Quadratic Blending Modes

Summary:
During the creation of Quadratic Blending Modes, I have did the following:

• • • Add new category suitable for quadratic blending modes
  • I copied and paste existing codes, and created new codes used to calculate blending of images accordingly to the Pegtop formula reference sheet
• I have tested the 4 new blending modes, and keep adjusting until the blending modes matches that of the Pegtop blending modes

• Before the testing plan, find a way to make freeze and heat with acceptable coding. Reflect Blend Mode has now been solved.

Test Plan:

• Have artists find usage of quadratic blend modes, and see if they find the blending modes useful
• Test results of quadratic blend modes with existing programs (As far as I"m concerned, only reflect and glow are available for testing)

-If all seem sounds, and ready to go, then maybe it can be patched in Krita

Reviewers: Krita, dkazakov

Subscribers: dkazakov

Tags: Krita

Differential Revision: https://phabricator.kde.org/D13383