Carna::base::GLContext Class Reference

Wraps and represents an OpenGL context. More...

#include <GLContext.h>

Inheritance diagram for Carna::base::GLContext:

Public Member Functions
virtual	~GLContext ()
	Deletes.
void	makeCurrent () const
	Makes the OpenGL context represented by this object the current one.
bool	isCurrent () const
	Tells whether the OpenGL context represented by this object is the current one.
void	setShader (const ShaderProgram &shader)
	Makes shader the current shader of the represented OpenGL context.
const ShaderProgram &	shader () const
	References the shader set last.
void	clearBuffers (unsigned int flags)
	Wraps glClear. Automatically enables on glDepthMask temporarily if the DEPTH_BUFFER_BIT is supplied.

Static Public Member Functions
static GLContext &	current ()
	References the current OpenGL context wrapper.

Public Attributes
const bool	isDoubleBuffered
	Tells whether the represented OpenGL context uses double buffering.

Static Public Attributes
static const unsigned int	DEPTH_BUFFER_BIT
	Wraps GL_DEPTH_BUFFER_BIT.
static const unsigned int	COLOR_BUFFER_BIT
	Wraps GL_COLOR_BUFFER_BIT

Protected Member Functions
	GLContext (bool isDoubleBuffered)
	Instantiates GLContext that represents the current OpenGL context.
void	pushRenderState (const RenderState &rs)
	Makes rs the current render state.
void	popRenderState ()
	Restores previous render state.
const RenderState &	currentRenderState () const
	References the latest render state.
virtual void	activate () const =0
	Activates the OpenGL context represented by this object.

Friends
class	RenderState

Detailed Description

Wraps and represents an OpenGL context.

This is a good explanation of the essence of OpenGL contexts:

‍An OpenGL context represents many things. A context stores all of the state associated with this instance of OpenGL. [...] Each context can represent a separate viewable surface, like a window in an application. Contexts can share many kinds of objects between each other. Any OpenGL object types which are not containers are sharable, as well as [...] GLSL Objects. [...] In order for any OpenGL commands to work, a context must be current; all OpenGL commands affect the state of whichever context is current. The current context is a thread-local variable, so a single process can have several threads, each of which has its own current context.

Reference: https://www.opengl.org/wiki/OpenGL_Context

Carna assumes that all OpenGL contexts within your application are capable of sharing objects. Carna does not support multi-threading environments, i.e. all Carna-related code must be run on the same thread. The states are maintained through the RenderState class.

Author

Leonid Kostrykin

Date

22.2.15 - 15.3.15

Definition at line 62 of file GLContext.h.

Member Function Documentation

activate()

virtual void Carna::base::GLContext::activate ( ) const

protectedpure virtual

Activates the OpenGL context represented by this object.

Implemented in Carna::base::QGLContextAdapter< QGLContext, QGLFormat >.

setShader()

void Carna::base::GLContext::setShader

(

const ShaderProgram &

shader

)

Makes shader the current shader of the represented OpenGL context.

Precondition

isCurrent() == true

shader()

const ShaderProgram & Carna::base::GLContext::shader

(

)

const

References the shader set last.

Precondition

setShader has been called previously.

Friends And Related Symbol Documentation

RenderState

friend class RenderState

friend

Definition at line 77 of file GLContext.h.

Member Data Documentation

COLOR_BUFFER_BIT

const unsigned int Carna::base::GLContext::COLOR_BUFFER_BIT

static

Wraps GL_COLOR_BUFFER_BIT

Definition at line 97 of file GLContext.h.

DEPTH_BUFFER_BIT

const unsigned int Carna::base::GLContext::DEPTH_BUFFER_BIT

static

Wraps GL_DEPTH_BUFFER_BIT.

Definition at line 96 of file GLContext.h.

isDoubleBuffered

const bool Carna::base::GLContext::isDoubleBuffered

Tells whether the represented OpenGL context uses double buffering.

Definition at line 107 of file GLContext.h.

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

• include/Carna/base/GLContext.h