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offscreen: Adds support for offscreen multisampling

This adds support for multisample rendering to offscreen framebuffers.
After an offscreen framebuffer is first instantiated using
cogl_offscreen_new_to_texture() it is then possible to use
cogl_framebuffer_set_samples_per_pixel() to request multisampling before
the framebuffer is allocated. This also adds
cogl_framebuffer_resolve_samples() for explicitly resolving point
samples into pixels. Even though we currently only support the
IMG_multisampled_render_to_texture extension which doesn't require an
explicit resolve, the plan is to also support the
EXT_framebuffer_multisample extension which uses the framebuffer_blit
extension to issue an explicit resolve.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
This commit is contained in:
Robert Bragg 2011-08-23 13:55:12 +01:00
parent a74c81ada3
commit dd7b16faf2
5 changed files with 488 additions and 236 deletions

View file

@ -333,18 +333,6 @@ COGL_EXT_FUNCTION (void, glBlitFramebuffer,
GLenum filter))
COGL_EXT_END ()
COGL_EXT_BEGIN (offscreen_multisample, 255, 255,
0, /* not in either GLES */
"EXT\0",
"framebuffer_multisample\0")
COGL_EXT_FUNCTION (void, glRenderbufferStorageMultisample,
(GLenum target,
GLsizei samples,
GLenum internalformat,
GLsizei width,
GLsizei height))
COGL_EXT_END ()
/* ARB_fragment_program */
COGL_EXT_BEGIN (arbfp, 255, 255,
0, /* not in either GLES */
@ -660,3 +648,21 @@ COGL_EXT_FUNCTION (void, glDiscardFramebuffer,
const GLenum *attachments))
COGL_EXT_END ()
COGL_EXT_BEGIN (IMG_multisampled_render_to_texture, 255, 255,
0, /* not in either GLES */
"\0",
"IMG_multisampled_render_to_texture\0")
COGL_EXT_FUNCTION (void, glRenderbufferStorageMultisampleIMG,
(GLenum target,
GLsizei samples,
GLenum internal_format,
GLsizei width,
GLsizei height))
COGL_EXT_FUNCTION (void, glFramebufferTexture2DMultisampleIMG,
(GLenum target,
GLenum attachment,
GLenum textarget,
GLuint texture,
GLint level,
GLsizei samples))
COGL_EXT_END ()

View file

@ -54,6 +54,12 @@ typedef struct
int samples_per_pixel;
} CoglFramebufferConfig;
/* Flags to pass to _cogl_offscreen_new_to_texture_full */
typedef enum
{
COGL_OFFSCREEN_DISABLE_DEPTH_AND_STENCIL = 1
} CoglOffscreenFlags;
struct _CoglFramebuffer
{
CoglObject _parent;
@ -121,13 +127,15 @@ typedef struct _CoglOffscreen
GSList *renderbuffers;
CoglTexture *texture;
} CoglOffscreen;
int texture_level;
int texture_level_width;
int texture_level_height;
/* Flags to pass to _cogl_offscreen_new_to_texture_full */
typedef enum
{
COGL_OFFSCREEN_DISABLE_DEPTH_AND_STENCIL = 1
} CoglOffscreenFlags;
/* FIXME: _cogl_offscreen_new_to_texture_full should be made to use
* fb->config to configure if we want a depth or stencil buffer so
* we can get rid of these flags */
CoglOffscreenFlags create_flags;
} CoglOffscreen;
#define COGL_OFFSCREEN(X) ((CoglOffscreen *)(X))

View file

@ -120,6 +120,12 @@ COGL_OBJECT_DEFINE_DEPRECATED_REF_COUNTING (offscreen);
* abstract class manually.
*/
GQuark
cogl_framebuffer_error_quark (void)
{
return g_quark_from_static_string ("cogl-framebuffer-error-quark");
}
gboolean
_cogl_is_framebuffer (void *object)
{
@ -681,144 +687,17 @@ _cogl_framebuffer_init_bits (CoglFramebuffer *framebuffer)
framebuffer->dirty_bitmasks = FALSE;
}
typedef struct
{
CoglTexture *texture;
unsigned int level;
unsigned int level_width;
unsigned int level_height;
} CoglFramebufferTryFBOData;
static gboolean
try_creating_fbo (CoglOffscreen *offscreen,
TryFBOFlags flags,
CoglFramebufferTryFBOData *data)
{
GLuint gl_depth_stencil_handle;
GLuint gl_depth_handle;
GLuint gl_stencil_handle;
GLuint tex_gl_handle;
GLenum tex_gl_target;
GLuint fbo_gl_handle;
GLenum status;
_COGL_GET_CONTEXT (ctx, FALSE);
if (!cogl_texture_get_gl_texture (data->texture,
&tex_gl_handle, &tex_gl_target))
return FALSE;
if (tex_gl_target != GL_TEXTURE_2D
#ifdef HAVE_COGL_GL
&& tex_gl_target != GL_TEXTURE_RECTANGLE_ARB
#endif
)
return FALSE;
/* We are about to generate and bind a new fbo, so we pretend to
* change framebuffer state so that the old framebuffer will be
* rebound again before drawing. */
ctx->dirty_bound_framebuffer = 1;
/* Generate framebuffer */
ctx->glGenFramebuffers (1, &fbo_gl_handle);
GE (ctx, glBindFramebuffer (GL_FRAMEBUFFER, fbo_gl_handle));
offscreen->fbo_handle = fbo_gl_handle;
GE (ctx, glFramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
tex_gl_target, tex_gl_handle, data->level));
if (flags & _TRY_DEPTH_STENCIL)
{
/* Create a renderbuffer for depth and stenciling */
GE (ctx, glGenRenderbuffers (1, &gl_depth_stencil_handle));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, gl_depth_stencil_handle));
GE (ctx, glRenderbufferStorage (GL_RENDERBUFFER, GL_DEPTH_STENCIL,
data->level_width,
data->level_height));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, 0));
GE (ctx, glFramebufferRenderbuffer (GL_FRAMEBUFFER,
GL_STENCIL_ATTACHMENT,
GL_RENDERBUFFER,
gl_depth_stencil_handle));
GE (ctx, glFramebufferRenderbuffer (GL_FRAMEBUFFER,
GL_DEPTH_ATTACHMENT,
GL_RENDERBUFFER,
gl_depth_stencil_handle));
offscreen->renderbuffers =
g_slist_prepend (offscreen->renderbuffers,
GUINT_TO_POINTER (gl_depth_stencil_handle));
}
if (flags & _TRY_DEPTH)
{
GE (ctx, glGenRenderbuffers (1, &gl_depth_handle));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, gl_depth_handle));
/* For now we just ask for GL_DEPTH_COMPONENT16 since this is all that's
* available under GLES */
GE (ctx, glRenderbufferStorage (GL_RENDERBUFFER, GL_DEPTH_COMPONENT16,
data->level_width,
data->level_height));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, 0));
GE (ctx, glFramebufferRenderbuffer (GL_FRAMEBUFFER,
GL_DEPTH_ATTACHMENT,
GL_RENDERBUFFER, gl_depth_handle));
offscreen->renderbuffers =
g_slist_prepend (offscreen->renderbuffers,
GUINT_TO_POINTER (gl_depth_handle));
}
if (flags & _TRY_STENCIL)
{
GE (ctx, glGenRenderbuffers (1, &gl_stencil_handle));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, gl_stencil_handle));
GE (ctx, glRenderbufferStorage (GL_RENDERBUFFER, GL_STENCIL_INDEX8,
data->level_width,
data->level_height));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, 0));
GE (ctx, glFramebufferRenderbuffer (GL_FRAMEBUFFER,
GL_STENCIL_ATTACHMENT,
GL_RENDERBUFFER, gl_stencil_handle));
offscreen->renderbuffers =
g_slist_prepend (offscreen->renderbuffers,
GUINT_TO_POINTER (gl_stencil_handle));
}
/* Make sure it's complete */
status = ctx->glCheckFramebufferStatus (GL_FRAMEBUFFER);
if (status != GL_FRAMEBUFFER_COMPLETE)
{
GSList *l;
GE (ctx, glDeleteFramebuffers (1, &fbo_gl_handle));
for (l = offscreen->renderbuffers; l; l = l->next)
{
GLuint renderbuffer = GPOINTER_TO_UINT (l->data);
GE (ctx, glDeleteRenderbuffers (1, &renderbuffer));
}
g_slist_free (offscreen->renderbuffers);
offscreen->renderbuffers = NULL;
return FALSE;
}
return TRUE;
}
CoglHandle
_cogl_offscreen_new_to_texture_full (CoglTexture *texture,
CoglOffscreenFlags create_flags,
unsigned int level)
{
CoglOffscreen *offscreen;
static TryFBOFlags flags;
static gboolean have_working_flags = FALSE;
unsigned int i;
CoglFramebufferTryFBOData data;
gboolean fbo_created;
CoglFramebuffer *fb;
int level_width;
int level_height;
int i;
CoglHandle ret;
_COGL_GET_CONTEXT (ctx, COGL_INVALID_HANDLE);
@ -833,98 +712,49 @@ _cogl_offscreen_new_to_texture_full (CoglTexture *texture,
if (cogl_texture_is_sliced (texture))
return COGL_INVALID_HANDLE;
data.texture = texture;
data.level = level;
/* Calculate the size of the texture at this mipmap level to ensure
that it's a valid level */
data.level_width = cogl_texture_get_width (texture);
data.level_height = cogl_texture_get_height (texture);
level_width = cogl_texture_get_width (texture);
level_height = cogl_texture_get_height (texture);
for (i = 0; i < level; i++)
{
/* If neither dimension can be further divided then the level is
invalid */
if (data.level_width == 1 && data.level_height == 1)
if (level_width == 1 && level_height == 1)
{
g_warning ("Invalid texture level passed to "
"_cogl_offscreen_new_to_texture_full");
return COGL_INVALID_HANDLE;
if (data.level_width > 1)
data.level_width >>= 1;
if (data.level_height > 1)
data.level_height >>= 1;
}
/* XXX: The framebuffer_object spec isn't clear in defining whether attaching
* a texture as a renderbuffer with mipmap filtering enabled while the
* mipmaps have not been uploaded should result in an incomplete framebuffer
* object. (different drivers make different decisions)
*
* To avoid an error with drivers that do consider this a problem we
* explicitly set non mipmapped filters here. These will later be reset when
* the texture is actually used for rendering according to the filters set on
* the corresponding CoglPipeline.
*/
_cogl_texture_set_filters (texture, GL_NEAREST, GL_NEAREST);
if (level_width > 1)
level_width >>= 1;
if (level_height > 1)
level_height >>= 1;
}
offscreen = g_new0 (CoglOffscreen, 1);
offscreen->texture = texture;
offscreen->texture = cogl_object_ref (texture);
offscreen->texture_level = level;
offscreen->texture_level_width = level_width;
offscreen->texture_level_height = level_height;
offscreen->create_flags = create_flags;
if ((create_flags & COGL_OFFSCREEN_DISABLE_DEPTH_AND_STENCIL))
fbo_created = try_creating_fbo (offscreen, 0, &data);
else
{
if ((have_working_flags &&
try_creating_fbo (offscreen, flags, &data)) ||
#ifdef HAVE_COGL_GL
(ctx->driver == COGL_DRIVER_GL &&
try_creating_fbo (offscreen, flags = _TRY_DEPTH_STENCIL, &data)) ||
#endif
try_creating_fbo (offscreen, flags = _TRY_DEPTH | _TRY_STENCIL,
&data) ||
try_creating_fbo (offscreen, flags = _TRY_STENCIL, &data) ||
try_creating_fbo (offscreen, flags = _TRY_DEPTH, &data) ||
try_creating_fbo (offscreen, flags = 0, &data))
{
/* Record that the last set of flags succeeded so that we can
try that set first next time */
have_working_flags = TRUE;
fbo_created = TRUE;
}
else
fbo_created = FALSE;
}
if (fbo_created)
{
CoglOffscreen *ret;
CoglFramebuffer *fb = COGL_FRAMEBUFFER (offscreen);
_COGL_GET_CONTEXT (ctx, COGL_INVALID_HANDLE);
fb = COGL_FRAMEBUFFER (offscreen);
_cogl_framebuffer_init (fb,
ctx,
COGL_FRAMEBUFFER_TYPE_OFFSCREEN,
cogl_texture_get_format (texture),
data.level_width,
data.level_height);
cogl_object_ref (offscreen->texture);
level_width,
level_height);
ret = _cogl_offscreen_object_new (offscreen);
_cogl_texture_associate_framebuffer (texture, COGL_FRAMEBUFFER (ret));
fb->allocated = TRUE;
_cogl_texture_associate_framebuffer (texture, fb);
return ret;
}
else
{
g_free (offscreen);
/* XXX: This API should probably have been defined to take a GError */
g_warning ("%s: Failed to create an OpenGL framebuffer", G_STRLOC);
return COGL_INVALID_HANDLE;
}
}
CoglHandle
@ -1028,6 +858,221 @@ cogl_onscreen_new (CoglContext *ctx, int width, int height)
return _cogl_onscreen_object_new (onscreen);
}
static gboolean
try_creating_fbo (CoglOffscreen *offscreen,
TryFBOFlags flags)
{
CoglFramebuffer *fb = COGL_FRAMEBUFFER (offscreen);
CoglContext *ctx = fb->context;
GLuint gl_depth_stencil_handle;
GLuint gl_depth_handle;
GLuint gl_stencil_handle;
GLuint tex_gl_handle;
GLenum tex_gl_target;
GLuint fbo_gl_handle;
GLenum status;
int n_samples;
int height;
int width;
if (!cogl_texture_get_gl_texture (offscreen->texture,
&tex_gl_handle, &tex_gl_target))
return FALSE;
if (tex_gl_target != GL_TEXTURE_2D
#ifdef HAVE_COGL_GL
&& tex_gl_target != GL_TEXTURE_RECTANGLE_ARB
#endif
)
return FALSE;
if (fb->config.samples_per_pixel)
{
if (!ctx->glFramebufferTexture2DMultisampleIMG)
return FALSE;
n_samples = fb->config.samples_per_pixel;
}
else
n_samples = 0;
width = offscreen->texture_level_width;
height = offscreen->texture_level_height;
/* We are about to generate and bind a new fbo, so we pretend to
* change framebuffer state so that the old framebuffer will be
* rebound again before drawing. */
ctx->dirty_bound_framebuffer = 1;
/* Generate framebuffer */
ctx->glGenFramebuffers (1, &fbo_gl_handle);
GE (ctx, glBindFramebuffer (GL_FRAMEBUFFER, fbo_gl_handle));
offscreen->fbo_handle = fbo_gl_handle;
if (n_samples)
{
GE (ctx, glFramebufferTexture2DMultisampleIMG (GL_FRAMEBUFFER,
GL_COLOR_ATTACHMENT0,
tex_gl_target, tex_gl_handle,
n_samples,
offscreen->texture_level));
}
else
GE (ctx, glFramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
tex_gl_target, tex_gl_handle,
offscreen->texture_level));
if (flags & _TRY_DEPTH_STENCIL)
{
/* Create a renderbuffer for depth and stenciling */
GE (ctx, glGenRenderbuffers (1, &gl_depth_stencil_handle));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, gl_depth_stencil_handle));
if (n_samples)
GE (ctx, glRenderbufferStorageMultisampleIMG (GL_RENDERBUFFER,
n_samples,
GL_DEPTH_STENCIL,
width, height));
else
GE (ctx, glRenderbufferStorage (GL_RENDERBUFFER, GL_DEPTH_STENCIL,
width, height));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, 0));
GE (ctx, glFramebufferRenderbuffer (GL_FRAMEBUFFER,
GL_STENCIL_ATTACHMENT,
GL_RENDERBUFFER,
gl_depth_stencil_handle));
GE (ctx, glFramebufferRenderbuffer (GL_FRAMEBUFFER,
GL_DEPTH_ATTACHMENT,
GL_RENDERBUFFER,
gl_depth_stencil_handle));
offscreen->renderbuffers =
g_slist_prepend (offscreen->renderbuffers,
GUINT_TO_POINTER (gl_depth_stencil_handle));
}
if (flags & _TRY_DEPTH)
{
GE (ctx, glGenRenderbuffers (1, &gl_depth_handle));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, gl_depth_handle));
/* For now we just ask for GL_DEPTH_COMPONENT16 since this is all that's
* available under GLES */
if (n_samples)
GE (ctx, glRenderbufferStorageMultisampleIMG (GL_RENDERBUFFER,
n_samples,
GL_DEPTH_COMPONENT16,
width, height));
else
GE (ctx, glRenderbufferStorage (GL_RENDERBUFFER, GL_DEPTH_COMPONENT16,
width, height));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, 0));
GE (ctx, glFramebufferRenderbuffer (GL_FRAMEBUFFER,
GL_DEPTH_ATTACHMENT,
GL_RENDERBUFFER, gl_depth_handle));
offscreen->renderbuffers =
g_slist_prepend (offscreen->renderbuffers,
GUINT_TO_POINTER (gl_depth_handle));
}
if (flags & _TRY_STENCIL)
{
GE (ctx, glGenRenderbuffers (1, &gl_stencil_handle));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, gl_stencil_handle));
if (n_samples)
GE (ctx, glRenderbufferStorageMultisampleIMG (GL_RENDERBUFFER,
n_samples,
GL_STENCIL_INDEX8,
width, height));
else
GE (ctx, glRenderbufferStorage (GL_RENDERBUFFER, GL_STENCIL_INDEX8,
width, height));
GE (ctx, glBindRenderbuffer (GL_RENDERBUFFER, 0));
GE (ctx, glFramebufferRenderbuffer (GL_FRAMEBUFFER,
GL_STENCIL_ATTACHMENT,
GL_RENDERBUFFER, gl_stencil_handle));
offscreen->renderbuffers =
g_slist_prepend (offscreen->renderbuffers,
GUINT_TO_POINTER (gl_stencil_handle));
}
/* Make sure it's complete */
status = ctx->glCheckFramebufferStatus (GL_FRAMEBUFFER);
if (status != GL_FRAMEBUFFER_COMPLETE)
{
GSList *l;
GE (ctx, glDeleteFramebuffers (1, &fbo_gl_handle));
for (l = offscreen->renderbuffers; l; l = l->next)
{
GLuint renderbuffer = GPOINTER_TO_UINT (l->data);
GE (ctx, glDeleteRenderbuffers (1, &renderbuffer));
}
g_slist_free (offscreen->renderbuffers);
offscreen->renderbuffers = NULL;
return FALSE;
}
return TRUE;
}
static gboolean
_cogl_offscreen_allocate (CoglOffscreen *offscreen,
GError **error)
{
CoglFramebuffer *fb = COGL_FRAMEBUFFER (offscreen);
CoglContext *ctx = fb->context;
static TryFBOFlags flags;
static gboolean have_working_flags = FALSE;
gboolean fbo_created;
/* XXX: The framebuffer_object spec isn't clear in defining whether attaching
* a texture as a renderbuffer with mipmap filtering enabled while the
* mipmaps have not been uploaded should result in an incomplete framebuffer
* object. (different drivers make different decisions)
*
* To avoid an error with drivers that do consider this a problem we
* explicitly set non mipmapped filters here. These will later be reset when
* the texture is actually used for rendering according to the filters set on
* the corresponding CoglPipeline.
*/
_cogl_texture_set_filters (offscreen->texture, GL_NEAREST, GL_NEAREST);
if ((offscreen->create_flags & COGL_OFFSCREEN_DISABLE_DEPTH_AND_STENCIL))
fbo_created = try_creating_fbo (offscreen, 0);
else
{
if ((have_working_flags &&
try_creating_fbo (offscreen, flags)) ||
#ifdef HAVE_COGL_GL
(ctx->driver == COGL_DRIVER_GL &&
try_creating_fbo (offscreen, flags = _TRY_DEPTH_STENCIL)) ||
#endif
try_creating_fbo (offscreen, flags = _TRY_DEPTH | _TRY_STENCIL) ||
try_creating_fbo (offscreen, flags = _TRY_STENCIL) ||
try_creating_fbo (offscreen, flags = _TRY_DEPTH) ||
try_creating_fbo (offscreen, flags = 0))
{
/* Record that the last set of flags succeeded so that we can
try that set first next time */
have_working_flags = TRUE;
fbo_created = TRUE;
}
else
fbo_created = FALSE;
}
if (!fbo_created)
{
g_set_error (error, COGL_FRAMEBUFFER_ERROR,
COGL_FRAMEBUFFER_ERROR_ALLOCATE,
"Failed to create an OpenGL framebuffer object");
return FALSE;
}
return TRUE;
}
gboolean
cogl_framebuffer_allocate (CoglFramebuffer *framebuffer,
GError **error)
@ -1038,13 +1083,16 @@ cogl_framebuffer_allocate (CoglFramebuffer *framebuffer,
if (framebuffer->allocated)
return TRUE;
/* XXX: with the current cogl_offscreen_new_to_texture() API the
* framebuffer is implicitly allocated before returning. */
g_return_val_if_fail (framebuffer->type == COGL_FRAMEBUFFER_TYPE_ONSCREEN,
TRUE);
if (framebuffer->type == COGL_FRAMEBUFFER_TYPE_ONSCREEN)
{
if (!winsys->onscreen_init (onscreen, error))
return FALSE;
}
else
{
if (!_cogl_offscreen_allocate (COGL_OFFSCREEN (framebuffer), error))
return FALSE;
}
framebuffer->allocated = TRUE;
@ -1591,6 +1639,61 @@ cogl_framebuffer_get_color_format (CoglFramebuffer *framebuffer)
return framebuffer->format;
}
void
cogl_framebuffer_set_samples_per_pixel (CoglFramebuffer *framebuffer,
int samples_per_pixel)
{
g_return_if_fail (!framebuffer->allocated);
framebuffer->config.samples_per_pixel = samples_per_pixel;
}
void
cogl_framebuffer_resolve_samples (CoglFramebuffer *framebuffer)
{
cogl_framebuffer_resolve_samples_region (framebuffer,
0, 0,
framebuffer->width,
framebuffer->height);
/* TODO: Make this happen implicitly when the resolve texture next gets used
* as a source, either via cogl_texture_get_data(), via cogl_read_pixels() or
* if used as a source for rendering. We would also implicitly resolve if
* necessary before freeing a CoglFramebuffer.
*
* This API should still be kept but it is optional, only necessary
* if the user wants to explicitly control when the resolve happens e.g.
* to ensure it's done in advance of it being used as a source.
*
* Every texture should have a CoglFramebuffer *needs_resolve member
* internally. When the texture gets validated before being used as a source
* we should first check the needs_resolve pointer and if set we'll
* automatically call cogl_framebuffer_resolve_samples ().
*
* Calling cogl_framebuffer_resolve_samples() or
* cogl_framebuffer_resolve_samples_region() should reset the textures
* needs_resolve pointer to NULL.
*
* Rendering anything to a framebuffer will cause the corresponding
* texture's ->needs_resolve pointer to be set.
*
* XXX: Note: we only need to address this TODO item when adding support for
* EXT_framebuffer_multisample because currently we only support hardware
* that resolves implicitly anyway.
*/
}
void
cogl_framebuffer_resolve_samples_region (CoglFramebuffer *framebuffer,
int x,
int y,
int width,
int height)
{
/* NOP for now since we don't support EXT_framebuffer_multisample yet which
* requires an explicit resolve. */
}
CoglContext *
cogl_framebuffer_get_context (CoglFramebuffer *framebuffer)
{

View file

@ -277,6 +277,128 @@ cogl_framebuffer_set_color_mask (CoglFramebuffer *framebuffer,
CoglPixelFormat
cogl_framebuffer_get_color_format (CoglFramebuffer *framebuffer);
#define cogl_framebuffer_set_samples_per_pixel \
cogl_framebuffer_set_samples_per_pixel_EXP
/**
* cogl_framebuffer_set_samples_per_pixel:
* @framebuffer: A #CoglFramebuffer framebuffer
* @n: The minimum number of samples per pixel
*
* Requires that when rendering to @framebuffer then @n point samples
* should be made per pixel which will all contribute to the final
* resolved color for that pixel. The idea is that the hardware aims
* to get quality similar to what you would get if you rendered
* everything twice as big (for 4 samples per pixel) and then scaled
* that image back down with filtering. It can effectively remove the
* jagged edges of polygons and should be more efficient than if you
* were to manually render at a higher resolution and downscale
* because the hardware is often able to take some shortcuts. For
* example the GPU may only calculate a single texture sample for all
* points of a single pixel, and for tile based architectures all the
* extra sample data (such as depth and stencil samples) may be
* handled on-chip and so avoid increased demand on system memory
* bandwidth.
*
* By default this value is usually set to 0 and that is referred to
* as "single-sample" rendering. A value of 1 or greater is referred
* to as "multisample" rendering.
*
* <note>There are some semantic differences between single-sample
* rendering and multisampling with just 1 point sample such as it
* being redundant to use the cogl_framebuffer_resolve_samples() and
* cogl_framebuffer_resolve_samples_region() apis with single-sample
* rendering.</note>
*
* <note>It's recommended that
* cogl_framebuffer_resolve_samples_region() be explicitly used at the
* end of rendering to a point sample buffer to minimize the number of
* samples that get resolved. By default Cogl will implicitly resolve
* all framebuffer samples but if only a small region of a
* framebuffer has changed this can lead to redundant work being
* done.</note>
*
* Since: 1.8
* Stability: unstable
*/
void
cogl_framebuffer_set_samples_per_pixel (CoglFramebuffer *framebuffer,
int samples_per_pixel);
#define cogl_framebuffer_resolve_samples \
cogl_framebuffer_resolve_samples_EXP
/**
* cogl_framebuffer_resolve_samples:
* @framebuffer: A #CoglFramebuffer framebuffer
*
* When point sample rendering (also known as multisample rendering)
* has been enabled via cogl_framebuffer_set_samples_per_pixel()
* then you can optionally call this function (or
* cogl_framebuffer_resolve_samples_region()) to explicitly resolve
* the point samples into values for the final color buffer.
*
* Some GPUs will implicitly resolve the point samples during
* rendering and so this function is effectively a nop, but with other
* architectures it is desirable to defer the resolve step until the
* end of the frame.
*
* Since Cogl will automatically ensure samples are resolved if the
* target color buffer is used as a source this API only needs to be
* used if explicit control is desired - perhaps because you want to
* ensure that the resolve is completed in advance to avoid later
* having to wait for the resolve to complete.
*
* If you are performing incremental updates to a framebuffer you
* should consider using cogl_framebuffer_resolve_samples_region()
* instead to avoid resolving redundant pixels.
*
* Since: 1.8
* Stability: unstable
*/
void
cogl_framebuffer_resolve_samples (CoglFramebuffer *framebuffer);
#define cogl_framebuffer_resolve_samples_region \
cogl_framebuffer_resolve_samples_region_EXP
/**
* cogl_framebuffer_resolve_samples_region:
* @framebuffer: A #CoglFramebuffer framebuffer
* @x: top-left x coordinate of region to resolve
* @y: top-left y coordinate of region to resolve
* @width: width of region to resolve
* @height: height of region to resolve
*
* When point sample rendering (also known as multisample rendering)
* has been enabled via cogl_framebuffer_set_samples_per_pixel()
* then you can optionally call this function (or
* cogl_framebuffer_resolve_samples()) to explicitly resolve the point
* samples into values for the final color buffer.
*
* Some GPUs will implicitly resolve the point samples during
* rendering and so this function is effectively a nop, but with other
* architectures it is desirable to defer the resolve step until the
* end of the frame.
*
* Use of this API is recommended if incremental, small updates to
* a framebuffer are being made because by default Cogl will
* implicitly resolve all the point samples of the framebuffer which
* can result in redundant work if only a small number of samples have
* changed.
*
* Because some GPUs implicitly resolve point samples this function
* only guarantees that at-least the region specified will be resolved
* and if you have rendered to a larger region then it's possible that
* other samples may be implicitly resolved.
*
* Since: 1.8
* Stability: unstable
*/
void
cogl_framebuffer_resolve_samples_region (CoglFramebuffer *framebuffer,
int x,
int y,
int width,
int height);
#define cogl_framebuffer_get_context cogl_framebuffer_get_context_EXP
/**
* @framebuffer: A #CoglFramebuffer
@ -598,6 +720,19 @@ cogl_get_draw_framebuffer (void);
#endif /* COGL_ENABLE_EXPERIMENTAL_API */
/* XXX: Note these are defined outside the COGL_ENABLE_EXPERIMENTAL_API guard since
* otherwise the glib-mkenums stuff will get upset. */
#define cogl_framebuffer_error_quark cogl_framebuffer_error_quark_EXP
GQuark
cogl_framebuffer_error_quark (void);
#define COGL_FRAMEBUFFER_ERROR (cogl_framebuffer_error_quark ())
typedef enum { /*< prefix=COGL_FRAMEBUFFER_ERROR >*/
COGL_FRAMEBUFFER_ERROR_ALLOCATE
} CoglFramebufferError;
G_END_DECLS
#endif /* __COGL_FRAMEBUFFER_H */

View file

@ -202,7 +202,7 @@ _cogl_gl_update_features (CoglContext *context,
if (context->glBlitFramebuffer)
flags |= COGL_FEATURE_OFFSCREEN_BLIT;
if (context->glRenderbufferStorageMultisample)
if (context->glRenderbufferStorageMultisampleIMG)
flags |= COGL_FEATURE_OFFSCREEN_MULTISAMPLE;
if (COGL_CHECK_GL_VERSION (gl_major, gl_minor, 2, 1) ||