Constants' Group CompositeOperation

Overview

Module

Use

Devguide

Index

Constants

Constants' Details

:: com :: sun :: star :: rendering ::

unpublished

constants group CompositeOperation

Description

These constants determine how the primitive color is combined with the background.

When performing this calculations, it is assumed that all color values are premultiplied with the corresponding alpha values (if no alpha is specified, 1.0 is assumed). Then, the following general compositing operation is performed:

C = Ca * Fa + Cb * Fb

where C is the result color, Ca and Cb are the input colors, premultiplied with alpha, and Fa and Fb are described for the different composite modes (wherein Aa and Ab denote source and destination alpha, respectively).

Since

OOo 2.0.0

Constants
CLEAR	Clear the destination.
SOURCE	Copy source as-is to the destination.
DESTINATION	Leave the destination as-is.
OVER	Copy the source over the destination.
UNDER	Copy the source under the destination.
INSIDE	Copy the source to the destination.
INSIDE_REVERSE	Leave the destination as is.
OUTSIDE	Copy the source to the destination
OUTSIDE_REVERSE	Leave the destination as is.
ATOP	Copy the source over the destination
ATOP_REVERSE	Copy the destination over the source.
XOR	Combine source and destination by exclusive or.
ADD	Add source and destination values.
SATURATE	Saturate source and destination.

Constants' Details

CLEAR

const byte CLEAR = 0; Description Clear the destination. Clear the destination area. The function values are: Fa = Fb = 0.

SOURCE

const byte SOURCE = 1; Description Copy source as-is to the destination. Copy source as-is to the destination. The function values are: Fa = 1, Fb = 0.

DESTINATION

const byte DESTINATION = 2; Description Leave the destination as-is. Leave the destination as-is. The function values are: Fa = 0, Fb = 1.

OVER

const byte OVER = 3; Description Copy the source over the destination. Copy the source over the destination. The function values are: Fa = 1, Fb = 1-Aa.

UNDER

const byte UNDER = 4; Description Copy the source under the destination. Copy the source under the destination. The function values are: Fa = 1-Ab, Fb = 1.

INSIDE

const byte INSIDE = 5; Description Copy the source to the destination. Copy the source to the destination, but limited to where the destination is. The function values are: Fa = Ab, Fb = 0.

INSIDE_REVERSE

const byte INSIDE_REVERSE = 6; Description Leave the destination as is. Leave the destination as is, but only where the source was. The function values are: Fa = 0, Fb = Aa.

OUTSIDE

const byte OUTSIDE = 7; Description Copy the source to the destination Copy the source to the destination, but limited to where the destination is not. The function values are: Fa = 1-Ab, Fb = 0.

OUTSIDE_REVERSE

const byte OUTSIDE_REVERSE = 8; Description Leave the destination as is. Leave the destination as is, but only where the source has not been. The function values are: Fa = 0, Fb = 1-Aa.

ATOP

const byte ATOP = 9; Description Copy the source over the destination Copy the source over the destination, but only where the destination is. Keep the destination. The function values are: Fa = Ab, Fb = 1-Aa.

ATOP_REVERSE

const byte ATOP_REVERSE = 10; Description Copy the destination over the source. Copy the destination over the source, but only where the source is. Keep the source. The function values are: Fa = 1-Ab, Fb = Aa.

XOR

const byte XOR = 11; Description Combine source and destination by exclusive or. Take only the parts where either source or destination, but not both visible. The function values are: Fa = 1-Ab, Fb = 1-Aa.

ADD

const byte ADD = 12; Description Add source and destination values. Simply add contributions of both source and destination. The resulting color values are limited to the permissible color range, and clipped to the maximal value, if exceeded. The function values are: Fa = 1, Fb = 1.

SATURATE

const byte SATURATE = 13; Description Saturate source and destination. Saturate destination with source values. The function values are: Fa = min(1,(1-Ab)/Aa), Fb = 1

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