2-D Camera Convenience API

A 2-D camera is an orthographic camera that looks straight down at the XY ground plane (Z = 0) in the Z-up world. More...

Functions
BGI_API int BGI_CALL	wxbgi_cam2d_create (const char *name)
	Creates a 2-D overhead camera.
BGI_API void BGI_CALL	wxbgi_cam2d_get_pan (const char *name, float *x, float *y)
	Retrieves the current pan position.
BGI_API void BGI_CALL	wxbgi_cam2d_get_rotation (const char *name, float *angleDeg)
	Retrieves the current rotation in degrees.
BGI_API void BGI_CALL	wxbgi_cam2d_get_zoom (const char *name, float *zoom)
	Retrieves the current zoom level.
BGI_API void BGI_CALL	wxbgi_cam2d_pan_by (const char *name, float dx, float dy)
	Pans the 2-D camera by a world-space delta.
BGI_API void BGI_CALL	wxbgi_cam2d_set_pan (const char *name, float x, float y)
	Sets the 2-D camera pan (world-space centre of the view).
BGI_API void BGI_CALL	wxbgi_cam2d_set_rotation (const char *name, float angleDeg)
	Sets the 2-D view rotation around the Z axis.
BGI_API void BGI_CALL	wxbgi_cam2d_set_world_height (const char *name, float worldUnitsHigh)
	Sets the number of world-units visible vertically at zoom = 1.
BGI_API void BGI_CALL	wxbgi_cam2d_set_zoom (const char *name, float zoom)
	Sets the zoom level (1 = nominal, 2 = 2× magnification).
BGI_API void BGI_CALL	wxbgi_cam2d_zoom_at (const char *name, float factor, float pivotX, float pivotY)
	Zooms around a pivot point in world space.

Detailed Description

A 2-D camera is an orthographic camera that looks straight down at the XY ground plane (Z = 0) in the Z-up world.

Pan, zoom, and rotation are managed through dedicated functions that keep the view always centred and aspect-correct.

Internally a 2-D camera is stored as a Camera3D with is2D = true; it participates in the same registry and all wxbgi_cam_* functions work on it as well.

Function Documentation

wxbgi_cam2d_create()

BGI_API int BGI_CALL wxbgi_cam2d_create

(

const char *

name

)

Creates a 2-D overhead camera.

Returns an error if a camera with the same name already exists. The reserved name "default" is always rejected. The initial view is centred on world origin (0,0), zoom = 1, no rotation, and the window height in world-units visible vertically.

Parameters

name	Camera identifier string (must not be NULL).

Returns

1 on success, 0 on invalid input, -1 if no window is open, -2 if a camera with that name already exists (sets graphresult() to grDuplicateName).

wxbgi_cam2d_get_pan()

BGI_API void BGI_CALL wxbgi_cam2d_get_pan	(	const char *	name,
		float *	x,
		float *	y
	)

Retrieves the current pan position.

wxbgi_cam2d_get_rotation()

BGI_API void BGI_CALL wxbgi_cam2d_get_rotation	(	const char *	name,
		float *	angleDeg
	)

Retrieves the current rotation in degrees.

wxbgi_cam2d_get_zoom()

BGI_API void BGI_CALL wxbgi_cam2d_get_zoom	(	const char *	name,
		float *	zoom
	)

Retrieves the current zoom level.

wxbgi_cam2d_pan_by()

BGI_API void BGI_CALL wxbgi_cam2d_pan_by	(	const char *	name,
		float	dx,
		float	dy
	)

Pans the 2-D camera by a world-space delta.

Parameters

name	Camera name, or NULL for the active camera.

wxbgi_cam2d_set_pan()

BGI_API void BGI_CALL wxbgi_cam2d_set_pan	(	const char *	name,
		float	x,
		float	y
	)

Sets the 2-D camera pan (world-space centre of the view).

Parameters

name	Camera name, or NULL for the active camera.

wxbgi_cam2d_set_rotation()

BGI_API void BGI_CALL wxbgi_cam2d_set_rotation	(	const char *	name,
		float	angleDeg
	)

Sets the 2-D view rotation around the Z axis.

Parameters

name	Camera name, or NULL for the active camera.
angleDeg	Rotation in degrees (positive = counter-clockwise).

wxbgi_cam2d_set_world_height()

BGI_API void BGI_CALL wxbgi_cam2d_set_world_height	(	const char *	name,
		float	worldUnitsHigh
	)

Sets the number of world-units visible vertically at zoom = 1.

Changing this value rescales the entire coordinate space without altering the zoom or pan. Default is 720 world-units (matching a 720-pixel-tall window at 1:1 scale).

Parameters

name	Camera name, or NULL for the active camera.
worldUnitsHigh	Visible world-unit height at zoom = 1.

wxbgi_cam2d_set_zoom()

BGI_API void BGI_CALL wxbgi_cam2d_set_zoom	(	const char *	name,
		float	zoom
	)

Sets the zoom level (1 = nominal, 2 = 2× magnification).

The zoom is clamped to a minimum of 1e-6 to prevent division by zero.

Parameters

name	Camera name, or NULL for the active camera.

wxbgi_cam2d_zoom_at()

BGI_API void BGI_CALL wxbgi_cam2d_zoom_at	(	const char *	name,
		float	factor,
		float	pivotX,
		float	pivotY
	)

Zooms around a pivot point in world space.

The world point under pivotX / pivotY remains stationary on screen while the zoom level is multiplied by factor.

Parameters

name	Camera name, or NULL for the active camera.
factor	Zoom multiplier (e.g. 1.1 to zoom in 10 %).
pivotX	World X of the zoom pivot.
pivotY	World Y of the zoom pivot.