/* cogl-shader.h: Shaders and programmable pipeline
* This file is part of Clutter
*
* Copyright (C) 2008 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_SHADER_H__
#define __COGL_SHADER_H__
#include <glib.h>
G_BEGIN_DECLS
/**
* SECTION:cogl-shaders
* @short_description: Fuctions for accessing the programmable GL pipeline
*
* COGL allows accessing the GL programmable pipeline in order to create
* vertex and fragment shaders.
*
* The only supported format is GLSL shaders.
*/
/**
* cogl_create_shader:
* @shader_type: CGL_VERTEX_SHADER or CGL_FRAGMENT_SHADER.
*
* Create a new shader handle, use #cogl_shader_source to set the source code
* to be used on it.
*
* Returns: a new shader handle.
*/
CoglHandle cogl_create_shader (COGLenum shader_type);
/**
* cogl_shader_ref:
* @handle: A #CoglHandle to a shader.
*
* Add an extra reference to a shader.
*
* Returns: @handle
*/
CoglHandle cogl_shader_ref (CoglHandle handle);
/**
* cogl_shader_unref:
* @handle: A #CoglHandle to a shader.
*
* Removes a reference to a shader. If it was the last reference the
* shader object will be destroyed.
*/
void cogl_shader_unref (CoglHandle handle);
/**
* cogl_is_shader:
* @handle: A CoglHandle
*
* Gets whether the given handle references an existing shader object.
*
* Returns: %TRUE if the handle references a shader,
* %FALSE otherwise
*/
gboolean cogl_is_shader (CoglHandle handle);
/**
* cogl_shader_source:
* @shader: #CoglHandle for a shader.
* @source: GLSL shader source.
*
* Replaces the current GLSL source associated with a shader with a new
* one.
*/
void cogl_shader_source (CoglHandle shader,
const gchar *source);
/**
* cogl_shader_compile:
* @handle: #CoglHandle for a shader.
*
* Compiles the shader, no return value, but the shader is now ready for
* linking into a program.
*/
void cogl_shader_compile (CoglHandle handle);
/**
* cogl_shader_get_info_log:
* @handle: #CoglHandle for a shader.
* @size: maximum number of bytes to retrieve.
* @buffer: location for info log.
*
* Retrieves the information log for a coglobject, can be used in conjunction
* with #cogl_shader_get_parameteriv to retrieve the compiler warnings/error
* messages that caused a shader to not compile correctly, mainly useful for
* debugging purposes.
*/
void cogl_shader_get_info_log (CoglHandle handle,
guint size,
gchar *buffer);
/**
* cogl_shader_get_parameteriv:
* @handle: #CoglHandle for a shader.
* @pname: the named COGL parameter to retrieve.
* @dest: storage location for COGLint return value.
*
* Retrieve a named parameter from a shader can be used to query to compile
* satus of a shader by passing in CGL_OBJECT_COMPILE_STATUS for @pname.
*/
void cogl_shader_get_parameteriv (CoglHandle handle,
COGLenum pname,
COGLint *dest);
/**
* cogl_create_program:
*
* Create a new cogl program object that can be used to replace parts of the GL
* rendering pipeline with custom code.
*
* Returns: a new cogl program.
*/
CoglHandle cogl_create_program (void);
/**
* cogl_program_ref:
* @handle: A #CoglHandle to a program.
*
* Add an extra reference to a program.
*
* Returns: @handle
*/
CoglHandle cogl_program_ref (CoglHandle handle);
/**
* cogl_program_unref:
* @handle: A #CoglHandle to a program.
*
* Removes a reference to a program. If it was the last reference the
* program object will be destroyed.
*/
void cogl_program_unref (CoglHandle handle);
/**
* cogl_is_program:
* @handle: A CoglHandle
*
* Gets whether the given handle references an existing program object.
*
* Returns: %TRUE if the handle references a program,
* %FALSE otherwise
*/
gboolean cogl_is_program (CoglHandle handle);
/**
* cogl_program_attach_shader:
* @program_handle: a #CoglHandle for a shdaer program.
* @shader_handle: a #CoglHandle for a vertex of fragment shader.
*
* Attaches a shader to a program object, a program can have one vertex shader
* and one fragment shader attached.
*/
void cogl_program_attach_shader (CoglHandle program_handle,
CoglHandle shader_handle);
/**
* cogl_program_link:
* @handle: a #CoglHandle for a shader program.
*
* Links a program making it ready for use.
*/
void cogl_program_link (CoglHandle handle);
/**
* cogl_program_use:
* @handle: a #CoglHandle for a shader program or %COGL_INVALID_HANDLE.
*
* Activate a specific shader program replacing that part of the GL
* rendering pipeline, if passed in %COGL_INVALID_HANDLE the default
* behavior of GL is reinstated.
*/
void cogl_program_use (CoglHandle handle);
/**
* cogl_program_get_uniform_location:
* @handle: a #CoglHandle for a shader program.
* @uniform_name: the name of a uniform.
*
* Retrieve the location (offset) of a uniform variable in a shader program,
* a uniform is a variable that is constant for all vertices/fragments for a
* shader object and is possible to modify as an external parameter.
*
* Return value: the offset of a uniform in a specified program.
* This uniform can be set using cogl_program_uniform_1f() when the
* program is in use.
*/
COGLint cogl_program_get_uniform_location
(CoglHandle handle,
const gchar *uniform_name);
/**
* cogl_program_uniform_1f:
* @uniform_no: the unform to set.
* @value: the new value of the uniform.
*
* Changes the value of a floating point uniform in the currently
* used (see cogl_program_use()) shader program.
*/
void cogl_program_uniform_1f (COGLint uniform_no,
gfloat value);
/**
* cogl_program_uniform_1i:
* @uniform_no: the unform to set.
* @value: the new value of the uniform.
*
* Changes the value of an integer uniform in the currently
* used (see cogl_program_use()) shader program.
*/
void cogl_program_uniform_1i (COGLint uniform_no,
gint value);
/**
* cogl_program_uniform_float:
* @uniform_no: the uniform to set.
* @size: Size of float vector.
* @count: Size of array of uniforms.
* @value: the new value of the uniform.
*
* Changes the value of a float vector uniform, or uniform array in the
* currently used (see #cogl_program_use) shader program.
*/
void cogl_program_uniform_float (COGLint uniform_no,
gint size,
gint count,
const GLfloat *value);
/**
* cogl_program_uniform_int:
* @uniform_no: the uniform to set.
* @size: Size of int vector.
* @count: Size of array of uniforms.
* @value: the new value of the uniform.
*
* Changes the value of a int vector uniform, or uniform array in the
* currently used (see cogl_program_use()) shader program.
*/
void cogl_program_uniform_int (COGLint uniform_no,
gint size,
gint count,
const COGLint *value);
/**
* cogl_program_uniform_matrix:
* @uniform_no: the uniform to set.
* @size: Size of matrix.
* @count: Size of array of uniforms.
* @transpose: Whether to transpose the matrix when setting the uniform.
* @value: the new value of the uniform.
*
* Changes the value of a matrix uniform, or uniform array in the
* currently used (see cogl_program_use()) shader program. The @size
* parameter is used to determine the square size of the matrix.
*/
void cogl_program_uniform_matrix (COGLint uniform_no,
gint size,
gint count,
gboolean transpose,
const GLfloat *value);
G_END_DECLS
#endif /* __COGL_SHADER_H__ */