Digital Dream Studio V2

Basic Concepts

In order to begin working with DDS V2, one must understand some of its basic concepts:

1. Layer. A layer is an independent image placed on the working surface. Besides the actual image it retains, this entity is defined by certain proprieties, such as global channeled opacity, local opacity (opacity map), blending mode, position, name. Each layer can be modified individually, without affecting the other layers.

2. Work Surface. It is the user-defined surface upon which the layers are displayed, in a certain order. The work surface has an uniform color and it is also associted with a selection map. The relative position and size can be set and several work surfaces can be independently used and saved into each DDS file.

3. Selection map. Defines the opacity with which a certain effect is applying on a certain area of the selected layer. It is actually a matrix, with the same size as the working surface, containing integers ranging from 0 to 255 (0 - transparent; 255 - opaque).

4. Effect. Transformation of the bitmap and opacity map of one layer. An effect can be applied using a certain type of blending (the method by which the original pixels and new pixels define the new status of the layer). Effects can only be applied on one layer at a certain time. The selection map can be used so that a certain area of the layer is targeted or the entire layer can be modified.

5. Plug-ins. Plug-ins are also a class of effects, but they are applied by an outside program. When a layer is sent to a plug-in, DDS saves it to a file; the plug-in is ran and DDS "locks down" until the plug-in finishes execution. Before the plug-in is terminated, it saves the data in the same file. DDS detects when the plug-in terminates, so the changes brought by the effect can be updated. As any other effect, plug-ins can be applied using an opacity mask and a blending mode. If, for one reason or another, the plug-in freezes or it becomes unable to work properly, the link between DDS can be manually "severed" by pressing the "Cut off!" button.

6. History. History can be optionally activated. If active, it keeps track of the the changes made upon the layers of one surface. It is a kind of multiple-step undo/redo. Different from the Undo option in other software, the DDS History is non-linear (or non-cronological). For example, if one wants to restore a change made five steps before, it is not necessary for all the five steps to be restored. Although History is optimized not to use up more memory than is required (if, for instance, a layer's opacity has been modified, there will be no redundant history entry about the layer's bitmap and opacity map), it is still memory-cosuming, thus a history limitor has been installed - it restricts the number of steps to a maximum (by default, it is set to 10).

7. Temporary surfaces (TS). There are 10 temporary surfaces (24 bit or 32 bit maps). The concept of temporary surface is quite simililar to that of clipboard. However, there are ten TS, that can be used as a buffer, for copy and paste operations, from one surface to another, from one layer's opacity to another's bitmap and so on. TS are available only within DDS and they are specialized in storing images. Automatic conversions (RGB->Alfa; RGBA->Alfa) are available and TS data can be loaded from and saved to image files.