Blender Git Loki

BGE: Various render improvements.

bge.logic.setRender(flag) to enable/disable render.
The render pass is enabled by default but it can be disabled with
bge.logic.setRender(False).
Once disabled, the render pass is skipped and a new logic frame starts
immediately. Note that VSync no longer limits the fps when render is off
but the 'Use Frame Rate' option in the Render Properties still does.
To run as many frames as possible, untick the option
This function is useful when you don't need the default render, e.g.
when doing offscreen render to an alternate device than the monitor.
Note that without VSync, you must limit the frame rate by other means.

fbo = bge.render.offScreenCreate(width,height,[,samples=0][,target=bge.render.RAS_OFS_RENDER_BUFFER])
Use this method to create an offscreen buffer of given size, with given MSAA
samples and targetting either a render buffer (bge.render.RAS_OFS_RENDER_BUFFER)
or a texture (bge.render.RAS_OFS_RENDER_TEXTURE). Use the former if you want to
retrieve the frame buffer on the host and the latter if you want to pass the render
to another context (texture are proper OGL object, render buffers aren't)
The object created by this function can only be used as a parameter of the
bge.texture.ImageRender() constructor to send the the render to the FBO rather
than to the frame buffer. This is best suited when you want to create a render
of specific size, or if you need an image with an alpha channel.

bge.texture.<imagetype>.refresh(buffer=None, format="RGBA", ts=-1.0)
Without arg, the refresh method of the image objects is pretty much a no-op, it
simply invalidates the image so that on next texture refresh, the image will
be recalculated.
It is now possible to pass an optional buffer object to transfer the image (and
recalculate it if it was invalid) to an external object. The object must implement
the 'buffer protocol'. The image will be transfered as "RGBA" or "BGRA" pixels
depending on format argument (only those 2 formats are supported) and ts is an
optional timestamp in the image depends on it (e.g. VideoFFmpeg playing a video file).
With this function you don't need anymore to link the image object to a Texture
object to use: the image object is self-sufficient.

bge.texture.ImageRender(scene, camera, fbo=None)
Render to buffer is possible by passing a FBO object (see offScreenCreate).

bge.texture.ImageRender.render()
Allows asynchronous render: call this method to render the scene but without
extracting the pixels yet. The function returns as soon as the render commands
have been send to the GPU. The render will proceed asynchronously in the GPU
while the host can perform other tasks.
To complete the render, you can either call refresh() directly of refresh the texture
to which this object is the source. Asynchronous render is useful to achieve optimal
performance: call render() on frame N and refresh() on frame N+1 to give as much as
time as possible to the GPU to render the frame while the game engine can perform other tasks.

Support negative scale on camera.
Camera scale was previously ignored in the BGE.
It is now injected in the modelview matrix as a vertical or horizontal flip
of the scene (respectively if scaleY<0 and scaleX<0).
Note that the actual value of the scale is not used, only the sign.
This allows to flip the image produced by ImageRender() without any performance
degradation: the flip is integrated in the render itself.

Optimized image transfer from ImageRender to buffer.
Previously, images that were transferred to the host were always going through
buffers in VideoTexture. It is now possible to transfer ImageRender
images to external buffer without intermediate copy (i.e. directly from OGL to buffer)
if the attributes of the ImageRender objects are set as follow:
flip=False, alpha=True, scale=False, depth=False, zbuff=False.
(if you need to flip the image, use camera negative scale)