Detailed Description

This class is passed in to GeomObject::GetRenderMesh() to allow objects to do view dependent rendering.

It is also passed to Control::EvalVisibility(). For example particle systems use this to have the particles exactly face the camera (if this option is enabled). If GetRenderMesh() is called by the renderer, the methods of this class are implemented by the system. If a plug-in is calling this method, they must implement these methods. The sample code below shown a null implementation that may be used if a viewport is not involved:

class NullView : public View
{
    Point2 ViewToScreen(Point3 p)
        { return Point2(p.x,p.y); }
    NullView() {
        worldToView.IdentityMatrix();
        screenW=640.0f; screenH = 480.0f;
    }
};

See also:: GeomObject, Interface, Control, Matrix3, Point3

#include <object.h>

Inheritance diagram for View:

[legend]

List of all members.

Public Member Functions
virtual Point2	ViewToScreen (Point3 p)=0
	This method is used to convert a point in view space to screen space.
virtual BOOL	CheckForRenderAbort ()
	This method should be used by GetRenderMesh() implementations that require a lot of processing time.
virtual INT_PTR	Execute (int cmd, ULONG_PTR arg1=0, ULONG_PTR arg2=0, ULONG_PTR arg3=0)
	Generic expansion function.
	View ()
Public Attributes
float	screenW
	The screen width in pixels.
float	screenH
	The screen height in pixels.
Matrix3	worldToView
	A transformation matrix from world into view space.
int	projType
	The view projection type: 0 is perspective, 1 is parallel.
float	fov
	The field of view in radians.
float	pixelSize
	The pixel size setting.
Matrix3	affineTM
	World to camera transformation matrix.
DWORD	flags
	Defined in Flags for the View class.

Constructor & Destructor Documentation

View ( ) [inline]

{ projType = -1; flags = RENDER_MESH_DISPLACEMENT_MAP; } // projType not set, this is to deal with older renderers.

Member Function Documentation

virtual Point2 ViewToScreen ( Point3 p ) [pure virtual]

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This method is used to convert a point in view space to screen space.

This includes any perspective projection.

Parameters:

p	The point in view space.

Returns:: The point in screen space (in pixel coordinates).

virtual BOOL CheckForRenderAbort ( ) [inline, virtual]

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This method should be used by GetRenderMesh() implementations that require a lot of processing time.

This allows these processes to be interrupted by the user. An example of this in use is the extensive computations done for displacement mapping. These may be interrupted by the user during a render. So, any implementation of GetRenderMesh() which takes a long time should periodically call this method to see if the user has canceled the render.