src/mesa/drivers/dri/i965/intel_pixel_read.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2003 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/glheader.h"
  29 #include "main/enums.h"
  30 #include "main/mtypes.h"
  31 #include "main/macros.h"
  32 #include "main/fbobject.h"
  33 #include "main/image.h"
  34 #include "main/bufferobj.h"
  35 #include "main/readpix.h"
  36 #include "main/state.h"
  37 #include "main/glformats.h"
  38
  39 #include "brw_context.h"
  40 #include "intel_screen.h"
  41 #include "intel_blit.h"
  42 #include "intel_buffers.h"
  43 #include "intel_fbo.h"
  44 #include "intel_mipmap_tree.h"
  45 #include "intel_pixel.h"
  46 #include "intel_buffer_objects.h"
  47
  48 #define FILE_DEBUG_FLAG DEBUG_PIXEL
  49
  50 /* For many applications, the new ability to pull the source buffers
  51  * back out of the GTT and then do the packing/conversion operations
  52  * in software will be as much of an improvement as trying to get the
  53  * blitter and/or texture engine to do the work.
  54  *
  55  * This step is gated on private backbuffers.
  56  *
  57  * Obviously the frontbuffer can't be pulled back, so that is either
  58  * an argument for blit/texture readpixels, or for blitting to a
  59  * temporary and then pulling that back.
  60  *
  61  * When the destination is a pbo, however, it's not clear if it is
  62  * ever going to be pulled to main memory (though the access param
  63  * will be a good hint).  So it sounds like we do want to be able to
  64  * choose between blit/texture implementation on the gpu and pullback
  65  * and cpu-based copying.
  66  *
  67  * Unless you can magically turn client memory into a PBO for the
  68  * duration of this call, there will be a cpu-based copying step in
  69  * any case.
  70  */
  71
  72 static bool
  73 do_blit_readpixels(struct gl_context * ctx,
  74                    GLint x, GLint y, GLsizei width, GLsizei height,
  75                    GLenum format, GLenum type,
  76                    const struct gl_pixelstore_attrib *pack, GLvoid * pixels)
  77 {
  78    struct brw_context *brw = brw_context(ctx);
  79    struct intel_buffer_object *dst = intel_buffer_object(pack->BufferObj);
  80    GLuint dst_offset;
  81    drm_intel_bo *dst_buffer;
  82    GLint dst_x, dst_y;
  83    GLuint dirty;
  84
  85    DBG("%s\n", __FUNCTION__);
  86
  87    assert(_mesa_is_bufferobj(pack->BufferObj));
  88
  89    struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
  90    struct intel_renderbuffer *irb = intel_renderbuffer(rb);
  91
  92    /* Currently this function only supports reading from color buffers. */
  93    if (!_mesa_is_color_format(format))
  94       return false;
  95
  96    assert(irb != NULL);
  97
  98    if (ctx->_ImageTransferState ||
  99        !_mesa_format_matches_format_and_type(irb->mt->format, format, type,
 100                                              false)) {
 101       DBG("%s - bad format for blit\n", __FUNCTION__);
 102       return false;
 103    }
 104
 105    if (pack->SwapBytes || pack->LsbFirst) {
 106       DBG("%s: bad packing params\n", __FUNCTION__);
 107       return false;
 108    }
 109
 110    int dst_stride = _mesa_image_row_stride(pack, width, format, type);
 111    bool dst_flip = false;
 112    /* Mesa flips the dst_stride for pack->Invert, but we want our mt to have a
 113     * normal dst_stride.
 114     */
 115    struct gl_pixelstore_attrib uninverted_pack = *pack;
 116    if (pack->Invert) {
 117       dst_stride = -dst_stride;
 118       dst_flip = true;
 119       uninverted_pack.Invert = false;
 120    }
 121
 122    dst_offset = (GLintptr)pixels;
 123    dst_offset += _mesa_image_offset(2, &uninverted_pack, width, height,
 124                                     format, type, 0, 0, 0);
 125
 126    if (!_mesa_clip_copytexsubimage(ctx,
 127                                    &dst_x, &dst_y,
 128                                    &x, &y,
 129                                    &width, &height)) {
 130       return true;
 131    }
 132
 133    dirty = brw->front_buffer_dirty;
 134    intel_prepare_render(brw);
 135    brw->front_buffer_dirty = dirty;
 136
 137    dst_buffer = intel_bufferobj_buffer(brw, dst,
 138                                        dst_offset, height * dst_stride);
 139
 140    struct intel_mipmap_tree *pbo_mt =
 141       intel_miptree_create_for_bo(brw,
 142                                   dst_buffer,
 143                                   irb->mt->format,
 144                                   dst_offset,
 145                                   width, height, 1,
 146                                   dst_stride);
 147
 148    if (!intel_miptree_blit(brw,
 149                            irb->mt, irb->mt_level, irb->mt_layer,
 150                            x, y, _mesa_is_winsys_fbo(ctx->ReadBuffer),
 151                            pbo_mt, 0, 0,
 152                            0, 0, dst_flip,
 153                            width, height, GL_COPY)) {
 154       return false;
 155    }
 156
 157    intel_miptree_release(&pbo_mt);
 158
 159    DBG("%s - DONE\n", __FUNCTION__);
 160
 161    return true;
 162 }
 163
 164 void
 165 intelReadPixels(struct gl_context * ctx,
 166                 GLint x, GLint y, GLsizei width, GLsizei height,
 167                 GLenum format, GLenum type,
 168                 const struct gl_pixelstore_attrib *pack, GLvoid * pixels)
 169 {
 170    struct brw_context *brw = brw_context(ctx);
 171    bool dirty;
 172
 173    DBG("%s\n", __FUNCTION__);
 174
 175    if (_mesa_is_bufferobj(pack->BufferObj)) {
 176       /* Using PBOs, so try the BLT based path. */
 177       if (do_blit_readpixels(ctx, x, y, width, height, format, type, pack,
 178                              pixels)) {
 179          return;
 180       }
 181
 182       perf_debug("%s: fallback to CPU mapping in PBO case\n", __FUNCTION__);
 183    }
 184
 185    /* glReadPixels() wont dirty the front buffer, so reset the dirty
 186     * flag after calling intel_prepare_render(). */
 187    dirty = brw->front_buffer_dirty;
 188    intel_prepare_render(brw);
 189    brw->front_buffer_dirty = dirty;
 190
 191    /* Update Mesa state before calling _mesa_readpixels().
 192     * XXX this may not be needed since ReadPixels no longer uses the
 193     * span code.
 194     */
 195
 196    if (ctx->NewState)
 197       _mesa_update_state(ctx);
 198
 199    _mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels);
 200
 201    /* There's an intel_prepare_render() call in intelSpanRenderStart(). */
 202    brw->front_buffer_dirty = dirty;
 203 }