TYPE: COP
TITLE: Color Curve

Adjusts the R,G,B and/or A channels based on a user-defined curve. This node
is normally editted interactively by clicking the 'Edit Color Curves' button.
This opens a popup curve editor.

To edit the curve in the curve editor, you can:

  - Left click to add a new curve point.

  - Left drag a point to a new location

  - Select points by Alt+LMB clicking them, or by Alt+LMB dragging a box around
    them.

  - Delete a point by pressing Del while over the point.

  - Increase the curves sharpness at a point by MMB dragging the point.

If you switch to a specific component (1,2,3,4) and then edit the curve, the 
operator will automatically switch to component mode. It is often easier to 
edit component curves alone by isolating the component.

Middle click on the dialog '?' help for more help on maskable pixel operations.


Parameters:

Color Curve
    Edit Color Curve  - Opens a curve editor for interactive editting.
    Curve Extend      - Before the first point and after the last, this defines
                       the curve's behaviour.
        Hold Last Value           - The first or last value is held, clamping the color
                                    range at those values.
        Continue Along Last Slope - The values continue to increase or decrease
                                    outside the curve, based on the slope of
                                    the curve at the endpoints.

    Global/Components - You can edit components individually, or globally with
                       one curve. The first time the mode is switched from
                       global to components, the global curve will be copied
                       into all the component curves.
        Global     - All components are controlled by a single curve.
        Components - Each component has its own curve.

    Curves (Global, Red, Green, Blue, Alpha) - The number of points in each curve.
        Point 1,2... - The U and V values of the point. The third value 
                       represents the points sharpness. A sharpness of 1
                       produces a hard, linear edge at the point, whereas 0
                       produces a smooth curve at the point.

Local Variables:
    L   - Sequence length
    S   - Start of sequence
    E   - End of sequence
    IL  - Input sequence length
    SR  - Sequence frame rate
    NP  - Number of planes in sequence
    W,H - Width and height of image
    I   - Image index (0 at start frame)
    IT  - Image time (0 at start frame)
    AI  - Current plane array index
    PI  - Current plane index
    PC  - Num of channels in current plane

See Also: ColorCorrect, HueCurve, Pixel Operations (pixelop.extra.html)