1 /*
2 * Copyright 2003 VMware, Inc.
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sublicense, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the
14 * next paragraph) shall be included in all copies or substantial portions
15 * of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
21 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
22 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
23 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 */
25
26 #include "main/enums.h"
27 #include "main/mtypes.h"
28 #include "main/macros.h"
29 #include "main/fbobject.h"
30 #include "main/image.h"
31 #include "main/bufferobj.h"
32 #include "main/readpix.h"
33 #include "main/state.h"
34 #include "main/glformats.h"
35 #include "program/prog_instruction.h"
36 #include "drivers/common/meta.h"
37
38 #include "brw_context.h"
39 #include "brw_blorp.h"
40 #include "brw_screen.h"
41 #include "brw_batch.h"
42 #include "brw_buffers.h"
43 #include "brw_fbo.h"
44 #include "brw_mipmap_tree.h"
45 #include "brw_pixel.h"
46 #include "brw_buffer_objects.h"
47
48 #define FILE_DEBUG_FLAG DEBUG_PIXEL
49
50 /**
51 * \brief A fast path for glReadPixels
52 *
53 * This fast path is taken when the source format is BGRA, RGBA,
54 * A or L and when the texture memory is X- or Y-tiled. It downloads
55 * the source data by directly mapping the memory without a GTT fence.
56 * This then needs to be de-tiled on the CPU before presenting the data to
57 * the user in the linear fasion.
58 *
59 * This is a performance win over the conventional texture download path.
60 * In the conventional texture download path, the texture is either mapped
61 * through the GTT or copied to a linear buffer with the blitter before
62 * handing off to a software path. This allows us to avoid round-tripping
63 * through the GPU (in the case where we would be blitting) and do only a
64 * single copy operation.
65 */
66 static bool
brw_readpixels_tiled_memcpy(struct gl_context * ctx,GLint xoffset,GLint yoffset,GLsizei width,GLsizei height,GLenum format,GLenum type,GLvoid * pixels,const struct gl_pixelstore_attrib * pack)67 brw_readpixels_tiled_memcpy(struct gl_context *ctx,
68 GLint xoffset, GLint yoffset,
69 GLsizei width, GLsizei height,
70 GLenum format, GLenum type,
71 GLvoid * pixels,
72 const struct gl_pixelstore_attrib *pack)
73 {
74 struct brw_context *brw = brw_context(ctx);
75 struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
76 const struct intel_device_info *devinfo = &brw->screen->devinfo;
77
78 /* This path supports reading from color buffers only */
79 if (rb == NULL)
80 return false;
81
82 struct brw_renderbuffer *irb = brw_renderbuffer(rb);
83 int dst_pitch;
84
85 /* The miptree's buffer. */
86 struct brw_bo *bo;
87
88 uint32_t cpp;
89 isl_memcpy_type copy_type;
90
91 /* This fastpath is restricted to specific renderbuffer types:
92 * a 2D BGRA, RGBA, L8 or A8 texture. It could be generalized to support
93 * more types.
94 */
95 if (!devinfo->has_llc ||
96 !(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) ||
97 pixels == NULL ||
98 pack->BufferObj ||
99 pack->Alignment > 4 ||
100 pack->SkipPixels > 0 ||
101 pack->SkipRows > 0 ||
102 (pack->RowLength != 0 && pack->RowLength != width) ||
103 pack->SwapBytes ||
104 pack->LsbFirst ||
105 pack->Invert)
106 return false;
107
108 /* Only a simple blit, no scale, bias or other mapping. */
109 if (ctx->_ImageTransferState)
110 return false;
111
112 /* It is possible that the renderbuffer (or underlying texture) is
113 * multisampled. Since ReadPixels from a multisampled buffer requires a
114 * multisample resolve, we can't handle this here
115 */
116 if (rb->NumSamples > 1)
117 return false;
118
119 /* We can't handle copying from RGBX or BGRX because the tiled_memcpy
120 * function doesn't set the last channel to 1. Note this checks BaseFormat
121 * rather than TexFormat in case the RGBX format is being simulated with an
122 * RGBA format.
123 */
124 if (rb->_BaseFormat == GL_RGB)
125 return false;
126
127 copy_type = brw_miptree_get_memcpy_type(rb->Format, format, type, &cpp);
128 if (copy_type == ISL_MEMCPY_INVALID)
129 return false;
130
131 if (!irb->mt ||
132 (irb->mt->surf.tiling != ISL_TILING_X &&
133 irb->mt->surf.tiling != ISL_TILING_Y0)) {
134 /* The algorithm is written only for X- or Y-tiled memory. */
135 return false;
136 }
137
138 /* tiled_to_linear() assumes that if the object is swizzled, it is using
139 * I915_BIT6_SWIZZLE_9_10 for X and I915_BIT6_SWIZZLE_9 for Y. This is only
140 * true on gfx5 and above.
141 *
142 * The killer on top is that some gfx4 have an L-shaped swizzle mode, where
143 * parts of the memory aren't swizzled at all. Userspace just can't handle
144 * that.
145 */
146 if (devinfo->ver < 5 && brw->has_swizzling)
147 return false;
148
149 /* Since we are going to read raw data to the miptree, we need to resolve
150 * any pending fast color clears before we start.
151 */
152 brw_miptree_access_raw(brw, irb->mt, irb->mt_level, irb->mt_layer, false);
153
154 bo = irb->mt->bo;
155
156 if (brw_batch_references(&brw->batch, bo)) {
157 perf_debug("Flushing before mapping a referenced bo.\n");
158 brw_batch_flush(brw);
159 }
160
161 void *map = brw_bo_map(brw, bo, MAP_READ | MAP_RAW);
162 if (map == NULL) {
163 DBG("%s: failed to map bo\n", __func__);
164 return false;
165 }
166
167 unsigned slice_offset_x, slice_offset_y;
168 brw_miptree_get_image_offset(irb->mt, irb->mt_level, irb->mt_layer,
169 &slice_offset_x, &slice_offset_y);
170 xoffset += slice_offset_x;
171 yoffset += slice_offset_y;
172
173 dst_pitch = _mesa_image_row_stride(pack, width, format, type);
174
175 /* For a window-system renderbuffer, the buffer is actually flipped
176 * vertically, so we need to handle that. Since the detiling function
177 * can only really work in the forwards direction, we have to be a
178 * little creative. First, we compute the Y-offset of the first row of
179 * the renderbuffer (in renderbuffer coordinates). We then match that
180 * with the last row of the client's data. Finally, we give
181 * tiled_to_linear a negative pitch so that it walks through the
182 * client's data backwards as it walks through the renderbufer forwards.
183 */
184 if (ctx->ReadBuffer->FlipY) {
185 yoffset = rb->Height - yoffset - height;
186 pixels += (ptrdiff_t) (height - 1) * dst_pitch;
187 dst_pitch = -dst_pitch;
188 }
189
190 /* We postponed printing this message until having committed to executing
191 * the function.
192 */
193 DBG("%s: x,y=(%d,%d) (w,h)=(%d,%d) format=0x%x type=0x%x "
194 "mesa_format=0x%x tiling=%d "
195 "pack=(alignment=%d row_length=%d skip_pixels=%d skip_rows=%d)\n",
196 __func__, xoffset, yoffset, width, height,
197 format, type, rb->Format, irb->mt->surf.tiling,
198 pack->Alignment, pack->RowLength, pack->SkipPixels,
199 pack->SkipRows);
200
201 isl_memcpy_tiled_to_linear(
202 xoffset * cpp, (xoffset + width) * cpp,
203 yoffset, yoffset + height,
204 pixels,
205 map + irb->mt->offset,
206 dst_pitch, irb->mt->surf.row_pitch_B,
207 brw->has_swizzling,
208 irb->mt->surf.tiling,
209 copy_type
210 );
211
212 brw_bo_unmap(bo);
213 return true;
214 }
215
216 static bool
brw_readpixels_blorp(struct gl_context * ctx,unsigned x,unsigned y,unsigned w,unsigned h,GLenum format,GLenum type,const void * pixels,const struct gl_pixelstore_attrib * packing)217 brw_readpixels_blorp(struct gl_context *ctx,
218 unsigned x, unsigned y,
219 unsigned w, unsigned h,
220 GLenum format, GLenum type, const void *pixels,
221 const struct gl_pixelstore_attrib *packing)
222 {
223 struct brw_context *brw = brw_context(ctx);
224 struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
225 if (!rb)
226 return false;
227
228 struct brw_renderbuffer *irb = brw_renderbuffer(rb);
229
230 /* _mesa_get_readpixels_transfer_ops() includes the cases of read
231 * color clamping along with the ctx->_ImageTransferState.
232 */
233 if (_mesa_get_readpixels_transfer_ops(ctx, rb->Format, format,
234 type, GL_FALSE))
235 return false;
236
237 GLenum dst_base_format = _mesa_unpack_format_to_base_format(format);
238 if (_mesa_need_rgb_to_luminance_conversion(rb->_BaseFormat,
239 dst_base_format))
240 return false;
241
242 unsigned swizzle;
243 if (irb->Base.Base._BaseFormat == GL_RGB) {
244 swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_ONE);
245 } else {
246 swizzle = SWIZZLE_XYZW;
247 }
248
249 return brw_blorp_download_miptree(brw, irb->mt, rb->Format, swizzle,
250 irb->mt_level, x, y, irb->mt_layer,
251 w, h, 1, GL_TEXTURE_2D, format, type,
252 ctx->ReadBuffer->FlipY, pixels, packing);
253 }
254
255 void
brw_readpixels(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum format,GLenum type,const struct gl_pixelstore_attrib * pack,GLvoid * pixels)256 brw_readpixels(struct gl_context *ctx,
257 GLint x, GLint y, GLsizei width, GLsizei height,
258 GLenum format, GLenum type,
259 const struct gl_pixelstore_attrib *pack, GLvoid *pixels)
260 {
261 bool ok;
262
263 struct brw_context *brw = brw_context(ctx);
264 bool dirty;
265
266 DBG("%s\n", __func__);
267
268 /* Reading pixels wont dirty the front buffer, so reset the dirty
269 * flag after calling brw_prepare_render().
270 */
271 dirty = brw->front_buffer_dirty;
272 brw_prepare_render(brw);
273 brw->front_buffer_dirty = dirty;
274
275 if (pack->BufferObj) {
276 if (brw_readpixels_blorp(ctx, x, y, width, height,
277 format, type, pixels, pack))
278 return;
279
280 perf_debug("%s: fallback to CPU mapping in PBO case\n", __func__);
281 }
282
283 ok = brw_readpixels_tiled_memcpy(ctx, x, y, width, height,
284 format, type, pixels, pack);
285 if(ok)
286 return;
287
288 /* Update Mesa state before calling _mesa_readpixels().
289 * XXX this may not be needed since ReadPixels no longer uses the
290 * span code.
291 */
292
293 if (ctx->NewState)
294 _mesa_update_state(ctx);
295
296 _mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels);
297
298 /* There's an brw_prepare_render() call in intelSpanRenderStart(). */
299 brw->front_buffer_dirty = dirty;
300 }
301