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mutter-performance-source/cogl/cogl-meta-texture.h
Robert Bragg a0441778ad This re-licenses Cogl 1.18 under the MIT license
Since the Cogl 1.18 branch is actively maintained in parallel with the
master branch; this is a counter part to commit 1b83ef938fc16b which
re-licensed the master branch to use the MIT license.

This re-licensing is a follow up to the proposal that was sent to the
Cogl mailing list:
http://lists.freedesktop.org/archives/cogl/2013-December/001465.html

Note: there was a copyright assignment policy in place for Clutter (and
therefore Cogl which was part of Clutter at the time) until the 11th of
June 2010 and so we only checked the details after that point (commit
0bbf50f905)

For each file, authors were identified via this Git command:
$ git blame -p -C -C -C20 -M -M10  0bbf50f905..HEAD

We received blanket approvals for re-licensing all Red Hat and Collabora
contributions which reduced how many people needed to be contacted
individually:
- http://lists.freedesktop.org/archives/cogl/2013-December/001470.html
- http://lists.freedesktop.org/archives/cogl/2014-January/001536.html

Individual approval requests were sent to all the other identified authors
who all confirmed the re-license on the Cogl mailinglist:
http://lists.freedesktop.org/archives/cogl/2014-January

As well as updating the copyright header in all sources files, the
COPYING file has been updated to reflect the license change and also
document the other licenses used in Cogl such as the SGI Free Software
License B, version 2.0 and the 3-clause BSD license.

This patch was not simply cherry-picked from master; but the same
methodology was used to check the source files.
2014-02-22 02:02:53 +00:00

194 lines
8.4 KiB
C

/*
* Cogl
*
* A Low Level GPU Graphics and Utilities API
*
* Copyright (C) 2011 Intel Corporation.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*
*/
#if !defined(__COGL_H_INSIDE__) && !defined(COGL_COMPILATION)
#error "Only <cogl/cogl.h> can be included directly."
#endif
#ifndef __COGL_META_TEXTURE_H__
#define __COGL_META_TEXTURE_H__
#include <cogl/cogl-pipeline-layer-state.h>
COGL_BEGIN_DECLS
/**
* SECTION:cogl-meta-texture
* @short_description: Interface for high-level textures built from
* low-level textures like #CoglTexture2D and
* #CoglTexture3D.
*
* Cogl helps to make it easy to deal with high level textures such
* as #CoglAtlasTexture<!-- -->s, #CoglSubTexture<!-- -->s,
* #CoglTexturePixmapX11 textures and #CoglTexture2DSliced textures
* consistently.
*
* A #CoglMetaTexture is a texture that might internally be
* represented by one or more low-level #CoglTexture<!-- -->s
* such as #CoglTexture2D or #CoglTexture3D. These low-level textures
* are the only ones that a GPU really understands but because
* applications often want more high-level texture abstractions
* (such as storing multiple textures inside one larger "atlas"
* texture) it's desirable to be able to deal with these
* using a common interface.
*
* For example the GPU is not able to automatically handle repeating a
* texture that is part of a larger atlas texture but if you use
* %COGL_PIPELINE_WRAP_MODE_REPEAT with an atlas texture when drawing
* with cogl_rectangle() you should see that it "Just Works™" - at
* least if you don't use multi-texturing. The reason this works is
* because cogl_rectangle() internally understands the #CoglMetaTexture
* interface and is able to manually resolve the low-level textures
* using this interface and by making multiple draw calls it can
* emulate the texture repeat modes.
*
* Cogl doesn't aim to pretend that meta-textures are just like real
* textures because it would get extremely complex to try and emulate
* low-level GPU semantics transparently for these textures. The low
* level drawing APIs of Cogl, such as cogl_primitive_draw() don't
* actually know anything about the #CoglMetaTexture interface and its
* the developer's responsibility to resolve all textures referenced
* by a #CoglPipeline to low-level textures before drawing.
*
* If you want to develop custom primitive APIs like
* cogl_framebuffer_draw_rectangle() and you want to support drawing
* with #CoglAtlasTexture<!-- -->s or #CoglSubTexture<!-- -->s for
* example, then you will need to use this #CoglMetaTexture interface
* to be able to resolve high-level textures into low-level textures
* before drawing with Cogl's low-level drawing APIs such as
* cogl_primitive_draw().
*
* <note>Most developers won't need to use this interface directly
* but still it is worth understanding the distinction between
* low-level and meta textures because you may find other references
* in the documentation that detail limitations of using
* meta-textures.</note>
*/
#ifdef __COGL_H_INSIDE__
/* For the public C api we typedef interface types as void to avoid needing
* lots of casting in code and instead we will rely on runtime type checking
* for these objects. */
typedef void CoglMetaTexture;
#else
typedef struct _CoglMetaTexture CoglMetaTexture;
#define COGL_META_TEXTURE(X) ((CoglMetaTexture *)X)
#endif
/**
* CoglMetaTextureCallback:
* @sub_texture: A low-level #CoglTexture making up part of a
* #CoglMetaTexture.
* @sub_texture_coords: A float 4-tuple ordered like
* (tx1,ty1,tx2,ty2) defining what region of the
* current @sub_texture maps to a sub-region of a
* #CoglMetaTexture. (tx1,ty1) is the top-left
* sub-region coordinate and (tx2,ty2) is the
* bottom-right. These are low-level texture
* coordinates.
* @meta_coords: A float 4-tuple ordered like (tx1,ty1,tx2,ty2)
* defining what sub-region of a #CoglMetaTexture this
* low-level @sub_texture maps too. (tx1,ty1) is
* the top-left sub-region coordinate and (tx2,ty2) is
* the bottom-right. These are high-level meta-texture
* coordinates.
* @user_data: A private pointer passed to
* cogl_meta_texture_foreach_in_region().
*
* A callback used with cogl_meta_texture_foreach_in_region() to
* retrieve details of all the low-level #CoglTexture<!-- -->s that
* make up a given #CoglMetaTexture.
*
* Since: 1.10
* Stability: unstable
*/
typedef void (*CoglMetaTextureCallback) (CoglTexture *sub_texture,
const float *sub_texture_coords,
const float *meta_coords,
void *user_data);
/**
* cogl_meta_texture_foreach_in_region:
* @meta_texture: An object implementing the #CoglMetaTexture
* interface.
* @tx_1: The top-left x coordinate of the region to iterate
* @ty_1: The top-left y coordinate of the region to iterate
* @tx_2: The bottom-right x coordinate of the region to iterate
* @ty_2: The bottom-right y coordinate of the region to iterate
* @wrap_s: The wrap mode for the x-axis
* @wrap_t: The wrap mode for the y-axis
* @callback: A #CoglMetaTextureCallback pointer to be called
* for each low-level texture within the specified region.
* @user_data: A private pointer that is passed to @callback.
*
* Allows you to manually iterate the low-level textures that define a
* given region of a high-level #CoglMetaTexture.
*
* For example cogl_texture_2d_sliced_new_with_size() can be used to
* create a meta texture that may slice a large image into multiple,
* smaller power-of-two sized textures. These high level textures are
* not directly understood by a GPU and so this API must be used to
* manually resolve the underlying textures for drawing.
*
* All high level textures (#CoglAtlasTexture, #CoglSubTexture,
* #CoglTexturePixmapX11, and #CoglTexture2DSliced) can be handled
* consistently using this interface which greately simplifies
* implementing primitives that support all texture types.
*
* For example if you use the cogl_rectangle() API then Cogl will
* internally use this API to resolve the low level textures of any
* meta textures you have associated with CoglPipeline layers.
*
* <note>The low level drawing APIs such as cogl_primitive_draw()
* don't understand the #CoglMetaTexture interface and so it is your
* responsibility to use this API to resolve all CoglPipeline textures
* into low-level textures before drawing.</note>
*
* For each low-level texture that makes up part of the given region
* of the @meta_texture, @callback is called specifying how the
* low-level texture maps to the original region.
*
* Since: 1.10
* Stability: unstable
*/
void
cogl_meta_texture_foreach_in_region (CoglMetaTexture *meta_texture,
float tx_1,
float ty_1,
float tx_2,
float ty_2,
CoglPipelineWrapMode wrap_s,
CoglPipelineWrapMode wrap_t,
CoglMetaTextureCallback callback,
void *user_data);
COGL_END_DECLS
#endif /* __COGL_META_TEXTURE_H__ */