src/offscreen.h File Reference

Code for managing offscreen rendering. More...

#include <GL/gl.h>

Go to the source code of this file.

Typedefs
typedef struct _offscreen	offscreen_t
	Public handel to the offsceen object.
Functions
offscreen_t *	offscreen_create (unsigned int width, unsigned int height)
	Creates an offscreen object with the sepcified dimensions.
void	offscreen_destroy (offscreen_t *o)
	Cleans up the memory accosiated with an offscreen object.
unsigned int	get_next_power_2 (unsigned int x)
	Returns a number that is the smallest power of two heigher that x.
GLuint	offscreen_get_texture (offscreen_t *o)
	Gets the OpenGL identifier for the texture that has been drawn to.
GLint	offscreen_get_texture_location (offscreen_t *o)
	Gets the location of the texture in the current glsl program.
void	offscreen_set_texture_location (offscreen_t *o, GLint loc)
	Sets the location of the texture in the current glsl program.
void	offscreen_load_texture (offscreen_t *o)
void	offscreen_get_texture_size (offscreen_t *o, unsigned int *width, unsigned int *height)
void	offscreen_start (offscreen_t *o)
	Begins drawing to the offscreen texture.
void	offscreen_stop (offscreen_t *o)
	Ends drawing to the offscreen texture.

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Detailed Description

Code for managing offscreen rendering.

Actual implimentation is either with fbo's (offscreen-fbo.c) or by copying the texture from the window system provided buffer.

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Typedef Documentation

typedef struct _offscreen offscreen_t

Public handel to the offsceen object.

---

Function Documentation

unsigned int get_next_power_2

(

unsigned int

x

)

Returns a number that is the smallest power of two heigher that x.

Parameters:

[in]

x

The number that the return value must be equall to or higher than.

Returns:

The power of two that is equal to or higher than x.

offscreen_t* offscreen_create	(	unsigned int	width,
		unsigned int	height
	)

Creates an offscreen object with the sepcified dimensions.

Parameters:

[in]	width	The width of the offscreen object in pixels.
[in]	height	The height of the offscreen object in pixels.

Returns:

A pointer to the new offscreen object.

void offscreen_destroy

(

offscreen_t *

o

)

Cleans up the memory accosiated with an offscreen object.

Parameters:

[in]

o

The object to be destroyed.

GLuint offscreen_get_texture

(

offscreen_t *

o

)

Gets the OpenGL identifier for the texture that has been drawn to.

Parameters:

[in]

o

The object for which we want the texture.

Returns:

The OpenGL identifier for the offscreen texture that has been drawn to.

GLint offscreen_get_texture_location

(

offscreen_t *

o

)

Gets the location of the texture in the current glsl program.

Parameters:

[in]

o

The offscreen object to query.

Returns:

The OpenGL identifier for the location.

void offscreen_get_texture_size	(	offscreen_t *	o,
		unsigned int *	width,
		unsigned int *	height
	)

Returns the size of the offscreen object in pixels.

Parameters:

[in]	o	The object to query.
[out]	width	Gets set to the width of the object in pixels.
[out]	height	Gets set to the height of the object in pixels.

void offscreen_load_texture

(

offscreen_t *

o

)

void offscreen_set_texture_location	(	offscreen_t *	o,
		GLint	loc
	)

Sets the location of the texture in the current glsl program.

Parameters:

[in]	o	The offscreen object to modify.
[in]	loc	The new location identifier.

void offscreen_start

(

offscreen_t *

o

)

Begins drawing to the offscreen texture.

Parameters:

[in]

o

The object to draw to.

void offscreen_stop

(

offscreen_t *

o

)

Ends drawing to the offscreen texture.

Parameters:

[in]

o

The object to stop drawing to.