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mutter-performance-source/cogl/cogl-pipeline.h
Neil Roberts 4553ca0695 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>
2011-11-16 16:32:11 +00:00

172 lines
5.2 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_H__
#define __COGL_PIPELINE_H__
#include <cogl/cogl-types.h>
G_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.
*/
typedef struct _CoglPipeline CoglPipeline;
#define COGL_PIPELINE(OBJECT) ((CoglPipeline *)OBJECT)
#define cogl_pipeline_new cogl_pipeline_new_EXP
/**
* cogl_pipeline_new:
*
* Allocates and initializes a default simple pipeline that will color
* a primitive white.
*
* Return value: a pointer to a new #CoglPipeline
*
* Since: 2.0
* Stability: Unstable
*/
CoglPipeline *
cogl_pipeline_new (void);
#define cogl_pipeline_copy cogl_pipeline_copy_EXP
/**
* 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.
*
* Returns: a pointer to the newly allocated #CoglPipeline
*
* Since: 2.0
* Stability: Unstable
*/
CoglPipeline *
cogl_pipeline_copy (CoglPipeline *source);
#define cogl_is_pipeline cogl_is_pipeline_EXP
/**
* cogl_is_pipeline:
* @handle: A CoglHandle
*
* Gets whether the given handle references an existing pipeline object.
*
* Return value: %TRUE if the handle references a #CoglPipeline,
* %FALSE otherwise
*
* Since: 2.0
* Stability: Unstable
*/
gboolean
cogl_is_pipeline (CoglHandle handle);
/**
* 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 gboolean (*CoglPipelineLayerCallback) (CoglPipeline *pipeline,
int layer_index,
void *user_data);
#define cogl_pipeline_foreach_layer cogl_pipeline_foreach_layer_EXP
/**
* cogl_pipeline_foreach_layer:
* @pipeline: A #CoglPipeline object
* @callback: A #CoglPipelineLayerCallback 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 @pipeline.
*
* Since: 2.0
* Stability: Unstable
*/
void
cogl_pipeline_foreach_layer (CoglPipeline *pipeline,
CoglPipelineLayerCallback callback,
void *user_data);
#define cogl_pipeline_get_uniform_location \
cogl_pipeline_get_uniform_location_EXP
/**
* 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 */
G_END_DECLS
#endif /* __COGL_PIPELINE_H__ */