Use FBOs and use cogl_read_pixels() to efficiently read partial textures

* cogl_texture_get_data() is converted to use
   _cogl_texture_foreach_sub_texture_in_region() to iterate
  through the underlying textures.

 * When we need to read only a portion of the underlying
   texture, we set up a FBO and use _cogl_read_pixels()
   to read the portion we need. This is enormously more
   efficient for reading a small portion of a large atlas
   texture.

 * The CoglAtlasTexture, CoglSubTexture, and CoglTexture2dSliced
   implementation of get_texture() are removed.

http://bugzilla.clutter-project.org/show_bug.cgi?id=2414
This commit is contained in:
Owen W. Taylor 2010-11-12 11:02:13 -05:00 committed by Neil Roberts
parent 519b6fe6f2
commit 8b4034cd06
4 changed files with 186 additions and 241 deletions

View File

@ -439,21 +439,6 @@ _cogl_atlas_texture_set_region (CoglTexture *tex,
bmp);
}
static gboolean
_cogl_atlas_texture_get_data (CoglTexture *tex,
CoglPixelFormat format,
unsigned int rowstride,
guint8 *data)
{
CoglAtlasTexture *atlas_tex = COGL_ATLAS_TEXTURE (tex);
/* Forward on to the sub texture */
return cogl_texture_get_data (atlas_tex->sub_texture,
format,
rowstride,
data);
}
static CoglPixelFormat
_cogl_atlas_texture_get_format (CoglTexture *tex)
{
@ -632,7 +617,7 @@ static const CoglTextureVtable
cogl_atlas_texture_vtable =
{
_cogl_atlas_texture_set_region,
_cogl_atlas_texture_get_data,
NULL, /* get_data */
_cogl_atlas_texture_foreach_sub_texture_in_region,
_cogl_atlas_texture_get_max_waste,
_cogl_atlas_texture_is_sliced,

View File

@ -416,74 +416,6 @@ _cogl_sub_texture_set_region (CoglTexture *tex,
bmp);
}
static void
_cogl_sub_texture_copy_region (guint8 *dst,
const guint8 *src,
int dst_x, int dst_y,
int src_x, int src_y,
int width, int height,
int dst_rowstride,
int src_rowstride,
int bpp)
{
int y;
dst += dst_x * bpp + dst_y * dst_rowstride;
src += src_x * bpp + src_y * src_rowstride;
for (y = 0; y < height; y++)
{
memcpy (dst, src, bpp * width);
dst += dst_rowstride;
src += src_rowstride;
}
}
static gboolean
_cogl_sub_texture_get_data (CoglTexture *tex,
CoglPixelFormat format,
unsigned int rowstride,
guint8 *data)
{
CoglSubTexture *sub_tex = COGL_SUB_TEXTURE (tex);
unsigned int full_rowstride;
guint8 *full_data;
gboolean ret = TRUE;
int bpp;
int full_tex_width, full_tex_height;
/* FIXME: This gets the full data from the full texture and then
copies a subregion of that. It would be better if there was a
texture_get_sub_data virtual and it can just munge the texture
coordinates */
full_tex_width = cogl_texture_get_width (sub_tex->full_texture);
full_tex_height = cogl_texture_get_height (sub_tex->full_texture);
bpp = _cogl_get_format_bpp (format);
full_rowstride = _cogl_get_format_bpp (format) * full_tex_width;
full_data = g_malloc (full_rowstride * full_tex_height);
if (cogl_texture_get_data (sub_tex->full_texture, format,
full_rowstride, full_data))
_cogl_sub_texture_copy_region (data, full_data,
0, 0,
sub_tex->sub_x,
sub_tex->sub_y,
sub_tex->sub_width,
sub_tex->sub_height,
rowstride,
full_rowstride,
bpp);
else
ret = FALSE;
g_free (full_data);
return ret;
}
static CoglPixelFormat
_cogl_sub_texture_get_format (CoglTexture *tex)
{
@ -520,7 +452,7 @@ static const CoglTextureVtable
cogl_sub_texture_vtable =
{
_cogl_sub_texture_set_region,
_cogl_sub_texture_get_data,
NULL, /* get_data */
_cogl_sub_texture_foreach_sub_texture_in_region,
_cogl_sub_texture_get_max_waste,
_cogl_sub_texture_is_sliced,

View File

@ -1335,153 +1335,6 @@ _cogl_texture_2d_sliced_set_region (CoglTexture *tex,
return TRUE;
}
static gboolean
_cogl_texture_2d_sliced_download_from_gl (
CoglTexture2DSliced *tex_2ds,
CoglBitmap *target_bmp,
GLuint target_gl_format,
GLuint target_gl_type)
{
CoglSpan *x_span;
CoglSpan *y_span;
CoglHandle slice_tex;
int bpp;
int x, y;
CoglBitmap *slice_bmp;
CoglPixelFormat target_format = _cogl_bitmap_get_format (target_bmp);
bpp = _cogl_get_format_bpp (target_format);
/* Iterate vertical slices */
for (y = 0; y < tex_2ds->slice_y_spans->len; ++y)
{
y_span = &g_array_index (tex_2ds->slice_y_spans, CoglSpan, y);
/* Iterate horizontal slices */
for (x = 0; x < tex_2ds->slice_x_spans->len; ++x)
{
/*if (x != 0 || y != 1) continue;*/
x_span = &g_array_index (tex_2ds->slice_x_spans, CoglSpan, x);
/* Pick the sliced texture */
slice_tex = g_array_index (tex_2ds->slice_textures, CoglHandle,
y * tex_2ds->slice_x_spans->len + x);
/* If there's any waste we need to copy manually
(no glGetTexSubImage) */
if (y_span->waste != 0 || x_span->waste != 0)
{
int rowstride = x_span->size * bpp;
guint8 *data = g_malloc (rowstride * y_span->size);
/* Setup temp bitmap for slice subregion */
slice_bmp = _cogl_bitmap_new_from_data (data,
target_format,
x_span->size,
y_span->size,
rowstride,
(CoglBitmapDestroyNotify)
g_free,
NULL);
/* Setup gl alignment to 0,0 top-left corner */
_cogl_texture_driver_prep_gl_for_pixels_download (rowstride, bpp);
if (!cogl_texture_get_data (slice_tex,
target_format,
rowstride,
data))
{
/* Free temp bitmap */
cogl_object_unref (slice_bmp);
return FALSE;
}
/* Copy portion of slice from temp to target bmp */
_cogl_bitmap_copy_subregion (slice_bmp,
target_bmp,
0, 0,
x_span->start,
y_span->start,
x_span->size - x_span->waste,
y_span->size - y_span->waste);
/* Free temp bitmap */
cogl_object_unref (slice_bmp);
}
else
{
guint8 *data;
GLvoid *dst;
gboolean ret;
int rowstride = _cogl_bitmap_get_rowstride (target_bmp);
data = _cogl_bitmap_map (target_bmp,
COGL_BUFFER_ACCESS_WRITE,
0);
if (data == NULL)
return FALSE;
dst = data + x_span->start * bpp + y_span->start * rowstride;
_cogl_texture_driver_prep_gl_for_pixels_download (rowstride, bpp);
/* Download slice image data */
ret = cogl_texture_get_data (slice_tex,
target_format,
rowstride,
dst);
_cogl_bitmap_unmap (target_bmp);
if (!ret)
return ret;
}
}
}
return TRUE;
}
static gboolean
_cogl_texture_2d_sliced_get_data (CoglTexture *tex,
CoglPixelFormat format,
unsigned int rowstride,
guint8 *data)
{
CoglTexture2DSliced *tex_2ds = COGL_TEXTURE_2D_SLICED (tex);
int bpp;
GLenum gl_format;
GLenum gl_type;
CoglBitmap *target_bmp;
gboolean ret;
bpp = _cogl_get_format_bpp (format);
_cogl_pixel_format_to_gl (format,
NULL, /* internal format */
&gl_format,
&gl_type);
target_bmp = _cogl_bitmap_new_from_data (data,
format,
tex_2ds->width,
tex_2ds->height,
rowstride,
NULL, /* destroy_fn */
NULL /* destroy_fn_data */);
/* Retrieve data from slices */
ret = _cogl_texture_2d_sliced_download_from_gl (tex_2ds,
target_bmp,
gl_format,
gl_type);
cogl_object_unref (target_bmp);
return ret;
}
static CoglPixelFormat
_cogl_texture_2d_sliced_get_format (CoglTexture *tex)
{
@ -1528,7 +1381,7 @@ static const CoglTextureVtable
cogl_texture_2d_sliced_vtable =
{
_cogl_texture_2d_sliced_set_region,
_cogl_texture_2d_sliced_get_data,
NULL, /* get_data */
_cogl_texture_2d_sliced_foreach_sub_texture_in_region,
_cogl_texture_2d_sliced_get_max_waste,
_cogl_texture_2d_sliced_is_sliced,

View File

@ -4,6 +4,7 @@
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009 Intel Corporation.
* Copyright (C) 2010 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@ -37,6 +38,7 @@
#include "cogl-bitmap-private.h"
#include "cogl-buffer-private.h"
#include "cogl-pixel-array-private.h"
#include "cogl-private.h"
#include "cogl-texture-private.h"
#include "cogl-texture-driver.h"
#include "cogl-texture-2d-sliced-private.h"
@ -1181,6 +1183,169 @@ _cogl_texture_draw_and_read (CoglHandle handle,
return TRUE;
}
static gboolean
get_texture_bits_via_offscreen (CoglHandle texture_handle,
int x,
int y,
int width,
int height,
guint8 *dst_bits,
unsigned int dst_rowstride,
CoglPixelFormat dst_format)
{
CoglFramebuffer *framebuffer;
_COGL_GET_CONTEXT (ctx, FALSE);
if (!cogl_features_available (COGL_FEATURE_OFFSCREEN))
return FALSE;
framebuffer = _cogl_offscreen_new_to_texture_full
(texture_handle,
COGL_OFFSCREEN_DISABLE_DEPTH_AND_STENCIL,
0);
if (framebuffer == NULL)
return FALSE;
cogl_push_framebuffer (framebuffer);
_cogl_read_pixels_with_rowstride (x, y, width, height,
COGL_READ_PIXELS_COLOR_BUFFER,
dst_format, dst_bits, dst_rowstride);
cogl_pop_framebuffer ();
cogl_object_unref (framebuffer);
return TRUE;
}
static gboolean
get_texture_bits_via_copy (CoglHandle texture_handle,
int x,
int y,
int width,
int height,
guint8 *dst_bits,
unsigned int dst_rowstride,
CoglPixelFormat dst_format)
{
CoglTexture *tex = COGL_TEXTURE (texture_handle);
unsigned int full_rowstride;
guint8 *full_bits;
gboolean ret = TRUE;
int bpp;
int full_tex_width, full_tex_height;
full_tex_width = cogl_texture_get_width (texture_handle);
full_tex_height = cogl_texture_get_height (texture_handle);
bpp = _cogl_get_format_bpp (dst_format);
full_rowstride = bpp * full_tex_width;
full_bits = g_malloc (full_rowstride * full_tex_height);
if (tex->vtable->get_data (tex,
dst_format,
full_rowstride,
full_bits))
{
guint8 *dst = dst_bits;
guint8 *src = full_bits + x * bpp + y * full_rowstride;
int i;
for (i = 0; i < height; i++)
{
memcpy (dst, src, bpp * width);
dst += dst_rowstride;
src += full_rowstride;
}
}
else
ret = FALSE;
g_free (full_bits);
return ret;
}
typedef struct
{
int orig_width;
int orig_height;
CoglBitmap *target_bmp;
guint8 *target_bits;
gboolean success;
} CoglTextureGetData;
static void
texture_get_cb (CoglHandle texture_handle,
const float *subtexture_coords,
const float *virtual_coords,
void *user_data)
{
CoglTexture *tex = COGL_TEXTURE (texture_handle);
CoglTextureGetData *tg_data = user_data;
CoglPixelFormat format = _cogl_bitmap_get_format (tg_data->target_bmp);
int bpp = _cogl_get_format_bpp (format);
unsigned int rowstride = _cogl_bitmap_get_rowstride (tg_data->target_bmp);
int subtexture_width = cogl_texture_get_width (texture_handle);
int subtexture_height = cogl_texture_get_height (texture_handle);
int x_in_subtexture = (int) (0.5 + subtexture_width * subtexture_coords[0]);
int y_in_subtexture = (int) (0.5 + subtexture_height * subtexture_coords[1]);
int width = ((int) (0.5 + subtexture_width * subtexture_coords[2])
- x_in_subtexture);
int height = ((int) (0.5 + subtexture_height * subtexture_coords[3])
- y_in_subtexture);
int x_in_bitmap = (int) (0.5 + tg_data->orig_width * virtual_coords[0]);
int y_in_bitmap = (int) (0.5 + tg_data->orig_height * virtual_coords[1]);
guint8 *dst_bits;
if (!tg_data->success)
return;
dst_bits = tg_data->target_bits + x_in_bitmap * bpp + y_in_bitmap * rowstride;
/* If we can read everything as a single slice, then go ahead and do that
* to avoid allocating an FBO. We'll leave it up to the GL implementation to
* do glGetTexImage as efficiently as possible. (GLES doesn't have that,
* so we'll fall through) */
if (x_in_subtexture == 0 && y_in_subtexture == 0 &&
width == subtexture_width && height == subtexture_height)
{
if (tex->vtable->get_data (tex,
format,
rowstride,
dst_bits))
return;
}
/* Next best option is a FBO and glReadPixels */
if (get_texture_bits_via_offscreen (texture_handle,
x_in_subtexture, y_in_subtexture,
width, height,
dst_bits,
rowstride,
format))
return;
/* Getting ugly: read the entire texture, copy out the part we want */
if (get_texture_bits_via_copy (texture_handle,
x_in_subtexture, y_in_subtexture,
width, height,
dst_bits,
rowstride,
format))
return;
/* No luck, the caller will fall back to the draw-to-backbuffer and
* read implementation */
tg_data->success = FALSE;
}
int
cogl_texture_get_data (CoglHandle handle,
CoglPixelFormat format,
@ -1196,13 +1361,14 @@ cogl_texture_get_data (CoglHandle handle,
GLenum closest_gl_type;
CoglBitmap *target_bmp;
CoglBitmap *new_bmp;
gboolean success;
guint8 *src;
guint8 *dst;
int y;
int tex_width;
int tex_height;
CoglTextureGetData tg_data;
if (!cogl_is_texture (handle))
return 0;
@ -1253,17 +1419,26 @@ cogl_texture_get_data (CoglHandle handle,
NULL);
}
if ((dst = _cogl_bitmap_map (target_bmp, COGL_BUFFER_ACCESS_WRITE,
COGL_BUFFER_MAP_HINT_DISCARD)) == NULL)
tg_data.orig_width = tex_width;
tg_data.orig_height = tex_height;
tg_data.target_bmp = target_bmp;
tg_data.target_bits = _cogl_bitmap_map (target_bmp, COGL_BUFFER_ACCESS_WRITE,
COGL_BUFFER_MAP_HINT_DISCARD);
if (tg_data.target_bits == NULL)
{
cogl_object_unref (target_bmp);
return 0;
}
tg_data.success = TRUE;
success = tex->vtable->get_data (tex,
closest_format,
rowstride,
dst);
/* Iterating through the subtextures allows piecing together
* the data for a sliced texture, and allows us to do the
* read-from-framebuffer logic here in a simple fashion rather than
* passing offsets down through the code. */
_cogl_texture_foreach_sub_texture_in_region (handle,
0, 0, 1, 1,
texture_get_cb,
&tg_data);
_cogl_bitmap_unmap (target_bmp);
@ -1271,7 +1446,7 @@ cogl_texture_get_data (CoglHandle handle,
* to read back the texture data; such as for GLES which doesn't
* support glGetTexImage, so here we fallback to drawing the
* texture and reading the pixels from the framebuffer. */
if (!success)
if (!tg_data.success)
_cogl_texture_draw_and_read (tex, target_bmp,
closest_gl_format,
closest_gl_type);