mutter/cogl/cogl-pipeline.h

/*
 * 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(COGL_COMPILATION)
#error "Only <cogl/cogl.h> can be included directly."
#endif

#ifndef __COGL_PIPELINE_H__
#define __COGL_PIPELINE_H__

/* We forward declare the CoglPipeline type here to avoid some circular
 * dependency issues with the following headers.
 */
typedef struct _CoglPipeline CoglPipeline;

#include <cogl/cogl-types.h>
#include <cogl/cogl-context.h>
#include <cogl/cogl-snippet.h>

COGL_BEGIN_DECLS

#ifdef COGL_ENABLE_EXPERIMENTAL_API

/**
 * SECTION:cogl-pipeline
 * @short_description: Functions for creating and manipulating the GPU
 *                     pipeline
 *
 * Cogl allows creating and manipulating objects representing the full
 * configuration of the GPU pipeline. In simplified terms the GPU
 * pipeline takes primitive geometry as the input, it first performs
 * vertex processing, allowing you to deform your geometry, then
 * rasterizes that (turning it from pure geometry into fragments) then
 * performs fragment processing including depth testing and texture
 * mapping. Finally it blends the result with the framebuffer.
 */

#define COGL_PIPELINE(OBJECT) ((CoglPipeline *)OBJECT)

/**
 * cogl_pipeline_new:
 * @context: a #CoglContext
 *
 * Allocates and initializes a default simple pipeline that will color
 * a primitive white.
 *
 * Return value: (transfer full): a pointer to a new #CoglPipeline
 *
 * Since: 2.0
 * Stability: Unstable
 */
CoglPipeline *
cogl_pipeline_new (CoglContext *context);

/**
 * cogl_pipeline_copy:
 * @source: a #CoglPipeline object to copy
 *
 * Creates a new pipeline with the configuration copied from the
 * source pipeline.
 *
 * We would strongly advise developers to always aim to use
 * cogl_pipeline_copy() instead of cogl_pipeline_new() whenever there will
 * be any similarity between two pipelines. Copying a pipeline helps Cogl
 * keep track of a pipelines ancestry which we may use to help minimize GPU
 * state changes.
 *
 * Return value: (transfer full): a pointer to the newly allocated #CoglPipeline
 *
 * Since: 2.0
 * Stability: Unstable
 */
CoglPipeline *
cogl_pipeline_copy (CoglPipeline *source);

/**
 * cogl_is_pipeline:
 * @object: A #CoglObject
 *
 * Gets whether the given @object references an existing pipeline object.
 *
 * Return value: %TRUE if the @object references a #CoglPipeline,
 *   %FALSE otherwise
 *
 * Since: 2.0
 * Stability: Unstable
 */
CoglBool
cogl_is_pipeline (void *object);

/**
 * CoglPipelineLayerCallback:
 * @pipeline: The #CoglPipeline whos layers are being iterated
 * @layer_index: The current layer index
 * @user_data: The private data passed to cogl_pipeline_foreach_layer()
 *
 * The callback prototype used with cogl_pipeline_foreach_layer() for
 * iterating all the layers of a @pipeline.
 *
 * Since: 2.0
 * Stability: Unstable
 */
typedef CoglBool (*CoglPipelineLayerCallback) (CoglPipeline *pipeline,
                                               int layer_index,
                                               void *user_data);

/**
 * cogl_pipeline_foreach_layer:
 * @pipeline: A #CoglPipeline object
 * @callback: (scope call): A #CoglPipelineLayerCallback to be
 *            called for each layer index
 * @user_data: (closure): Private data that will be passed to the
 *             callback
 *
 * Iterates all the layer indices of the given @pipeline.
 *
 * Since: 2.0
 * Stability: Unstable
 */
void
cogl_pipeline_foreach_layer (CoglPipeline *pipeline,
                             CoglPipelineLayerCallback callback,
                             void *user_data);

/**
 * cogl_pipeline_get_uniform_location:
 * @pipeline: A #CoglPipeline object
 * @uniform_name: The name of a uniform
 *
 * This is used to get an integer representing the uniform with the
 * name @uniform_name. The integer can be passed to functions such as
 * cogl_pipeline_set_uniform_1f() to set the value of a uniform.
 *
 * This function will always return a valid integer. Ie, unlike
 * OpenGL, it does not return -1 if the uniform is not available in
 * this pipeline so it can not be used to test whether uniforms are
 * present. It is not necessary to set the program on the pipeline
 * before calling this function.
 *
 * Return value: A integer representing the location of the given uniform.
 *
 * Since: 2.0
 * Stability: Unstable
 */
int
cogl_pipeline_get_uniform_location (CoglPipeline *pipeline,
                                    const char *uniform_name);


#endif /* COGL_ENABLE_EXPERIMENTAL_API */

COGL_END_DECLS

#endif /* __COGL_PIPELINE_H__ */