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

   1 /**************************************************************************
   2  *
   3  * Copyright 2003 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/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
  38 #include "brw_context.h"
  39 #include "intel_screen.h"
  40 #include "intel_blit.h"
  41 #include "intel_buffers.h"
  42 #include "intel_fbo.h"
  43 #include "intel_mipmap_tree.h"
  44 #include "intel_regions.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 intel_context *intel = intel_context(ctx);
  79    struct intel_buffer_object *dst = intel_buffer_object(pack->BufferObj);
  80    GLuint dst_offset;
  81    drm_intel_bo *dst_buffer;
  82    bool all;
  83    GLint dst_x, dst_y;
  84    GLuint dirty;
  85
  86    DBG("%s\n", __FUNCTION__);
  87
  88    assert(_mesa_is_bufferobj(pack->BufferObj));
  89
  90    struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
  91    struct intel_renderbuffer *irb = intel_renderbuffer(rb);
  92
  93    if (ctx->_ImageTransferState ||
  94        !_mesa_format_matches_format_and_type(irb->mt->format, format, type,
  95                                              false)) {
  96       DBG("%s - bad format for blit\n", __FUNCTION__);
  97       return false;
  98    }
  99
 100    if (pack->SwapBytes || pack->LsbFirst) {
 101       DBG("%s: bad packing params\n", __FUNCTION__);
 102       return false;
 103    }
 104
 105    int dst_stride = _mesa_image_row_stride(pack, width, format, type);
 106    bool dst_flip = false;
 107    /* Mesa flips the dst_stride for pack->Invert, but we want our mt to have a
 108     * normal dst_stride.
 109     */
 110    if (pack->Invert) {
 111       dst_stride = -dst_stride;
 112       dst_flip = true;
 113    }
 114
 115    dst_offset = (GLintptr)pixels;
 116    dst_offset += _mesa_image_offset(2, pack, width, height,
 117                                     format, type, 0, 0, 0);
 118
 119    if (!_mesa_clip_copytexsubimage(ctx,
 120                                    &dst_x, &dst_y,
 121                                    &x, &y,
 122                                    &width, &height)) {
 123       return true;
 124    }
 125
 126    dirty = intel->front_buffer_dirty;
 127    intel_prepare_render(intel);
 128    intel->front_buffer_dirty = dirty;
 129
 130    all = (width * height * irb->mt->cpp == dst->Base.Size &&
 131           x == 0 && dst_offset == 0);
 132
 133    dst_buffer = intel_bufferobj_buffer(intel, dst,
 134                                        all ? INTEL_WRITE_FULL :
 135                                        INTEL_WRITE_PART);
 136
 137    struct intel_mipmap_tree *pbo_mt =
 138       intel_miptree_create_for_bo(intel,
 139                                   dst_buffer,
 140                                   irb->mt->format,
 141                                   dst_offset,
 142                                   width, height,
 143                                   dst_stride, I915_TILING_NONE);
 144
 145    if (!intel_miptree_blit(intel,
 146                            irb->mt, irb->mt_level, irb->mt_layer,
 147                            x, y, _mesa_is_winsys_fbo(ctx->ReadBuffer),
 148                            pbo_mt, 0, 0,
 149                            0, 0, dst_flip,
 150                            width, height, GL_COPY)) {
 151       return false;
 152    }
 153
 154    intel_miptree_release(&pbo_mt);
 155
 156    DBG("%s - DONE\n", __FUNCTION__);
 157
 158    return true;
 159 }
 160
 161 void
 162 intelReadPixels(struct gl_context * ctx,
 163                 GLint x, GLint y, GLsizei width, GLsizei height,
 164                 GLenum format, GLenum type,
 165                 const struct gl_pixelstore_attrib *pack, GLvoid * pixels)
 166 {
 167    struct intel_context *intel = intel_context(ctx);
 168    bool dirty;
 169
 170    DBG("%s\n", __FUNCTION__);
 171
 172    if (_mesa_is_bufferobj(pack->BufferObj)) {
 173       /* Using PBOs, so try the BLT based path. */
 174       if (do_blit_readpixels(ctx, x, y, width, height, format, type, pack,
 175                              pixels)) {
 176          return;
 177       }
 178
 179       perf_debug("%s: fallback to CPU mapping in PBO case\n", __FUNCTION__);
 180    }
 181
 182    /* glReadPixels() wont dirty the front buffer, so reset the dirty
 183     * flag after calling intel_prepare_render(). */
 184    dirty = intel->front_buffer_dirty;
 185    intel_prepare_render(intel);
 186    intel->front_buffer_dirty = dirty;
 187
 188    /* Update Mesa state before calling _mesa_readpixels().
 189     * XXX this may not be needed since ReadPixels no longer uses the
 190     * span code.
 191     */
 192
 193    if (ctx->NewState)
 194       _mesa_update_state(ctx);
 195
 196    _mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels);
 197
 198    /* There's an intel_prepare_render() call in intelSpanRenderStart(). */
 199    intel->front_buffer_dirty = dirty;
 200 }