Render Stages

Render Stages are a core mechanism of the pipeline. The pipeline collects all render stages, forms a pipe out of them, and executes them in order, to get the final result.

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Each render stage can specify which pipes and inputs it needs, and also which pipes and inputs it produces. Render stages can also modify a pipe, by simply specifying the same pipe as input and output pipe.

A simple render stage looks like this:

class MyStage(RenderStage):
    
    """ Specify all required pipes here. They will be made available as
    a shader input to all contained targets """
    required_pipes = ["SomePipe1", "SomePipe2"]

    """ Specify all required inputs here. They will be made available
    as a shader input aswell. """
    required_inputs = ["some_input", "another_input"]

    def __init__(self, pipeline):
        RenderStage.__init__(self, pipeline)

    def create(self):
        """ This method gets called when the stage actually gets created.
        You should setup all RenderTargets here. """

        # Construct a single Render Target, see the RenderTarget API
        self._target = self._create_target("My Target")
        self._target.add_color_texture(bits=16)
        self._target.prepare_offscreen_buffer()

    def set_shaders(self):
        """ This method gets called after the create method, aswell as on
        manual shader reload. It should set all required shaders on the 
        render targets """
        # MyStage.frag.glsl should be located in the Plugin directory at
        # Shader/Stages/MyStage.frag.glsl
        self._target.set_shader(self.load_plugin_shader("MyStage.frag.glsl"))
        
    def resize(self):
        """ This method gets called when the window got resized. """
    
    def cleanup(self):
        """ This method gets called when the stage got removed, you should
        remove all targets here """