mutter/cogl/cogl-pipeline-state.h

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/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009,2011 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
*
*/
#if !defined(__COGL_H_INSIDE__) && !defined(COGL_COMPILATION)
#error "Only <cogl/cogl.h> can be included directly."
#endif
#ifndef __COGL_PIPELINE_STATE_H__
#define __COGL_PIPELINE_STATE_H__
#include <cogl/cogl-pipeline.h>
#include <cogl/cogl-color.h>
#include <cogl/cogl-depth-state.h>
COGL_BEGIN_DECLS
#ifdef COGL_ENABLE_EXPERIMENTAL_API
/**
* cogl_pipeline_set_color:
* @pipeline: A #CoglPipeline object
* @color: The components of the color
*
* Sets the basic color of the pipeline, used when no lighting is enabled.
*
* Note that if you don't add any layers to the pipeline 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: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_color (CoglPipeline *pipeline,
const CoglColor *color);
/**
* cogl_pipeline_set_color4ub:
* @pipeline: A #CoglPipeline object
* @red: The red component
* @green: The green component
* @blue: The blue component
* @alpha: The alpha component
*
* Sets the basic color of the pipeline, used when no lighting is enabled.
*
* The default value is (0xff, 0xff, 0xff, 0xff)
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_color4ub (CoglPipeline *pipeline,
uint8_t red,
uint8_t green,
uint8_t blue,
uint8_t alpha);
/**
* cogl_pipeline_set_color4f:
* @pipeline: A #CoglPipeline object
* @red: The red component
* @green: The green component
* @blue: The blue component
* @alpha: The alpha component
*
* Sets the basic color of the pipeline, used when no lighting is enabled.
*
* The default value is (1.0, 1.0, 1.0, 1.0)
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_color4f (CoglPipeline *pipeline,
float red,
float green,
float blue,
float alpha);
/**
* cogl_pipeline_get_color:
* @pipeline: A #CoglPipeline object
* @color: (out): The location to store the color
*
* Retrieves the current pipeline color.
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_get_color (CoglPipeline *pipeline,
CoglColor *color);
/**
* cogl_pipeline_set_ambient:
* @pipeline: A #CoglPipeline object
* @ambient: The components of the desired ambient color
*
* Sets the pipeline'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: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_ambient (CoglPipeline *pipeline,
const CoglColor *ambient);
/**
* cogl_pipeline_get_ambient:
* @pipeline: A #CoglPipeline object
* @ambient: The location to store the ambient color
*
* Retrieves the current ambient color for @pipeline
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_get_ambient (CoglPipeline *pipeline,
CoglColor *ambient);
/**
* cogl_pipeline_set_diffuse:
* @pipeline: A #CoglPipeline object
* @diffuse: The components of the desired diffuse color
*
* Sets the pipeline'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: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_diffuse (CoglPipeline *pipeline,
const CoglColor *diffuse);
/**
* cogl_pipeline_get_diffuse:
* @pipeline: A #CoglPipeline object
* @diffuse: The location to store the diffuse color
*
* Retrieves the current diffuse color for @pipeline
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_get_diffuse (CoglPipeline *pipeline,
CoglColor *diffuse);
/**
* cogl_pipeline_set_ambient_and_diffuse:
* @pipeline: A #CoglPipeline object
* @color: The components of the desired ambient and diffuse colors
*
* Conveniently sets the diffuse and ambient color of @pipeline at the same
* time. See cogl_pipeline_set_ambient() and cogl_pipeline_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: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_ambient_and_diffuse (CoglPipeline *pipeline,
const CoglColor *color);
/**
* cogl_pipeline_set_specular:
* @pipeline: A #CoglPipeline object
* @specular: The components of the desired specular color
*
* Sets the pipeline'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: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_specular (CoglPipeline *pipeline,
const CoglColor *specular);
/**
* cogl_pipeline_get_specular:
* @pipeline: A #CoglPipeline object
* @specular: The location to store the specular color
*
* Retrieves the pipelines current specular color.
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_get_specular (CoglPipeline *pipeline,
CoglColor *specular);
/**
* cogl_pipeline_set_shininess:
* @pipeline: A #CoglPipeline object
* @shininess: The desired shininess; must be >= 0.0
*
* Sets the shininess of the pipeline, 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: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_shininess (CoglPipeline *pipeline,
float shininess);
/**
* cogl_pipeline_get_shininess:
* @pipeline: A #CoglPipeline object
*
* Retrieves the pipelines current emission color.
*
* Return value: The pipelines current shininess value
*
* Since: 2.0
* Stability: Unstable
*/
float
cogl_pipeline_get_shininess (CoglPipeline *pipeline);
/**
* cogl_pipeline_set_emission:
* @pipeline: A #CoglPipeline object
* @emission: The components of the desired emissive color
*
* Sets the pipeline'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: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_emission (CoglPipeline *pipeline,
const CoglColor *emission);
/**
* cogl_pipeline_get_emission:
* @pipeline: A #CoglPipeline object
* @emission: The location to store the emission color
*
* Retrieves the pipelines current emission color.
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_get_emission (CoglPipeline *pipeline,
CoglColor *emission);
/**
* CoglPipelineAlphaFunc:
* @COGL_PIPELINE_ALPHA_FUNC_NEVER: Never let the fragment through.
* @COGL_PIPELINE_ALPHA_FUNC_LESS: Let the fragment through if the incoming
* alpha value is less than the reference alpha value
* @COGL_PIPELINE_ALPHA_FUNC_EQUAL: Let the fragment through if the incoming
* alpha value equals the reference alpha value
* @COGL_PIPELINE_ALPHA_FUNC_LEQUAL: Let the fragment through if the incoming
* alpha value is less than or equal to the reference alpha value
* @COGL_PIPELINE_ALPHA_FUNC_GREATER: Let the fragment through if the incoming
* alpha value is greater than the reference alpha value
* @COGL_PIPELINE_ALPHA_FUNC_NOTEQUAL: Let the fragment through if the incoming
* alpha value does not equal the reference alpha value
* @COGL_PIPELINE_ALPHA_FUNC_GEQUAL: Let the fragment through if the incoming
* alpha value is greater than or equal to the reference alpha value.
* @COGL_PIPELINE_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 #CoglPipelineAlphaFunc
* determines how the comparison is done.
*/
typedef enum {
COGL_PIPELINE_ALPHA_FUNC_NEVER = 0x0200,
COGL_PIPELINE_ALPHA_FUNC_LESS = 0x0201,
COGL_PIPELINE_ALPHA_FUNC_EQUAL = 0x0202,
COGL_PIPELINE_ALPHA_FUNC_LEQUAL = 0x0203,
COGL_PIPELINE_ALPHA_FUNC_GREATER = 0x0204,
COGL_PIPELINE_ALPHA_FUNC_NOTEQUAL = 0x0205,
COGL_PIPELINE_ALPHA_FUNC_GEQUAL = 0x0206,
COGL_PIPELINE_ALPHA_FUNC_ALWAYS = 0x0207
} CoglPipelineAlphaFunc;
/* NB: these values come from the equivalents in gl.h */
/**
* cogl_pipeline_set_alpha_test_function:
* @pipeline: A #CoglPipeline object
* @alpha_func: A @CoglPipelineAlphaFunc 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_PIPELINE_ALPHA_FUNC_ALWAYS
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_alpha_test_function (CoglPipeline *pipeline,
CoglPipelineAlphaFunc alpha_func,
float alpha_reference);
/**
* cogl_pipeline_get_alpha_test_function:
* @pipeline: A #CoglPipeline object
*
* Return value: The alpha test function of @pipeline.
*
* Since: 2.0
* Stability: Unstable
*/
CoglPipelineAlphaFunc
cogl_pipeline_get_alpha_test_function (CoglPipeline *pipeline);
/**
* cogl_pipeline_get_alpha_test_reference:
* @pipeline: A #CoglPipeline object
*
* Return value: The alpha test reference value of @pipeline.
*
* Since: 2.0
* Stability: Unstable
*/
float
cogl_pipeline_get_alpha_test_reference (CoglPipeline *pipeline);
/**
* cogl_pipeline_set_blend:
* @pipeline: A #CoglPipeline object
* @blend_string: A <link linkend="cogl-Blend-Strings">Cogl blend string</link>
* describing the desired blend function.
Adds CoglError api Although we use GLib internally in Cogl we would rather not leak GLib api through Cogl's own api, except through explicitly namespaced cogl_glib_ / cogl_gtype_ feature apis. One of the benefits we see to not leaking GLib through Cogl's public API is that documentation for Cogl won't need to first introduce the Glib API to newcomers, thus hopefully lowering the barrier to learning Cogl. This patch provides a Cogl specific typedef for reporting runtime errors which by no coincidence matches the typedef for GError exactly. If Cogl is built with --enable-glib (default) then developers can even safely assume that a CoglError is a GError under the hood. This patch also enforces a consistent policy for when NULL is passed as an error argument and an error is thrown. In this case we log the error and abort the application, instead of silently ignoring it. In common cases where nothing has been implemented to handle a particular error and/or where applications are just printing the error and aborting themselves then this saves some typing. This also seems more consistent with language based exceptions which usually cause a program to abort if they are not explicitly caught (which passing a non-NULL error signifies in this case) Since this policy for NULL error pointers is stricter than the standard GError convention, there is a clear note in the documentation to warn developers that are used to using the GError api. Reviewed-by: Neil Roberts <neil@linux.intel.com> (cherry picked from commit b068d5ea09ab32c37e8c965fc8582c85d1b2db46) Note: Since we can't change the Cogl 1.x api the patch was changed to not rename _error_quark() functions to be _error_domain() functions and although it's a bit ugly, instead of providing our own CoglError type that's compatible with GError we simply #define CoglError to GError unless Cogl is built with glib disabled. Note: this patch does technically introduce an API break since it drops the cogl_error_get_type() symbol generated by glib-mkenum (Since the CoglError enum was replaced by a CoglSystemError enum) but for now we are assuming that this will not affect anyone currently using the Cogl API. If this does turn out to be a problem in practice then we would be able to fix this my manually copying an implementation of cogl_error_get_type() generated by glib-mkenum into a compatibility source file and we could also define the original COGL_ERROR_ enums for compatibility too. Note: another minor concern with cherry-picking this patch to the 1.14 branch is that an api scanner would be lead to believe that some APIs have changed, and for example the gobject-introspection parser which understands the semantics of GError will not understand the semantics of CoglError. We expect most people that have tried to use gobject-introspection with Cogl already understand though that it is not well suited to generating bindings of the Cogl api anyway and we aren't aware or anyone depending on such bindings for apis involving GErrors. (GnomeShell only makes very-very minimal use of Cogl via the gjs bindings for the cogl_rectangle and cogl_color apis.) The main reason we have cherry-picked this patch to the 1.14 branch even given the above concerns is that without it it would become very awkward for us to cherry-pick other beneficial patches from master.
2012-08-31 14:28:27 -04:00
* @error: return location for a #CoglError 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;))
* ]|
*
* 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_pipeline_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 pipeline
* 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: 2.0
* Stability: Unstable
*/
CoglBool
cogl_pipeline_set_blend (CoglPipeline *pipeline,
const char *blend_string,
Adds CoglError api Although we use GLib internally in Cogl we would rather not leak GLib api through Cogl's own api, except through explicitly namespaced cogl_glib_ / cogl_gtype_ feature apis. One of the benefits we see to not leaking GLib through Cogl's public API is that documentation for Cogl won't need to first introduce the Glib API to newcomers, thus hopefully lowering the barrier to learning Cogl. This patch provides a Cogl specific typedef for reporting runtime errors which by no coincidence matches the typedef for GError exactly. If Cogl is built with --enable-glib (default) then developers can even safely assume that a CoglError is a GError under the hood. This patch also enforces a consistent policy for when NULL is passed as an error argument and an error is thrown. In this case we log the error and abort the application, instead of silently ignoring it. In common cases where nothing has been implemented to handle a particular error and/or where applications are just printing the error and aborting themselves then this saves some typing. This also seems more consistent with language based exceptions which usually cause a program to abort if they are not explicitly caught (which passing a non-NULL error signifies in this case) Since this policy for NULL error pointers is stricter than the standard GError convention, there is a clear note in the documentation to warn developers that are used to using the GError api. Reviewed-by: Neil Roberts <neil@linux.intel.com> (cherry picked from commit b068d5ea09ab32c37e8c965fc8582c85d1b2db46) Note: Since we can't change the Cogl 1.x api the patch was changed to not rename _error_quark() functions to be _error_domain() functions and although it's a bit ugly, instead of providing our own CoglError type that's compatible with GError we simply #define CoglError to GError unless Cogl is built with glib disabled. Note: this patch does technically introduce an API break since it drops the cogl_error_get_type() symbol generated by glib-mkenum (Since the CoglError enum was replaced by a CoglSystemError enum) but for now we are assuming that this will not affect anyone currently using the Cogl API. If this does turn out to be a problem in practice then we would be able to fix this my manually copying an implementation of cogl_error_get_type() generated by glib-mkenum into a compatibility source file and we could also define the original COGL_ERROR_ enums for compatibility too. Note: another minor concern with cherry-picking this patch to the 1.14 branch is that an api scanner would be lead to believe that some APIs have changed, and for example the gobject-introspection parser which understands the semantics of GError will not understand the semantics of CoglError. We expect most people that have tried to use gobject-introspection with Cogl already understand though that it is not well suited to generating bindings of the Cogl api anyway and we aren't aware or anyone depending on such bindings for apis involving GErrors. (GnomeShell only makes very-very minimal use of Cogl via the gjs bindings for the cogl_rectangle and cogl_color apis.) The main reason we have cherry-picked this patch to the 1.14 branch even given the above concerns is that without it it would become very awkward for us to cherry-pick other beneficial patches from master.
2012-08-31 14:28:27 -04:00
CoglError **error);
/**
* cogl_pipeline_set_blend_constant:
* @pipeline: A #CoglPipeline 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: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_blend_constant (CoglPipeline *pipeline,
const CoglColor *constant_color);
/**
* cogl_pipeline_set_point_size:
* @pipeline: a #CoglPipeline pointer
* @point_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: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_point_size (CoglPipeline *pipeline,
float point_size);
/**
* cogl_pipeline_get_point_size:
* @pipeline: a #CoglPipeline pointer
*
* 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 @pipeline.
*
* Since: 2.0
* Stability: Unstable
*/
float
cogl_pipeline_get_point_size (CoglPipeline *pipeline);
/**
* cogl_pipeline_get_color_mask:
* @pipeline: a #CoglPipeline object.
*
* Gets the current #CoglColorMask of which channels would be written to the
* current framebuffer. Each bit set in the mask means that the
* corresponding color would be written.
*
* Returns: A #CoglColorMask
* Since: 1.8
* Stability: unstable
*/
CoglColorMask
cogl_pipeline_get_color_mask (CoglPipeline *pipeline);
/**
* cogl_pipeline_set_color_mask:
* @pipeline: a #CoglPipeline object.
* @color_mask: A #CoglColorMask of which color channels to write to
* the current framebuffer.
*
* Defines a bit mask of which color channels should be written to the
* current framebuffer. If a bit is set in @color_mask that means that
* color will be written.
*
* Since: 1.8
* Stability: unstable
*/
void
cogl_pipeline_set_color_mask (CoglPipeline *pipeline,
CoglColorMask color_mask);
/**
* cogl_pipeline_get_user_program:
* @pipeline: a #CoglPipeline object.
*
* Queries what user program has been associated with the given
* @pipeline using cogl_pipeline_set_user_program().
*
* Return value: The current user program or %COGL_INVALID_HANDLE.
*
* Since: 2.0
* Stability: Unstable
*/
CoglHandle
cogl_pipeline_get_user_program (CoglPipeline *pipeline);
/**
* cogl_pipeline_set_user_program:
* @pipeline: a #CoglPipeline object.
* @program: A #CoglHandle to a linked CoglProgram
*
* Associates a linked CoglProgram with the given pipeline 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 #CoglPipeline:
* |[
* CoglHandle shader;
* CoglHandle program;
* CoglPipeline *pipeline;
*
* 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);
*
* pipeline = cogl_pipeline_new ();
* cogl_pipeline_set_user_program (pipeline, 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: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_user_program (CoglPipeline *pipeline,
CoglHandle program);
/**
* cogl_pipeline_set_depth_state:
* @pipeline: A #CoglPipeline object
* @state: A #CoglDepthState struct
Adds CoglError api Although we use GLib internally in Cogl we would rather not leak GLib api through Cogl's own api, except through explicitly namespaced cogl_glib_ / cogl_gtype_ feature apis. One of the benefits we see to not leaking GLib through Cogl's public API is that documentation for Cogl won't need to first introduce the Glib API to newcomers, thus hopefully lowering the barrier to learning Cogl. This patch provides a Cogl specific typedef for reporting runtime errors which by no coincidence matches the typedef for GError exactly. If Cogl is built with --enable-glib (default) then developers can even safely assume that a CoglError is a GError under the hood. This patch also enforces a consistent policy for when NULL is passed as an error argument and an error is thrown. In this case we log the error and abort the application, instead of silently ignoring it. In common cases where nothing has been implemented to handle a particular error and/or where applications are just printing the error and aborting themselves then this saves some typing. This also seems more consistent with language based exceptions which usually cause a program to abort if they are not explicitly caught (which passing a non-NULL error signifies in this case) Since this policy for NULL error pointers is stricter than the standard GError convention, there is a clear note in the documentation to warn developers that are used to using the GError api. Reviewed-by: Neil Roberts <neil@linux.intel.com> (cherry picked from commit b068d5ea09ab32c37e8c965fc8582c85d1b2db46) Note: Since we can't change the Cogl 1.x api the patch was changed to not rename _error_quark() functions to be _error_domain() functions and although it's a bit ugly, instead of providing our own CoglError type that's compatible with GError we simply #define CoglError to GError unless Cogl is built with glib disabled. Note: this patch does technically introduce an API break since it drops the cogl_error_get_type() symbol generated by glib-mkenum (Since the CoglError enum was replaced by a CoglSystemError enum) but for now we are assuming that this will not affect anyone currently using the Cogl API. If this does turn out to be a problem in practice then we would be able to fix this my manually copying an implementation of cogl_error_get_type() generated by glib-mkenum into a compatibility source file and we could also define the original COGL_ERROR_ enums for compatibility too. Note: another minor concern with cherry-picking this patch to the 1.14 branch is that an api scanner would be lead to believe that some APIs have changed, and for example the gobject-introspection parser which understands the semantics of GError will not understand the semantics of CoglError. We expect most people that have tried to use gobject-introspection with Cogl already understand though that it is not well suited to generating bindings of the Cogl api anyway and we aren't aware or anyone depending on such bindings for apis involving GErrors. (GnomeShell only makes very-very minimal use of Cogl via the gjs bindings for the cogl_rectangle and cogl_color apis.) The main reason we have cherry-picked this patch to the 1.14 branch even given the above concerns is that without it it would become very awkward for us to cherry-pick other beneficial patches from master.
2012-08-31 14:28:27 -04:00
* @error: A #CoglError to report failures to setup the given @state.
*
* This commits all the depth state configured in @state struct to the
* given @pipeline. The configuration values are copied into the
* pipeline so there is no requirement to keep the #CoglDepthState
* struct around if you don't need it any more.
*
* Note: Since some platforms do not support the depth range feature
* it is possible for this function to fail and report an @error.
*
* Returns: TRUE if the GPU supports all the given @state else %FALSE
* and returns an @error.
*
* Since: 2.0
* Stability: Unstable
*/
CoglBool
cogl_pipeline_set_depth_state (CoglPipeline *pipeline,
const CoglDepthState *state,
Adds CoglError api Although we use GLib internally in Cogl we would rather not leak GLib api through Cogl's own api, except through explicitly namespaced cogl_glib_ / cogl_gtype_ feature apis. One of the benefits we see to not leaking GLib through Cogl's public API is that documentation for Cogl won't need to first introduce the Glib API to newcomers, thus hopefully lowering the barrier to learning Cogl. This patch provides a Cogl specific typedef for reporting runtime errors which by no coincidence matches the typedef for GError exactly. If Cogl is built with --enable-glib (default) then developers can even safely assume that a CoglError is a GError under the hood. This patch also enforces a consistent policy for when NULL is passed as an error argument and an error is thrown. In this case we log the error and abort the application, instead of silently ignoring it. In common cases where nothing has been implemented to handle a particular error and/or where applications are just printing the error and aborting themselves then this saves some typing. This also seems more consistent with language based exceptions which usually cause a program to abort if they are not explicitly caught (which passing a non-NULL error signifies in this case) Since this policy for NULL error pointers is stricter than the standard GError convention, there is a clear note in the documentation to warn developers that are used to using the GError api. Reviewed-by: Neil Roberts <neil@linux.intel.com> (cherry picked from commit b068d5ea09ab32c37e8c965fc8582c85d1b2db46) Note: Since we can't change the Cogl 1.x api the patch was changed to not rename _error_quark() functions to be _error_domain() functions and although it's a bit ugly, instead of providing our own CoglError type that's compatible with GError we simply #define CoglError to GError unless Cogl is built with glib disabled. Note: this patch does technically introduce an API break since it drops the cogl_error_get_type() symbol generated by glib-mkenum (Since the CoglError enum was replaced by a CoglSystemError enum) but for now we are assuming that this will not affect anyone currently using the Cogl API. If this does turn out to be a problem in practice then we would be able to fix this my manually copying an implementation of cogl_error_get_type() generated by glib-mkenum into a compatibility source file and we could also define the original COGL_ERROR_ enums for compatibility too. Note: another minor concern with cherry-picking this patch to the 1.14 branch is that an api scanner would be lead to believe that some APIs have changed, and for example the gobject-introspection parser which understands the semantics of GError will not understand the semantics of CoglError. We expect most people that have tried to use gobject-introspection with Cogl already understand though that it is not well suited to generating bindings of the Cogl api anyway and we aren't aware or anyone depending on such bindings for apis involving GErrors. (GnomeShell only makes very-very minimal use of Cogl via the gjs bindings for the cogl_rectangle and cogl_color apis.) The main reason we have cherry-picked this patch to the 1.14 branch even given the above concerns is that without it it would become very awkward for us to cherry-pick other beneficial patches from master.
2012-08-31 14:28:27 -04:00
CoglError **error);
/**
* cogl_pipeline_get_depth_state
* @pipeline: A #CoglPipeline object
* @state_out: (out): A destination #CoglDepthState struct
*
* Retrieves the current depth state configuration for the given
* @pipeline as previously set using cogl_pipeline_set_depth_state().
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_get_depth_state (CoglPipeline *pipeline,
CoglDepthState *state_out);
/**
* CoglPipelineCullFaceMode:
* @COGL_PIPELINE_CULL_FACE_MODE_NONE: Neither face will be
* culled. This is the default.
* @COGL_PIPELINE_CULL_FACE_MODE_FRONT: Front faces will be culled.
* @COGL_PIPELINE_CULL_FACE_MODE_BACK: Back faces will be culled.
* @COGL_PIPELINE_CULL_FACE_MODE_BOTH: All faces will be culled.
*
* Specifies which faces should be culled. This can be set on a
* pipeline using cogl_pipeline_set_cull_face_mode().
*/
typedef enum
{
COGL_PIPELINE_CULL_FACE_MODE_NONE,
COGL_PIPELINE_CULL_FACE_MODE_FRONT,
COGL_PIPELINE_CULL_FACE_MODE_BACK,
COGL_PIPELINE_CULL_FACE_MODE_BOTH
} CoglPipelineCullFaceMode;
/**
* cogl_pipeline_set_cull_face_mode:
* @pipeline: A #CoglPipeline
* @cull_face_mode: The new mode to set
*
* Sets which faces will be culled when drawing. Face culling can be
* used to increase efficiency by avoiding drawing faces that would
* get overridden. For example, if a model has gaps so that it is
* impossible to see the inside then faces which are facing away from
* the screen will never be seen so there is no point in drawing
* them. This can be acheived by setting the cull face mode to
* %COGL_PIPELINE_CULL_FACE_MODE_BACK.
*
* Face culling relies on the primitives being drawn with a specific
* order to represent which faces are facing inside and outside the
* model. This order can be specified by calling
* cogl_pipeline_set_front_face_winding().
*
* Status: Unstable
* Since: 2.0
*/
void
cogl_pipeline_set_cull_face_mode (CoglPipeline *pipeline,
CoglPipelineCullFaceMode cull_face_mode);
/**
* cogl_pipeline_get_cull_face_mode:
*
* Return value: the cull face mode that was previously set with
* cogl_pipeline_set_cull_face_mode().
*
* Status: Unstable
* Since: 2.0
*/
CoglPipelineCullFaceMode
cogl_pipeline_get_cull_face_mode (CoglPipeline *pipeline);
/**
* cogl_pipeline_set_front_face_winding:
* @pipeline: a #CoglPipeline
* @front_winding: the winding order
*
* The order of the vertices within a primitive specifies whether it
* is considered to be front or back facing. This function specifies
* which order is considered to be the front
* faces. %COGL_WINDING_COUNTER_CLOCKWISE sets the front faces to
* primitives with vertices in a counter-clockwise order and
* %COGL_WINDING_CLOCKWISE sets them to be clockwise. The default is
* %COGL_WINDING_COUNTER_CLOCKWISE.
*
* Status: Unstable
* Since: 2.0
*/
void
cogl_pipeline_set_front_face_winding (CoglPipeline *pipeline,
CoglWinding front_winding);
/**
* cogl_pipeline_get_front_face_winding:
* @pipeline: a #CoglPipeline
*
* The order of the vertices within a primitive specifies whether it
* is considered to be front or back facing. This function specifies
* which order is considered to be the front
* faces. %COGL_WINDING_COUNTER_CLOCKWISE sets the front faces to
* primitives with vertices in a counter-clockwise order and
* %COGL_WINDING_CLOCKWISE sets them to be clockwise. The default is
* %COGL_WINDING_COUNTER_CLOCKWISE.
*
* Returns: The @pipeline front face winding
*
* Status: Unstable
* Since: 2.0
*/
CoglWinding
cogl_pipeline_get_front_face_winding (CoglPipeline *pipeline);
cogl-pipeline: Add support for setting uniform values This adds the following new public experimental functions to set uniform values on a CoglPipeline: void cogl_pipeline_set_uniform_1f (CoglPipeline *pipeline, int uniform_location, float value); void cogl_pipeline_set_uniform_1i (CoglPipeline *pipeline, int uniform_location, int value); void cogl_pipeline_set_uniform_float (CoglPipeline *pipeline, int uniform_location, int n_components, int count, const float *value); void cogl_pipeline_set_uniform_int (CoglPipeline *pipeline, int uniform_location, int n_components, int count, const int *value); void cogl_pipeline_set_uniform_matrix (CoglPipeline *pipeline, int uniform_location, int dimensions, int count, gboolean transpose, const float *value); These are similar to the old functions used to set uniforms on a CoglProgram. To get a value to pass in as the uniform_location there is also: int cogl_pipeline_get_uniform_location (CoglPipeline *pipeline, const char *uniform_name); Conceptually the uniform locations are tied to the pipeline so that whenever setting a value for a new pipeline the application is expected to call this function. However in practice the uniform locations are global to the CoglContext. The names are stored in a linked list where the position in the list is the uniform location. The global indices are used so that each pipeline can store a mask of which uniforms it overrides. That way it is quicker to detect which uniforms are different from the last pipeline that used the same CoglProgramState so it can avoid flushing uniforms that haven't changed. Currently the values are not actually compared which means that it will only avoid flushing a uniform if there is a common ancestor that sets the value (or if the same pipeline is being flushed again - in which case the pipeline and its common ancestor are the same thing). The uniform values are stored in the big state of the pipeline as a sparse linked list. A bitmask stores which values have been overridden and only overridden values are stored in the linked list. Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-11-03 13:20:43 -04:00
/**
* cogl_pipeline_set_uniform_1f:
* @pipeline: A #CoglPipeline object
* @uniform_location: The uniform's location identifier
* @value: The new value for the uniform
*
* Sets a new value for the uniform at @uniform_location. If this
* pipeline has a user program attached and is later used as a source
* for drawing, the given value will be assigned to the uniform which
* can be accessed from the shader's source. The value for
* @uniform_location should be retrieved from the string name of the
* uniform by calling cogl_pipeline_get_uniform_location().
*
* This function should be used to set uniforms that are of type
* float. It can also be used to set a single member of a float array
* uniform.
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_uniform_1f (CoglPipeline *pipeline,
int uniform_location,
float value);
/**
* cogl_pipeline_set_uniform_1i:
* @pipeline: A #CoglPipeline object
* @uniform_location: The uniform's location identifier
* @value: The new value for the uniform
*
* Sets a new value for the uniform at @uniform_location. If this
* pipeline has a user program attached and is later used as a source
* for drawing, the given value will be assigned to the uniform which
* can be accessed from the shader's source. The value for
* @uniform_location should be retrieved from the string name of the
* uniform by calling cogl_pipeline_get_uniform_location().
*
* This function should be used to set uniforms that are of type
* int. It can also be used to set a single member of a int array
* uniform or a sampler uniform.
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_uniform_1i (CoglPipeline *pipeline,
int uniform_location,
int value);
/**
* cogl_pipeline_set_uniform_float:
* @pipeline: A #CoglPipeline object
* @uniform_location: The uniform's location identifier
* @n_components: The number of components in the corresponding uniform's type
* @count: The number of values to set
* @value: Pointer to the new values to set
*
* Sets new values for the uniform at @uniform_location. If this
* pipeline has a user program attached and is later used as a source
* for drawing, the given values will be assigned to the uniform which
* can be accessed from the shader's source. The value for
* @uniform_location should be retrieved from the string name of the
* uniform by calling cogl_pipeline_get_uniform_location().
*
* This function can be used to set any floating point type uniform,
* including float arrays and float vectors. For example, to set a
* single vec4 uniform you would use 4 for @n_components and 1 for
* @count. To set an array of 8 float values, you could use 1 for
* @n_components and 8 for @count.
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_uniform_float (CoglPipeline *pipeline,
int uniform_location,
int n_components,
int count,
const float *value);
/**
* cogl_pipeline_set_uniform_int:
* @pipeline: A #CoglPipeline object
* @uniform_location: The uniform's location identifier
* @n_components: The number of components in the corresponding uniform's type
* @count: The number of values to set
* @value: Pointer to the new values to set
*
* Sets new values for the uniform at @uniform_location. If this
* pipeline has a user program attached and is later used as a source
* for drawing, the given values will be assigned to the uniform which
* can be accessed from the shader's source. The value for
* @uniform_location should be retrieved from the string name of the
* uniform by calling cogl_pipeline_get_uniform_location().
*
* This function can be used to set any integer type uniform,
* including int arrays and int vectors. For example, to set a single
* ivec4 uniform you would use 4 for @n_components and 1 for
* @count. To set an array of 8 int values, you could use 1 for
* @n_components and 8 for @count.
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_uniform_int (CoglPipeline *pipeline,
int uniform_location,
int n_components,
int count,
const int *value);
/**
* cogl_pipeline_set_uniform_matrix:
* @pipeline: A #CoglPipeline object
* @uniform_location: The uniform's location identifier
* @dimensions: The size of the matrix
* @count: The number of values to set
* @transpose: Whether to transpose the matrix
* @value: Pointer to the new values to set
*
* Sets new values for the uniform at @uniform_location. If this
* pipeline has a user program attached and is later used as a source
* for drawing, the given values will be assigned to the uniform which
* can be accessed from the shader's source. The value for
* @uniform_location should be retrieved from the string name of the
* uniform by calling cogl_pipeline_get_uniform_location().
*
* This function can be used to set any matrix type uniform, including
* matrix arrays. For example, to set a single mat4 uniform you would
* use 4 for @dimensions and 1 for @count. To set an array of 8
* mat3 values, you could use 3 for @dimensions and 8 for @count.
*
* If @transpose is %FALSE then the matrix is expected to be in
* column-major order or if it is %TRUE then the matrix is in
* row-major order. You can pass a #CoglMatrix by calling by passing
* the result of cogl_matrix_get_array() in @value and setting
* @transpose to %FALSE.
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_set_uniform_matrix (CoglPipeline *pipeline,
int uniform_location,
int dimensions,
int count,
CoglBool transpose,
cogl-pipeline: Add support for setting uniform values This adds the following new public experimental functions to set uniform values on a CoglPipeline: void cogl_pipeline_set_uniform_1f (CoglPipeline *pipeline, int uniform_location, float value); void cogl_pipeline_set_uniform_1i (CoglPipeline *pipeline, int uniform_location, int value); void cogl_pipeline_set_uniform_float (CoglPipeline *pipeline, int uniform_location, int n_components, int count, const float *value); void cogl_pipeline_set_uniform_int (CoglPipeline *pipeline, int uniform_location, int n_components, int count, const int *value); void cogl_pipeline_set_uniform_matrix (CoglPipeline *pipeline, int uniform_location, int dimensions, int count, gboolean transpose, const float *value); These are similar to the old functions used to set uniforms on a CoglProgram. To get a value to pass in as the uniform_location there is also: int cogl_pipeline_get_uniform_location (CoglPipeline *pipeline, const char *uniform_name); Conceptually the uniform locations are tied to the pipeline so that whenever setting a value for a new pipeline the application is expected to call this function. However in practice the uniform locations are global to the CoglContext. The names are stored in a linked list where the position in the list is the uniform location. The global indices are used so that each pipeline can store a mask of which uniforms it overrides. That way it is quicker to detect which uniforms are different from the last pipeline that used the same CoglProgramState so it can avoid flushing uniforms that haven't changed. Currently the values are not actually compared which means that it will only avoid flushing a uniform if there is a common ancestor that sets the value (or if the same pipeline is being flushed again - in which case the pipeline and its common ancestor are the same thing). The uniform values are stored in the big state of the pipeline as a sparse linked list. A bitmask stores which values have been overridden and only overridden values are stored in the linked list. Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-11-03 13:20:43 -04:00
const float *value);
cogl-pipeline: Add two hook points for adding shader snippets This adds two new public experimental functions for attaching CoglSnippets to two hook points on a CoglPipeline: void cogl_pipeline_add_vertex_hook (CoglPipeline *, CoglSnippet *) void cogl_pipeline_add_fragment_hook (CoglPipeline *, CoglSnippet *) The hooks are intended to be around the entire vertex or fragment processing. That means the pre string in the snippet will be inserted at the very top of the main function and the post function will be inserted at the very end. The declarations get inserted in the global scope. The snippets are stored in two separate linked lists with a structure containing an enum representing the hook point and a pointer to the snippet. The lists are meant to be for hooks that affect the vertex shader and fragment shader respectively. Although there are currently only two hooks and the names match these two lists, the intention is *not* that each new hook will be in a separate list. The separation of the lists is just to make it easier to determine which shader needs to be regenerated when a new snippet is added. When a pipeline becomes the authority for either the vertex or fragment snipper state, it simply copies the entire list from the previous authority (although of course the shader snippet objects are referenced instead of copied so it doesn't duplicate the source strings). Each string is inserted into its own block in the shader. This means that each string has its own scope so it doesn't need to worry about name collisions with variables in other snippets. However it does mean that the pre and post strings can't share variables. It could be possible to wrap both parts in one block and then wrap the actual inner hook code in another block, however this would mean that any further snippets within the outer snippet would be able to see those variables. Perhaps something to consider would be to put each snippet into its own function which calls another function between the pre and post strings to do further processing. The pipeline cache for generated programs was previously shared with the fragment shader cache because the state that affects vertex shaders was a subset of the state that affects fragment shaders. This is no longer the case because there is a separate state mask for vertex snippets so the program cache now has its own hash table. Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-11-17 11:52:21 -05:00
/**
* cogl_pipeline_add_snippet:
cogl-pipeline: Add two hook points for adding shader snippets This adds two new public experimental functions for attaching CoglSnippets to two hook points on a CoglPipeline: void cogl_pipeline_add_vertex_hook (CoglPipeline *, CoglSnippet *) void cogl_pipeline_add_fragment_hook (CoglPipeline *, CoglSnippet *) The hooks are intended to be around the entire vertex or fragment processing. That means the pre string in the snippet will be inserted at the very top of the main function and the post function will be inserted at the very end. The declarations get inserted in the global scope. The snippets are stored in two separate linked lists with a structure containing an enum representing the hook point and a pointer to the snippet. The lists are meant to be for hooks that affect the vertex shader and fragment shader respectively. Although there are currently only two hooks and the names match these two lists, the intention is *not* that each new hook will be in a separate list. The separation of the lists is just to make it easier to determine which shader needs to be regenerated when a new snippet is added. When a pipeline becomes the authority for either the vertex or fragment snipper state, it simply copies the entire list from the previous authority (although of course the shader snippet objects are referenced instead of copied so it doesn't duplicate the source strings). Each string is inserted into its own block in the shader. This means that each string has its own scope so it doesn't need to worry about name collisions with variables in other snippets. However it does mean that the pre and post strings can't share variables. It could be possible to wrap both parts in one block and then wrap the actual inner hook code in another block, however this would mean that any further snippets within the outer snippet would be able to see those variables. Perhaps something to consider would be to put each snippet into its own function which calls another function between the pre and post strings to do further processing. The pipeline cache for generated programs was previously shared with the fragment shader cache because the state that affects vertex shaders was a subset of the state that affects fragment shaders. This is no longer the case because there is a separate state mask for vertex snippets so the program cache now has its own hash table. Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-11-17 11:52:21 -05:00
* @pipeline: A #CoglPipeline
* @snippet: The #CoglSnippet to add to the vertex processing hook
*
* Adds a shader snippet to @pipeline. The snippet will wrap around or
* replace some part of the pipeline as defined by the hook point in
* @snippet. Note that some hook points are specific to a layer and
* must be added with cogl_pipeline_add_layer_snippet() instead.
cogl-pipeline: Add two hook points for adding shader snippets This adds two new public experimental functions for attaching CoglSnippets to two hook points on a CoglPipeline: void cogl_pipeline_add_vertex_hook (CoglPipeline *, CoglSnippet *) void cogl_pipeline_add_fragment_hook (CoglPipeline *, CoglSnippet *) The hooks are intended to be around the entire vertex or fragment processing. That means the pre string in the snippet will be inserted at the very top of the main function and the post function will be inserted at the very end. The declarations get inserted in the global scope. The snippets are stored in two separate linked lists with a structure containing an enum representing the hook point and a pointer to the snippet. The lists are meant to be for hooks that affect the vertex shader and fragment shader respectively. Although there are currently only two hooks and the names match these two lists, the intention is *not* that each new hook will be in a separate list. The separation of the lists is just to make it easier to determine which shader needs to be regenerated when a new snippet is added. When a pipeline becomes the authority for either the vertex or fragment snipper state, it simply copies the entire list from the previous authority (although of course the shader snippet objects are referenced instead of copied so it doesn't duplicate the source strings). Each string is inserted into its own block in the shader. This means that each string has its own scope so it doesn't need to worry about name collisions with variables in other snippets. However it does mean that the pre and post strings can't share variables. It could be possible to wrap both parts in one block and then wrap the actual inner hook code in another block, however this would mean that any further snippets within the outer snippet would be able to see those variables. Perhaps something to consider would be to put each snippet into its own function which calls another function between the pre and post strings to do further processing. The pipeline cache for generated programs was previously shared with the fragment shader cache because the state that affects vertex shaders was a subset of the state that affects fragment shaders. This is no longer the case because there is a separate state mask for vertex snippets so the program cache now has its own hash table. Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-11-17 11:52:21 -05:00
*
* Since: 1.10
* Stability: Unstable
*/
void
cogl_pipeline_add_snippet (CoglPipeline *pipeline,
CoglSnippet *snippet);
cogl-pipeline: Add two hook points for adding shader snippets This adds two new public experimental functions for attaching CoglSnippets to two hook points on a CoglPipeline: void cogl_pipeline_add_vertex_hook (CoglPipeline *, CoglSnippet *) void cogl_pipeline_add_fragment_hook (CoglPipeline *, CoglSnippet *) The hooks are intended to be around the entire vertex or fragment processing. That means the pre string in the snippet will be inserted at the very top of the main function and the post function will be inserted at the very end. The declarations get inserted in the global scope. The snippets are stored in two separate linked lists with a structure containing an enum representing the hook point and a pointer to the snippet. The lists are meant to be for hooks that affect the vertex shader and fragment shader respectively. Although there are currently only two hooks and the names match these two lists, the intention is *not* that each new hook will be in a separate list. The separation of the lists is just to make it easier to determine which shader needs to be regenerated when a new snippet is added. When a pipeline becomes the authority for either the vertex or fragment snipper state, it simply copies the entire list from the previous authority (although of course the shader snippet objects are referenced instead of copied so it doesn't duplicate the source strings). Each string is inserted into its own block in the shader. This means that each string has its own scope so it doesn't need to worry about name collisions with variables in other snippets. However it does mean that the pre and post strings can't share variables. It could be possible to wrap both parts in one block and then wrap the actual inner hook code in another block, however this would mean that any further snippets within the outer snippet would be able to see those variables. Perhaps something to consider would be to put each snippet into its own function which calls another function between the pre and post strings to do further processing. The pipeline cache for generated programs was previously shared with the fragment shader cache because the state that affects vertex shaders was a subset of the state that affects fragment shaders. This is no longer the case because there is a separate state mask for vertex snippets so the program cache now has its own hash table. Reviewed-by: Robert Bragg <robert@linux.intel.com>
2011-11-17 11:52:21 -05:00
#endif /* COGL_ENABLE_EXPERIMENTAL_API */
COGL_END_DECLS
#endif /* __COGL_PIPELINE_STATE_H__ */