gles2: Support the GL_EXT_unpack_subimage extension

This extension lets you upload texture data from a subregion of a
buffer by passing GL_UNPACK_ROW_LENGTH, GL_UNPACK_SKIP_PIXELS and
GL_UNPACK_SKIP_ROWS to glPixelStore. When this extension is available
the GLES texture driver will now avoid making a copy of the bitmap
when a subregion is used.

Note that Mesa doesn't currently advertise this extension but I've
made a patch to propose it:

http://lists.freedesktop.org/archives/mesa-dev/2012-March/020191.html
This commit is contained in:
Neil Roberts 2012-03-21 17:51:51 +00:00
parent 21e304b339
commit ae5f8323c1
3 changed files with 56 additions and 10 deletions

View File

@ -101,7 +101,8 @@ typedef enum
COGL_PRIVATE_FEATURE_VBOS = 1L<<6,
COGL_PRIVATE_FEATURE_EXT_PACKED_DEPTH_STENCIL = 1L<<7,
COGL_PRIVATE_FEATURE_OES_PACKED_DEPTH_STENCIL = 1L<<8,
COGL_PRIVATE_FEATURE_TEXTURE_FORMAT_BGRA8888 = 1L<<9
COGL_PRIVATE_FEATURE_TEXTURE_FORMAT_BGRA8888 = 1L<<9,
COGL_PRIVATE_FEATURE_UNPACK_SUBIMAGE = 1L<<10
} CoglPrivateFeatureFlags;
/* Sometimes when evaluating pipelines, either during comparisons or

View File

@ -293,6 +293,9 @@ _cogl_driver_update_features (CoglContext *context,
if (_cogl_check_extension ("GL_EXT_texture_format_BGRA8888", gl_extensions))
private_flags |= COGL_PRIVATE_FEATURE_TEXTURE_FORMAT_BGRA8888;
if (_cogl_check_extension ("GL_EXT_unpack_subimage", gl_extensions))
private_flags |= COGL_PRIVATE_FEATURE_UNPACK_SUBIMAGE;
/* Cache features */
context->private_feature_flags |= private_flags;
context->feature_flags |= flags;

View File

@ -52,6 +52,18 @@
#define GL_MAX_3D_TEXTURE_SIZE_OES 0x8073
#endif
/* This extension isn't available for GLES 1.1 so these won't be
defined */
#ifndef GL_UNPACK_ROW_LENGTH
#define GL_UNPACK_ROW_LENGTH 0x0CF2
#endif
#ifndef GL_UNPACK_SKIP_ROWS
#define GL_UNPACK_SKIP_ROWS 0x0CF3
#endif
#ifndef GL_UNPACK_SKIP_PIXELS
#define GL_UNPACK_SKIP_PIXELS 0x0CF4
#endif
static void
_cogl_texture_driver_gen (CoglContext *ctx,
GLenum gl_target,
@ -83,11 +95,38 @@ _cogl_texture_driver_gen (CoglContext *ctx,
}
static void
_cogl_texture_driver_prep_gl_for_pixels_upload (CoglContext *context,
prep_gl_for_pixels_upload_full (CoglContext *ctx,
int pixels_rowstride,
int pixels_src_x,
int pixels_src_y,
int pixels_bpp)
{
if ((ctx->private_feature_flags & COGL_PRIVATE_FEATURE_UNPACK_SUBIMAGE))
{
GE( ctx, glPixelStorei (GL_UNPACK_ROW_LENGTH,
pixels_rowstride / pixels_bpp) );
GE( ctx, glPixelStorei (GL_UNPACK_SKIP_PIXELS, pixels_src_x) );
GE( ctx, glPixelStorei (GL_UNPACK_SKIP_ROWS, pixels_src_y) );
}
else
{
g_assert (pixels_src_x == 0);
g_assert (pixels_src_y == 0);
}
_cogl_texture_prep_gl_alignment_for_pixels_upload (pixels_rowstride);
}
static void
_cogl_texture_driver_prep_gl_for_pixels_upload (CoglContext *ctx,
int pixels_rowstride,
int pixels_bpp)
{
_cogl_texture_prep_gl_alignment_for_pixels_upload (pixels_rowstride);
prep_gl_for_pixels_upload_full (ctx,
pixels_rowstride,
0, 0, /* src_x/y */
pixels_bpp);
}
static void
@ -108,7 +147,8 @@ prepare_bitmap_alignment_for_upload (CoglContext *ctx,
int width = cogl_bitmap_get_width (src_bmp);
int alignment = 1;
if (src_rowstride == 0)
if ((ctx->private_feature_flags & COGL_PRIVATE_FEATURE_UNPACK_SUBIMAGE) ||
src_rowstride == 0)
return cogl_object_ref (src_bmp);
/* Work out the alignment of the source rowstride */
@ -146,11 +186,13 @@ _cogl_texture_driver_upload_subregion_to_gl (CoglContext *ctx,
CoglBitmap *slice_bmp;
int rowstride;
/* If we are copying a sub region of the source bitmap then we need
to copy it because GLES does not support GL_UNPACK_ROW_LENGTH */
if (src_x != 0 || src_y != 0 ||
width != cogl_bitmap_get_width (source_bmp) ||
height != cogl_bitmap_get_height (source_bmp))
/* If we have the GL_EXT_unpack_subimage extension then we can
upload from subregions directly. Otherwise we may need to copy
the bitmap */
if (!(ctx->private_feature_flags & COGL_PRIVATE_FEATURE_UNPACK_SUBIMAGE) &&
(src_x != 0 || src_y != 0 ||
width != cogl_bitmap_get_width (source_bmp) ||
height != cogl_bitmap_get_height (source_bmp)))
{
slice_bmp =
_cogl_bitmap_new_with_malloc_buffer (ctx,
@ -168,7 +210,7 @@ _cogl_texture_driver_upload_subregion_to_gl (CoglContext *ctx,
rowstride = cogl_bitmap_get_rowstride (slice_bmp);
/* Setup gl alignment to match rowstride and top-left corner */
_cogl_texture_driver_prep_gl_for_pixels_upload (ctx, rowstride, bpp);
prep_gl_for_pixels_upload_full (ctx, rowstride, src_x, src_y, bpp);
data = _cogl_bitmap_bind (slice_bmp, COGL_BUFFER_ACCESS_READ, 0);