mutter/gles/cogl-texture-private.h
Robert Bragg 509928cc76 [multi-texturing] This adds a new cogl_multi_texture API for GL,GLES1 + GLES2
Multitexturing allows blending multiple layers of texture data when texturing
some geometry. A common use is for pre-baked light maps which can give nice
lighting effects relativly cheaply. Another is for dot-3 bump mapping, and
another is applying alpha channel masks.

The dot-3 bump mapping would be really nice one day, but currently cogl doesn't
support lighting so that's not dealt with in this patch.

notable limitations:
- It can only texture rectangles a.t.m - and like cogl_texture_rectangle there
is no support for rotated texturing.
- Sliced textures are not supported. I think I've figured out how to handle
layers with different slice sizes at least for rectangular geometry, but I'm
not sure how complex it becomes once rotations are possible and texturing
arbitrary cogl_polygons.
- Except for this new API, cogl still doesn't know about more than one texture
unit, and so has no way of caching any enables related to other units. So that
things don't break it's currently necessary to disable anything to do with
additional units as soon as we are done with them which isn't ideal.
- No clutter API yet.
2008-12-22 16:35:51 +00:00

87 lines
2.4 KiB
C

/*
* Clutter COGL
*
* A basic GL/GLES Abstraction/Utility Layer
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2007 OpenedHand
*
* 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.h"
typedef struct _CoglTexture CoglTexture;
typedef struct _CoglTexSliceSpan CoglTexSliceSpan;
typedef struct _CoglSpanIter CoglSpanIter;
typedef struct _CoglMultiTexture CoglMultiTexture;
typedef struct _CoglMultiTextureLayer CoglMultiTextureLayer;
struct _CoglTexSliceSpan
{
gint start;
gint size;
gint waste;
};
struct _CoglTexture
{
guint ref_count;
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;
COGLenum min_filter;
COGLenum mag_filter;
gboolean is_foreign;
GLint wrap_mode;
gboolean auto_mipmap;
};
struct _CoglMultiTextureLayer
{
guint ref_count;
guint index; /*!< lowest index is blended first then others
on top */
CoglTexture *tex; /*!< The texture for this layer, or NULL
for an empty layer */
/* TODO: Add more control over the texture environment for each texture
* unit. For example we should support dot3 normal mapping. */
};
struct _CoglMultiTexture
{
guint ref_count;
GList *layers;
};
CoglTexture*
_cogl_texture_pointer_from_handle (CoglHandle handle);
#endif /* __COGL_TEXTURE_H */