mutter/cogl/cogl-texture-private.h
Neil Roberts ae7825275e cogl: Make CoglSubTexture only work for quad rendering
The sub texture backend doesn't work well as a completely general
texture backend because for example when rendering with cogl_polygon
it needs to be able to tranform arbitrary texture coordinates without
reference to the other coordintes. This can't be done when the texture
coordinates are a multiple of one because sometimes the coordinate
should represent the left or top edge and sometimes it should
represent the bottom or top edge. For example if the s coordinates are
0 and 1 then 1 represents the right edge but if they are 1 and 2 then
1 represents the left edge.

Instead the sub-textures are now documented not to support coordinates
outside the range [0,1]. The coordinates for the sub-region are now
represented as integers as this helps avoid rounding issues. The
region can no longer be a super-region of the texture as this
simplifies the code quite a lot.

There are two new texture virtual functions:

transform_quad_coords_to_gl - This transforms two pairs of coordinates
     representing a quad. It will return FALSE if the coordinates can
     not be transformed. The sub texture backend uses this to detect
     coordinates that require repeating which causes cogl-primitives
     to use manual repeating.

ensure_non_quad_rendering - This is used in cogl_polygon and
     cogl_vertex_buffer to inform the texture backend that
     transform_quad_to_gl is going to be used. The atlas backend
     migrates the texture out of the atlas when it hits this.
2010-01-18 09:22:04 +00:00

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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_PRIVATE_H
#define __COGL_TEXTURE_PRIVATE_H
#include "cogl-bitmap-private.h"
#include "cogl-handle.h"
#include "cogl-material-private.h"
#define COGL_TEXTURE(tex) ((CoglTexture *)(tex))
typedef struct _CoglTexture CoglTexture;
typedef struct _CoglTextureVtable CoglTextureVtable;
typedef struct _CoglTextureUploadData CoglTextureUploadData;
typedef void (*CoglTextureSliceCallback) (CoglHandle handle,
GLuint gl_handle,
GLenum gl_target,
const float *slice_coords,
const float *virtual_coords,
void *user_data);
typedef void (* CoglTextureManualRepeatCallback) (const float *coords,
void *user_data);
struct _CoglTextureVtable
{
/* Virtual functions that must be implemented for a texture
backend */
gboolean (* set_region) (CoglTexture *tex,
int src_x,
int src_y,
int dst_x,
int dst_y,
unsigned int dst_width,
unsigned int dst_height,
int width,
int height,
CoglPixelFormat format,
unsigned int rowstride,
const guint8 *data);
int (* get_data) (CoglTexture *tex,
CoglPixelFormat format,
unsigned int rowstride,
guint8 *data);
void (* foreach_sub_texture_in_region) (CoglTexture *tex,
float virtual_tx_1,
float virtual_ty_1,
float virtual_tx_2,
float virtual_ty_2,
CoglTextureSliceCallback callback,
void *user_data);
gint (* get_max_waste) (CoglTexture *tex);
gboolean (* is_sliced) (CoglTexture *tex);
gboolean (* can_hardware_repeat) (CoglTexture *tex);
void (* transform_coords_to_gl) (CoglTexture *tex,
float *s,
float *t);
gboolean (* transform_quad_coords_to_gl) (CoglTexture *tex,
float *coords);
gboolean (* get_gl_texture) (CoglTexture *tex,
GLuint *out_gl_handle,
GLenum *out_gl_target);
void (* set_filters) (CoglTexture *tex,
GLenum min_filter,
GLenum mag_filter);
void (* ensure_mipmaps) (CoglTexture *tex);
void (* ensure_non_quad_rendering) (CoglTexture *tex);
void (* set_wrap_mode_parameter) (CoglTexture *tex,
GLenum wrap_mode);
CoglPixelFormat (* get_format) (CoglTexture *tex);
GLenum (* get_gl_format) (CoglTexture *tex);
gint (* get_width) (CoglTexture *tex);
gint (* get_height) (CoglTexture *tex);
};
/* This represents the state needed to upload texture data. There are
utility functions in cogl-texture which use this state */
struct _CoglTextureUploadData
{
CoglBitmap bitmap;
gboolean bitmap_owner;
GLenum gl_intformat;
GLenum gl_format;
GLenum gl_type;
};
struct _CoglTexture
{
CoglHandleObject _parent;
const CoglTextureVtable *vtable;
};
void
_cogl_texture_foreach_sub_texture_in_region (CoglHandle handle,
float virtual_tx_1,
float virtual_ty_1,
float virtual_tx_2,
float virtual_ty_2,
CoglTextureSliceCallback callback,
void *user_data);
gboolean
_cogl_texture_can_hardware_repeat (CoglHandle handle);
void
_cogl_texture_transform_coords_to_gl (CoglHandle handle,
float *s,
float *t);
gboolean
_cogl_texture_transform_quad_coords_to_gl (CoglHandle handle,
float *coords);
GLenum
_cogl_texture_get_gl_format (CoglHandle handle);
void
_cogl_texture_set_wrap_mode_parameter (CoglHandle handle,
GLenum wrap_mode);
void
_cogl_texture_set_filters (CoglHandle handle,
GLenum min_filter,
GLenum mag_filter);
void
_cogl_texture_ensure_mipmaps (CoglHandle handle);
void
_cogl_texture_ensure_non_quad_rendering (CoglHandle handle);
/* Utility functions to help uploading a bitmap. These are intended to
* be used by CoglTexture implementations or drivers... */
void
_cogl_texture_upload_data_free (CoglTextureUploadData *data);
void
_cogl_texture_upload_data_swap_bitmap (CoglTextureUploadData *data,
CoglBitmap *new_bitmap);
gboolean
_cogl_texture_upload_data_prepare_format
(CoglTextureUploadData *data,
CoglPixelFormat *internal_format);
gboolean
_cogl_texture_upload_data_convert (CoglTextureUploadData *data,
CoglPixelFormat internal_format);
gboolean
_cogl_texture_upload_data_prepare (CoglTextureUploadData *data,
CoglPixelFormat internal_format);
void
_cogl_texture_prep_gl_alignment_for_pixels_upload (int pixels_rowstride);
void
_cogl_texture_prep_gl_alignment_for_pixels_download (int pixels_rowstride);
/* Utility function for implementing manual repeating. Even texture
backends that always support hardware repeating need this because
when foreach_sub_texture_in_region is invoked Cogl will set the
wrap mode to GL_CLAMP_TO_EDGE so hardware repeating can't be
done */
void
_cogl_texture_iterate_manual_repeats (CoglTextureManualRepeatCallback callback,
float tx_1, float ty_1,
float tx_2, float ty_2,
void *user_data);
/* Utility function to use as a fallback for getting the data of any
texture via the framebuffer */
gboolean
_cogl_texture_draw_and_read (CoglHandle handle,
CoglBitmap *target_bmp,
GLuint target_gl_format,
GLuint target_gl_type);
#endif /* __COGL_TEXTURE_PRIVATE_H */