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
38#include "intel_screen.h"
39#include "intel_context.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
72static bool
73do_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   GLint dst_x, dst_y;
83   GLuint dirty;
84
85   DBG("%s\n", __func__);
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   if (ctx->_ImageTransferState ||
93       !_mesa_format_matches_format_and_type(irb->mt->format, format, type,
94                                             false, NULL)) {
95      DBG("%s - bad format for blit\n", __func__);
96      return false;
97   }
98
99   if (pack->SwapBytes || pack->LsbFirst) {
100      DBG("%s: bad packing params\n", __func__);
101      return false;
102   }
103
104   int dst_stride = _mesa_image_row_stride(pack, width, format, type);
105   bool dst_flip = false;
106   /* Mesa flips the dst_stride for pack->Invert, but we want our mt to have a
107    * normal dst_stride.
108    */
109   if (pack->Invert) {
110      dst_stride = -dst_stride;
111      dst_flip = true;
112   }
113
114   dst_offset = (GLintptr)pixels;
115   dst_offset += _mesa_image_offset(2, pack, width, height,
116				    format, type, 0, 0, 0);
117
118   if (!_mesa_clip_copytexsubimage(ctx,
119				   &dst_x, &dst_y,
120				   &x, &y,
121				   &width, &height)) {
122      return true;
123   }
124
125   dirty = intel->front_buffer_dirty;
126   intel_prepare_render(intel);
127   intel->front_buffer_dirty = dirty;
128
129   dst_buffer = intel_bufferobj_buffer(intel, dst);
130
131   struct intel_mipmap_tree *pbo_mt =
132      intel_miptree_create_for_bo(intel,
133                                  dst_buffer,
134                                  irb->mt->format,
135                                  dst_offset,
136                                  width, height,
137                                  dst_stride, I915_TILING_NONE);
138
139   if (!intel_miptree_blit(intel,
140                           irb->mt, irb->mt_level, irb->mt_layer,
141                           x, y, _mesa_is_winsys_fbo(ctx->ReadBuffer),
142                           pbo_mt, 0, 0,
143                           0, 0, dst_flip,
144                           width, height, COLOR_LOGICOP_COPY)) {
145      intel_miptree_release(&pbo_mt);
146      return false;
147   }
148
149   intel_miptree_release(&pbo_mt);
150
151   DBG("%s - DONE\n", __func__);
152
153   return true;
154}
155
156void
157intelReadPixels(struct gl_context * ctx,
158                GLint x, GLint y, GLsizei width, GLsizei height,
159                GLenum format, GLenum type,
160                const struct gl_pixelstore_attrib *pack, GLvoid * pixels)
161{
162   struct intel_context *intel = intel_context(ctx);
163   bool dirty;
164
165   intel_flush_rendering_to_batch(ctx);
166
167   DBG("%s\n", __func__);
168
169   if (_mesa_is_bufferobj(pack->BufferObj)) {
170      /* Using PBOs, so try the BLT based path. */
171      if (do_blit_readpixels(ctx, x, y, width, height, format, type, pack,
172                             pixels)) {
173         return;
174      }
175
176      perf_debug("%s: fallback to CPU mapping in PBO case\n", __func__);
177   }
178
179   /* glReadPixels() wont dirty the front buffer, so reset the dirty
180    * flag after calling intel_prepare_render(). */
181   dirty = intel->front_buffer_dirty;
182   intel_prepare_render(intel);
183   intel->front_buffer_dirty = dirty;
184
185   /* Update Mesa state before calling _mesa_readpixels().
186    * XXX this may not be needed since ReadPixels no longer uses the
187    * span code.
188    */
189
190   if (ctx->NewState)
191      _mesa_update_state(ctx);
192
193   _mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels);
194
195   /* There's an intel_prepare_render() call in intelSpanRenderStart(). */
196   intel->front_buffer_dirty = dirty;
197}
198