engine::graphics::OpenGL Class Reference

This class serves as the OpenGL interface for your app, since the engine doesn't directly link OpenGL to the app executable. More...

#include <OpenGL.hpp>

Public Types
using	ShaderProgramId = uint32_t

Static Public Member Functions
template<typename TResult , typename... TOpenGLArgs, typename... Args>
static TResult	call (std::source_location location, TResult(*glfun)(TOpenGLArgs...), Args... args)
	Performs a checked OpenGL call. If the OpenGL call fails, it throws util::OpenGLError.
static int32_t	shader_type_to_opengl_type (resources::ShaderType type)
	Converts resources::ShaderType to the OpenGL shader type enum.
static uint32_t	generate_texture (const std::filesystem::path &path, bool flip_uvs)
	Loads the texture from path into the OpenGL context.
static int32_t	texture_format (int32_t number_of_channels)
	Get texture format for a number_of_channels.
static uint32_t	init_skybox_cube ()
	Initializes the cube Vertex Array Object used for skybox drawing. Caches the vao result.
static bool	shader_compiled_successfully (uint32_t shader_id)
	Check if the shader with the shader_id compiled successfully.
static uint32_t	compile_shader (const std::string &shader_source, resources::ShaderType shader_type)
	Compiles the shader from source.
static uint32_t	load_skybox_textures (const std::filesystem::path &path, bool flip_uvs=false)
	Loads the skybox textures from the path. Make sure that images are named: front.jpg, back.jpg, up.jpg, down.jpg, left.jpg, down.jpg. They can be of the other extension as well, but the function will assign each texture to the appropriate side of the cubemap based on the texture file name.
static void	enable_depth_testing ()
	Enables depth testing.
static void	disable_depth_testing ()
	Disables depth testing.
static void	clear_buffers ()
	Clears GL_DEPTH_BUFFER_BIT, GL_COLOR_BUFFER_BIT, and GL_STENCIL_BUFFER_BIT.
static std::string	get_compilation_error_message (uint32_t shader_id)
	Retrieve the shader compilation error log message.

Static Private Member Functions
static void	assert_no_error (std::source_location location)
	Throws util::OpenGLError if an OpenGL error occurred. Used internally.

Detailed Description

This class serves as the OpenGL interface for your app, since the engine doesn't directly link OpenGL to the app executable.

Any OpenGL additional direct OpenGL calls you need should be added here.

Member Typedef Documentation

ShaderProgramId

using engine::graphics::OpenGL::ShaderProgramId = uint32_t

Member Function Documentation

call()

template<typename TResult , typename... TOpenGLArgs, typename... Args>

static TResult engine::graphics::OpenGL::call ( std::source_location  location, TResult(*)(TOpenGLArgs...)  glfun, Args...  args  )

inlinestatic

Performs a checked OpenGL call. If the OpenGL call fails, it throws util::OpenGLError.

Parameters

location	Source location of where the call was made.
glfun	OpenGL function to call.
args	OpenGL function arguments.

Returns

Return value if the glfun has it, otherwise void.

shader_type_to_opengl_type()

int32_t engine::graphics::OpenGL::shader_type_to_opengl_type ( resources::ShaderType  type )

static

Converts resources::ShaderType to the OpenGL shader type enum.

Returns

GL_VERTEX_SHADER, GL_FRAGMENT_SHADER, GL_GEOMETRY_SHADER

generate_texture()

uint32_t engine::graphics::OpenGL::generate_texture ( const std::filesystem::path &  path, bool  flip_uvs  )

static

Loads the texture from path into the OpenGL context.

Parameters

path	path to a texture file.
flip_uvs	flip_uvs on load.

Returns

OpenGL id of a texture object.

texture_format()

int32_t engine::graphics::OpenGL::texture_format ( int32_t  number_of_channels )

static

Get texture format for a number_of_channels.

Parameters

number_of_channels

that the texture has.

Returns

GL_RED, GL_RGB, GL_RGBA for the number_of_channels=[1,3,4] respectively.

init_skybox_cube()

uint32_t engine::graphics::OpenGL::init_skybox_cube ( )

static

Initializes the cube Vertex Array Object used for skybox drawing. Caches the vao result.

Returns

VAO of the cube used for skybox drawing.

shader_compiled_successfully()

bool engine::graphics::OpenGL::shader_compiled_successfully ( uint32_t  shader_id )

static

Check if the shader with the shader_id compiled successfully.

Returns

true if the shader compilation succeeded, false otherwise.

compile_shader()

uint32_t engine::graphics::OpenGL::compile_shader ( const std::string &  shader_source, resources::ShaderType  shader_type  )

static

Compiles the shader from source.

Parameters

shader_source	source code for the shader
shader_type	the type of the shader to create1

Returns

OpenGL context object of the shader.

load_skybox_textures()

uint32_t engine::graphics::OpenGL::load_skybox_textures ( const std::filesystem::path &  path, bool  flip_uvs = false  )

static

Loads the skybox textures from the path. Make sure that images are named: front.jpg, back.jpg, up.jpg, down.jpg, left.jpg, down.jpg. They can be of the other extension as well, but the function will assign each texture to the appropriate side of the cubemap based on the texture file name.

Parameters

path	directory in which cubemap textures are located.
flip_uvs	wheater to flip_uvs on texture loading.

Returns

OpenGL id to the cubemap texture

enable_depth_testing()

void engine::graphics::OpenGL::enable_depth_testing ( )

static

Enables depth testing.

disable_depth_testing()

void engine::graphics::OpenGL::disable_depth_testing ( )

static

Disables depth testing.

clear_buffers()

void engine::graphics::OpenGL::clear_buffers ( )

static

Clears GL_DEPTH_BUFFER_BIT, GL_COLOR_BUFFER_BIT, and GL_STENCIL_BUFFER_BIT.

get_compilation_error_message()

std::string engine::graphics::OpenGL::get_compilation_error_message ( uint32_t  shader_id )

static

Retrieve the shader compilation error log message.

Parameters

shader_id

Shader id for which the compilation failed.

Returns

shader compilation error message.

assert_no_error()

void engine::graphics::OpenGL::assert_no_error ( std::source_location  location )

staticprivate

Throws util::OpenGLError if an OpenGL error occurred. Used internally.

Parameters

location

Source location from where the OpenGL call was made.

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

• engine/include/engine/graphics/OpenGL.hpp
• engine/src/OpenGL.cpp