Picker Class Reference

Base class for picking mechanism. More...

#include <easy3d/gui/picker.h>

Inheritance diagram for Picker:

Public Member Functions
	Picker (const Camera *cam)
const Camera *	camera () const
	Returns the pointer of the camera.
Line3	picking_line (int x, int y) const
	Construct a picking line. More...
vec3	picking_dir (int x, int y) const
	The picking direction, pointing inside the screen. More...
vec3	project (const vec3 &p) const
	Project a 3D point in the world coordinate system onto the 2D screen coordinate system. More...
vec3	unproject (int x, int y, float depth) const
	Compute the world coordinates of a point defined in the screen coordinate system. More...
void	screen_to_opengl (int x, int y, int &gl_x, int &gl_y, int width, int height) const
	Convert a point expressed in the screen coordinate system (with an origin in the upper left corner) into the OpenGL coordinate system (with an origin in the lower left corner). The high DPI scaling is also taken into consideration, so the result always corresponds to its image pixel. More...

Detailed Description

Base class for picking mechanism.

See also

ModelPicker, PointCloudPicker, SurfaceMeshPicker

Member Function Documentation

picking_dir()

vec3 picking_dir ( int  x, int  y  ) const

inline

The picking direction, pointing inside the screen.

Parameters

x	The cursor x-coordinate, relative to the left edge of the content area.
y	The cursor y-coordinate, relative to the top edge of the content area.

Attention

The screen point is expressed in the screen coordinate system with an origin in the upper left corner. So it doesn't necessarily correspond to a pixel on High DPI devices, e.g. a Mac with a Retina display.

picking_line()

Line3 picking_line ( int  x, int  y  ) const

inline

Construct a picking line.

Parameters

x	The cursor x-coordinate, relative to the left edge of the content area.
y	The cursor y-coordinate, relative to the top edge of the content area.

Attention

The screen point is expressed in the screen coordinate system with an origin in the upper left corner. So it doesn't necessarily correspond to a pixel on High DPI devices, e.g. a Mac with a Retina display.

project()

vec3 project ( const vec3 &  p ) const

inline

Project a 3D point in the world coordinate system onto the 2D screen coordinate system.

Parameters

p	A 3D point in the world coordinate system.

Returns

The x and y components of the returned value denote the projected screen point expressed in the screen coordinate system, with (0, 0) being the upper left corner of the content area. The z component ranges between 0.0 (near plane) and 1.0 (excluded, far plane).

Attention

The screen point is expressed in the screen coordinate system with an origin in the upper left corner. So it doesn't necessarily correspond to a pixel on High DPI devices, e.g. a Mac with a Retina display.

screen_to_opengl()

void screen_to_opengl	(	int	x,
		int	y,
		int &	gl_x,
		int &	gl_y,
		int	width,
		int	height
	)		const

Convert a point expressed in the screen coordinate system (with an origin in the upper left corner) into the OpenGL coordinate system (with an origin in the lower left corner). The high DPI scaling is also taken into consideration, so the result always corresponds to its image pixel.

Parameters

x	The x-coordinate, relative to the left edge of the content area.
y	The y-coordinate, relative to the top edge of the content area.
gl_x	Returns the x component of the point in the OpenGL coordinate system.
gl_y	Returns the y component of the point in the OpenGL coordinate system.
width	The width of the OpenGL viewport (may not be identical to the width of the screen in pixels).
height	The width of the OpenGL viewport (may not be identical to the height of the screen in pixels).

unproject()

vec3 unproject ( int  x, int  y, float  depth  ) const

inline

Compute the world coordinates of a point defined in the screen coordinate system.

Parameters

x	The cursor x-coordinate, relative to the left edge of the content area.
y	The cursor y-coordinate, relative to the top edge of the content area.
depth	The depth value of the screen point, ranging between 0.0 and 1.0 (excluded).

Returns

The world unprojected coordinates of the screen point.

Attention

The screen point is expressed in the screen coordinate system with an origin in the upper left corner. So it doesn't necessarily correspond to a pixel on High DPI devices, e.g. a Mac with a Retina display.

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

• /Users/lnan/Documents/Projects/Easy3D/easy3d/gui/picker.h
• /Users/lnan/Documents/Projects/Easy3D/easy3d/gui/picker.cpp