/**************************************************************************
*
* Copyright 2003 VMware, Inc.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**************************************************************************/
#include "main/glheader.h"
#include "main/enums.h"
#include "main/mtypes.h"
#include "main/macros.h"
#include "main/fbobject.h"
#include "main/image.h"
#include "main/bufferobj.h"
#include "main/readpix.h"
#include "main/state.h"
#include "main/glformats.h"
#include "drivers/common/meta.h"
#include "brw_context.h"
#include "intel_screen.h"
#include "intel_batchbuffer.h"
#include "intel_blit.h"
#include "intel_buffers.h"
#include "intel_fbo.h"
#include "intel_mipmap_tree.h"
#include "intel_pixel.h"
#include "intel_buffer_objects.h"
#include "intel_tiled_memcpy.h"
#define FILE_DEBUG_FLAG DEBUG_PIXEL
/**
* \brief A fast path for glReadPixels
*
* This fast path is taken when the source format is BGRA, RGBA,
* A or L and when the texture memory is X- or Y-tiled. It downloads
* the source data by directly mapping the memory without a GTT fence.
* This then needs to be de-tiled on the CPU before presenting the data to
* the user in the linear fasion.
*
* This is a performance win over the conventional texture download path.
* In the conventional texture download path, the texture is either mapped
* through the GTT or copied to a linear buffer with the blitter before
* handing off to a software path. This allows us to avoid round-tripping
* through the GPU (in the case where we would be blitting) and do only a
* single copy operation.
*/
static bool
intel_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)
{
struct brw_context *brw = brw_context(ctx);
struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
/* This path supports reading from color buffers only */
if (rb == NULL)
return false;
struct intel_renderbuffer *irb = intel_renderbuffer(rb);
int dst_pitch;
/* The miptree's buffer. */
drm_intel_bo *bo;
int error = 0;
uint32_t cpp;
mem_copy_fn mem_copy = NULL;
/* This fastpath is restricted to specific renderbuffer types:
* a 2D BGRA, RGBA, L8 or A8 texture. It could be generalized to support
* more types.
*/
if (!brw->has_llc ||
!(type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) ||
pixels == NULL ||
_mesa_is_bufferobj(pack->BufferObj) ||
pack->Alignment > 4 ||
pack->SkipPixels > 0 ||
pack->SkipRows > 0 ||
(pack->RowLength != 0 && pack->RowLength != width) ||
pack->SwapBytes ||
pack->LsbFirst ||
pack->Invert)
return false;
/* This renderbuffer can come from a texture. In this case, we impose
* some of the same restrictions we have for textures and adjust for
* miplevels.
*/
if (rb->TexImage) {
if (rb->TexImage->TexObject->Target != GL_TEXTURE_2D &&
rb->TexImage->TexObject->Target != GL_TEXTURE_RECTANGLE)
return false;
int level = rb->TexImage->Level + rb->TexImage->TexObject->MinLevel;
/* Adjust x and y offset based on miplevel */
xoffset += irb->mt->level[level].level_x;
yoffset += irb->mt->level[level].level_y;
}
/* It is possible that the renderbuffer (or underlying texture) is
* multisampled. Since ReadPixels from a multisampled buffer requires a
* multisample resolve, we can't handle this here
*/
if (rb->NumSamples > 1)
return false;
/* We can't handle copying from RGBX or BGRX because the tiled_memcpy
* function doesn't set the last channel to 1.
*/
if (rb->Format == MESA_FORMAT_B8G8R8X8_UNORM ||
rb->Format == MESA_FORMAT_R8G8B8X8_UNORM)
return false;
if (!intel_get_memcpy(rb->Format, format, type, &mem_copy, &cpp,
INTEL_DOWNLOAD))
return false;
if (!irb->mt ||
(irb->mt->tiling != I915_TILING_X &&
irb->mt->tiling != I915_TILING_Y)) {
/* The algorithm is written only for X- or Y-tiled memory. */
return false;
}
/* Since we are going to read raw data to the miptree, we need to resolve
* any pending fast color clears before we start.
*/
intel_miptree_resolve_color(brw, irb->mt);
bo = irb->mt->bo;
if (drm_intel_bo_references(brw->batch.bo, bo)) {
perf_debug("Flushing before mapping a referenced bo.\n");
intel_batchbuffer_flush(brw);
}
error = brw_bo_map(brw, bo, false /* write enable */, "miptree");
if (error) {
DBG("%s: failed to map bo\n", __func__);
return false;
}
dst_pitch = _mesa_image_row_stride(pack, width, format, type);
/* For a window-system renderbuffer, the buffer is actually flipped
* vertically, so we need to handle that. Since the detiling function
* can only really work in the forwards direction, we have to be a
* little creative. First, we compute the Y-offset of the first row of
* the renderbuffer (in renderbuffer coordinates). We then match that
* with the last row of the client's data. Finally, we give
* tiled_to_linear a negative pitch so that it walks through the
* client's data backwards as it walks through the renderbufer forwards.
*/
if (rb->Name == 0) {
yoffset = rb->Height - yoffset - height;
pixels += (ptrdiff_t) (height - 1) * dst_pitch;
dst_pitch = -dst_pitch;
}
/* We postponed printing this message until having committed to executing
* the function.
*/
DBG("%s: x,y=(%d,%d) (w,h)=(%d,%d) format=0x%x type=0x%x "
"mesa_format=0x%x tiling=%d "
"pack=(alignment=%d row_length=%d skip_pixels=%d skip_rows=%d)\n",
__func__, xoffset, yoffset, width, height,
format, type, rb->Format, irb->mt->tiling,
pack->Alignment, pack->RowLength, pack->SkipPixels,
pack->SkipRows);
tiled_to_linear(
xoffset * cpp, (xoffset + width) * cpp,
yoffset, yoffset + height,
pixels - (ptrdiff_t) yoffset * dst_pitch - (ptrdiff_t) xoffset * cpp,
bo->virtual,
dst_pitch, irb->mt->pitch,
brw->has_swizzling,
irb->mt->tiling,
mem_copy
);
drm_intel_bo_unmap(bo);
return true;
}
void
intelReadPixels(struct gl_context * ctx,
GLint x, GLint y, GLsizei width, GLsizei height,
GLenum format, GLenum type,
const struct gl_pixelstore_attrib *pack, GLvoid * pixels)
{
bool ok;
struct brw_context *brw = brw_context(ctx);
bool dirty;
DBG("%s\n", __func__);
if (_mesa_is_bufferobj(pack->BufferObj)) {
if (_mesa_meta_pbo_GetTexSubImage(ctx, 2, NULL, x, y, 0, width, height, 1,
format, type, pixels, pack)) {
/* _mesa_meta_pbo_GetTexSubImage() implements PBO transfers by
* binding the user-provided BO as a fake framebuffer and rendering
* to it. This breaks the invariant of the GL that nothing is able
* to render to a BO, causing nondeterministic corruption issues
* because the render cache is not coherent with a number of other
* caches that the BO could potentially be bound to afterwards.
*
* This could be solved in the same way that we guarantee texture
* coherency after a texture is attached to a framebuffer and
* rendered to, but that would involve checking *all* BOs bound to
* the pipeline for the case we need to emit a cache flush due to
* previous rendering to any of them -- Including vertex, index,
* uniform, atomic counter, shader image, transform feedback,
* indirect draw buffers, etc.
*
* That would increase the per-draw call overhead even though it's
* very unlikely that any of the BOs bound to the pipeline has been
* rendered to via a PBO at any point, so it seems better to just
* flush here unconditionally.
*/
intel_batchbuffer_emit_mi_flush(brw);
return;
}
perf_debug("%s: fallback to CPU mapping in PBO case\n", __func__);
}
ok = intel_readpixels_tiled_memcpy(ctx, x, y, width, height,
format, type, pixels, pack);
if(ok)
return;
/* glReadPixels() wont dirty the front buffer, so reset the dirty
* flag after calling intel_prepare_render(). */
dirty = brw->front_buffer_dirty;
intel_prepare_render(brw);
brw->front_buffer_dirty = dirty;
/* Update Mesa state before calling _mesa_readpixels().
* XXX this may not be needed since ReadPixels no longer uses the
* span code.
*/
if (ctx->NewState)
_mesa_update_state(ctx);
_mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels);
/* There's an intel_prepare_render() call in intelSpanRenderStart(). */
brw->front_buffer_dirty = dirty;
}