formZ SDK | 4.0 Call Back Reference | Renderer

# fz_rndr_cbak_image_disp

Description

Image display function. The image display function is the main function of a renderer. It is called by formZ anytime the rendering on the screen needs to be refreshed. It is always called after the image init function and before the image finit function. The sub_image argument is only passed as non NULL for static pixel renderers. If passed as NULL, the renderer is expected to render the entire image. If it is non NULL, the sub_image rectangle outlines a rectangular portion of the image to be rendered. It is the responsibility of the renderer to not pass more than (sub_image->bottom - sub_image->top) number of scanlines to and to make sure that each scanline is exactly (sub_image->right - sub_image->left) pixels wide. The sub_image rectangle is, for example, passed in if the Set Image Size option is checked by the user, or if the renderer is used by the network rendering environment and is asked to render one or more bands of an image.
If the image init function generated an error, it is passed into the display function. This gives the display function the opportunity to perform any necessary cleanup because of the error. The display function is expected to NOT render the image, if an error is passed in.

Plugin Prototype

fzrt_error_td fz_rndr_cbak_image_disp(

fzrt_int | windex,
fzrt_error_td | prep_err,
fzrt_rect * | subimage )

Parameters

windex [Input]

project window index

prep_err [Input]

error code generated by the image init function.

subimage [Input, Optional]

If passed as NULL, the renderer is expected to display the entire image. If non NULL, the rectangle passed in outlines a sub area of the image to be rendered. This parameter is only used for static pixel renderers.

Returns

Error codes

Availability

5.0.0.0

Function Set

fz_rndr_cbak_fset

Defined in

fz_rndr_api.h