mimas::mesa_base Class Reference

Abstract base class for mesa-functionality. More...

#include <mesa_base.h>

Inheritance diagram for mimas::mesa_base:

[legend]Collaboration diagram for mimas::mesa_base:


Public Member Functions
virtual	~mesa_base (void)
	Destructor.
virtual void	finish (void)
	Finish output on the image.
virtual void	ortho2D (void) const =0
	Switch to two-dimensional drawing mode.
virtual void	ortho2D (int x1, int y1, int x2, int y2) const =0
	Switch to two-dimensional drawing mode with clipping.
void	setColor (const rgba< unsigned char > &color) const
	Set color.
void	setGray (unsigned char gray) const
	Set luminance.
void	rectangle (int x1, int y1, int x2, int y2) const
	Draw rectangle.
void	text (const std::string &s) const
	Write text.
Protected Member Functions
	mesa_base (x11_display _display, XVisualInfo _visualInfo) throw (mimasexception)
	Protected constructor.
void	glWrap (bool condition, const char *message) throw (mimasexception)
	Wrapper for converting OpenGL error messages to exceptions.
Protected Attributes
x11_display *	display
	X11-display.
XVisualInfo *	visualInfo
	X11-visual with desired attributes.
bool	finishBase
	State of object.
Static Protected Attributes
static bool	existInstance
	There must be only one instance of this class.

Detailed Description

Abstract base class for mesa-functionality.

The mesa-functionality mainly consists in offering initialisation of an OpenGL-context for on-screen- or off-screen-rendering.

After initialisation of a deriving non-abstract class, the OpenGL functionality can be either accessed directly using the OpenGL methods bypassing this class or accessed indirectly by using one of the few wrappers for setting the color, for drawing rectangles and for displaying text, being provided by this class.

At any time there must be only one instance of this class to avoid crashes of X11, side-effects or deadlocks.

Xorg 6.9.0 does not display gray images properly (GL_LUMINANCE). A bug report was filed: https://bugs.freedesktop.org/show_bug.cgi?id=7444

If you experience problems, you may want to try:

    export LIBGL_ALWAYS_INDIRECT=1

This disables hardware rendering.

If it works:

the problem is likely with the display driver
it will be very slow

If it doesn't:

there is a different bug, we need to fix

Do not forget to initialise glut at the beginning of your program:

    glutInit( &argc, argv );

References:

https://www.gamedev.net/download/redbook.pdf
Author:
Jan Wedekind (jan at wedesoft.de)

Date:
Wed Mar 30 19:35:05 UTC 2005

Definition at line 58 of file mesa_base.h.

Constructor & Destructor Documentation

virtual mimas::mesa_base::~mesa_base ( void ) [virtual]

Destructor.

The destructor just calls the method finish() .

See also:: finish

mimas::mesa_base::mesa_base	(	x11_display *	_display,
		XVisualInfo *	_visualInfo
	)			throw (mimasexception) `[protected]`

Protected constructor.

The display and visualInfo variables must be destructed by the calling program.

Parameters:

	_display	X11 display variable.
	_visualInfo	X11 visual info structure.

Member Function Documentation

virtual void mimas::mesa_base::finish ( void ) [virtual]

Finish output on the image.

This method allows finalising of the output without having to destruct this object immediately.

Only call after having finished rendering. This object has to be destructed afterwards.

Reimplemented in mimas::mesa_offscreen< T >, and mimas::mesa_onscreen.

virtual void mimas::mesa_base::ortho2D ( void ) const [pure virtual]

Switch to two-dimensional drawing mode.

The coordinate system has the origin in the "top-left" corner of the image.

Implemented in mimas::mesa_offscreen< T >, and mimas::mesa_onscreen.

virtual void mimas::mesa_base::ortho2D	(	int	x1,
		int	y1,
		int	x2,
		int	y2
	)			const `[pure virtual]`

Switch to two-dimensional drawing mode with clipping.

The coordinate system has the origin in the "top-left" corner of the image.

Implemented in mimas::mesa_offscreen< T >, and mimas::mesa_onscreen.

void mimas::mesa_base::setColor ( const rgba< unsigned char > & color ) const [inline]

Set color.

Parameters:

color

Color-object. The alpha-component is ignored.

Definition at line 82 of file mesa_base.h.

References mimas::rgba< T >::getBlue(), mimas::rgba< T >::getGreen(), and mimas::rgba< T >::getRed().

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void mimas::mesa_base::setGray ( unsigned char gray ) const [inline]

Set luminance.

Parameters:

gray

The gray-value.

Definition at line 86 of file mesa_base.h.

void mimas::mesa_base::rectangle	(	int	x1,
		int	y1,
		int	x2,
		int	y2
	)			const

Draw rectangle.

Parameters:

	x1	x-coordinate of upper-left corner of rectangle.
	y1	y-coordinate of upper-left corner of rectangle.
	x2	x-coordinate of lower-right corner of rectangle.
	y2	y-coordinate of lower-right corner of rectangle.