[−][src]Module gaclen::graphics::frame

Frames are transient images on the screen and is the core of presenting the game to the user.

Drawing frames happens in a few steps, the first one is initializing all the resources necessary:

  • A Device that will be drawing the frame.
  • One or more instances of GraphicalPass which configure how the device draws.
  • Data that is to be drawn (depends highly on the application).

Once the above is ready a frame can be drawn:

  1. Begin frame by Frame::begin().
  2. Set up the GraphicalPass to be used by calling Frame::begin_pass().
  3. Invoke one or more draw calls in order to draw the geometry.
  4. End the pass (by calling PassInFrame::finish_pass()).
  5. (optionally) repeat steps 2-4.
  6. Finish the frame by calling Frame::finish().

Note that gaclen hides some of the underlying mechanisms for ease of use, namely - command buffers, a core concept in using vulkan effectively. The GPU is technically does not receive any commands until Frame::finish() is invoked. The draw calls correspond to recording GPU commands related to drawing given data with given context, but the execution happens completely separately after Frame::finish() is invoked. Additionally the frame will be presented (shown on the screen) as soon as it's available, depending exactly on the Swapchain being used. Currently there is no functionality to wait until a frame is drawn or draw a frame without presenting it.

Structs

Frame

A frame in the process of being drawn.

PassInFrame

A frame in the process of being drawn using a given GraphicalPass.

Viewport

State of a single viewport.

Enums

FrameFinishError

Error finishing the frame.