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4/8/2010

This structure describes the initialization parameters for a physics engine object. To create a physics engine, you must pass a pointer to this structure to TKCreatePhysicsEngine.

Syntax 

typedef struct tagPHYSICSENGINEINIT {
	DWORD cbSize;
	DWORD dwEngineType;
	DWORD dwFlags;
	LONG lInitialVelocity; 
	DWORD dwInitialAngle;
	BYTE bXAxisMovementMode;
	BYTE bXAxisBoundaryMode;
	BYTE bYAxisMovementMode;
	BYTE bYAxisBoundaryMode;
	RECT rcBoundary;
	SIZE sizeView;
	POINT ptInitialPosition;
	SIZE sizeItem;
} PHYSICSENGINEINIT;

Members

cbSize

Specifies the size of the PHYSICSENGINEINIT structure in bytes. You must set this value to sizeof(PHYSICSENGINEINIT).

dwEngineType

Reserved; set to 0 (zero).

dwFlags

Specifies the flags which control the behavior of the engine. Valid values are:

0 (zero)

Default mode.

PHYSICSENGINE_FLAG_USERTIME

User specified time mode.

In default mode the physics engine reads the time from the system clock.

In user specified time mode, you must call TKSetPhysicsEngineUserTimeto set the time.

lInitialVelocity

Specifies the initial velocity of the touch gesture animation in pixels per second.

dwInitialAngle

Specifies the initial angle for the animation to occur. The angle is specified as a value in the range 0-65536, where 0 is -2pi radians, pointing east, and 65536 is +2pi radians. Angles increase in a counter-clockwise direction.

bXAxisMovementMode

Specifies the X-axis movement mode. You must set this value to PHYSICSENGINE_MOVEMENT_MODE_DECELERATE.

bXAxisBoundaryMode

Specifies the animation behavior when the boundary is reached on the X-axis. Valid values are:

PHYSICSENGINE_BOUNDARY_MODE_NONE

No animation.

PHYSICSENGINE_BOUNDARY_MODE_RUBBERBAND

Rubber band animation.

bYAxisMovementMode

Specifies the Y-axis movement mode. You must set this value to PHYSICSENGINE_MOVEMENT_MODE_DECELERATE.

bYAxisBoundaryMode

Specifies the animation behavior when the boundary is reached on the Y-axis. Acceptable values are

PHYSICSENGINE_BOUNDARY_MODE_NONE

No animation.

PHYSICSENGINE_BOUNDARY_MODE_RUBBERBAND

Rubber band animation.

rcBoundary

Specifies a rectangle that defines the boundary of the content. The boundary contains all content including the entire user control.

sizeView

Specifies the size of the visible region.

ptInitialPosition

Specifies the initial position of the top-left corner of the viewable region.

sizeItem

Specifies the size of an item for snapping. An item size that is less than 1 in either dimension is treated as 1. The physics engine only stops an animation on item boundaries. An item size of 1 lets the physics engine stop at any point on that axis.

Remarks

If any member of the structure contains invalid data, TKCreatePhysicsEngine will return E_INVALIDARG.

Requirements

Header GesturePhysicsEngine.h

See Also