0f5f4e8645
We've had complaints that our Cogl code/headers are a bit "special" so
this is a first pass at tidying things up by giving them some
consistency. These changes are all consistent with how new code in Cogl
is being written, but the style isn't consistently applied across all
code yet.
There are two parts to this patch; but since each one required a large
amount of effort to maintain tidy indenting it made sense to combine the
changes to reduce the time spent re indenting the same lines.
The first change is to use a consistent style for declaring function
prototypes in headers. Cogl headers now consistently use this style for
prototypes:
return_type
cogl_function_name (CoglType arg0,
CoglType arg1);
Not everyone likes this style, but it seems that most of the currently
active Cogl developers agree on it.
The second change is to constrain the use of redundant glib data types
in Cogl. Uses of gint, guint, gfloat, glong, gulong and gchar have all
been replaced with int, unsigned int, float, long, unsigned long and char
respectively. When talking about pixel data; use of guchar has been
replaced with guint8, otherwise unsigned char can be used.
The glib types that we continue to use for portability are gboolean,
gint{8,16,32,64}, guint{8,16,32,64} and gsize.
The general intention is that Cogl should look palatable to the widest
range of C programmers including those outside the Gnome community so
- especially for the public API - we want to minimize the number of
foreign looking typedefs.
841 lines
27 KiB
C
841 lines
27 KiB
C
/*
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* Cogl
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*
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* An object oriented GL/GLES Abstraction/Utility Layer
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*
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* Copyright (C) 2007,2008,2009 Intel Corporation.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
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#error "Only <cogl/cogl.h> can be included directly."
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#endif
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#ifndef __COGL_MATERIAL_H__
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#define __COGL_MATERIAL_H__
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G_BEGIN_DECLS
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#include <cogl/cogl-types.h>
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#include <cogl/cogl-matrix.h>
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/**
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* SECTION:cogl-material
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* @short_description: Fuctions for creating and manipulating materials
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*
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* COGL allows creating and manipulating materials used to fill in
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* geometry. Materials may simply be lighting attributes (such as an
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* ambient and diffuse colour) or might represent one or more textures
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* blended together.
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*/
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/**
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* CoglMaterialFilter:
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* @COGL_MATERIAL_FILTER_NEAREST: Measuring in manhatten distance from the,
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* current pixel center, use the nearest texture texel
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* @COGL_MATERIAL_FILTER_LINEAR: Use the weighted average of the 4 texels
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* nearest the current pixel center
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* @COGL_MATERIAL_FILTER_NEAREST_MIPMAP_NEAREST: Select the mimap level whose
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* texel size most closely matches the current pixel, and use the
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* %COGL_MATERIAL_FILTER_NEAREST criterion
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* @COGL_MATERIAL_FILTER_LINEAR_MIPMAP_NEAREST: Select the mimap level whose
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* texel size most closely matches the current pixel, and use the
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* %COGL_MATERIAL_FILTER_LINEAR criterion
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* @COGL_MATERIAL_FILTER_NEAREST_MIPMAP_LINEAR: Select the two mimap levels
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* whose texel size most closely matches the current pixel, use
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* the %COGL_MATERIAL_FILTER_NEAREST criterion on each one and take
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* their weighted average
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* @COGL_MATERIAL_FILTER_LINEAR_MIPMAP_LINEAR: Select the two mimap levels
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* whose texel size most closely matches the current pixel, use
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* the %COGL_MATERIAL_FILTER_LINEAR criterion on each one and take
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* their weighted average
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*
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* Texture filtering is used whenever the current pixel maps either to more
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* than one texture element (texel) or less than one. These filter enums
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* correspond to different strategies used to come up with a pixel color, by
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* possibly referring to multiple neighbouring texels and taking a weighted
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* average or simply using the nearest texel.
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*/
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typedef enum {
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COGL_MATERIAL_FILTER_NEAREST = GL_NEAREST,
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COGL_MATERIAL_FILTER_LINEAR = GL_LINEAR,
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COGL_MATERIAL_FILTER_NEAREST_MIPMAP_NEAREST = GL_NEAREST_MIPMAP_NEAREST,
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COGL_MATERIAL_FILTER_LINEAR_MIPMAP_NEAREST = GL_LINEAR_MIPMAP_NEAREST,
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COGL_MATERIAL_FILTER_NEAREST_MIPMAP_LINEAR = GL_NEAREST_MIPMAP_LINEAR,
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COGL_MATERIAL_FILTER_LINEAR_MIPMAP_LINEAR = GL_LINEAR_MIPMAP_LINEAR
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} CoglMaterialFilter;
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/**
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* cogl_material_new:
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*
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* Allocates and initializes a blank white material
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*
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* Return value: a handle to the new material
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*/
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CoglHandle
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cogl_material_new (void);
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/**
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* cogl_material_copy:
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*
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* Creates a new material handle with the configuration copied from the
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* source material.
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*
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* We would strongly advise developers to always aim to use
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* cogl_material_copy() instead of cogl_material_new() whenever there will
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* be any similarity between two materials. Copying a material helps Cogl
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* keep track of a materials ancestry which we may use to help minimize GPU
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* state changes.
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*
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* Returns: a handle to the new material
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*
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* Since: 1.2
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*/
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CoglHandle
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cogl_material_copy (CoglHandle source);
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#ifndef COGL_DISABLE_DEPRECATED
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/**
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* cogl_material_ref:
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* @handle: a @CoglHandle.
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*
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* Increment the reference count for a cogl material.
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*
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* Return value: the @handle.
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*
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* Since: 1.0
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*
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* Deprecated: 1.2: Use cogl_handle_ref() instead
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*/
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CoglHandle
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cogl_material_ref (CoglHandle handle);
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/**
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* cogl_material_unref:
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* @handle: a @CoglHandle.
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*
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* Decrement the reference count for a cogl material.
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*
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* Since: 1.0
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*
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* Deprecated: 1.2: Use cogl_handle_unref() instead
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*/
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void
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cogl_material_unref (CoglHandle handle);
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#endif /* COGL_DISABLE_DEPRECATED */
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/**
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* cogl_is_material:
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* @handle: A CoglHandle
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*
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* Gets whether the given handle references an existing material object.
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*
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* Return value: %TRUE if the handle references a #CoglMaterial,
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* %FALSE otherwise
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*/
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gboolean
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cogl_is_material (CoglHandle handle);
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/**
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* cogl_material_set_color:
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* @material: A CoglMaterial object
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* @color: The components of the color
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*
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* Sets the basic color of the material, used when no lighting is enabled.
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*
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* Note that if you don't add any layers to the material then the color
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* will be blended unmodified with the destination; the default blend
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* expects premultiplied colors: for example, use (0.5, 0.0, 0.0, 0.5) for
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* semi-transparent red. See cogl_color_premultiply().
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*
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* The default value is (1.0, 1.0, 1.0, 1.0)
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*
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* Since: 1.0
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*/
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void
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cogl_material_set_color (CoglHandle material,
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const CoglColor *color);
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/**
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* cogl_material_set_color4ub:
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* @material: A CoglMaterial object
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* @red: The red component
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* @green: The green component
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* @blue: The blue component
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* @alpha: The alpha component
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*
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* Sets the basic color of the material, used when no lighting is enabled.
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*
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* The default value is (0xff, 0xff, 0xff, 0xff)
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*
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* Since: 1.0
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*/
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void
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cogl_material_set_color4ub (CoglHandle material,
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guint8 red,
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guint8 green,
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guint8 blue,
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guint8 alpha);
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/**
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* cogl_material_set_color4f:
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* @material: A CoglMaterial object
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* @red: The red component
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* @green: The green component
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* @blue: The blue component
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* @alpha: The alpha component
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*
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* Sets the basic color of the material, used when no lighting is enabled.
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*
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* The default value is (1.0, 1.0, 1.0, 1.0)
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*
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* Since: 1.0
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*/
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void
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cogl_material_set_color4f (CoglHandle material,
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float red,
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float green,
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float blue,
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float alpha);
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/**
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* cogl_material_get_color:
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* @material: A CoglMaterial object
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* @color: (out): The location to store the color
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*
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* Retrieves the current material color.
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*
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* Since: 1.0
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*/
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void
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cogl_material_get_color (CoglHandle material,
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CoglColor *color);
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/**
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* cogl_material_set_ambient:
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* @material: A CoglMaterial object
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* @ambient: The components of the desired ambient color
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*
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* Sets the material's ambient color, in the standard OpenGL lighting
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* model. The ambient color affects the overall color of the object.
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*
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* Since the diffuse color will be intense when the light hits the surface
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* directly, the ambient will be most apparent where the light hits at a
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* slant.
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*
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* The default value is (0.2, 0.2, 0.2, 1.0)
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*
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* Since: 1.0
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*/
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void
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cogl_material_set_ambient (CoglHandle material,
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const CoglColor *ambient);
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/**
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* cogl_material_get_ambient:
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* @material: A CoglMaterial object
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* @ambient: The location to store the ambient color
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*
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* Retrieves the current ambient color for @material
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*
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* Since: 1.0
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*/
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void
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cogl_material_get_ambient (CoglHandle material,
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CoglColor *ambient);
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/**
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* cogl_material_set_diffuse:
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* @material: A CoglMaterial object
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* @diffuse: The components of the desired diffuse color
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*
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* Sets the material's diffuse color, in the standard OpenGL lighting
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* model. The diffuse color is most intense where the light hits the
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* surface directly - perpendicular to the surface.
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*
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* The default value is (0.8, 0.8, 0.8, 1.0)
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*
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* Since: 1.0
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*/
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void
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cogl_material_set_diffuse (CoglHandle material,
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const CoglColor *diffuse);
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/**
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* cogl_material_get_diffuse:
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* @material: A CoglMaterial object
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* @diffuse: The location to store the diffuse color
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*
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* Retrieves the current diffuse color for @material
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*
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* Since: 1.0
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*/
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void
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cogl_material_get_diffuse (CoglHandle material,
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CoglColor *diffuse);
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/**
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* cogl_material_set_ambient_and_diffuse:
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* @material: A CoglMaterial object
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* @color: The components of the desired ambient and diffuse colors
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*
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* Conveniently sets the diffuse and ambient color of @material at the same
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* time. See cogl_material_set_ambient() and cogl_material_set_diffuse().
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*
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* The default ambient color is (0.2, 0.2, 0.2, 1.0)
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*
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* The default diffuse color is (0.8, 0.8, 0.8, 1.0)
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*
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* Since: 1.0
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*/
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void
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cogl_material_set_ambient_and_diffuse (CoglHandle material,
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const CoglColor *color);
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/**
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* cogl_material_set_specular:
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* @material: A CoglMaterial object
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* @specular: The components of the desired specular color
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*
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* Sets the material's specular color, in the standard OpenGL lighting
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* model. The intensity of the specular color depends on the viewport
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* position, and is brightest along the lines of reflection.
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*
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* The default value is (0.0, 0.0, 0.0, 1.0)
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*
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* Since: 1.0
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*/
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void
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cogl_material_set_specular (CoglHandle material,
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const CoglColor *specular);
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/**
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* cogl_material_get_specular:
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* @material: A CoglMaterial object
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* @specular: The location to store the specular color
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*
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* Retrieves the materials current specular color.
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*
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* Since: 1.0
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*/
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void
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cogl_material_get_specular (CoglHandle material,
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CoglColor *specular);
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/**
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* cogl_material_set_shininess:
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* @material: A CoglMaterial object
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* @shininess: The desired shininess; range: [0.0, 1.0]
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*
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* Sets the materials shininess, in the standard OpenGL lighting model,
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* which determines how specular highlights are calculated. A higher
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* @shininess will produce smaller brigher highlights.
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*
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* The default value is 0.0
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*
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* Since: 1.0
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*/
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void
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cogl_material_set_shininess (CoglHandle material,
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float shininess);
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/**
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* cogl_material_get_shininess:
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* @material: A CoglMaterial object
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*
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* Retrieves the materials current emission color.
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*
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* Return value: The materials current shininess value
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*
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* Since: 1.0
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*/
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float
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cogl_material_get_shininess (CoglHandle material);
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/**
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* cogl_material_set_emission:
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* @material: A CoglMaterial object
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* @emission: The components of the desired emissive color
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*
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* Sets the material's emissive color, in the standard OpenGL lighting
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* model. It will look like the surface is a light source emitting this
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* color.
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*
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* The default value is (0.0, 0.0, 0.0, 1.0)
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*
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* Since: 1.0
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*/
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void
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cogl_material_set_emission (CoglHandle material,
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const CoglColor *emission);
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/**
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* cogl_material_get_emission:
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* @material: A CoglMaterial object
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* @emission: The location to store the emission color
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*
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* Retrieves the materials current emission color.
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*
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* Since: 1.0
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*/
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void
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cogl_material_get_emission (CoglHandle material,
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CoglColor *emission);
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/**
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* CoglMaterialAlphaFunc:
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* @COGL_MATERIAL_ALPHA_FUNC_NEVER: Never let the fragment through.
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* @COGL_MATERIAL_ALPHA_FUNC_LESS: Let the fragment through if the incoming
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* alpha value is less than the reference alpha value
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* @COGL_MATERIAL_ALPHA_FUNC_EQUAL: Let the fragment through if the incoming
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* alpha value equals the reference alpha value
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* @COGL_MATERIAL_ALPHA_FUNC_LEQUAL: Let the fragment through if the incoming
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* alpha value is less than or equal to the reference alpha value
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* @COGL_MATERIAL_ALPHA_FUNC_GREATER: Let the fragment through if the incoming
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* alpha value is greater than the reference alpha value
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* @COGL_MATERIAL_ALPHA_FUNC_NOTEQUAL: Let the fragment through if the incoming
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* alpha value does not equal the reference alpha value
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* @COGL_MATERIAL_ALPHA_FUNC_GEQUAL: Let the fragment through if the incoming
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* alpha value is greater than or equal to the reference alpha value.
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* @COGL_MATERIAL_ALPHA_FUNC_ALWAYS: Always let the fragment through.
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*
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* Alpha testing happens before blending primitives with the framebuffer and
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* gives an opportunity to discard fragments based on a comparison with the
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* incoming alpha value and a reference alpha value. The #CoglMaterialAlphaFunc
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* determines how the comparison is done.
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*/
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typedef enum {
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COGL_MATERIAL_ALPHA_FUNC_NEVER = GL_NEVER,
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COGL_MATERIAL_ALPHA_FUNC_LESS = GL_LESS,
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COGL_MATERIAL_ALPHA_FUNC_EQUAL = GL_EQUAL,
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COGL_MATERIAL_ALPHA_FUNC_LEQUAL = GL_LEQUAL,
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COGL_MATERIAL_ALPHA_FUNC_GREATER = GL_GREATER,
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COGL_MATERIAL_ALPHA_FUNC_NOTEQUAL = GL_NOTEQUAL,
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COGL_MATERIAL_ALPHA_FUNC_GEQUAL = GL_GEQUAL,
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COGL_MATERIAL_ALPHA_FUNC_ALWAYS = GL_ALWAYS
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} CoglMaterialAlphaFunc;
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/**
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* cogl_material_set_alpha_test_function:
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* @material: A CoglMaterial object
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* @alpha_func: A @CoglMaterialAlphaFunc constant
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* @alpha_reference: A reference point that the chosen alpha function uses
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* to compare incoming fragments to.
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*
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* Before a primitive is blended with the framebuffer, it goes through an
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* alpha test stage which lets you discard fragments based on the current
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* alpha value. This function lets you change the function used to evaluate
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* the alpha channel, and thus determine which fragments are discarded
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* and which continue on to the blending stage.
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*
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* The default is %COGL_MATERIAL_ALPHA_FUNC_ALWAYS
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*
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* Since: 1.0
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*/
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void
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cogl_material_set_alpha_test_function (CoglHandle material,
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CoglMaterialAlphaFunc alpha_func,
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float alpha_reference);
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/**
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* cogl_material_set_blend:
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* @material: A CoglMaterial object
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* @blend_string: A <link linkend="cogl-Blend-Strings">Cogl blend string</link>
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* describing the desired blend function.
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* @error: return location for a #GError that may report lack of driver
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* support if you give separate blend string statements for the alpha
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* channel and RGB channels since some drivers, or backends such as
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* GLES 1.1, don't support this feature. May be %NULL, in which case a
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* warning will be printed out using GLib's logging facilities if an
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* error is encountered.
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*
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* If not already familiar; please refer <link linkend="cogl-Blend-Strings">here</link>
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* for an overview of what blend strings are, and their syntax.
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*
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* Blending occurs after the alpha test function, and combines fragments with
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* the framebuffer.
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* Currently the only blend function Cogl exposes is ADD(). So any valid
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* blend statements will be of the form:
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*
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* |[
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* <channel-mask>=ADD(SRC_COLOR*(<factor>), DST_COLOR*(<factor>))
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* ]|
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*
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* <warning>The brackets around blend factors are currently not
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* optional!</warning>
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*
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|
* This is the list of source-names usable as blend factors:
|
|
* <itemizedlist>
|
|
* <listitem><para>SRC_COLOR: The color of the in comming fragment</para></listitem>
|
|
* <listitem><para>DST_COLOR: The color of the framebuffer</para></listitem>
|
|
* <listitem><para>CONSTANT: The constant set via cogl_material_set_blend_constant()</para></listitem>
|
|
* </itemizedlist>
|
|
*
|
|
* The source names can be used according to the
|
|
* <link linkend="cogl-Blend-String-syntax">color-source and factor syntax</link>,
|
|
* so for example "(1-SRC_COLOR[A])" would be a valid factor, as would
|
|
* "(CONSTANT[RGB])"
|
|
*
|
|
* These can also be used as factors:
|
|
* <itemizedlist>
|
|
* <listitem>0: (0, 0, 0, 0)</listitem>
|
|
* <listitem>1: (1, 1, 1, 1)</listitem>
|
|
* <listitem>SRC_ALPHA_SATURATE_FACTOR: (f,f,f,1) where f = MIN(SRC_COLOR[A],1-DST_COLOR[A])</listitem>
|
|
* </itemizedlist>
|
|
*
|
|
* <note>Remember; all color components are normalized to the range [0, 1]
|
|
* before computing the result of blending.</note>
|
|
*
|
|
* <example id="cogl-Blend-Strings-blend-unpremul">
|
|
* <title>Blend Strings/1</title>
|
|
* <para>Blend a non-premultiplied source over a destination with
|
|
* premultiplied alpha:</para>
|
|
* <programlisting>
|
|
* "RGB = ADD(SRC_COLOR*(SRC_COLOR[A]), DST_COLOR*(1-SRC_COLOR[A]))"
|
|
* "A = ADD(SRC_COLOR, DST_COLOR*(1-SRC_COLOR[A]))"
|
|
* </programlisting>
|
|
* </example>
|
|
*
|
|
* <example id="cogl-Blend-Strings-blend-premul">
|
|
* <title>Blend Strings/2</title>
|
|
* <para>Blend a premultiplied source over a destination with
|
|
* premultiplied alpha</para>
|
|
* <programlisting>
|
|
* "RGBA = ADD(SRC_COLOR, DST_COLOR*(1-SRC_COLOR[A]))"
|
|
* </programlisting>
|
|
* </example>
|
|
*
|
|
* The default blend string is:
|
|
* |[
|
|
* RGBA = ADD (SRC_COLOR, DST_COLOR*(1-SRC_COLOR[A]))
|
|
* ]|
|
|
*
|
|
* That gives normal alpha-blending when the calculated color for the material
|
|
* is in premultiplied form.
|
|
*
|
|
* Return value: %TRUE if the blend string was successfully parsed, and the
|
|
* described blending is supported by the underlying driver/hardware. If
|
|
* there was an error, %FALSE is returned and @error is set accordingly (if
|
|
* present).
|
|
*
|
|
* Since: 1.0
|
|
*/
|
|
gboolean
|
|
cogl_material_set_blend (CoglHandle material,
|
|
const char *blend_string,
|
|
GError **error);
|
|
|
|
/**
|
|
* cogl_material_set_blend_constant:
|
|
* @material: A CoglMaterial object
|
|
* @constant_color: The constant color you want
|
|
*
|
|
* When blending is setup to reference a CONSTANT blend factor then
|
|
* blending will depend on the constant set with this function.
|
|
*
|
|
* Since: 1.0
|
|
*/
|
|
void
|
|
cogl_material_set_blend_constant (CoglHandle material,
|
|
CoglColor *constant_color);
|
|
|
|
/**
|
|
* cogl_material_set_layer:
|
|
* @material: A #CoglHandle for a material object
|
|
* @layer_index: the index of the layer
|
|
* @texture: a #CoglHandle for the layer object
|
|
*
|
|
* In addition to the standard OpenGL lighting model a Cogl material may have
|
|
* one or more layers comprised of textures that can be blended together in
|
|
* order, with a number of different texture combine modes. This function
|
|
* defines a new texture layer.
|
|
*
|
|
* The index values of multiple layers do not have to be consecutive; it is
|
|
* only their relative order that is important.
|
|
*
|
|
* <note>In the future, we may define other types of material layers, such
|
|
* as purely GLSL based layers.</note>
|
|
*
|
|
* Since: 1.0
|
|
*/
|
|
void
|
|
cogl_material_set_layer (CoglHandle material,
|
|
int layer_index,
|
|
CoglHandle texture);
|
|
|
|
/**
|
|
* cogl_material_remove_layer:
|
|
* @material: A CoglMaterial object
|
|
* @layer_index: Specifies the layer you want to remove
|
|
*
|
|
* This function removes a layer from your material
|
|
*/
|
|
void
|
|
cogl_material_remove_layer (CoglHandle material,
|
|
int layer_index);
|
|
|
|
|
|
/**
|
|
* cogl_material_set_layer_combine:
|
|
* @material: A CoglMaterial object
|
|
* @layer_index: Specifies the layer you want define a combine function for
|
|
* @blend_string: A <link linkend="cogl-Blend-Strings">Cogl blend string</link>
|
|
* describing the desired texture combine function.
|
|
* @error: A #GError that may report parse errors or lack of GPU/driver
|
|
* support. May be %NULL, in which case a warning will be printed out if an
|
|
* error is encountered.
|
|
*
|
|
* If not already familiar; you can refer
|
|
* <link linkend="cogl-Blend-Strings">here</link> for an overview of what blend
|
|
* strings are and there syntax.
|
|
*
|
|
* These are all the functions available for texture combining:
|
|
* <itemizedlist>
|
|
* <listitem>REPLACE(arg0) = arg0</listitem>
|
|
* <listitem>MODULATE(arg0, arg1) = arg0 x arg1</listitem>
|
|
* <listitem>ADD(arg0, arg1) = arg0 + arg1</listitem>
|
|
* <listitem>ADD_SIGNED(arg0, arg1) = arg0 + arg1 - 0.5</listitem>
|
|
* <listitem>INTERPOLATE(arg0, arg1, arg2) = arg0 x arg2 + arg1 x (1 - arg2)</listitem>
|
|
* <listitem>SUBTRACT(arg0, arg1) = arg0 - arg1</listitem>
|
|
* <listitem>
|
|
* <programlisting>
|
|
* DOT3_RGB(arg0, arg1) = 4 x ((arg0[R] - 0.5)) * (arg1[R] - 0.5) +
|
|
* (arg0[G] - 0.5)) * (arg1[G] - 0.5) +
|
|
* (arg0[B] - 0.5)) * (arg1[B] - 0.5))
|
|
* </programlisting>
|
|
* </listitem>
|
|
* <listitem>
|
|
* <programlisting>
|
|
* DOT3_RGBA(arg0, arg1) = 4 x ((arg0[R] - 0.5)) * (arg1[R] - 0.5) +
|
|
* (arg0[G] - 0.5)) * (arg1[G] - 0.5) +
|
|
* (arg0[B] - 0.5)) * (arg1[B] - 0.5))
|
|
* </programlisting>
|
|
* </listitem>
|
|
* </itemizedlist>
|
|
*
|
|
* Refer to the
|
|
* <link linkend="cogl-Blend-String-syntax">color-source syntax</link> for
|
|
* describing the arguments. The valid source names for texture combining
|
|
* are:
|
|
* <variablelist>
|
|
* <varlistentry>
|
|
* <term>TEXTURE</term>
|
|
* <listitem>Use the color from the current texture layer</listitem>
|
|
* </varlistentry>
|
|
* <varlistentry>
|
|
* <term>TEXTURE_0, TEXTURE_1, etc</term>
|
|
* <listitem>Use the color from the specified texture layer</listitem>
|
|
* </varlistentry>
|
|
* <varlistentry>
|
|
* <term>CONSTANT</term>
|
|
* <listitem>Use the color from the constant given with
|
|
* cogl_material_set_layer_constant()</listitem>
|
|
* </varlistentry>
|
|
* <varlistentry>
|
|
* <term>PRIMARY</term>
|
|
* <listitem>Use the color of the material as set with
|
|
* cogl_material_set_color()</listitem>
|
|
* </varlistentry>
|
|
* <varlistentry>
|
|
* <term>PREVIOUS</term>
|
|
* <listitem>Either use the texture color from the previous layer, or
|
|
* if this is layer 0, use the color of the material as set with
|
|
* cogl_material_set_color()</listitem>
|
|
* </varlistentry>
|
|
* </variablelist>
|
|
*
|
|
* <refsect2 id="cogl-Layer-Combine-Examples">
|
|
* <title>Layer Combine Examples</title>
|
|
* <para>This is effectively what the default blending is:</para>
|
|
* <informalexample><programlisting>
|
|
* RGBA = MODULATE (PREVIOUS, TEXTURE)
|
|
* </programlisting></informalexample>
|
|
* <para>This could be used to cross-fade between two images, using
|
|
* the alpha component of a constant as the interpolator. The constant
|
|
* color is given by calling cogl_material_set_layer_constant.</para>
|
|
* <informalexample><programlisting>
|
|
* RGBA = INTERPOLATE (PREVIOUS, TEXTURE, CONSTANT[A])
|
|
* </programlisting></informalexample>
|
|
* </refsect2>
|
|
*
|
|
* <note>You can't give a multiplication factor for arguments as you can
|
|
* with blending.</note>
|
|
*
|
|
* Return value: %TRUE if the blend string was successfully parsed, and the
|
|
* described texture combining is supported by the underlying driver and
|
|
* or hardware. On failure, %FALSE is returned and @error is set
|
|
*
|
|
* Since: 1.0
|
|
*/
|
|
gboolean
|
|
cogl_material_set_layer_combine (CoglHandle material,
|
|
int layer_index,
|
|
const char *blend_string,
|
|
GError **error);
|
|
|
|
/**
|
|
* cogl_material_set_layer_combine_constant:
|
|
* @material: A CoglMaterial object
|
|
* @layer_index: Specifies the layer you want to specify a constant used
|
|
* for texture combining
|
|
* @constant: The constant color you want
|
|
*
|
|
* When you are using the 'CONSTANT' color source in a layer combine
|
|
* description then you can use this function to define its value.
|
|
*
|
|
* Since: 1.0
|
|
*/
|
|
void
|
|
cogl_material_set_layer_combine_constant (CoglHandle material,
|
|
int layer_index,
|
|
CoglColor *constant);
|
|
|
|
/**
|
|
* cogl_material_set_layer_matrix:
|
|
* @material: A CoglMaterial object
|
|
* @layer_index: the index for the layer inside @material
|
|
* @matrix: the transformation matrix for the layer
|
|
*
|
|
* This function lets you set a matrix that can be used to e.g. translate
|
|
* and rotate a single layer of a material used to fill your geometry.
|
|
*/
|
|
void
|
|
cogl_material_set_layer_matrix (CoglHandle material,
|
|
int layer_index,
|
|
CoglMatrix *matrix);
|
|
|
|
/**
|
|
* cogl_material_get_layers:
|
|
* @material: a #CoglHandle for a material
|
|
*
|
|
* This function lets you access a materials internal list of layers
|
|
* for iteration.
|
|
*
|
|
* Return value: (element-type Handle) (transfer none): A list of
|
|
* #CoglHandle<!-- -->'s that can be passed to the cogl_material_layer_*
|
|
* functions. The list is owned by COGL and it should not be modified or
|
|
* freed
|
|
*/
|
|
G_CONST_RETURN GList *
|
|
cogl_material_get_layers (CoglHandle material);
|
|
|
|
/**
|
|
* cogl_material_get_n_layers:
|
|
* @material: a #CoglHandle for a material
|
|
*
|
|
* Retrieves the number of layers defined for the given @material
|
|
*
|
|
* Return value: the number of layers
|
|
*
|
|
* Since: 1.0
|
|
*/
|
|
int
|
|
cogl_material_get_n_layers (CoglHandle material);
|
|
|
|
/**
|
|
* CoglMaterialLayerType:
|
|
* @COGL_MATERIAL_LAYER_TYPE_TEXTURE: The layer represents a
|
|
* <link linkend="cogl-Textures">texture</link>
|
|
*
|
|
* Available types of layers for a #CoglMaterial. This enumeration
|
|
* might be expanded in later versions.
|
|
*
|
|
* Since: 1.0
|
|
*/
|
|
typedef enum {
|
|
COGL_MATERIAL_LAYER_TYPE_TEXTURE
|
|
} CoglMaterialLayerType;
|
|
|
|
|
|
/**
|
|
* cogl_material_layer_get_type:
|
|
* @layer: A #CoglHandle for a material layer
|
|
*
|
|
* Retrieves the type of the layer
|
|
*
|
|
* Currently there is only one type of layer defined:
|
|
* %COGL_MATERIAL_LAYER_TYPE_TEXTURE, but considering we may add purely GLSL
|
|
* based layers in the future, you should write code that checks the type
|
|
* first.
|
|
*
|
|
* Return value: the type of the layer
|
|
*/
|
|
CoglMaterialLayerType
|
|
cogl_material_layer_get_type (CoglHandle layer);
|
|
|
|
/**
|
|
* cogl_material_layer_get_texture:
|
|
* @layer: A #CoglHandle for a material layer
|
|
*
|
|
* Extracts a texture handle for a specific layer.
|
|
*
|
|
* <note>In the future Cogl may support purely GLSL based layers; for those
|
|
* layers this function which will likely return %COGL_INVALID_HANDLE if you
|
|
* try to get the texture handle from them. Considering this scenario, you
|
|
* should call cogl_material_layer_get_type() first in order check it is of
|
|
* type %COGL_MATERIAL_LAYER_TYPE_TEXTURE before calling this function.</note>
|
|
*
|
|
* Return value: a #CoglHandle for the texture inside the layer
|
|
*/
|
|
CoglHandle
|
|
cogl_material_layer_get_texture (CoglHandle layer);
|
|
|
|
/**
|
|
* cogl_material_layer_get_min_filter:
|
|
* @layer: a #CoglHandle for a material layer
|
|
*
|
|
* Queries the currently set downscaling filter for a material layer
|
|
*
|
|
* Return value: the current downscaling filter
|
|
*/
|
|
CoglMaterialFilter
|
|
cogl_material_layer_get_min_filter (CoglHandle layer);
|
|
|
|
/**
|
|
* cogl_material_layer_get_mag_filter:
|
|
* @layer: a #CoglHandle for a material layer
|
|
*
|
|
* Queries the currently set downscaling filter for a material later
|
|
*
|
|
* Return value: the current downscaling filter
|
|
*/
|
|
CoglMaterialFilter
|
|
cogl_material_layer_get_mag_filter (CoglHandle layer);
|
|
|
|
/**
|
|
* cogl_material_set_layer_filters:
|
|
* @material: a #CoglHandle to a material.
|
|
* @layer_index: the layer number to change.
|
|
* @min_filter: the filter used when scaling a texture down.
|
|
* @mag_filter: the filter used when magnifying a texture.
|
|
*
|
|
* Changes the decimation and interpolation filters used when a texture is
|
|
* drawn at other scales than 100%.
|
|
*/
|
|
void
|
|
cogl_material_set_layer_filters (CoglHandle material,
|
|
int layer_index,
|
|
CoglMaterialFilter min_filter,
|
|
CoglMaterialFilter mag_filter);
|
|
|
|
G_END_DECLS
|
|
|
|
#endif /* __COGL_MATERIAL_H__ */
|