mutter/cogl/cogl-material.h
Robert Bragg 16c64054b9 material: Adds experimental cogl_material_foreach_layer API
This adds a way to iterate the layer indices of the given material since
cogl_material_get_layers has been deprecated. The user provides a
callback to be called once for each layer.

Because modification of layers in the callback may potentially
invalidate any number of the internal CoglMaterialLayer structures and
invalidate the material's layer cache this should be more robust than
cogl_material_get_layers() which used to return a const GList *
pointing directly to internal state.
2010-09-15 14:07:50 +01:00

1389 lines
46 KiB
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, see <http://www.gnu.org/licenses/>.
*
*
*/
#if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
#error "Only <cogl/cogl.h> can be included directly."
#endif
#ifndef __COGL_MATERIAL_H__
#define __COGL_MATERIAL_H__
G_BEGIN_DECLS
#include <cogl/cogl-types.h>
#include <cogl/cogl-matrix.h>
/**
* SECTION:cogl-material
* @short_description: Fuctions for creating and manipulating materials
*
* COGL allows creating and manipulating materials used to fill in
* geometry. Materials may simply be lighting attributes (such as an
* ambient and diffuse colour) or might represent one or more textures
* blended together.
*/
typedef struct _CoglMaterial CoglMaterial;
typedef struct _CoglMaterialLayer CoglMaterialLayer;
#define COGL_MATERIAL(OBJECT) ((CoglMaterial *)OBJECT)
/**
* CoglMaterialFilter:
* @COGL_MATERIAL_FILTER_NEAREST: Measuring in manhatten distance from the,
* current pixel center, use the nearest texture texel
* @COGL_MATERIAL_FILTER_LINEAR: Use the weighted average of the 4 texels
* nearest the current pixel center
* @COGL_MATERIAL_FILTER_NEAREST_MIPMAP_NEAREST: Select the mimap level whose
* texel size most closely matches the current pixel, and use the
* %COGL_MATERIAL_FILTER_NEAREST criterion
* @COGL_MATERIAL_FILTER_LINEAR_MIPMAP_NEAREST: Select the mimap level whose
* texel size most closely matches the current pixel, and use the
* %COGL_MATERIAL_FILTER_LINEAR criterion
* @COGL_MATERIAL_FILTER_NEAREST_MIPMAP_LINEAR: Select the two mimap levels
* whose texel size most closely matches the current pixel, use
* the %COGL_MATERIAL_FILTER_NEAREST criterion on each one and take
* their weighted average
* @COGL_MATERIAL_FILTER_LINEAR_MIPMAP_LINEAR: Select the two mimap levels
* whose texel size most closely matches the current pixel, use
* the %COGL_MATERIAL_FILTER_LINEAR criterion on each one and take
* their weighted average
*
* Texture filtering is used whenever the current pixel maps either to more
* than one texture element (texel) or less than one. These filter enums
* correspond to different strategies used to come up with a pixel color, by
* possibly referring to multiple neighbouring texels and taking a weighted
* average or simply using the nearest texel.
*/
typedef enum {
COGL_MATERIAL_FILTER_NEAREST = GL_NEAREST,
COGL_MATERIAL_FILTER_LINEAR = GL_LINEAR,
COGL_MATERIAL_FILTER_NEAREST_MIPMAP_NEAREST = GL_NEAREST_MIPMAP_NEAREST,
COGL_MATERIAL_FILTER_LINEAR_MIPMAP_NEAREST = GL_LINEAR_MIPMAP_NEAREST,
COGL_MATERIAL_FILTER_NEAREST_MIPMAP_LINEAR = GL_NEAREST_MIPMAP_LINEAR,
COGL_MATERIAL_FILTER_LINEAR_MIPMAP_LINEAR = GL_LINEAR_MIPMAP_LINEAR
} CoglMaterialFilter;
/**
* CoglMaterialWrapMode:
* @COGL_MATERIAL_WRAP_MODE_REPEAT: The texture will be repeated. This
* is useful for example to draw a tiled background.
* @COGL_MATERIAL_WRAP_MODE_CLAMP_TO_EDGE: The coordinates outside the
* range 0→1 will sample copies of the edge pixels of the
* texture. This is useful to avoid artifacts if only one copy of
* the texture is being rendered.
* @COGL_MATERIAL_WRAP_MODE_AUTOMATIC: Cogl will try to automatically
* decide which of the above two to use. For cogl_rectangle(), it
* will use repeat mode if any of the texture coordinates are
* outside the range 0→1, otherwise it will use clamp to edge. For
* cogl_polygon() it will always use repeat mode. For
* cogl_vertex_buffer_draw() it will use repeat mode except for
* layers that have point sprite coordinate generation enabled. This
* is the default value.
*
* The wrap mode specifies what happens when texture coordinates
* outside the range 0→1 are used. Note that if the filter mode is
* anything but %COGL_MATERIAL_FILTER_NEAREST then texels outside the
* range 0→1 might be used even when the coordinate is exactly 0 or 1
* because OpenGL will try to sample neighbouring pixels. For example
* if you are trying to render the full texture then you may get
* artifacts around the edges when the pixels from the other side are
* merged in if the wrap mode is set to repeat.
*
* Since: 1.4
*/
/* GL_ALWAYS is just used here as a value that is known not to clash
* with any valid GL wrap modes
*
* XXX: keep the values in sync with the CoglMaterialWrapModeInternal
* enum so no conversion is actually needed.
*/
typedef enum {
COGL_MATERIAL_WRAP_MODE_REPEAT = GL_REPEAT,
COGL_MATERIAL_WRAP_MODE_CLAMP_TO_EDGE = GL_CLAMP_TO_EDGE,
COGL_MATERIAL_WRAP_MODE_AUTOMATIC = GL_ALWAYS
} CoglMaterialWrapMode;
/**
* cogl_material_new:
*
* Allocates and initializes a blank white material
*
* Return value: a pointer to a new #CoglMaterial
*/
CoglMaterial *
cogl_material_new (void);
/**
* cogl_material_copy:
* @source: a #CoglMaterial object to copy
*
* Creates a new material with the configuration copied from the
* source material.
*
* We would strongly advise developers to always aim to use
* cogl_material_copy() instead of cogl_material_new() whenever there will
* be any similarity between two materials. Copying a material helps Cogl
* keep track of a materials ancestry which we may use to help minimize GPU
* state changes.
*
* Returns: a pointer to the newly allocated #CoglMaterial
*
* Since: 1.2
*/
CoglMaterial *
cogl_material_copy (CoglMaterial *source);
#ifndef COGL_DISABLE_DEPRECATED
/**
* cogl_material_ref:
* @material: a #CoglMaterial object.
*
* Increment the reference count for a #CoglMaterial.
*
* Return value: the @material.
*
* Since: 1.0
*
* Deprecated: 1.2: Use cogl_object_ref() instead
*/
CoglHandle
cogl_material_ref (CoglHandle handle) G_GNUC_DEPRECATED;
/**
* cogl_material_unref:
* @material: a #CoglMaterial object.
*
* Decrement the reference count for a #CoglMaterial.
*
* Since: 1.0
*
* Deprecated: 1.2: Use cogl_object_unref() instead
*/
void
cogl_material_unref (CoglHandle handle) G_GNUC_DEPRECATED;
#endif /* COGL_DISABLE_DEPRECATED */
/**
* cogl_is_material:
* @handle: A CoglHandle
*
* Gets whether the given handle references an existing material object.
*
* Return value: %TRUE if the handle references a #CoglMaterial,
* %FALSE otherwise
*/
gboolean
cogl_is_material (CoglHandle handle);
/**
* cogl_material_set_color:
* @material: A #CoglMaterial object
* @color: The components of the color
*
* Sets the basic color of the material, used when no lighting is enabled.
*
* Note that if you don't add any layers to the material then the color
* will be blended unmodified with the destination; the default blend
* expects premultiplied colors: for example, use (0.5, 0.0, 0.0, 0.5) for
* semi-transparent red. See cogl_color_premultiply().
*
* The default value is (1.0, 1.0, 1.0, 1.0)
*
* Since: 1.0
*/
void
cogl_material_set_color (CoglMaterial *material,
const CoglColor *color);
/**
* cogl_material_set_color4ub:
* @material: A #CoglMaterial object
* @red: The red component
* @green: The green component
* @blue: The blue component
* @alpha: The alpha component
*
* Sets the basic color of the material, used when no lighting is enabled.
*
* The default value is (0xff, 0xff, 0xff, 0xff)
*
* Since: 1.0
*/
void
cogl_material_set_color4ub (CoglMaterial *material,
guint8 red,
guint8 green,
guint8 blue,
guint8 alpha);
/**
* cogl_material_set_color4f:
* @material: A #CoglMaterial object
* @red: The red component
* @green: The green component
* @blue: The blue component
* @alpha: The alpha component
*
* Sets the basic color of the material, used when no lighting is enabled.
*
* The default value is (1.0, 1.0, 1.0, 1.0)
*
* Since: 1.0
*/
void
cogl_material_set_color4f (CoglMaterial *material,
float red,
float green,
float blue,
float alpha);
/**
* cogl_material_get_color:
* @material: A #CoglMaterial object
* @color: (out): The location to store the color
*
* Retrieves the current material color.
*
* Since: 1.0
*/
void
cogl_material_get_color (CoglMaterial *material,
CoglColor *color);
/**
* cogl_material_set_ambient:
* @material: A #CoglMaterial object
* @ambient: The components of the desired ambient color
*
* Sets the material's ambient color, in the standard OpenGL lighting
* model. The ambient color affects the overall color of the object.
*
* Since the diffuse color will be intense when the light hits the surface
* directly, the ambient will be most apparent where the light hits at a
* slant.
*
* The default value is (0.2, 0.2, 0.2, 1.0)
*
* Since: 1.0
*/
void
cogl_material_set_ambient (CoglMaterial *material,
const CoglColor *ambient);
/**
* cogl_material_get_ambient:
* @material: A #CoglMaterial object
* @ambient: The location to store the ambient color
*
* Retrieves the current ambient color for @material
*
* Since: 1.0
*/
void
cogl_material_get_ambient (CoglMaterial *material,
CoglColor *ambient);
/**
* cogl_material_set_diffuse:
* @material: A #CoglMaterial object
* @diffuse: The components of the desired diffuse color
*
* Sets the material's diffuse color, in the standard OpenGL lighting
* model. The diffuse color is most intense where the light hits the
* surface directly - perpendicular to the surface.
*
* The default value is (0.8, 0.8, 0.8, 1.0)
*
* Since: 1.0
*/
void
cogl_material_set_diffuse (CoglMaterial *material,
const CoglColor *diffuse);
/**
* cogl_material_get_diffuse:
* @material: A #CoglMaterial object
* @diffuse: The location to store the diffuse color
*
* Retrieves the current diffuse color for @material
*
* Since: 1.0
*/
void
cogl_material_get_diffuse (CoglMaterial *material,
CoglColor *diffuse);
/**
* cogl_material_set_ambient_and_diffuse:
* @material: A #CoglMaterial object
* @color: The components of the desired ambient and diffuse colors
*
* Conveniently sets the diffuse and ambient color of @material at the same
* time. See cogl_material_set_ambient() and cogl_material_set_diffuse().
*
* The default ambient color is (0.2, 0.2, 0.2, 1.0)
*
* The default diffuse color is (0.8, 0.8, 0.8, 1.0)
*
* Since: 1.0
*/
void
cogl_material_set_ambient_and_diffuse (CoglMaterial *material,
const CoglColor *color);
/**
* cogl_material_set_specular:
* @material: A #CoglMaterial object
* @specular: The components of the desired specular color
*
* Sets the material's specular color, in the standard OpenGL lighting
* model. The intensity of the specular color depends on the viewport
* position, and is brightest along the lines of reflection.
*
* The default value is (0.0, 0.0, 0.0, 1.0)
*
* Since: 1.0
*/
void
cogl_material_set_specular (CoglMaterial *material,
const CoglColor *specular);
/**
* cogl_material_get_specular:
* @material: A #CoglMaterial object
* @specular: The location to store the specular color
*
* Retrieves the materials current specular color.
*
* Since: 1.0
*/
void
cogl_material_get_specular (CoglMaterial *material,
CoglColor *specular);
/**
* cogl_material_set_shininess:
* @material: A #CoglMaterial object
* @shininess: The desired shininess; must be >= 0.0
*
* Sets the shininess of the material, in the standard OpenGL lighting
* model, which determines the size of the specular highlights. A
* higher @shininess will produce smaller highlights which makes the
* object appear more shiny.
*
* The default value is 0.0
*
* Since: 1.0
*/
void
cogl_material_set_shininess (CoglMaterial *material,
float shininess);
/**
* cogl_material_get_shininess:
* @material: A #CoglMaterial object
*
* Retrieves the materials current emission color.
*
* Return value: The materials current shininess value
*
* Since: 1.0
*/
float
cogl_material_get_shininess (CoglMaterial *material);
/**
* cogl_material_set_emission:
* @material: A #CoglMaterial object
* @emission: The components of the desired emissive color
*
* Sets the material's emissive color, in the standard OpenGL lighting
* model. It will look like the surface is a light source emitting this
* color.
*
* The default value is (0.0, 0.0, 0.0, 1.0)
*
* Since: 1.0
*/
void
cogl_material_set_emission (CoglMaterial *material,
const CoglColor *emission);
/**
* cogl_material_get_emission:
* @material: A #CoglMaterial object
* @emission: The location to store the emission color
*
* Retrieves the materials current emission color.
*
* Since: 1.0
*/
void
cogl_material_get_emission (CoglMaterial *material,
CoglColor *emission);
/**
* CoglMaterialAlphaFunc:
* @COGL_MATERIAL_ALPHA_FUNC_NEVER: Never let the fragment through.
* @COGL_MATERIAL_ALPHA_FUNC_LESS: Let the fragment through if the incoming
* alpha value is less than the reference alpha value
* @COGL_MATERIAL_ALPHA_FUNC_EQUAL: Let the fragment through if the incoming
* alpha value equals the reference alpha value
* @COGL_MATERIAL_ALPHA_FUNC_LEQUAL: Let the fragment through if the incoming
* alpha value is less than or equal to the reference alpha value
* @COGL_MATERIAL_ALPHA_FUNC_GREATER: Let the fragment through if the incoming
* alpha value is greater than the reference alpha value
* @COGL_MATERIAL_ALPHA_FUNC_NOTEQUAL: Let the fragment through if the incoming
* alpha value does not equal the reference alpha value
* @COGL_MATERIAL_ALPHA_FUNC_GEQUAL: Let the fragment through if the incoming
* alpha value is greater than or equal to the reference alpha value.
* @COGL_MATERIAL_ALPHA_FUNC_ALWAYS: Always let the fragment through.
*
* Alpha testing happens before blending primitives with the framebuffer and
* gives an opportunity to discard fragments based on a comparison with the
* incoming alpha value and a reference alpha value. The #CoglMaterialAlphaFunc
* determines how the comparison is done.
*/
typedef enum {
COGL_MATERIAL_ALPHA_FUNC_NEVER = GL_NEVER,
COGL_MATERIAL_ALPHA_FUNC_LESS = GL_LESS,
COGL_MATERIAL_ALPHA_FUNC_EQUAL = GL_EQUAL,
COGL_MATERIAL_ALPHA_FUNC_LEQUAL = GL_LEQUAL,
COGL_MATERIAL_ALPHA_FUNC_GREATER = GL_GREATER,
COGL_MATERIAL_ALPHA_FUNC_NOTEQUAL = GL_NOTEQUAL,
COGL_MATERIAL_ALPHA_FUNC_GEQUAL = GL_GEQUAL,
COGL_MATERIAL_ALPHA_FUNC_ALWAYS = GL_ALWAYS
} CoglMaterialAlphaFunc;
/**
* cogl_material_set_alpha_test_function:
* @material: A #CoglMaterial object
* @alpha_func: A @CoglMaterialAlphaFunc constant
* @alpha_reference: A reference point that the chosen alpha function uses
* to compare incoming fragments to.
*
* Before a primitive is blended with the framebuffer, it goes through an
* alpha test stage which lets you discard fragments based on the current
* alpha value. This function lets you change the function used to evaluate
* the alpha channel, and thus determine which fragments are discarded
* and which continue on to the blending stage.
*
* The default is %COGL_MATERIAL_ALPHA_FUNC_ALWAYS
*
* Since: 1.0
*/
void
cogl_material_set_alpha_test_function (CoglMaterial *material,
CoglMaterialAlphaFunc alpha_func,
float alpha_reference);
/**
* cogl_material_set_blend:
* @material: A #CoglMaterial object
* @blend_string: A <link linkend="cogl-Blend-Strings">Cogl blend string</link>
* describing the desired blend function.
* @error: return location for a #GError that may report lack of driver
* support if you give separate blend string statements for the alpha
* channel and RGB channels since some drivers, or backends such as
* GLES 1.1, don't support this feature. May be %NULL, in which case a
* warning will be printed out using GLib's logging facilities if an
* error is encountered.
*
* If not already familiar; please refer <link linkend="cogl-Blend-Strings">here</link>
* for an overview of what blend strings are, and their syntax.
*
* Blending occurs after the alpha test function, and combines fragments with
* the framebuffer.
* Currently the only blend function Cogl exposes is ADD(). So any valid
* blend statements will be of the form:
*
* |[
* &lt;channel-mask&gt;=ADD(SRC_COLOR*(&lt;factor&gt;), DST_COLOR*(&lt;factor&gt;))
* ]|
*
* <warning>The brackets around blend factors are currently not
* optional!</warning>
*
* 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 (CoglMaterial *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 (CoglMaterial *material,
const CoglColor *constant_color);
/**
* cogl_material_set_point_size:
* @material: a #CoglHandle to a material.
* @size: the new point size.
*
* Changes the size of points drawn when %COGL_VERTICES_MODE_POINTS is
* used with the vertex buffer API. Note that typically the GPU will
* only support a limited minimum and maximum range of point sizes. If
* the chosen point size is outside that range then the nearest value
* within that range will be used instead. The size of a point is in
* screen space so it will be the same regardless of any
* transformations. The default point size is 1.0.
*
* Since: 1.4
*/
void
cogl_material_set_point_size (CoglHandle material,
float point_size);
/**
* cogl_material_get_point_size:
* @material: a #CoglHandle to a material.
*
* Get the size of points drawn when %COGL_VERTICES_MODE_POINTS is
* used with the vertex buffer API.
*
* Return value: the point size of the material.
*
* Since: 1.4
*/
float
cogl_material_get_point_size (CoglHandle material);
/**
* cogl_material_get_user_program:
* @material: a #CoglMaterial object.
*
* Queries what user program has been associated with the given
* @material using cogl_material_set_user_program().
*
* Return value: The current user program or %COGL_INVALID_HANDLE.
*
* Since: 1.4
*/
CoglHandle
cogl_material_get_user_program (CoglMaterial *material);
/**
* cogl_material_set_user_program:
* @material: a #CoglMaterial object.
* @program: A #CoglHandle to a linked CoglProgram
*
* Associates a linked CoglProgram with the given material so that the
* program can take full control of vertex and/or fragment processing.
*
* This is an example of how it can be used to associate an ARBfp
* program with a #CoglMaterial:
* |[
* CoglHandle shader;
* CoglHandle program;
* CoglMaterial *material;
*
* shader = cogl_create_shader (COGL_SHADER_TYPE_FRAGMENT);
* cogl_shader_source (shader,
* "!!ARBfp1.0\n"
* "MOV result.color,fragment.color;\n"
* "END\n");
* cogl_shader_compile (shader);
*
* program = cogl_create_program ();
* cogl_program_attach_shader (program, shader);
* cogl_program_link (program);
*
* material = cogl_material_new ();
* cogl_material_set_user_program (material, program);
*
* cogl_set_source_color4ub (0xff, 0x00, 0x00, 0xff);
* cogl_rectangle (0, 0, 100, 100);
* ]|
*
* It is possibly worth keeping in mind that this API is not part of
* the long term design for how we want to expose shaders to Cogl
* developers (We are planning on deprecating the cogl_program and
* cogl_shader APIs in favour of a "snippet" framework) but in the
* meantime we hope this will handle most practical GLSL and ARBfp
* requirements.
*
* Also remember you need to check for either the
* %COGL_FEATURE_SHADERS_GLSL or %COGL_FEATURE_SHADERS_ARBFP before
* using the cogl_program or cogl_shader API.
*
* Since: 1.4
*/
void
cogl_material_set_user_program (CoglMaterial *material,
CoglHandle program);
/**
* cogl_material_set_layer:
* @material: A #CoglMaterial 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 (CoglMaterial *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 (CoglMaterial *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 (CoglMaterial *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 (CoglMaterial *material,
int layer_index,
const 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 (CoglMaterial *material,
int layer_index,
const CoglMatrix *matrix);
/**
* cogl_material_get_layers:
* @material: A #CoglMaterial object
*
* This function lets you access a material's internal list of layers
* for iteration.
*
* <note>You should avoid using this API if possible since it was only
* made public by mistake and will be deprecated when we have
* suitable alternative.</note>
*
* <note>It's important to understand that the list returned may not
* remain valid if you modify the material or any of the layers in any
* way and so you would have to re-get the list in that
* situation.</note>
*
* Return value: (element-type CoglMaterialLayer) (transfer none): A
* list of #CoglMaterialLayer<!-- -->'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 (CoglMaterial *material);
/**
* cogl_material_get_n_layers:
* @material: A #CoglMaterial object
*
* 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 (CoglMaterial *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 #CoglMaterialLayer object
*
* 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 (CoglMaterialLayer *layer);
/**
* cogl_material_layer_get_texture:
* @layer: A #CoglMaterialLayer object
*
* 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: (transfer none): a #CoglHandle for the texture inside the layer
*/
CoglHandle
cogl_material_layer_get_texture (CoglMaterialLayer *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 (CoglMaterialLayer *layer);
/**
* cogl_material_layer_get_mag_filter:
* @layer: A #CoglMaterialLayer object
*
* Queries the currently set downscaling filter for a material later
*
* Return value: the current downscaling filter
*/
CoglMaterialFilter
cogl_material_layer_get_mag_filter (CoglMaterialLayer *layer);
/**
* cogl_material_set_layer_filters:
* @material: A #CoglMaterial object
* @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 (CoglMaterial *material,
int layer_index,
CoglMaterialFilter min_filter,
CoglMaterialFilter mag_filter);
/**
* cogl_material_set_layer_point_sprite_coords_enabled:
* @material: a #CoglHandle to a material.
* @layer_index: the layer number to change.
* @enable: whether to enable point sprite coord generation.
* @error: A return location for a GError, or NULL to ignore errors.
*
* When rendering points, if @enable is %TRUE then the texture
* coordinates for this layer will be replaced with coordinates that
* vary from 0.0 to 1.0 across the primitive. The top left of the
* point will have the coordinates 0.0,0.0 and the bottom right will
* have 1.0,1.0. If @enable is %FALSE then the coordinates will be
* fixed for the entire point.
*
* This function will only work if %COGL_FEATURE_POINT_SPRITE is
* available. If the feature is not available then the function will
* return %FALSE and set @error.
*
* Return value: %TRUE if the function succeeds, %FALSE otherwise.
* Since: 1.4
*/
gboolean
cogl_material_set_layer_point_sprite_coords_enabled (CoglMaterial *material,
int layer_index,
gboolean enable,
GError **error);
/**
* cogl_material_get_layer_point_sprite_coords_enabled:
* @material: a #CoglHandle to a material.
* @layer_index: the layer number to check.
*
* Gets whether point sprite coordinate generation is enabled for this
* texture layer.
*
* Return value: whether the texture coordinates will be replaced with
* point sprite coordinates.
*
* Since: 1.4
*/
gboolean
cogl_material_get_layer_point_sprite_coords_enabled (CoglMaterial *material,
int layer_index);
/**
* cogl_material_set_layer_wrap_mode_s:
* @material: A #CoglMaterial object
* @layer_index: the layer number to change.
* @mode: the new wrap mode
*
* Sets the wrap mode for the 's' coordinate of texture lookups on this layer.
*
* Since: 1.4
*/
void
cogl_material_set_layer_wrap_mode_s (CoglMaterial *material,
int layer_index,
CoglMaterialWrapMode mode);
/**
* cogl_material_set_layer_wrap_mode_t:
* @material: A #CoglMaterial object
* @layer_index: the layer number to change.
* @mode: the new wrap mode
*
* Sets the wrap mode for the 't' coordinate of texture lookups on this layer.
*
* Since: 1.4
*/
void
cogl_material_set_layer_wrap_mode_t (CoglMaterial *material,
int layer_index,
CoglMaterialWrapMode mode);
/**
* cogl_material_set_layer_wrap_mode_p:
* @material: A #CoglMaterial object
* @layer_index: the layer number to change.
* @mode: the new wrap mode
*
* Sets the wrap mode for the 'p' coordinate of texture lookups on
* this layer. 'p' is the third coordinate.
*
* Since: 1.4
*/
void
cogl_material_set_layer_wrap_mode_p (CoglMaterial *material,
int layer_index,
CoglMaterialWrapMode mode);
/**
* cogl_material_set_layer_wrap_mode:
* @material: A #CoglMaterial object
* @layer_index: the layer number to change.
* @mode: the new wrap mode
*
* Sets the wrap mode for all three coordinates of texture lookups on
* this layer. This is equivalent to calling
* cogl_material_set_layer_wrap_mode_s(),
* cogl_material_set_layer_wrap_mode_t() and
* cogl_material_set_layer_wrap_mode_p() separately.
*
* Since: 1.4
*/
void
cogl_material_set_layer_wrap_mode (CoglMaterial *material,
int layer_index,
CoglMaterialWrapMode mode);
/**
* cogl_material_layer_get_wrap_mode_s:
* @layer: A #CoglMaterialLayer object
*
* Gets the wrap mode for the 's' coordinate of texture lookups on this layer.
*
* Return value: the wrap mode value for the s coordinate.
*
* Since: 1.4
*/
CoglMaterialWrapMode
cogl_material_layer_get_wrap_mode_s (CoglMaterialLayer *layer);
/**
* cogl_material_layer_get_wrap_mode_t:
* @layer: A #CoglMaterialLayer object
*
* Gets the wrap mode for the 't' coordinate of texture lookups on this layer.
*
* Return value: the wrap mode value for the t coordinate.
*
* Since: 1.4
*/
CoglMaterialWrapMode
cogl_material_layer_get_wrap_mode_t (CoglMaterialLayer *layer);
/**
* cogl_material_layer_get_wrap_mode_p:
* @layer: A #CoglMaterialLayer object
*
* Gets the wrap mode for the 'p' coordinate of texture lookups on
* this layer. 'p' is the third coordinate.
*
* Return value: the wrap mode value for the p coordinate.
*
* Since: 1.4
*/
CoglMaterialWrapMode
cogl_material_layer_get_wrap_mode_p (CoglMaterialLayer *layer);
/* XXX: should this be CoglMaterialDepthTestFunction?
* It makes it very verbose but would be consistent with
* CoglMaterialWrapMode */
/**
* CoglDepthTestFunction:
* @COGL_DEPTH_TEST_FUNCTION_NEVER: Never passes.
* @COGL_DEPTH_TEST_FUNCTION_LESS: Passes if the fragment's depth
* value is less than the value currently in the depth buffer.
* @COGL_DEPTH_TEST_FUNCTION_EQUAL: Passes if the fragment's depth
* value is equal to the value currently in the depth buffer.
* @COGL_DEPTH_TEST_FUNCTION_LEQUAL: Passes if the fragment's depth
* value is less or equal to the value currently in the depth buffer.
* @COGL_DEPTH_TEST_FUNCTION_GREATER: Passes if the fragment's depth
* value is greater than the value currently in the depth buffer.
* @COGL_DEPTH_TEST_FUNCTION_NOTEQUAL: Passes if the fragment's depth
* value is not equal to the value currently in the depth buffer.
* @COGL_DEPTH_TEST_FUNCTION_GEQUAL: Passes if the fragment's depth
* value greater than or equal to the value currently in the depth buffer.
* @COGL_DEPTH_TEST_FUNCTION_ALWAYS: Always passes.
*
* When using depth testing one of these functions is used to compare
* the depth of an incoming fragment against the depth value currently
* stored in the depth buffer. The function is changed using
* cogl_material_set_depth_test_function().
*
* The test is only done when depth testing is explicitly enabled. (See
* cogl_material_set_depth_test_enabled())
*/
typedef enum
{
COGL_DEPTH_TEST_FUNCTION_NEVER = GL_NEVER,
COGL_DEPTH_TEST_FUNCTION_LESS = GL_LESS,
COGL_DEPTH_TEST_FUNCTION_EQUAL = GL_EQUAL,
COGL_DEPTH_TEST_FUNCTION_LEQUAL = GL_LEQUAL,
COGL_DEPTH_TEST_FUNCTION_GREATER = GL_GREATER,
COGL_DEPTH_TEST_FUNCTION_NOTEQUAL = GL_NOTEQUAL,
COGL_DEPTH_TEST_FUNCTION_GEQUAL = GL_GEQUAL,
COGL_DEPTH_TEST_FUNCTION_ALWAYS = GL_ALWAYS
} CoglDepthTestFunction;
/* XXX: to avoid having to split this into a separate include that can
* in #included internally without needing the
* COGL_ENABLE_EXPERIMENTAL_API define this isn't guarded. It's still
* considered experimental but it's guarded instead by the fact that
* there's no corresponding API. */
#ifdef COGL_ENABLE_EXPERIMENTAL_API
/**
* cogl_material_set_depth_test_enabled:
* @material: A #CoglMaterial object
* @enable: The enable state you want
*
* Enables or disables depth testing according to the value of
* @enable.
*
* If depth testing is enable then the #CoglDepthTestFunction set
* using cogl_material_set_depth_test_function() us used to evaluate
* the depth value of incoming fragments against the corresponding
* value stored in the current depth buffer, and if the test passes
* then the fragments depth value is used to update the depth buffer.
* (unless you have disabled depth writing via
* cogl_material_set_depth_writing_enabled ())
*
* By default depth testing is disabled.
*
* Since: 1.4
* Stability: Unstable
*/
void
cogl_material_set_depth_test_enabled (CoglMaterial *material,
gboolean enable);
/**
* cogl_material_get_depth_test_enabled:
* @material: A #CoglMaterial object
*
* Gets the current depth test enabled state as previously set by
* cogl_material_set_depth_test_enabled().
*
* Returns: The material's current depth test enabled state.
* Since: 1.4
* Stability: Unstable
*/
gboolean
cogl_material_get_depth_test_enabled (CoglMaterial *material);
/**
* cogl_material_set_depth_writing_enabled:
* @material: A #CoglMaterial object
* @enable: The enable state you want
*
* Enables or disables depth buffer writing according to the value of
* @enable. Normally when depth testing is enabled and the comparison
* between a fragment's depth value and the corresponding depth buffer
* value passes then the fragment's depth is written to the depth
* buffer unless writing is disabled here.
*
* By default depth writing is enabled
*
* Since: 1.4
* Stability: Unstable
*/
void
cogl_material_set_depth_writing_enabled (CoglMaterial *material,
gboolean enable);
/**
* cogl_material_get_depth_writing_enabled:
* @material: A #CoglMaterial object
*
* Gets the depth writing enable state as set by the corresponding
* cogl_material_set_depth_writing_enabled.
*
* Returns: The current depth writing enable state
* Since: 1.4
* Stability: Unstable
*/
gboolean
cogl_material_get_depth_writing_enabled (CoglMaterial *material);
/**
* cogl_material_set_depth_test_function:
* @material: A #CoglMaterial object
* @function: The #CoglDepthTestFunction to set
*
* Sets the #CoglDepthTestFunction used to compare the depth value of
* an incoming fragment against the corresponding value in the current
* depth buffer.
*
* Since: 1.4
* Stability: Unstable
*/
void
cogl_material_set_depth_test_function (CoglMaterial *material,
CoglDepthTestFunction function);
/**
* cogl_material_get_depth_test_function:
* @material: A #CoglMaterial object
*
* Gets the current depth test enable state as previously set via
* cogl_material_set_depth_test_enabled().
*
* Returns: The current depth test enable state.
* Since: 1.4
* Stability: Unstable
*/
CoglDepthTestFunction
cogl_material_get_depth_test_function (CoglMaterial *material);
/**
* cogl_material_set_depth_range:
* @material: A #CoglMaterial object
* @near_val: The near component of the desired depth range which will be
* clamped to the range [0, 1]
* @far_val: The far component of the desired depth range which will be
* clamped to the range [0, 1]
* @error: location to store an error of type #CoglError
*
* Sets the range to map depth values in normalized device coordinates
* to before writing out to a depth buffer.
*
* After your geometry has be transformed, clipped and had perspective
* division applied placing it in normalized device
* coordinates all depth values between the near and far z clipping
* planes are in the range -1 to 1. Before writing any depth value to
* the depth buffer though the value is mapped into the range [0, 1].
*
* With this function you can change the range which depth values are
* mapped too although the range must still lye within the range [0,
* 1].
*
* If your driver does not support this feature (for example you are
* using GLES 1 drivers) then this will return %FALSE and set an error
* if @error isn't NULL. You can check ahead of time for the
* %COGL_FEATURE_DEPTH_RANGE feature with cogl_features_available() to
* know if this function will succeed.
*
* By default normalized device coordinate depth values are mapped to
* the full range of depth buffer values, [0, 1].
*
* Returns: %TRUE if driver support is available else %FALSE.
*
* Since: 1.4
* Stability: Unstable
*/
gboolean
cogl_material_set_depth_range (CoglMaterial *material,
float near_val,
float far_val,
GError **error);
/**
* cogl_material_get_depth_range_mapping:
* @material: A #CoglMaterial object
* @near_val: A pointer to store the near component of the depth range
* @far_val: A pointer to store the far component of the depth range
*
* Gets the current range to which normalized depth values are mapped
* before writing to the depth buffer. This corresponds to the range
* set with cogl_material_set_depth_range().
*
* Since: 1.4
* Stability: Unstable
*/
void
cogl_material_get_depth_range (CoglMaterial *material,
float *near_val,
float *far_val);
/**
* CoglMaterialLayerCallback:
* @material: The #CoglMaterial whos layers are being iterated
* @layer_index: The current layer index
* @user_data: The private data passed to cogl_material_foreach_layer()
*
* The callback prototype used with cogl_material_foreach_layer() for
* iterating all the layers of a @material.
*
* Since: 1.4
* Stability: Unstable
*/
typedef gboolean (*CoglMaterialLayerCallback) (CoglMaterial *material,
int layer_index,
void *user_data);
/**
* cogl_material_foreach_layer:
* @material: A #CoglMaterial object
* @callback: A #CoglMaterialLayerCallback to be called for each layer
* index
* @user_data: Private data that will be passed to the callback
*
* Iterates all the layer indices of the given @material.
*
* Since: 1.4
* Stability: Unstable
*/
void
cogl_material_foreach_layer (CoglMaterial *material,
CoglMaterialLayerCallback callback,
void *user_data);
#endif /* COGL_ENABLE_EXPERIMENTAL_API */
G_END_DECLS
#endif /* __COGL_MATERIAL_H__ */