90f106117f
This exposes CoglTextureRectangle in the experimental cogl 2.0 api. For now we just expose a single constructor; cogl_texture_rectangle_new_with_size() but we can add more later. This is part of going work to improve our texture apis with more emphasis on providing low-level access to the varying semantics of different texture types understood by the gpu instead of only trying to present a lowest common denominator api. CoglTextureRectangle is notably useful for never being restricted to power of two sizes and for being sampled with non-normalized texture coordinates which can be convenient for use a lookup tables in glsl due to not needing separate uniforms for mapping normalized coordinates to texels. Unlike CoglTexture2D though rectangle textures can't have a mipmap and they only support the _CLAMP_TO_EDGE wrap mode. Applications wanting to use CoglTextureRectangle should first check cogl_has_feature (COGL_FEATURE_ID_TEXTURE_RECTANGLE). Reviewed-by: Neil Roberts <neil@linux.intel.com>
119 lines
4.2 KiB
C
119 lines
4.2 KiB
C
/*
|
|
* Cogl
|
|
*
|
|
* An object oriented GL/GLES Abstraction/Utility Layer
|
|
*
|
|
* Copyright (C) 2011 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, see
|
|
* <http://www.gnu.org/licenses/>.
|
|
*
|
|
*
|
|
* Authors:
|
|
* Robert Bragg <robert@linux.intel.com>
|
|
*/
|
|
|
|
#ifndef __COGL_TEXURE_RECTANGLE_H
|
|
#define __COGL_TEXURE_RECTANGLE_H
|
|
|
|
#include "cogl-context.h"
|
|
|
|
G_BEGIN_DECLS
|
|
|
|
/**
|
|
* SECTION:cogl-texture-rectangle
|
|
* @short_description: Functions for creating and manipulating rectangle
|
|
* textures for use with non-normalized coordinates.
|
|
*
|
|
* These functions allow low-level "rectangle" textures to be allocated.
|
|
* These textures are never constrained to power-of-two sizes but they
|
|
* also don't support having a mipmap and can only be wrapped with
|
|
* %COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE.
|
|
*
|
|
* The most notable difference between rectangle textures and 2D
|
|
* textures is that rectangle textures are sampled using un-normalized
|
|
* texture coordinates, so instead of using coordinates (0,0) and
|
|
* (1,1) to map to the top-left and bottom right corners of the
|
|
* texture you would instead use (0,0) and (width,height).
|
|
*
|
|
* The use of non-normalized coordinates can be particularly
|
|
* convenient when writing glsl shaders that use a texture as a lookup
|
|
* table since you don't need to upload separate uniforms to map
|
|
* normalized coordinates to texels.
|
|
*
|
|
* If you want to sample from a rectangle texture from GLSL you should
|
|
* use the sampler2DRect sampler type.
|
|
*
|
|
* Applications wanting to use #CoglTextureRectangle should first check
|
|
* for the %COGL_FEATURE_ID_TEXTURE_RECTANGLE feature using
|
|
* cogl_has_feature().
|
|
*/
|
|
|
|
typedef struct _CoglTextureRectangle CoglTextureRectangle;
|
|
#define COGL_TEXTURE_RECTANGLE(X) ((CoglTextureRectangle *)X)
|
|
|
|
#define cogl_is_texture_rectangle cogl_is_texture_rectangle_EXP
|
|
/**
|
|
* cogl_is_texture_rectangle:
|
|
* @object: A #CoglObject
|
|
*
|
|
* Gets whether the given object references an existing
|
|
* #CoglTextureRectangle object.
|
|
*
|
|
* Return value: %TRUE if the object references a
|
|
* #CoglTextureRectangle, %FALSE otherwise.
|
|
*/
|
|
gboolean
|
|
cogl_is_texture_rectangle (void *object);
|
|
|
|
#define cogl_texture_rectangle_new_with_size \
|
|
cogl_texture_rectangle_new_with_size_EXP
|
|
/**
|
|
* cogl_texture_rectangle_new_with_size:
|
|
* @context: A #CoglContext pointer
|
|
* @width: The texture width to allocate
|
|
* @height: The texture height to allocate
|
|
* @internal_format: The desired internal texture format
|
|
* @error: An optional GError pointer for reporting exceptions
|
|
*
|
|
* Allocates a new #CoglRectangle texture with a given @width, @height
|
|
* and @internal_format. This texture is a low-level texture that
|
|
* the GPU can sample from directly unlike high-level textures such
|
|
* as #CoglTexture2DSliced and #CoglAtlasTexture.
|
|
*
|
|
* <note>If you want to sample from a rectangle texture from GLSL you
|
|
* should use the sampler2DRect sampler type.</note>
|
|
*
|
|
* <note>Applications wanting to use #CoglTextureRectangle should
|
|
* first check for the %COGL_FEATURE_ID_TEXTURE_RECTANGLE feature
|
|
* using cogl_has_feature().</note>
|
|
*
|
|
* Returns: A pointer to a newly allocated #CoglRectangle texture
|
|
* or if the size was too large or there wasn't enough memory
|
|
* %NULL is returned and @error set.
|
|
*
|
|
* Since: 1.10
|
|
* Stability: unstable
|
|
*/
|
|
CoglTextureRectangle *
|
|
cogl_texture_rectangle_new_with_size (CoglContext *ctx,
|
|
int width,
|
|
int height,
|
|
CoglPixelFormat internal_format,
|
|
GError **error);
|
|
|
|
G_END_DECLS
|
|
|
|
#endif /* __COGL_TEXURE_RECTANGLE_H */
|