mutter/cogl/cogl-framebuffer-private.h
Robert Bragg 4c3dadd35e Add a strong CoglTexture type to replace CoglHandle
As part of the on going, incremental effort to purge the non type safe
CoglHandle type from the Cogl API this patch tackles most of the
CoglHandle uses relating to textures.

We'd postponed making this change for quite a while because we wanted to
have a clearer understanding of how we wanted to evolve the texture APIs
towards Cogl 2.0 before exposing type safety here which would be
difficult to change later since it would imply breaking APIs.

The basic idea that we are steering towards now is that CoglTexture
can be considered to be the most primitive interface we have for any
object representing a texture. The texture interface would provide
roughly these methods:

  cogl_texture_get_width
  cogl_texture_get_height
  cogl_texture_can_repeat
  cogl_texture_can_mipmap
  cogl_texture_generate_mipmap;
  cogl_texture_get_format
  cogl_texture_set_region
  cogl_texture_get_region

Besides the texture interface we will then start to expose types
corresponding to specific texture types: CoglTexture2D,
CoglTexture3D, CoglTexture2DSliced, CoglSubTexture, CoglAtlasTexture and
CoglTexturePixmapX11.

We will then also expose an interface for the high-level texture types
we have (such as CoglTexture2DSlice, CoglSubTexture and
CoglAtlasTexture) called CoglMetaTexture. CoglMetaTexture is an
additional interface that lets you iterate a virtual region of a meta
texture and get mappings of primitive textures to sub-regions of that
virtual region. Internally we already have this kind of abstraction for
dealing with sliced texture, sub-textures and atlas textures in a
consistent way, so this will just make that abstraction public. The aim
here is to clarify that there is a difference between primitive textures
(CoglTexture2D/3D) and some of the other high-level textures, and also
enable developers to implement primitives that can support meta textures
since they can only be used with the cogl_rectangle API currently.

The thing that's not so clean-cut with this are the texture constructors
we have currently; such as cogl_texture_new_from_file which no longer
make sense when CoglTexture is considered to be an interface.  These
will basically just become convenient factory functions and it's just a
bit unusual that they are within the cogl_texture namespace.  It's worth
noting here that all the texture type APIs will also have their own type
specific constructors so these functions will only be used for the
convenience of being able to create a texture without really wanting to
know the details of what type of texture you need.  Longer term for 2.0
we may come up with replacement names for these factory functions or the
other thing we are considering is designing some asynchronous factory
functions instead since it's so often detrimental to application
performance to be blocked waiting for a texture to be uploaded to the
GPU.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-09-21 15:27:03 +01:00

336 lines
11 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
*
*/
#ifndef __COGL_FRAMEBUFFER_PRIVATE_H
#define __COGL_FRAMEBUFFER_PRIVATE_H
#include "cogl-object-private.h"
#include "cogl-matrix-stack.h"
#include "cogl-clip-state-private.h"
#include "cogl-journal-private.h"
#ifdef COGL_HAS_XLIB_SUPPORT
#include <X11/Xlib.h>
#endif
#ifdef COGL_HAS_GLX_SUPPORT
#include <GL/glx.h>
#include <GL/glxext.h>
#endif
#ifdef COGL_HAS_WIN32_SUPPORT
#include <windows.h>
#endif
typedef enum _CoglFramebufferType {
COGL_FRAMEBUFFER_TYPE_ONSCREEN,
COGL_FRAMEBUFFER_TYPE_OFFSCREEN
} CoglFramebufferType;
struct _CoglFramebuffer
{
CoglObject _parent;
CoglContext *context;
CoglFramebufferType type;
int width;
int height;
/* Format of the pixels in the framebuffer (including the expected
premult state) */
CoglPixelFormat format;
gboolean allocated;
CoglMatrixStack *modelview_stack;
CoglMatrixStack *projection_stack;
float viewport_x;
float viewport_y;
float viewport_width;
float viewport_height;
CoglClipState clip_state;
gboolean dirty_bitmasks;
int red_bits;
int blue_bits;
int green_bits;
int alpha_bits;
gboolean dither_enabled;
CoglColorMask color_mask;
/* We journal the textured rectangles we want to submit to OpenGL so
* we have an oppertunity to batch them together into less draw
* calls. */
CoglJournal *journal;
/* The scene of a given framebuffer may depend on images in other
* framebuffers... */
GList *deps;
/* As part of an optimization for reading-back single pixels from a
* framebuffer in some simple cases where the geometry is still
* available in the journal we need to track the bounds of the last
* region cleared, its color and we need to track when something
* does in fact draw to that region so it is no longer clear.
*/
float clear_color_red;
float clear_color_green;
float clear_color_blue;
float clear_color_alpha;
int clear_clip_x0;
int clear_clip_y0;
int clear_clip_x1;
int clear_clip_y1;
gboolean clear_clip_dirty;
};
typedef struct _CoglOffscreen
{
CoglFramebuffer _parent;
GLuint fbo_handle;
GSList *renderbuffers;
CoglTexture *texture;
} CoglOffscreen;
/* Flags to pass to _cogl_offscreen_new_to_texture_full */
typedef enum
{
COGL_OFFSCREEN_DISABLE_DEPTH_AND_STENCIL = 1
} CoglOffscreenFlags;
#define COGL_OFFSCREEN(X) ((CoglOffscreen *)(X))
struct _CoglOnscreen
{
CoglFramebuffer _parent;
#ifdef COGL_HAS_X11_SUPPORT
guint32 foreign_xid;
CoglOnscreenX11MaskCallback foreign_update_mask_callback;
void *foreign_update_mask_data;
#endif
#ifdef COGL_HAS_WIN32_SUPPORT
HWND foreign_hwnd;
#endif
gboolean swap_throttled;
void *winsys;
};
void
_cogl_framebuffer_state_init (void);
void
_cogl_framebuffer_winsys_update_size (CoglFramebuffer *framebuffer,
int width, int height);
void
_cogl_framebuffer_clear_without_flush4f (CoglFramebuffer *framebuffer,
unsigned long buffers,
float red,
float green,
float blue,
float alpha);
void
_cogl_framebuffer_dirty (CoglFramebuffer *framebuffer);
CoglClipState *
_cogl_framebuffer_get_clip_state (CoglFramebuffer *framebuffer);
/*
* _cogl_framebuffer_get_clip_stack:
* @framebuffer: A #CoglFramebuffer
*
* Gets a pointer to the current clip stack. This can be used to later
* return to the same clip stack state with
* _cogl_framebuffer_set_clip_stack(). A reference is not taken on the
* stack so if you want to keep it you should call
* _cogl_clip_stack_ref().
*
* Return value: a pointer to the @framebuffer clip stack.
*/
CoglClipStack *
_cogl_framebuffer_get_clip_stack (CoglFramebuffer *framebuffer);
/*
* _cogl_framebuffer_set_clip_stack:
* @framebuffer: A #CoglFramebuffer
* @stack: a pointer to the replacement clip stack
*
* Replaces the @framebuffer clip stack with @stack.
*/
void
_cogl_framebuffer_set_clip_stack (CoglFramebuffer *framebuffer,
CoglClipStack *stack);
CoglMatrixStack *
_cogl_framebuffer_get_modelview_stack (CoglFramebuffer *framebuffer);
CoglMatrixStack *
_cogl_framebuffer_get_projection_stack (CoglFramebuffer *framebuffer);
void
_cogl_framebuffer_add_dependency (CoglFramebuffer *framebuffer,
CoglFramebuffer *dependency);
void
_cogl_framebuffer_remove_all_dependencies (CoglFramebuffer *framebuffer);
void
_cogl_framebuffer_flush_journal (CoglFramebuffer *framebuffer);
void
_cogl_framebuffer_flush_dependency_journals (CoglFramebuffer *framebuffer);
gboolean
_cogl_framebuffer_try_fast_read_pixel (CoglFramebuffer *framebuffer,
int x,
int y,
CoglReadPixelsFlags source,
CoglPixelFormat format,
guint8 *pixel);
typedef enum _CoglFramebufferFlushFlags
{
/* XXX: When using this, that imples you are going to manually load the
* modelview matrix (via glLoadMatrix). _cogl_matrix_stack_flush_to_gl wont
* be called for framebuffer->modelview_stack, and the modelview_stack will
* also be marked as dirty. */
COGL_FRAMEBUFFER_FLUSH_SKIP_MODELVIEW = 1L<<0,
/* Similarly this flag implies you are going to flush the clip state
yourself */
COGL_FRAMEBUFFER_FLUSH_SKIP_CLIP_STATE = 1L<<1,
/* When using this all that will be updated is the glBindFramebuffer
* state and corresponding winsys state to make the framebuffer
* current if it is a CoglOnscreen framebuffer. */
COGL_FRAMEBUFFER_FLUSH_BIND_ONLY = 1L<<2
} CoglFramebufferFlushFlags;
void
_cogl_framebuffer_flush_state (CoglFramebuffer *draw_buffer,
CoglFramebuffer *read_buffer,
CoglFramebufferFlushFlags flags);
CoglFramebuffer *
_cogl_get_read_framebuffer (void);
GSList *
_cogl_create_framebuffer_stack (void);
void
_cogl_free_framebuffer_stack (GSList *stack);
/*
* _cogl_offscreen_new_to_texture_full:
* @texture: A #CoglTexture pointer
* @create_flags: Flags specifying how to create the FBO
* @level: The mipmap level within the texture to target
*
* Creates a new offscreen buffer which will target the given
* texture. By default the buffer will have a depth and stencil
* buffer. This can be disabled by passing
* %COGL_OFFSCREEN_DISABLE_DEPTH_AND_STENCIL in @create_flags.
*
* Return value: the new CoglOffscreen object.
*/
CoglHandle
_cogl_offscreen_new_to_texture_full (CoglTexture *texture,
CoglOffscreenFlags create_flags,
unsigned int level);
/*
* _cogl_push_framebuffers:
* @draw_buffer: A pointer to the buffer used for drawing
* @read_buffer: A pointer to the buffer used for reading back pixels
*
* Redirects drawing and reading to the specified framebuffers as in
* cogl_push_framebuffer() except that it allows the draw and read
* buffer to be different. The buffers are pushed as a pair so that
* they can later both be restored with a single call to
* cogl_pop_framebuffer().
*/
void
_cogl_push_framebuffers (CoglFramebuffer *draw_buffer,
CoglFramebuffer *read_buffer);
/*
* _cogl_blit_framebuffer:
* @src_x: Source x position
* @src_y: Source y position
* @dst_x: Destination x position
* @dst_y: Destination y position
* @width: Width of region to copy
* @height: Height of region to copy
*
* This blits a region of the color buffer of the current draw buffer
* to the current read buffer. The draw and read buffers can be set up
* using _cogl_push_framebuffers(). This function should only be
* called if the COGL_FEATURE_OFFSCREEN_BLIT feature is
* advertised. The two buffers must both be offscreen and have the
* same format.
*
* Note that this function differs a lot from the glBlitFramebuffer
* function provided by the GL_EXT_framebuffer_blit extension. Notably
* it doesn't support having different sizes for the source and
* destination rectangle. This isn't supported by the corresponding
* GL_ANGLE_framebuffer_blit extension on GLES2.0 and it doesn't seem
* like a particularly useful feature. If the application wanted to
* scale the results it may make more sense to draw a primitive
* instead.
*
* We can only really support blitting between two offscreen buffers
* for this function on GLES2.0. This is because we effectively render
* upside down to offscreen buffers to maintain Cogl's representation
* of the texture coordinate system where 0,0 is the top left of the
* texture. If we were to blit from an offscreen to an onscreen buffer
* then we would need to mirror the blit along the x-axis but the GLES
* extension does not support this.
*
* The GL function is documented to be affected by the scissor. This
* function therefore ensure that an empty clip stack is flushed
* before performing the blit which means the scissor is effectively
* ignored.
*
* The function also doesn't support specifying the buffers to copy
* and instead only the color buffer is copied. When copying the depth
* or stencil buffers the extension on GLES2.0 only supports copying
* the full buffer which would be awkward to document with this
* API. If we wanted to support that feature it may be better to have
* a separate function to copy the entire buffer for a given mask.
*/
void
_cogl_blit_framebuffer (unsigned int src_x,
unsigned int src_y,
unsigned int dst_x,
unsigned int dst_y,
unsigned int width,
unsigned int height);
CoglOnscreen *
_cogl_onscreen_new (void);
#endif /* __COGL_FRAMEBUFFER_PRIVATE_H */