if (!dst) {
 165       goto fallback;
 166    }
 167
 168    blit.src.resource = src;
 169    blit.src.level = strb->rtt_level;
 170    blit.src.format = src_format;
 171    blit.dst.resource = dst;
 172    blit.dst.level = 0;
 173    blit.dst.format = dst->format;
 174    blit.src.box.x = x;
 175    blit.dst.box.x = 0;
 176    blit.src.box.y = y;
 177    blit.dst.box.y = 0;
 178    blit.src.box.z = strb->rtt_face + strb->rtt_slice;
 179    blit.dst.box.z = 0;
 180    blit.src.box.width = blit.dst.box.width = width;
 181    blit.src.box.height = blit.dst.box.height = height;
 182    blit.src.box.depth = blit.dst.box.depth = 1;
 183    blit.mask = st_get_blit_mask(rb->_BaseFormat, format);
 184    blit.filter = PIPE_TEX_FILTER_NEAREST;
 185    blit.scissor_enable = FALSE;
 186
 187    if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
 188       blit.src.box.y = rb->Height - blit.src.box.y;
 189       blit.src.box.height = -blit.src.box.height;
 190    }
 191
 192    /* blit */
 193    st->pipe->blit(st->pipe, &blit);
 194
 195    /* map resources */
 196    pixels = _mesa_map_pbo_dest(ctx, pack, pixels);
 197
 198    map = pipe_transfer_map_3d(pipe, dst, 0, PIPE_TRANSFER_READ,
 199                               0, 0, 0, width, height, 1, &tex_xfer);
 200    if (!map) {
 201       _mesa_unmap_pbo_dest(ctx, pack);
 202       pipe_resource_reference(&dst, NULL);
 203       goto fallback;
 204    }
 205
 206    /* memcpy data into a user buffer */
 207    {
 208       const uint bytesPerRow = width * util_format_get_blocksize(dst_format);
 209       GLuint row;
 210
 211       for (row = 0; row < (unsigned) height; row++) {
 212          GLvoid *dest = _mesa_image_address3d(pack, pixels,
 213                                               width, height, format,
 214                                               type, 0, row, 0);
 215          memcpy(dest, map, bytesPerRow);
 216          map += tex_xfer->stride;
 217       }
 218    }
 219
 220    pipe_transfer_unmap(pipe, tex_xfer);
 221    _mesa_unmap_pbo_dest(ctx, pack);
 222    pipe_resource_reference(&dst, NULL);
 223    return;
 224
 225 fallback:
 226    _mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels);
 227 }
 228
 229 void st_init_readpixels_functions(struct dd_function_table *functions)
 230 {
 231    functions->ReadPixels = st_readpixels;
 232 }