[PATCH 07/20] glamor: Add simple upload/download functions in glamor_transfer
Markus Wick
markus at selfnet.de
Wed Mar 19 04:42:59 PDT 2014
Am 2014-03-19 06:09, schrieb Keith Packard:
> These use glTexSubimage2D for upload and glReadPixels for
> download. There are a variety of interfaces to the basic function as
> needed by the callers.
>
> Signed-off-by: Keith Packard <keithp at keithp.com>
> ---
> glamor/Makefile.am | 2 +
> glamor/glamor_transfer.c | 260
> +++++++++++++++++++++++++++++++++++++++++++++++
> glamor/glamor_transfer.h | 55 ++++++++++
> 3 files changed, 317 insertions(+)
> create mode 100644 glamor/glamor_transfer.c
> create mode 100644 glamor/glamor_transfer.h
>
> diff --git a/glamor/Makefile.am b/glamor/Makefile.am
> index dec6467..9544923 100644
> --- a/glamor/Makefile.am
> +++ b/glamor/Makefile.am
> @@ -23,6 +23,8 @@ libglamor_la_SOURCES = \
> glamor_render.c \
> glamor_gradient.c \
> glamor_program.c \
> + glamor_transfer.c \
> + glamor_transfer.h \
> glamor_transform.c \
> glamor_trapezoid.c \
> glamor_tile.c \
> diff --git a/glamor/glamor_transfer.c b/glamor/glamor_transfer.c
> new file mode 100644
> index 0000000..d25c659
> --- /dev/null
> +++ b/glamor/glamor_transfer.c
> @@ -0,0 +1,260 @@
> +/*
> + * Copyright © 2014 Keith Packard
> + *
> + * Permission to use, copy, modify, distribute, and sell this software
> and its
> + * documentation for any purpose is hereby granted without fee,
> provided that
> + * the above copyright notice appear in all copies and that both that
> copyright
> + * notice and this permission notice appear in supporting
> documentation, and
> + * that the name of the copyright holders not be used in advertising
> or
> + * publicity pertaining to distribution of the software without
> specific,
> + * written prior permission. The copyright holders make no
> representations
> + * about the suitability of this software for any purpose. It is
> provided "as
> + * is" without express or implied warranty.
> + *
> + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
> SOFTWARE,
> + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
> NO
> + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL,
> INDIRECT OR
> + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
> OF USE,
> + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
> OTHER
> + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
> PERFORMANCE
> + * OF THIS SOFTWARE.
> + */
> +
> +#include "glamor_priv.h"
> +#include "glamor_transfer.h"
> +
> +/* XXX a kludge for now */
> +void
> +glamor_format_for_pixmap(PixmapPtr pixmap, GLenum *format, GLenum
> *type)
> +{
> + switch (pixmap->drawable.depth) {
> + case 24:
> + case 32:
> + *format = GL_BGRA;
> + *type = GL_UNSIGNED_INT_8_8_8_8_REV;
> + break;
> + case 16:
> + *format = GL_RGB;
> + *type = GL_UNSIGNED_SHORT_5_6_5;
> + break;
> + case 15:
> + *format = GL_BGRA;
> + *type = GL_UNSIGNED_SHORT_1_5_5_5_REV;
> + break;
> + case 8:
> + *format = GL_ALPHA;
> + *type = GL_UNSIGNED_BYTE;
> + break;
> + default:
> + FatalError("Invalid pixmap depth %d\n",
> pixmap->drawable.depth);
> + break;
> + }
> +}
> +
> +/*
> + * Write a region of bits into a pixmap
> + */
> +void
> +glamor_upload_boxes(PixmapPtr pixmap, BoxPtr in_boxes, int in_nbox,
> + int dx_src, int dy_src,
> + int dx_dst, int dy_dst,
> + uint8_t *bits, uint32_t byte_stride)
> +{
> + ScreenPtr screen = pixmap->drawable.pScreen;
> + glamor_screen_private *glamor_priv =
> glamor_get_screen_private(screen);
> + glamor_pixmap_private *priv =
> glamor_get_pixmap_private(pixmap);
> + int box_x, box_y;
> + int bytes_per_pixel =
> pixmap->drawable.bitsPerPixel >> 3;
> + GLenum type;
> + GLenum format;
> +
> + glamor_format_for_pixmap(pixmap, &format, &type);
> +
> + glamor_get_context(glamor_priv);
> +
> + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
> + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
> +
> + glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
> + glPixelStorei(GL_UNPACK_ROW_LENGTH, byte_stride /
> bytes_per_pixel);
> +
> + glamor_pixmap_loop(priv, box_x, box_y) {
> + BoxPtr box = glamor_pixmap_box_at(priv,
> box_x, box_y);
> + glamor_pixmap_fbo *fbo = glamor_pixmap_fbo_at(priv,
> box_x, box_y);
> + BoxPtr boxes = in_boxes;
> + int nbox = in_nbox;
> +
> + glActiveTexture(GL_TEXTURE0);
> + glBindTexture(GL_TEXTURE_2D, fbo->tex);
> +
> + while (nbox--) {
> +
> + /* compute drawable coordinates */
> + int x1 = boxes->x1 + dx_dst;
> + int x2 = boxes->x2 + dx_dst;
> + int y1 = boxes->y1 + dy_dst;
> + int y2 = boxes->y2 + dy_dst;
> +
> + if (x1 < box->x1)
> + x1 = box->x1;
> + if (box->x2 < x2)
> + x2 = box->x2;
x1 = MAX(x1, box->x1);
x2 = MIN(x2, box->x2);
> +
> + if (x2 <= x1)
> + continue;
> +
> + if (y1 < box->y1)
> + y1 = box->y1;
> + if (box->y2 < y2)
> + y2 = box->y2;
> +
> + if (y2 <= y1)
> + continue;
So a box coverage pre-check should be moved to glamor_utils. Maybe also
the box loop?
> +
> + glPixelStorei(GL_UNPACK_SKIP_ROWS, y1 - dy_dst + dy_src);
Isn't this the same as an offset in glTexSubImage2D?
> + glPixelStorei(GL_UNPACK_SKIP_PIXELS, x1 - dx_dst +
> dx_src);
> +
> + glTexSubImage2D(GL_TEXTURE_2D, 0,
> + x1 - box->x1, y1 - box->y1,
> + x2 - x1, y2 - y1,
> + format, type,
> + bits);
I think in theory, this won't do any redundant uploads, but we shouldn't
do so many uploading calls. As we pretty much always need a temporary
staging buffer (in the driver) to avoid stalling, we could do this
explicit with a PBO.
But PBO shouldn't be used with uncommon pixel types as some of them are
emulated on the CPU...
> + }
> + }
> +
> + glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
> + glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
> + glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
> + glamor_put_context(glamor_priv);
> +}
> +
> +/*
> + * Upload a region of data
> + */
> +
> +void
> +glamor_upload_region(PixmapPtr pixmap, RegionPtr region,
> + int region_x, int region_y,
> + uint8_t *bits, uint32_t byte_stride)
> +{
> + glamor_upload_boxes(pixmap, RegionRects(region),
> RegionNumRects(region),
> + -region_x, -region_y,
> + 0, 0,
> + bits, byte_stride);
> +}
> +
> +/*
> + * Take the data in the pixmap and stuff it back into the FBO
> + */
> +void
> +glamor_upload_pixmap(PixmapPtr pixmap)
> +{
> + BoxRec box;
> +
> + box.x1 = 0;
> + box.x2 = pixmap->drawable.width;
> + box.y1 = 0;
> + box.y2 = pixmap->drawable.height;
> + glamor_upload_boxes(pixmap, &box, 1, 0, 0, 0, 0,
> + pixmap->devPrivate.ptr, pixmap->devKind);
> +}
> +
> +/*
> + * Read stuff from the pixmap FBOs and write to memory
> + */
> +void
> +glamor_download_boxes(PixmapPtr pixmap, BoxPtr in_boxes, int in_nbox,
> + int dx_src, int dy_src,
> + int dx_dst, int dy_dst,
> + uint8_t *bits, uint32_t byte_stride)
> +{
> + ScreenPtr screen = pixmap->drawable.pScreen;
> + glamor_screen_private *glamor_priv =
> glamor_get_screen_private(screen);
> + glamor_pixmap_private *priv = glamor_get_pixmap_private(pixmap);
> + int box_x, box_y;
> + int bytes_per_pixel = pixmap->drawable.bitsPerPixel >> 3;
> + GLenum type;
> + GLenum format;
> +
> + glamor_format_for_pixmap(pixmap, &format, &type);
> +
> + glamor_get_context(glamor_priv);
> +
> + glPixelStorei(GL_PACK_ALIGNMENT, 4);
> + glPixelStorei(GL_PACK_ROW_LENGTH, byte_stride / bytes_per_pixel);
> +
> + glamor_pixmap_loop(priv, box_x, box_y) {
> + BoxPtr box = glamor_pixmap_box_at(priv,
> box_x, box_y);
> + glamor_pixmap_fbo *fbo = glamor_pixmap_fbo_at(priv,
> box_x, box_y);
> + BoxPtr boxes = in_boxes;
> + int nbox = in_nbox;
> +
> + glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo->fb);
> +
> + while (nbox--) {
> +
> + /* compute drawable coordinates */
> + int x1 = boxes->x1 + dx_src;
> + int x2 = boxes->x2 + dx_src;
> + int y1 = boxes->y1 + dy_src;
> + int y2 = boxes->y2 + dy_src;
> +
> + if (x1 < box->x1)
> + x1 = box->x1;
> + if (box->x2 < x2)
> + x2 = box->x2;
> +
> + if (y1 < box->y1)
> + y1 = box->y1;
> + if (box->y2 < y2)
> + y2 = box->y2;
> +
> + if (x2 <= x1)
> + continue;
> + if (y2 <= y1)
> + continue;
> +
> + glPixelStorei(GL_PACK_SKIP_PIXELS, x1 - dx_src + dx_dst);
> + glPixelStorei(GL_PACK_SKIP_ROWS, y1 - dy_src + dy_dst);
> + glReadPixels(x1 - box->x1, y1 - box->y1, x2 - x1, y2 -
> y1, format, type, bits);
Here, a PBO is more important to not stall once per box. i965 may not
stall, but on dedicated GPUs, the framebuffer can't be accessed without
a round trip time.
> + }
> + }
> + glPixelStorei(GL_PACK_ROW_LENGTH, 0);
> + glPixelStorei(GL_PACK_SKIP_ROWS, 0);
> + glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
> + glamor_put_context(glamor_priv);
> +}
> +
> +/*
> + * Read data from the pixmap FBO
> + */
> +void
> +glamor_download_rect(PixmapPtr pixmap, int x, int y, int w, int h,
> uint8_t *bits)
> +{
> + BoxRec box;
> +
> + box.x1 = x;
> + box.x2 = x + w;
> + box.y1 = y;
> + box.y2 = y + h;
> +
> + glamor_download_boxes(pixmap, &box, 1, 0, 0, -x, -y,
> + bits, PixmapBytePad(w,
> pixmap->drawable.depth));
> +}
> +
> +/*
> + * Pull the data from the FBO down to the pixmap
> + */
> +void
> +glamor_download_pixmap(PixmapPtr pixmap)
> +{
> + BoxRec box;
> +
> + box.x1 = 0;
> + box.x2 = pixmap->drawable.width;
> + box.y1 = 0;
> + box.y2 = pixmap->drawable.height;
> +
> + glamor_download_boxes(pixmap, &box, 1, 0, 0, 0, 0,
> + pixmap->devPrivate.ptr, pixmap->devKind);
> +}
> diff --git a/glamor/glamor_transfer.h b/glamor/glamor_transfer.h
> new file mode 100644
> index 0000000..de8186a
> --- /dev/null
> +++ b/glamor/glamor_transfer.h
> @@ -0,0 +1,55 @@
> +/*
> + * Copyright © 2014 Keith Packard
> + *
> + * Permission to use, copy, modify, distribute, and sell this software
> and its
> + * documentation for any purpose is hereby granted without fee,
> provided that
> + * the above copyright notice appear in all copies and that both that
> copyright
> + * notice and this permission notice appear in supporting
> documentation, and
> + * that the name of the copyright holders not be used in advertising
> or
> + * publicity pertaining to distribution of the software without
> specific,
> + * written prior permission. The copyright holders make no
> representations
> + * about the suitability of this software for any purpose. It is
> provided "as
> + * is" without express or implied warranty.
> + *
> + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
> SOFTWARE,
> + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
> NO
> + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL,
> INDIRECT OR
> + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
> OF USE,
> + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
> OTHER
> + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
> PERFORMANCE
> + * OF THIS SOFTWARE.
> + */
> +
> +#ifndef _GLAMOR_TRANSFER_H_
> +#define _GLAMOR_TRANSFER_H_
> +
> +void
> +glamor_format_for_pixmap(PixmapPtr pixmap, GLenum *format, GLenum
> *type);
> +
> +void
> +glamor_upload_boxes(PixmapPtr pixmap, BoxPtr in_boxes, int in_nbox,
> + int dx_src, int dy_src,
> + int dx_dst, int dy_dst,
> + uint8_t *bits, uint32_t byte_stride);
> +
> +void
> +glamor_upload_region(PixmapPtr pixmap, RegionPtr region,
> + int region_x, int region_y,
> + uint8_t *bits, uint32_t byte_stride);
> +
> +void
> +glamor_upload_pixmap(PixmapPtr pixmap);
> +
> +void
> +glamor_download_boxes(PixmapPtr pixmap, BoxPtr in_boxes, int in_nbox,
> + int dx_src, int dy_src,
> + int dx_dst, int dy_dst,
> + uint8_t *bits, uint32_t byte_stride);
> +
> +void
> +glamor_download_rect(PixmapPtr pixmap, int x, int y, int w, int h,
> uint8_t *bits);
> +
> +void
> +glamor_download_pixmap(PixmapPtr pixmap);
> +
> +#endif /* _GLAMOR_TRANSFER_H_ */
So in the end, I suggest to use PBO all the time. It's likely an
overhead compared to the internal staging buffer of the driver, but imo
this shouldn't matter compared with the memcpy time.
But on shared memory systems, this is a huge overhead as it has to
memcpy the texture twice. The driver doesn't have to do this when either
the texture isn't in use (unlikely) or we update the complete texture
(not that unlikely).
How should we deal with plattforms without ARB_pbo? I think glamor
should work, but performance doesn't matter that hard. I don't want to
fork this function to work fast with and without PBO.
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