Wavepacket Glut Library Wrapper [Wavepacket GLUT Libraries]

Mostly this library is here only as a convenient placeholder. More...

Collaboration diagram for Wavepacket Glut Library Wrapper:

Classes
class	glut::Viewer
class	glut::Material
	A Material is anything that needs to be set up prior to drawing, and possibly requiring some cleanup afterwards. More...
struct	glut::fcolor_t
	base floating point color object More...
class	glut::Host
	If a client wants to use this library's glut helper entry point, it needs to supply an object that supports this interface. More...
class	glut::Task
	Create one of these (you'll have to inherit) if you have openGL work you need to submit to requestTask(). More...
Modules
	OpenGL Effects Library
	Several useful OpenGL effects.
	Cameras and OpenGL
	Basically, use GL_PROJECTION to set up the camera properties but NOT position or rotation.
	Wavepacket OpenGL Threading
	Threading in OpenGL is non-trivial! Just do some internet searches for "OpenGL multithreading context" and you'll see what I mean.
Functions
void	glut::start (IN int argc, IN const char *argv[], IN int width,IN int height,IN const char *title,IN const char *gameModeString,IN smart_ptr< Host > &host)
	clients can call this to get common glut setup
typedef rect2d_t< int >	glut::recti_t
void	glut::getViewFrustum (IN const camera_t &camera, IN const Viewer &viewer, OUT frustum_t &viewFrustum) throw ()
	This is a method to determine the view frustum given the current camera settings and viewer orientation.
void	glut::drawFrustumEdges (IN const frustum_t &f, IN const glut_color_t &color) throw ()
	helper method to draw the edges of a frustum
void	glut::push2D (IN int screenWidth, IN int screenHeight)
	switches to 2D drawing.
void	glut::pop2D (void)
	restores 3D drawing (make sure to call this after calling push2D()!).
void	glut::drawCursor (IN int x, IN int y)
int	glut::createTextureFromImage (IN const media::image_t &image)

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Detailed Description

Mostly this library is here only as a convenient placeholder.

Code with glut dependencies can refer to this module in the build, and then the right directories will be searched for include files, the right libraries linked, etc.

This library does provide a few helper objects and methods to make using glut easier, and to abstract away common setup code.

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Typedef Documentation

typedef rect2d_t<int> glut::recti_t

Definition at line 50 of file renderable.h.

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Function Documentation

void glut::getViewFrustum	(	IN const camera_t &	camera,
		IN const Viewer &	viewer,
		OUT frustum_t &	viewFrustum
	)			throw ()

This is a method to determine the view frustum given the current camera settings and viewer orientation.

What is a frustum? It is a basic 3D solid. See http://en.wikipedia.org/wiki/Frustum In particular, this is a clipped 4-sided pyramid, also called a right square frustum. In 3D rendering, a frustum defines the area of space that can be seen from the current camera, given its position and orientation. This is called the view frustrum. Given other objects, we can quickly test if they are inside the view frustrum or not. If not, we can avoid rendering them altogether. This is called culling. If you have partitioned your object space (always a good idea), you can cull dozens or hundreds of objects with a single frustum/rectangle test.

For more links on view frustrum culling try:

• http://www.lighthouse3d.com/opengl/viewfrustum/index.php?intro
• http://www.racer.nl/reference/vfc.htm

Or for an up-to-date search: http://www.google.com/search?q=opengl+view+frustum+culling

Parameters:

viewFrustum

view frustum

void glut::push2D	(	IN int	screenWidth,
		IN int	screenHeight
	)

switches to 2D drawing.

NOTE: for historical reasons, I don't follow the usual OpenGL coordinate conventions here. In 2D coordinates, positive Y down, not up. y=0 is the top of the screen. (OpenGL is flipped: positive Y is up). So be aware when 2D drawing.

int glut::createTextureFromImage

(

IN const media::image_t &

image

)

creates a texture from the given image, and returns the new texture ID

void glut::start	(	IN int	argc,
		IN const char *	argv[],
		IN int	width,
		IN int	height,
		IN const char *	title,
		IN const char *	gameModeString,
		IN smart_ptr< Host > &	host
	)

clients can call this to get common glut setup

Parameters:

	width	window width, pixels
	height	window height, pixels
	title	window title
	gameModeString	optional

void glut::drawFrustumEdges	(	IN const frustum_t &	f,
		IN const glut_color_t &	c
	)			throw ()

helper method to draw the edges of a frustum

void glut::pop2D

(

void

)

restores 3D drawing (make sure to call this after calling push2D()!).

void glut::drawCursor	(	IN int	x,
		IN int	y
	)