formZ SDK | 4.0 Call Back Reference | Renderer

# fz_rndr_cbak_image_dirty

Description

The image dirty function. formZ calls this function to find out whether any changes made by the user since the image was rendered last have made the image invalid. This function is especially useful when the renderer is a static pixel renderer. As fzrt_int as the image is valid and the screen needs to be redrawn formZ will automatically draw the image buffer, instead of asking the renderer to re-render the scene. In order to accomplish this, the renderer needs to tell formZ, that nothing has occurred in the meantime, that would invalidate the image. The recommended mechanism for this is for the renderer to install a notification function set. In this function set the three callback functions fz_notf_cbak_proj, fz_notf_cbak_wind and fz_notf_cbak_objt should be defined. The fz_notf_cbak_wind function, for example, is called each time an aspect of the window in which a rendering takes place changes. What kind of change occurred is identified by an enum argument to the function. The renderer's window notification callback should then set a "dirty" marker in its window data block. When the fz_rndr_cbak_image_dirty function is invoked by formZ, the renderer then passes back the value of the dirty marker.

Plugin Prototype

fzrt_boolean fz_rndr_cbak_image_dirty(

fzrt_int | windex )

Parameters

windex [Input]

project window index

Returns

TRUE, if the image is no longer valid, FALSE otherwise.

Availability

5.0.0.0

Function Set

fz_rndr_cbak_fset

Defined in

fz_rndr_api.h