mutter/cogl/cogl-pipeline-layer-state.h
Robert Bragg db6c452aaa pipeline: split out all layer state apis
As part of an on-going effort to get cogl-pipeline.c into a more
maintainable state this splits out all the apis relating just to
layer state. This just leaves code relating to the core CoglPipeline
and CoglPipelineLayer design left in cogl-pipeline.c.

This splits out around 2k more lines from cogl-pipeline.c although we
are still left with nearly 4k lines so we still have some way to go!

Reviewed-by: Neil Roberts <neil@linux.intel.com>
2011-09-19 16:40:00 +01:00

504 lines
18 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_PIPELINE_LAYER_STATE_H__
#define __COGL_PIPELINE_LAYER_STATE_H__
#include <cogl/cogl-pipeline.h>
#include <cogl/cogl-color.h>
#include <cogl/cogl-matrix.h>
#include <cogl/cogl-texture.h>
#include <glib.h>
G_BEGIN_DECLS
#ifdef COGL_ENABLE_EXPERIMENTAL_API
/**
* CoglPipelineFilter:
* @COGL_PIPELINE_FILTER_NEAREST: Measuring in manhatten distance from the,
* current pixel center, use the nearest texture texel
* @COGL_PIPELINE_FILTER_LINEAR: Use the weighted average of the 4 texels
* nearest the current pixel center
* @COGL_PIPELINE_FILTER_NEAREST_MIPMAP_NEAREST: Select the mimap level whose
* texel size most closely matches the current pixel, and use the
* %COGL_PIPELINE_FILTER_NEAREST criterion
* @COGL_PIPELINE_FILTER_LINEAR_MIPMAP_NEAREST: Select the mimap level whose
* texel size most closely matches the current pixel, and use the
* %COGL_PIPELINE_FILTER_LINEAR criterion
* @COGL_PIPELINE_FILTER_NEAREST_MIPMAP_LINEAR: Select the two mimap levels
* whose texel size most closely matches the current pixel, use
* the %COGL_PIPELINE_FILTER_NEAREST criterion on each one and take
* their weighted average
* @COGL_PIPELINE_FILTER_LINEAR_MIPMAP_LINEAR: Select the two mimap levels
* whose texel size most closely matches the current pixel, use
* the %COGL_PIPELINE_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_PIPELINE_FILTER_NEAREST = 0x2600,
COGL_PIPELINE_FILTER_LINEAR = 0x2601,
COGL_PIPELINE_FILTER_NEAREST_MIPMAP_NEAREST = 0x2700,
COGL_PIPELINE_FILTER_LINEAR_MIPMAP_NEAREST = 0x2701,
COGL_PIPELINE_FILTER_NEAREST_MIPMAP_LINEAR = 0x2702,
COGL_PIPELINE_FILTER_LINEAR_MIPMAP_LINEAR = 0x2703
} CoglPipelineFilter;
/* NB: these values come from the equivalents in gl.h */
/**
* CoglPipelineWrapMode:
* @COGL_PIPELINE_WRAP_MODE_REPEAT: The texture will be repeated. This
* is useful for example to draw a tiled background.
* @COGL_PIPELINE_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_PIPELINE_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_PIPELINE_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: 2.0
*/
/* 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 CoglPipelineWrapModeInternal
* enum so no conversion is actually needed.
*/
typedef enum {
COGL_PIPELINE_WRAP_MODE_REPEAT = 0x2901,
COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE = 0x812F,
COGL_PIPELINE_WRAP_MODE_AUTOMATIC = 0x0207
} CoglPipelineWrapMode;
/* NB: these values come from the equivalents in gl.h */
#define cogl_pipeline_set_layer_texture cogl_pipeline_set_layer_texture_EXP
/**
* cogl_pipeline_set_layer:
* @pipeline: A #CoglPipeline 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 pipeline 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 pipeline layers, such
* as purely GLSL based layers.</note>
*
* Since: 2.0
*/
void
cogl_pipeline_set_layer_texture (CoglPipeline *pipeline,
int layer_index,
CoglHandle texture);
#define cogl_pipeline_remove_layer cogl_pipeline_remove_layer_EXP
/**
* cogl_pipeline_remove_layer:
* @pipeline: A #CoglPipeline object
* @layer_index: Specifies the layer you want to remove
*
* This function removes a layer from your pipeline
*/
void
cogl_pipeline_remove_layer (CoglPipeline *pipeline,
int layer_index);
#define cogl_pipeline_set_layer_combine cogl_pipeline_set_layer_combine_EXP
/**
* cogl_pipeline_set_layer_combine:
* @pipeline: A #CoglPipeline 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_pipeline_set_layer_constant()</listitem>
* </varlistentry>
* <varlistentry>
* <term>PRIMARY</term>
* <listitem>Use the color of the pipeline as set with
* cogl_pipeline_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 pipeline as set with
* cogl_pipeline_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_pipeline_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: 2.0
*/
gboolean
cogl_pipeline_set_layer_combine (CoglPipeline *pipeline,
int layer_index,
const char *blend_string,
GError **error);
#define cogl_pipeline_set_layer_combine_constant \
cogl_pipeline_set_layer_combine_constant_EXP
/**
* cogl_pipeline_set_layer_combine_constant:
* @pipeline: A #CoglPipeline 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: 2.0
*/
void
cogl_pipeline_set_layer_combine_constant (CoglPipeline *pipeline,
int layer_index,
const CoglColor *constant);
#define cogl_pipeline_set_layer_matrix cogl_pipeline_set_layer_matrix_EXP
/**
* cogl_pipeline_set_layer_matrix:
* @pipeline: A #CoglPipeline object
* @layer_index: the index for the layer inside @pipeline
* @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 pipeline used to fill your geometry.
*/
void
cogl_pipeline_set_layer_matrix (CoglPipeline *pipeline,
int layer_index,
const CoglMatrix *matrix);
#define cogl_pipeline_get_n_layers cogl_pipeline_get_n_layers_EXP
/**
* cogl_pipeline_get_n_layers:
* @pipeline: A #CoglPipeline object
*
* Retrieves the number of layers defined for the given @pipeline
*
* Return value: the number of layers
*
* Since: 2.0
*/
int
cogl_pipeline_get_n_layers (CoglPipeline *pipeline);
#define cogl_pipeline_set_layer_filters cogl_pipeline_set_layer_filters_EXP
/**
* cogl_pipeline_set_layer_filters:
* @pipeline: A #CoglPipeline 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_pipeline_set_layer_filters (CoglPipeline *pipeline,
int layer_index,
CoglPipelineFilter min_filter,
CoglPipelineFilter mag_filter);
#define cogl_pipeline_set_layer_point_sprite_coords_enabled \
cogl_pipeline_set_layer_point_sprite_coords_enabled_EXP
/**
* cogl_pipeline_set_layer_point_sprite_coords_enabled:
* @pipeline: a #CoglHandle to a pipeline.
* @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: 2.0
*/
gboolean
cogl_pipeline_set_layer_point_sprite_coords_enabled (CoglPipeline *pipeline,
int layer_index,
gboolean enable,
GError **error);
#define cogl_pipeline_get_layer_point_sprite_coords_enabled \
cogl_pipeline_get_layer_point_sprite_coords_enabled_EXP
/**
* cogl_pipeline_get_layer_point_sprite_coords_enabled:
* @pipeline: a #CoglHandle to a pipeline.
* @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: 2.0
*/
gboolean
cogl_pipeline_get_layer_point_sprite_coords_enabled (CoglPipeline *pipeline,
int layer_index);
#define cogl_pipeline_get_layer_wrap_mode_s \
cogl_pipeline_get_layer_wrap_mode_s_EXP
/**
* cogl_pipeline_get_layer_wrap_mode_s:
* @pipeline: A #CoglPipeline object
* @layer_index: the layer number to change.
*
* Returns the wrap mode for the 's' coordinate of texture lookups on this
* layer.
*
* Return value: the wrap mode for the 's' coordinate of texture lookups on
* this layer.
*
* Since: 1.6
*/
CoglPipelineWrapMode
cogl_pipeline_get_layer_wrap_mode_s (CoglPipeline *pipeline,
int layer_index);
#define cogl_pipeline_set_layer_wrap_mode_s \
cogl_pipeline_set_layer_wrap_mode_s_EXP
/**
* cogl_pipeline_set_layer_wrap_mode_s:
* @pipeline: A #CoglPipeline 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: 2.0
*/
void
cogl_pipeline_set_layer_wrap_mode_s (CoglPipeline *pipeline,
int layer_index,
CoglPipelineWrapMode mode);
#define cogl_pipeline_get_layer_wrap_mode_t \
cogl_pipeline_get_layer_wrap_mode_t_EXP
/**
* cogl_pipeline_get_layer_wrap_mode_t:
* @pipeline: A #CoglPipeline object
* @layer_index: the layer number to change.
*
* Returns the wrap mode for the 't' coordinate of texture lookups on this
* layer.
*
* Return value: the wrap mode for the 't' coordinate of texture lookups on
* this layer.
*
* Since: 1.6
*/
CoglPipelineWrapMode
cogl_pipeline_get_layer_wrap_mode_t (CoglPipeline *pipeline,
int layer_index);
#define cogl_pipeline_set_layer_wrap_mode_t \
cogl_pipeline_set_layer_wrap_mode_t_EXP
/**
* cogl_pipeline_set_layer_wrap_mode_t:
* @pipeline: A #CoglPipeline 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: 2.0
*/
void
cogl_pipeline_set_layer_wrap_mode_t (CoglPipeline *pipeline,
int layer_index,
CoglPipelineWrapMode mode);
#define cogl_pipeline_get_layer_wrap_mode_p \
cogl_pipeline_get_layer_wrap_mode_p_EXP
/**
* cogl_pipeline_get_layer_wrap_mode_p:
* @pipeline: A #CoglPipeline object
* @layer_index: the layer number to change.
*
* Returns the wrap mode for the 'p' coordinate of texture lookups on this
* layer.
*
* Return value: the wrap mode for the 'p' coordinate of texture lookups on
* this layer.
*
* Since: 1.6
*/
CoglPipelineWrapMode
cogl_pipeline_get_layer_wrap_mode_p (CoglPipeline *pipeline,
int layer_index);
#define cogl_pipeline_set_layer_wrap_mode_p \
cogl_pipeline_set_layer_wrap_mode_p_EXP
/**
* cogl_pipeline_set_layer_wrap_mode_p:
* @pipeline: A #CoglPipeline 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: 2.0
*/
void
cogl_pipeline_set_layer_wrap_mode_p (CoglPipeline *pipeline,
int layer_index,
CoglPipelineWrapMode mode);
#define cogl_pipeline_set_layer_wrap_mode \
cogl_pipeline_set_layer_wrap_mode_EXP
/**
* cogl_pipeline_set_layer_wrap_mode:
* @pipeline: A #CoglPipeline 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_pipeline_set_layer_wrap_mode_s(),
* cogl_pipeline_set_layer_wrap_mode_t() and
* cogl_pipeline_set_layer_wrap_mode_p() separately.
*
* Since: 2.0
*/
void
cogl_pipeline_set_layer_wrap_mode (CoglPipeline *pipeline,
int layer_index,
CoglPipelineWrapMode mode);
#endif /* COGL_ENABLE_EXPERIMENTAL_API */
G_END_DECLS
#endif /* __COGL_PIPELINE_LAYER_STATE_H__ */