Renders a bitmap image in the effect pipeline.

The ImageFX class will render a source image into a given rectangle within the current user coordinate system. The client has the option of providing a pre-allocated Bitmap or the path to a Picture file as the source.

If a pre-allocated Bitmap is to be used, it must be created under the ownership of the ImageFX object, and this must be configured prior to initialisation. It is required that the bitmap uses 32 bits per pixel and that the alpha channel is enabled.

If a source picture file is referenced, it will be upscaled to meet the requirements automatically as needed.

Technically the ImageFX object is represented by a new viewport, the bounds of which are defined by attributes X, Y, Width and Height. The placement and scaling of the referenced image is controlled by the AspectRatio field.

Structure

The ImageFX class consists of the following fields:

Access

Name

Type

Comment

AspectRatio INT SVG compliant aspect ratio settings.

Name	Description
ARF::MEET	Aspect ratio is preserved. The entire viewbox will be visible in the viewport. The viewbox is scaled up as much as possible.
ARF::NONE	Scale the viewbox to match the size of the viewport. Aspect ratio is not preserved.
ARF::SLICE	Aspect ratio is preserved. The viewbox can extend beyond the viewport's edges on one axis. The viewbox is scaled up as much as possible.
ARF::X_MAX	Align to the right.
ARF::X_MID	Align to the horizontal center.
ARF::X_MIN	Align to the left.
ARF::Y_MAX	Align to the bottom.
ARF::Y_MID	Align to the vertical center.
ARF::Y_MIN	Align to the top.

Bitmap OBJECTPTR The Bitmap being used as the image source.

Reading the Bitmap field will return the Bitmap that is being used as the image source. Note that if a custom Bitmap is to be used, the correct way to do this as to assign it to the ImageFX object via ownership rules.

If a picture image has been processed by setting the Path, the Bitmap will refer to the content that has been processed.

Path STRING Path to an image file supported by the Picture class.

ResampleMethod INT The resample algorithm to use for transforming the source image.

Name	Description
VSM::AUTO	The default option is chosen by the system. This will typically be `BILINEAR`, but slow machines may switch to nearest neighbour and high speed machines could use more advanced methods.
VSM::BESSEL
VSM::BICUBIC	Produces a similar result to `BILINEAR` with a marginally sharper after-effect.
VSM::BILINEAR	Bilinear is a common algorithm that produces a reasonable quality image quickly.
VSM::BLACKMAN3	Five times slower than `BILINEAR`, the final result will lack sharpness when compared to SINC3.
VSM::BLACKMAN8	15 times slower than `BILINEAR`, the final result is of excellent quality and sharpness is well balanced.
VSM::GAUSSIAN
VSM::KAISER
VSM::LANCZOS3	This well known algorithm may serve as a point of comparison for evaluating the results of other methods. It shares characteristics with `SINC` and `BLACKMAN`.
VSM::LANCZOS8
VSM::MITCHELL
VSM::NEIGHBOUR	Nearest neighbour is the fastest sampler at the cost of poor quality.
VSM::QUADRIC
VSM::SINC3	Five times slower than `BILINEAR`, the final result is of very good quality.
VSM::SINC8	15 times slower than `BILINEAR`, the final result is of excellent quality but may be marginally over-sharpened.
VSM::SPLINE16	About half the speed of `BILINEAR`, this method produces a considerably better result.

XMLDef STRING Returns an SVG compliant XML string that describes the filter.

Actions

The following actions are currently supported:

Name

Comment

Draw

Render the effect to the target bitmap.

ERR acDraw(*Object, DOUBLE X, DOUBLE Y, DOUBLE Width, DOUBLE Height)

Input	Description
X	The X position of the region to be drawn.
Y	The Y position of the region to be drawn.
Width	The width of the region to be drawn.
Height	The height of the region to be drawn.

ARF Type

Aspect ratios control alignment, scaling and clipping.

Name	Description
ARF::MEET	Aspect ratio is preserved. The entire viewbox will be visible in the viewport. The viewbox is scaled up as much as possible.
ARF::NONE	Scale the viewbox to match the size of the viewport. Aspect ratio is not preserved.
ARF::SLICE	Aspect ratio is preserved. The viewbox can extend beyond the viewport's edges on one axis. The viewbox is scaled up as much as possible.
ARF::X_MAX	Align to the right.
ARF::X_MID	Align to the horizontal center.
ARF::X_MIN	Align to the left.
ARF::Y_MAX	Align to the bottom.
ARF::Y_MID	Align to the vertical center.
ARF::Y_MIN	Align to the top.

VSM Type

Name	Description
VSM::AUTO	The default option is chosen by the system. This will typically be `BILINEAR`, but slow machines may switch to nearest neighbour and high speed machines could use more advanced methods.
VSM::BESSEL
VSM::BICUBIC	Produces a similar result to `BILINEAR` with a marginally sharper after-effect.
VSM::BILINEAR	Bilinear is a common algorithm that produces a reasonable quality image quickly.
VSM::BLACKMAN3	Five times slower than `BILINEAR`, the final result will lack sharpness when compared to SINC3.
VSM::BLACKMAN8	15 times slower than `BILINEAR`, the final result is of excellent quality and sharpness is well balanced.
VSM::GAUSSIAN
VSM::KAISER
VSM::LANCZOS3	This well known algorithm may serve as a point of comparison for evaluating the results of other methods. It shares characteristics with `SINC` and `BLACKMAN`.
VSM::LANCZOS8
VSM::MITCHELL
VSM::NEIGHBOUR	Nearest neighbour is the fastest sampler at the cost of poor quality.
VSM::QUADRIC
VSM::SINC3	Five times slower than `BILINEAR`, the final result is of very good quality.
VSM::SINC8	15 times slower than `BILINEAR`, the final result is of excellent quality but may be marginally over-sharpened.
VSM::SPLINE16	About half the speed of `BILINEAR`, this method produces a considerably better result.

Class Info
ID	ID_IMAGEFX
Category	Graphics
Include	modules/imagefx.h
Version	1

ImageFX Class

Structure

Actions

ARF Type

VSM Type

Class Info

Class List