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mutter/cogl/cogl-sub-texture-private.h

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cogl: Add a sub texture backend This adds a new texture backend which represents a sub texture of a larger texture. The texture is created with a reference to the full texture and a set of coordinates describing the region. The backend simply defers to the full texture for all operations and maps the coordinates to the other range. You can also use coordinates outside the range [0,1] to create a repeated version of the full texture. A new public API function called cogl_texture_new_from_sub_texture is available to create the sub texture.
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/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 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_SUB_TEXTURE_H
#define __COGL_SUB_TEXTURE_H
#include "cogl-handle.h"
#include "cogl-texture-private.h"
#define COGL_SUB_TEXTURE(tex) ((CoglSubTexture *) tex)
typedef struct _CoglSubTexture CoglSubTexture;
struct _CoglSubTexture
{
CoglTexture _parent;
CoglHandle full_texture;
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.
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/* The region represented by this sub-texture */
gint sub_x;
gint sub_y;
gint sub_width;
gint sub_height;
cogl: Add a sub texture backend This adds a new texture backend which represents a sub texture of a larger texture. The texture is created with a reference to the full texture and a set of coordinates describing the region. The backend simply defers to the full texture for all operations and maps the coordinates to the other range. You can also use coordinates outside the range [0,1] to create a repeated version of the full texture. A new public API function called cogl_texture_new_from_sub_texture is available to create the sub texture.
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};
GQuark
_cogl_handle_sub_texture_get_type (void);
CoglHandle
_cogl_sub_texture_new (CoglHandle full_texture,
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 04:22:04 -05:00
gint sub_x, gint sub_y,
gint sub_width, gint sub_height);
cogl: Add a sub texture backend This adds a new texture backend which represents a sub texture of a larger texture. The texture is created with a reference to the full texture and a set of coordinates describing the region. The backend simply defers to the full texture for all operations and maps the coordinates to the other range. You can also use coordinates outside the range [0,1] to create a repeated version of the full texture. A new public API function called cogl_texture_new_from_sub_texture is available to create the sub texture.
2009-11-27 11:39:16 -05:00
#endif /* __COGL_SUB_TEXTURE_H */
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