OpenGL Shader Compilation. More...

#include <easy3d/renderer/shader_program.h>

Public Types
enum	AttribType { POSITION , COLOR , NORMAL , TEXCOORD }

enum	ShaderType { VERTEX , FRAGMENT , GEOMETRY , TESS_CONTROL , TESS_EVALUATION , COMPUTE , NUM_SHADER_TYPES }

typedef std::pair< ShaderProgram::AttribType, std::string >	Attribute

Public Member Functions
	ShaderProgram (const std::string &name="unknown")

void	set_name (const std::string &name)

const std::string &	name () const

void	set_verbose (bool v)
	Sets true to log any issues found.

unsigned int	get_program () const
	Returns the program index.

void	clear ()
	Removes (deletes) all shaders.

bool	load_shader_from_file (ShaderType st, const std::string &file_name, const std::string &inc_id="#include")

bool	load_shader_from_code (ShaderType st, const std::string &code)

void	set_attrib_name (ShaderProgram::AttribType at, const std::string &name) const

void	set_attrib_names (const std::vector< ShaderProgram::Attribute > &attributes) const

bool	link_program ()

void	set_program_output (int index, const std::string &name) const

int	program_output (const std::string &name) const

void	bind () const
	Starts using the program.

ShaderProgram *	set_uniform (const std::string &name, const void *value)

ShaderProgram *	set_uniform (const std::string &name, int value)

ShaderProgram *	set_uniform (const std::string &name, unsigned int value)

ShaderProgram *	set_uniform (const std::string &name, float value)

ShaderProgram *	set_block (const std::string &name, const void *value)

ShaderProgram *	set_block_uniform (const std::string &blockName, const std::string &uniformName, const void *value)

ShaderProgram *	set_block_uniform_array_element (const std::string &blockName, const std::string &uniformName, int arrayIndex, const void *value)

ShaderProgram *	bind_texture (const std::string &name, unsigned int tex_id, int unit, unsigned int tex_target=0x0DE1)

ShaderProgram *	release_texture (unsigned int tex_target=0x0DE1)

void	release () const
	Ends using the program.

int	get_attribute_location (const std::string &name) const

bool	is_uniform_used (const std::string &name)

bool	is_attribute_used (const std::string &name)

bool	is_program_valid () const

bool	is_program_linked () const
	Returns true if program linked, false otherwise.

bool	is_bound () const
	Returns true if the program is being used (i.e., between bind() and release()).

bool	shader_info_log (std::string &log, unsigned int shader) const
	returns a string with a shader's infolog

bool	program_info_log (std::string &log) const
	returns a string with the program's infolog

void	print_active_attributes ()

void	print_active_uniforms ()

void	print_active_uniform_blocks ()

bool	load_binary (const std::string &file_name)

bool	save_binary (const std::string &file_name)

Static Public Member Functions
static bool	is_supported ()

static std::string	load_shader_source (const std::string &file_name, const std::string &inc_id="#include")

Friends
class	ShaderManager

Detailed Description

OpenGL Shader Compilation.

To use the shader program class, you need to do the following:

Call load_shader_from_code(ShaderProgram::VERTEX, vert_file) to create vertex shader and load_shader_from_code(ShaderProgram::FRAGMENT, frag_file) to create fragment shader (you may also need to create other types of shaders depending on your needs).
Call set_attrib_name(ShaderProgram::POSITION, "position") for vertex attribute "position". You may also need to set other attributes like normal, color, etc. To know what vertex attributes need to be set, check your shader code or call print_active_attributes().
Call link_program() to link the program.

For rendering

Call bind();
Call set_uniform() to set all the necessary uniforms. You may also need to call set_block(), set_block_uniform(), and/or set_block_uniform_array_element(). To know what uniforms need to be set, check your shader code or call print_active_uniforms(), print_active_uniform_blocks().
Call the drawable's draw() function
Call release();

To retrieve the model view projection matrix, call camera's modelViewProjectionMatrix()

Examples: Tutorial_207_RealCamera, Tutorial_501_AmbientOcclusion, Tutorial_505_EyeDomeLighting, and Tutorial_506_DepthMaps.

Constructor & Destructor Documentation

◆ ShaderProgram()

ShaderProgram ( const std::string & name = "unknown" )

explicit

Constructor.

Parameters

name	A unique name for a program, convenient to distinguish multiple programs. This is quite helpful in identifying issues when multiple programs are used. It is suggested to use the source file name.

Member Function Documentation

◆ link_program()

bool link_program ( )

Prepares program for usage. Links it and collects information about uniform variables and uniform blocks.

◆ load_shader_from_code()

bool load_shader_from_code	(	ShaderType	st,
		const std::string &	code
	)

Loads the code to the source of the specified shader

Parameters

st	one of the enum values of ShaderType
code	the string of the shader source code

◆ load_shader_from_file()

bool load_shader_from_file	(	ShaderType	st,
		const std::string &	file_name,
		const std::string &	inc_id = `"#include"`
	)

Loads the text in the file to the source of the specified shader

Parameters

st	one of the enum values of ShaderType
file_name	the full path of the file where the source is to be found
inc_id	the include identifier string (e.g., "#include")

◆ load_shader_source()

std::string load_shader_source	(	const std::string &	file_name,
		const std::string &	inc_id = `"#include"`
	)

static

Auxiliary function that loads the shader source code from a file.

Parameters

file_name	the full path of the file where the source is to be found
inc_id	the include identifier string (e.g., "#include")

◆ program_output()

int program_output ( const std::string & name ) const

Returns the fragment shader color number bound to a user-defined varying out variable Note: linking is required for this operation to take effect (call method prepare_program afterwards)

Parameters

the	name of the fragment's shader variable

Returns: the fragment color number

◆ set_attrib_name()

void set_attrib_name	(	ShaderProgram::AttribType	at,
		const std::string &	name
	)		const

Defines semantics for the input vertex attributes. This is required for other libraries to know how to send data to the shader.

Parameters

at	The semantic of the attribute
name	The name of the vertex attribute

Note: To specify a location for an attribute you must do it prior to linking the program, or, if the program is already linked, to link it again afterwards (call method link_program)

◆ set_block()

ShaderProgram * set_block	(	const std::string &	name,
		const void *	value
	)

Sets a uniform block as a whole

◆ set_block_uniform()

ShaderProgram * set_block_uniform	(	const std::string &	blockName,
		const std::string &	uniformName,
		const void *	value
	)

Sets a uniform inside a named block Warning: Be careful when using uniform blocks. Please refer to OpenGL Specification Version 4.5 (Core Profile) - May 28, 2015 (https://www.opengl.org/registry/doc/glspec45.core.pdf#page=159) In "Standard Uniform Block Layout", it says "If the member is a three-component vector with components consuming N basic machine units, the base alignment is 4N" (see rule 3 of section 7.6.2.2 in page.159). That means the array stride (the bytes between array elements) is always rounded up to the size of a vec4 (i.e., 16-bytes). So we have to avoid using vec3/mat3 (use vec4/mat4/mat43 instead) in a uniform block. Otherwise, you have to manually pad your structures/arrays out.

Examples: Tutorial_501_AmbientOcclusion.

◆ set_block_uniform_array_element()

ShaderProgram * set_block_uniform_array_element	(	const std::string &	blockName,
		const std::string &	uniformName,
		int	arrayIndex,
		const void *	value
	)

Sets an element of an array of uniforms inside a block

◆ set_program_output()

void set_program_output	(	int	index,
		const std::string &	name
	)		const

Bind a user-defined varying out variable to a fragment shader color number Note: linking is required for this operation to take effect (call method prepare_program afterwards)

Parameters

index	The fragment color number
name	The name of the fragment's shader variable

The documentation for this class was generated from the following files:

/Users/lnan/Documents/Projects/Easy3D/easy3d/renderer/shader_program.h
/Users/lnan/Documents/Projects/Easy3D/easy3d/renderer/shader_program.cpp

Public Types

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

◆ ShaderProgram()

Member Function Documentation

◆ link_program()

◆ load_shader_from_code()

◆ load_shader_from_file()

◆ load_shader_source()

◆ program_output()

◆ set_attrib_name()

◆ set_block()

◆ set_block_uniform()

◆ set_block_uniform_array_element()

◆ set_program_output()