mutter/clutter/cogl/gl/cogl-texture-private.h
Robert Bragg 845ff67301 [cogl] Improving Cogl journal to minimize driver overheads + GPU state changes
Previously the journal was always flushed at the end of
_cogl_rectangles_with_multitexture_coords, (i.e.  the end of any
cogl_rectangle* calls) but now we have broadened the potential for batching
geometry.  In ideal circumstances we will only flush once per scene.

In summary the journal works like this:

When you use any of the cogl_rectangle* APIs then nothing is emitted to the
GPU at this point, we just log one or more quads into the journal.  A
journal entry consists of the quad coordinates, an associated material
reference, and a modelview matrix.  Ideally the journal only gets flushed
once at the end of a scene, but in fact there are things to consider that
may cause unwanted flushing, including:

- modifying materials mid-scene
    This is because each quad in the journal has an associated material
    reference (i.e. not copy), so if you try and modify a material that is
    already referenced in the journal we force a flush first)

    NOTE: For now this means you should avoid using cogl_set_source_color()
	      since that currently uses a single shared material. Later we
	  should change it to use a pool of materials that is recycled
	  when the journal is flushed.

- modifying any state that isn't currently logged, such as depth, fog and
  backface culling enables.

The first thing that happens when flushing, is to upload all the vertex data
associated with the journal into a single VBO.

We then go through a process of splitting up the journal into batches that
have compatible state so they can be emitted to the GPU together.  This is
currently broken up into 3 levels so we can stagger the state changes:

1) we break the journal up according to changes in the number of material layers
   associated with logged quads. The number of layers in a material determines
   the stride of the associated vertices, so we have to update our vertex
   array offsets at this level. (i.e. calling gl{Vertex,Color},Pointer etc)
2) we further split batches up according to material compatability. (e.g.
   materials with different textures) We flush material state at this level.
3) Finally we split batches up according to modelview changes. At this level
   we update the modelview matrix and actually emit the actual draw command.

This commit is largely about putting the initial design in-place; this will be
followed by other changes that take advantage of the extended batching.
2009-06-30 17:13:34 +01:00

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4.3 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef __COGL_TEXTURE_H
#define __COGL_TEXTURE_H
#include "cogl-bitmap-private.h"
#include "cogl-handle.h"
#include "cogl-material-private.h"
typedef struct _CoglTexture CoglTexture;
typedef struct _CoglTexSliceSpan CoglTexSliceSpan;
typedef struct _CoglSpanIter CoglSpanIter;
typedef struct _CoglTexturePixel CoglTexturePixel;
struct _CoglTexSliceSpan
{
gint start;
gint size;
gint waste;
};
struct _CoglSpanIter
{
gint index;
GArray *array;
CoglTexSliceSpan *span;
float pos;
float next_pos;
float origin;
float cover_start;
float cover_end;
float intersect_start;
float intersect_end;
float intersect_start_local;
float intersect_end_local;
gboolean intersects;
};
/* This is used to store the first pixel of each slice. This is only
used when glGenerateMipmap is not available */
struct _CoglTexturePixel
{
/* We need to store the format of the pixel because we store the
data in the source format which might end up being different for
each slice if a subregion is updated with a different format */
GLenum gl_format;
GLenum gl_type;
guint8 data[4];
};
struct _CoglTexture
{
CoglHandleObject _parent;
CoglBitmap bitmap;
gboolean bitmap_owner;
GLenum gl_target;
GLenum gl_intformat;
GLenum gl_format;
GLenum gl_type;
GArray *slice_x_spans;
GArray *slice_y_spans;
GArray *slice_gl_handles;
gint max_waste;
GLenum min_filter;
GLenum mag_filter;
gboolean is_foreign;
GLint wrap_mode;
gboolean auto_mipmap;
gboolean mipmaps_dirty;
/* This holds a copy of the first pixel in each slice. It is only
used to force an automatic update of the mipmaps when
glGenerateMipmap is not available. */
CoglTexturePixel *first_pixels;
};
/* To improve batching of geometry when submitting vertices to OpenGL we
* log the texture rectangles we want to draw to a journal, so when we
* later flush the journal we aim to batch data, and gl draw calls. */
typedef struct _CoglJournalEntry
{
CoglHandle material;
int n_layers;
CoglMaterialFlushOptions flush_options;
CoglMatrix model_view;
/* XXX: These entries are pretty big now considering the padding in
* CoglMaterialFlushOptions and CoglMatrix, so we might need to optimize this
* later. */
} CoglJournalEntry;
CoglTexture*
_cogl_texture_pointer_from_handle (CoglHandle handle);
void
_cogl_texture_set_wrap_mode_parameter (CoglTexture *tex,
GLenum wrap_mode);
void
_cogl_texture_set_filters (CoglHandle handle,
GLenum min_filter,
GLenum mag_filter);
void
_cogl_texture_ensure_mipmaps (CoglHandle handle);
gboolean
_cogl_texture_span_has_waste (CoglTexture *tex,
gint x_span_index,
gint y_span_index);
void
_cogl_span_iter_begin (CoglSpanIter *iter,
GArray *array,
float origin,
float cover_start,
float cover_end);
gboolean
_cogl_span_iter_end (CoglSpanIter *iter);
void
_cogl_span_iter_next (CoglSpanIter *iter);
#endif /* __COGL_TEXTURE_H */