filter: Add "MSAA" filter to CommonFilters

This provides an easy way to enable MSAA for the offscreen color buffer only without having to enable it on the main window.

When using this filter, it is important to have framebuffer-multisample turned off in Config.prc.

direct/src/filter/CommonFilters.py

@@ -26,7 +26,7 @@ from .filterCopy import COPY
 from .filterDown4 import DOWN_4
 from panda3d.core import LVecBase4, LPoint2
 from panda3d.core import Filename
-from panda3d.core import AuxBitplaneAttrib
+from panda3d.core import AuxBitplaneAttrib, AntialiasAttrib
 from panda3d.core import Texture, Shader, ATSNone
 from panda3d.core import FrameBufferProperties
 from panda3d.core import getDefaultCoordinateSystem, CS_zup_right, CS_zup_left
@@ -189,11 +189,22 @@ class CommonFilters:
                 fbprops.setSrgbColor(False)
                 clamping = False
 
+            if "MSAA" in configuration:
+                if fbprops is None:
+                    fbprops = FrameBufferProperties()
+                fbprops.setMultisamples(configuration["MSAA"].samples)
+
             self.finalQuad = self.manager.renderSceneInto(textures = self.textures, auxbits=auxbits, fbprops=fbprops, clamping=clamping)
             if (self.finalQuad == None):
                 self.cleanup()
                 return False
 
+            if "MSAA" in configuration:
+                camNode = self.manager.camera.node()
+                state = camNode.getInitialState()
+                state.setAttrib(AntialiasAttrib.make(AntialiasAttrib.M_multisample))
+                camNode.setInitialState(state)
+
             if ("BlurSharpen" in configuration):
                 blur0=self.textures["blur0"]
                 blur1=self.textures["blur1"]
@@ -454,6 +465,19 @@ class CommonFilters:
         if task != None:
             return task.cont
 
+    def setMSAA(self, samples):
+        fullrebuild = "MSAA" not in self.configuration or self.configuration["MSAA"].samples != samples
+        newconfig = FilterConfig()
+        newconfig.samples = samples
+        self.configuration["MSAA"] = newconfig
+        return self.reconfigure(fullrebuild, "MSAA")
+
+    def delMSAA(self):
+        if "MSAA" in self.configuration:
+            del self.configuration["MSAA"]
+            return self.reconfigure(True, "MSAA")
+        return True
+
     def setCartoonInk(self, separation=1, color=(0, 0, 0, 1)):
         fullrebuild = (("CartoonInk" in self.configuration) == False)
         newconfig = FilterConfig()
@@ -673,6 +697,8 @@ class CommonFilters:
         return True
 
     #snake_case alias:
+    set_msaa = setMSAA
+    del_msaa = delMSAA
     del_cartoon_ink = delCartoonInk
     set_half_pixel_shift = setHalfPixelShift
     del_half_pixel_shift = delHalfPixelShift