panda3d/samples/distortion/main.py

#!/usr/bin/env python

# Author: Tree Form [email protected]

from direct.showbase.ShowBase import ShowBase
from panda3d.core import FrameBufferProperties, TextNode, BitMask32, LPoint3
from panda3d.core import WindowProperties, GraphicsOutput, Texture, GraphicsPipe
from direct.showbase.DirectObject import DirectObject
from direct.gui.OnscreenText import OnscreenText
from sys import exit

# Function to put instructions on the screen.
def addInstructions(pos, msg):
    return OnscreenText(text=msg, style=1, fg=(1, 1, 1, 1),
                        pos=(-1.25, pos), align=TextNode.ALeft, scale=.05)

# Function to put title on the screen.
def addTitle(text):
    return OnscreenText(text=text, style=1, fg=(1, 1, 1, 1), shadow=(0, 0, 0, 1),
                        pos=(1.25, -0.95), align=TextNode.ARight, scale=.07)


class DistortionDemo(ShowBase):
    def __init__(self):
        # Initialize the ShowBase class from which we inherit, which will
        # create a window and set up everything we need for rendering into it.
        ShowBase.__init__(self)

        if not base.win.getGsg().getSupportsBasicShaders():
            t = addTitle("Distortion Demo: Video driver says Cg shaders not supported.")
            return

        self.disableMouse()
        self.setBackgroundColor(0, 0, 0)

        # Show the instructions
        self.title = addTitle("Panda3D: Tutorial - Distortion Effect")
        self.inst1 = addInstructions(0.92, "ESC: Quit")
        self.inst2 = addInstructions(0.86, "Space: Toggle distortion filter On/Off")
        self.inst4 = addInstructions(0.80, "V: View the render-to-texture results")

        # Load background
        self.seascape = loader.loadModel("models/plane")
        self.seascape.reparentTo(render)
        self.seascape.setPosHpr(0, 145, 0, 0, 0, 0)
        self.seascape.setScale(100)
        self.seascape.setTexture(loader.loadTexture("models/ocean.jpg"))

        # Create the distortion buffer. This buffer renders like a normal
        # scene,
        self.distortionBuffer = self.makeFBO("model buffer")
        self.distortionBuffer.setSort(-3)
        self.distortionBuffer.setClearColor((0, 0, 0, 0))

        # We have to attach a camera to the distortion buffer. The distortion camera
        # must have the same frustum as the main camera. As long as the aspect
        # ratios match, the rest will take care of itself.
        distortionCamera = self.makeCamera(self.distortionBuffer, scene=render,
                                           lens=self.cam.node().getLens(), mask=BitMask32.bit(4))

        # load the object with the distortion
        self.distortionObject = loader.loadModel("models/boat")
        self.distortionObject.setScale(1)
        self.distortionObject.setPos(0, 20, -3)
        self.distortionObject.hprInterval(10, LPoint3(360, 0, 0)).loop()
        self.distortionObject.reparentTo(render)

        # Create the shader that will determime what parts of the scene will
        # distortion
        distortionShader = loader.loadShader("distortion.sha")
        self.distortionObject.setShader(distortionShader)
        self.distortionObject.hide(BitMask32.bit(4))

        # Textures
        tex1 = loader.loadTexture("models/water.png")
        self.distortionObject.setShaderInput("waves", tex1)

        self.texDistortion = Texture()
        self.distortionBuffer.addRenderTexture(
            self.texDistortion, GraphicsOutput.RTMBindOrCopy, GraphicsOutput.RTPColor)
        self.distortionObject.setShaderInput("screen", self.texDistortion)

        # Panda contains a built-in viewer that lets you view the results of
        # your render-to-texture operations.  This code configures the viewer.
        self.accept("v", self.bufferViewer.toggleEnable)
        self.accept("V", self.bufferViewer.toggleEnable)
        self.bufferViewer.setPosition("llcorner")
        self.bufferViewer.setLayout("hline")
        self.bufferViewer.setCardSize(0.652, 0)

        # event handling
        self.accept("space", self.toggleDistortion)
        self.accept("escape", exit, [0])
        self.distortionOn = True

    def makeFBO(self, name):
        # This routine creates an offscreen buffer.  All the complicated
        # parameters are basically demanding capabilities from the offscreen
        # buffer - we demand that it be able to render to texture on every
        # bitplane, that it can support aux bitplanes, that it track
        # the size of the host window, that it can render to texture
        # cumulatively, and so forth.
        winprops = WindowProperties()
        props = FrameBufferProperties()
        props.setRgbColor(1)
        return self.graphicsEngine.makeOutput(
            self.pipe, "model buffer", -2, props, winprops,
            GraphicsPipe.BFSizeTrackHost | GraphicsPipe.BFRefuseWindow,
            self.win.getGsg(), self.win)

    def toggleDistortion(self):
        # Toggles the distortion on/off.
        if self.distortionOn:
            self.distortionObject.hide()
        else:
            self.distortionObject.show()
        self.distortionOn = not(self.distortionOn)

demo = DistortionDemo()
demo.run()