mutter/cogl/cogl-framebuffer-private.h
Robert Bragg 92c3063014 framebuffer: Add cogl_framebuffer draw methods
This adds cogl_framebuffer_ apis for drawing attributes and primitives
that replace corresponding apis that depend on the default CoglContext.
This is part of the on going effort to adapt the Cogl api so it no
longer depends on a global context variable.

All the new drawing functions also take an explicit pipeline argument
since we are also aiming to avoid being a stateful api like Cairo and
OpenGL. Being stateless makes it easier for orthogonal components to
share access to the GPU. Being stateless should also minimize any
impedance miss-match for those wanting to build higher level stateless
apis on top of Cogl.

Note: none of the legacy, global state options such as
cogl_set_depth_test_enabled(), cogl_set_backface_culling_enabled() or
cogl_program_use() are supported by these new drawing apis and if set
will simply be silently ignored.

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-02-09 13:09:15 +00:00

402 lines
14 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"
#include "cogl-winsys-private.h"
#include "cogl-attribute-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
typedef enum _CoglFramebufferType {
COGL_FRAMEBUFFER_TYPE_ONSCREEN,
COGL_FRAMEBUFFER_TYPE_OFFSCREEN
} CoglFramebufferType;
typedef struct
{
CoglSwapChain *swap_chain;
gboolean need_stencil;
int samples_per_pixel;
gboolean swap_throttled;
} CoglFramebufferConfig;
/* Flags to pass to _cogl_offscreen_new_to_texture_full */
typedef enum
{
COGL_OFFSCREEN_DISABLE_DEPTH_AND_STENCIL = 1
} CoglOffscreenFlags;
/* XXX: The order of these indices determines the order they are
* flushed.
*
* Flushing clip state may trash the modelview and projection matrices
* so we must do it before flushing the matrices.
*/
typedef enum _CoglFramebufferStateIndex
{
COGL_FRAMEBUFFER_STATE_INDEX_BIND = 0,
COGL_FRAMEBUFFER_STATE_INDEX_VIEWPORT = 1,
COGL_FRAMEBUFFER_STATE_INDEX_CLIP = 2,
COGL_FRAMEBUFFER_STATE_INDEX_DITHER = 3,
COGL_FRAMEBUFFER_STATE_INDEX_MODELVIEW = 4,
COGL_FRAMEBUFFER_STATE_INDEX_PROJECTION = 5,
COGL_FRAMEBUFFER_STATE_INDEX_COLOR_MASK = 6,
COGL_FRAMEBUFFER_STATE_INDEX_FRONT_FACE_WINDING = 7,
COGL_FRAMEBUFFER_STATE_INDEX_MAX = 8
} CoglFramebufferStateIndex;
typedef enum _CoglFramebufferState
{
COGL_FRAMEBUFFER_STATE_BIND = 1<<0,
COGL_FRAMEBUFFER_STATE_VIEWPORT = 1<<1,
COGL_FRAMEBUFFER_STATE_CLIP = 1<<2,
COGL_FRAMEBUFFER_STATE_DITHER = 1<<3,
COGL_FRAMEBUFFER_STATE_MODELVIEW = 1<<4,
COGL_FRAMEBUFFER_STATE_PROJECTION = 1<<5,
COGL_FRAMEBUFFER_STATE_COLOR_MASK = 1<<6,
COGL_FRAMEBUFFER_STATE_FRONT_FACE_WINDING = 1<<7
} CoglFramebufferState;
#define COGL_FRAMEBUFFER_STATE_ALL ((1<<COGL_FRAMEBUFFER_STATE_INDEX_MAX) - 1)
struct _CoglFramebuffer
{
CoglObject _parent;
CoglContext *context;
CoglFramebufferType type;
/* The user configuration before allocation... */
CoglFramebufferConfig config;
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;
int samples_per_pixel;
/* 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;
int texture_level;
int texture_level_width;
int texture_level_height;
/* 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))
void
_cogl_framebuffer_init (CoglFramebuffer *framebuffer,
CoglContext *ctx,
CoglFramebufferType type,
CoglPixelFormat format,
int width,
int height);
void _cogl_framebuffer_free (CoglFramebuffer *framebuffer);
const CoglWinsysVtable *
_cogl_framebuffer_get_winsys (CoglFramebuffer *framebuffer);
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);
void
_cogl_framebuffer_flush_state (CoglFramebuffer *draw_buffer,
CoglFramebuffer *read_buffer,
CoglFramebufferState state);
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_PRIVATE_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);
void
_cogl_framebuffer_push_projection (CoglFramebuffer *framebuffer);
void
_cogl_framebuffer_pop_projection (CoglFramebuffer *framebuffer);
void
_cogl_framebuffer_save_clip_stack (CoglFramebuffer *framebuffer);
void
_cogl_framebuffer_restore_clip_stack (CoglFramebuffer *framebuffer);
void
_cogl_framebuffer_unref (CoglFramebuffer *framebuffer);
void
_cogl_framebuffer_draw_primitive (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
CoglPrimitive *primitive,
CoglDrawFlags flags);
/* This can be called directly by the CoglJournal to draw attributes
* skipping the implicit journal flush, the framebuffer flush and
* pipeline validation. */
void
_cogl_framebuffer_draw_attributes (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
CoglVerticesMode mode,
int first_vertex,
int n_vertices,
CoglAttribute **attributes,
int n_attributes,
CoglDrawFlags flags);
void
_cogl_framebuffer_draw_indexed_attributes (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
CoglVerticesMode mode,
int first_vertex,
int n_vertices,
CoglIndices *indices,
CoglAttribute **attributes,
int n_attributes,
CoglDrawFlags flags);
#endif /* __COGL_FRAMEBUFFER_PRIVATE_H */