void
cogl_read_pixels (int x,
int y,
int width,
int height,
CoglReadPixelsFlags source,
CoglPixelFormat format,
uint8_t *pixels)
{
int bpp = _cogl_pixel_format_get_bytes_per_pixel (format);
CoglBitmap *bitmap;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
bitmap = cogl_bitmap_new_for_data (ctx,
width, height,
format,
bpp * width, /* rowstride */
pixels);
cogl_framebuffer_read_pixels_into_bitmap (_cogl_get_read_framebuffer (),
x, y,
source,
bitmap);
cogl_object_unref (bitmap);
}
void
cogl_begin_gl (void)
{
CoglPipeline *pipeline;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
if (ctx->in_begin_gl_block)
{
static CoglBool shown = FALSE;
if (!shown)
g_warning ("You should not nest cogl_begin_gl/cogl_end_gl blocks");
shown = TRUE;
return;
}
ctx->in_begin_gl_block = TRUE;
/* Flush all batched primitives */
cogl_flush ();
/* Flush framebuffer state, including clip state, modelview and
* projection matrix state
*
* NB: _cogl_framebuffer_flush_state may disrupt various state (such
* as the pipeline state) when flushing the clip stack, so should
* always be done first when preparing to draw. */
_cogl_framebuffer_flush_state (cogl_get_draw_framebuffer (),
_cogl_get_read_framebuffer (),
COGL_FRAMEBUFFER_STATE_ALL);
/* Setup the state for the current pipeline */
/* We considered flushing a specific, minimal pipeline here to try and
* simplify the GL state, but decided to avoid special cases and second
* guessing what would be actually helpful.
*
* A user should instead call cogl_set_source_color4ub() before
* cogl_begin_gl() to simplify the state flushed.
*
* XXX: note defining n_tex_coord_attribs using
* cogl_pipeline_get_n_layers is a hack, but the problem is that
* n_tex_coord_attribs is usually defined when drawing a primitive
* which isn't happening here.
*
* Maybe it would be more useful if this code did flush the
* opaque_color_pipeline and then call into cogl-pipeline-opengl.c to then
* restore all state for the material's backend back to default OpenGL
* values.
*/
pipeline = cogl_get_source ();
_cogl_pipeline_flush_gl_state (ctx,
pipeline,
cogl_get_draw_framebuffer (),
FALSE,
FALSE);
/* Disable any cached vertex arrays */
_cogl_gl_disable_all_attributes (ctx);
}
void
_cogl_read_pixels_with_rowstride (int x,
int y,
int width,
int height,
CoglReadPixelsFlags source,
CoglPixelFormat format,
guint8 *pixels,
int rowstride)
{
CoglFramebuffer *framebuffer = _cogl_get_read_framebuffer ();
int framebuffer_height;
int bpp;
CoglBitmap *bmp;
GLenum gl_intformat;
GLenum gl_format;
GLenum gl_type;
CoglPixelFormat bmp_format;
gboolean pack_invert_set;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
_COGL_RETURN_IF_FAIL (source == COGL_READ_PIXELS_COLOR_BUFFER);
if (width == 1 && height == 1 && !framebuffer->clear_clip_dirty)
{
/* If everything drawn so far for this frame is still in the
* Journal then if all of the rectangles only have a flat
* opaque color we have a fast-path for reading a single pixel
* that avoids the relatively high cost of flushing primitives
* to be drawn on the GPU (considering how simple the geometry
* is in this case) and then blocking on the long GPU pipelines
* for the result.
*/
if (_cogl_framebuffer_try_fast_read_pixel (framebuffer,
x, y, source, format,
pixels))
return;
}
/* make sure any batched primitives get emitted to the GL driver
* before issuing our read pixels...
*
* XXX: Note we currently use cogl_flush to ensure *all* journals
* are flushed here and not _cogl_journal_flush because we don't
* track the dependencies between framebuffers so we don't know if
* the current framebuffer depends on the contents of other
* framebuffers which could also have associated journal entries.
*/
cogl_flush ();
_cogl_framebuffer_flush_state (cogl_get_draw_framebuffer (),
framebuffer,
COGL_FRAMEBUFFER_STATE_BIND);
framebuffer_height = cogl_framebuffer_get_height (framebuffer);
/* The y co-ordinate should be given in OpenGL's coordinate system
* so 0 is the bottom row
*
* NB: all offscreen rendering is done upside down so no conversion
* is necissary in this case.
*/
if (!cogl_is_offscreen (framebuffer))
y = framebuffer_height - y - height;
/* Initialise the CoglBitmap */
bpp = _cogl_get_format_bpp (format);
bmp_format = format;
if ((format & COGL_A_BIT))
{
/* We match the premultiplied state of the target buffer to the
* premultiplied state of the framebuffer so that it will get
* converted to the right format below */
if ((framebuffer->format & COGL_PREMULT_BIT))
bmp_format |= COGL_PREMULT_BIT;
else
bmp_format &= ~COGL_PREMULT_BIT;
}
bmp = _cogl_bitmap_new_from_data (pixels,
bmp_format, width, height, rowstride,
NULL, NULL);
ctx->texture_driver->pixel_format_to_gl (format,
&gl_intformat,
&gl_format,
&gl_type);
/* NB: All offscreen rendering is done upside down so there is no need
* to flip in this case... */
if ((ctx->private_feature_flags & COGL_PRIVATE_FEATURE_MESA_PACK_INVERT) &&
!cogl_is_offscreen (framebuffer))
{
GE (ctx, glPixelStorei (GL_PACK_INVERT_MESA, TRUE));
pack_invert_set = TRUE;
}
else
pack_invert_set = FALSE;
/* Under GLES only GL_RGBA with GL_UNSIGNED_BYTE as well as an
implementation specific format under
GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES and
GL_IMPLEMENTATION_COLOR_READ_TYPE_OES is supported. We could try
to be more clever and check if the requested type matches that
but we would need some reliable functions to convert from GL
types to Cogl types. For now, lets just always read in
GL_RGBA/GL_UNSIGNED_BYTE and convert if necessary. We also need
to use this intermediate buffer if the rowstride has padding
because GLES does not support setting GL_ROW_LENGTH */
if (ctx->driver != COGL_DRIVER_GL &&
(gl_format != GL_RGBA || gl_type != GL_UNSIGNED_BYTE ||
rowstride != 4 * width))
{
CoglBitmap *tmp_bmp, *dst_bmp;
guint8 *tmp_data = g_malloc (width * height * 4);
tmp_bmp = _cogl_bitmap_new_from_data (tmp_data,
COGL_PIXEL_FORMAT_RGBA_8888 |
(bmp_format & COGL_PREMULT_BIT),
width, height, 4 * width,
(CoglBitmapDestroyNotify) g_free,
NULL);
ctx->texture_driver->prep_gl_for_pixels_download (4 * width, 4);
GE( ctx, glReadPixels (x, y, width, height,
GL_RGBA, GL_UNSIGNED_BYTE,
tmp_data) );
/* CoglBitmap doesn't currently have a way to convert without
allocating its own buffer so we have to copy the data
again */
if ((dst_bmp = _cogl_bitmap_convert_format_and_premult (tmp_bmp,
format)))
{
_cogl_bitmap_copy_subregion (dst_bmp,
bmp,
0, 0,
0, 0,
width, height);
cogl_object_unref (dst_bmp);
}
else
{
/* FIXME: there's no way to report an error here so we'll
just have to leave the data initialised */
}
cogl_object_unref (tmp_bmp);
}
else
{
ctx->texture_driver->prep_gl_for_pixels_download (rowstride, bpp);
GE( ctx, glReadPixels (x, y, width, height, gl_format, gl_type, pixels) );
/* Convert to the premult format specified by the caller
in-place. This will do nothing if the premult status is already
correct. */
_cogl_bitmap_convert_premult_status (bmp, format);
}
/* Currently this function owns the pack_invert state and we don't want this
* to interfere with other Cogl components so all other code can assume that
* we leave the pack_invert state off. */
if (pack_invert_set)
GE (ctx, glPixelStorei (GL_PACK_INVERT_MESA, FALSE));
/* NB: All offscreen rendering is done upside down so there is no need
* to flip in this case... */
if (!cogl_is_offscreen (framebuffer) && !pack_invert_set)
{
guint8 *temprow = g_alloca (rowstride * sizeof (guint8));
/* vertically flip the buffer in-place */
for (y = 0; y < height / 2; y++)
{
if (y != height - y - 1) /* skip center row */
{
memcpy (temprow,
pixels + y * rowstride, rowstride);
memcpy (pixels + y * rowstride,
pixels + (height - y - 1) * rowstride, rowstride);
memcpy (pixels + (height - y - 1) * rowstride,
temprow,
rowstride);
}
}
}
cogl_object_unref (bmp);
}