They perform the equations res.rgba = max(dst.rgba, src.rgba) and res.rgba = min(dst.rgba, src.rgba) respectively.
They only work when the "premultiplied" blend alpha mode is used, and an error occurs otherwise. They also aren't supported on some non-iOS OpenGL ES 2 systems. Check for support with love.graphics.getSupported().lighten.
Some nvidia GPUs in OS X fail to render geometry that uses an OpenGL index buffer and client-side vertex arrays. This affected ParticleSystems and love.graphics.print. The code for those has been changed to use a client-side index array instead of an OpenGL index buffer.
- Each canvas (and the screen) has an invisible stencil value associated with each pixel. Stencil values are between [0, 255].
- love.graphics.stencil takes a function argument which draws things, and makes the geometry of what's drawn set the stencil values of pixels instead of coloring the pixels.
- Its second argument is a 'stencil action' which determines what happens to the stencil values of pixels. The possible stencil actions are 'replace' (the default), 'invert', 'increment', 'decrement', 'incrementwrap', and 'decrementwrap'. If the stencil action is 'replace', the third argument of love.graphics.stencil is a number between [0, 255] which determines what the stencil value of each pixel that touches drawn objects is replaced with.
The fourth argument is a boolean which determines whether the previous stencil values of all pixels on-screen should be kept (true), or cleared to 0 (false, the default.) love.graphics.clear also clears the stencil values.
- love.graphics.setStencilTest allows for anything drawn to be affected by a comparison between the arguments to setStencilTest and the existing stencil value of the pixels that are touched by what's drawn. Its first argument is a compare mode which can be 'equal', 'notequal', 'less', 'lequal', 'gequal', or 'greater', and the second argument is an integer value (between 0 and 255) used in the comparison with the value in the stencil buffer.
For example, love.graphics.setStencilTest("greater", 0) will cause any geometry drawn afterwards to only appear on pixels whose stencil value is greater than 0.
The basic APIs are:
video = love.graphics.newVideo("myvideo.ogv")
love.graphics.draw(video, ...) -- Video objects are Drawables.
video:play(), video:pause()
video:getDuration(), video:tell(), video:rewind(), video:seek(seconds)
video:getSource()
video:getWidth(), video:getHeight(), video:setFilter(min, mag)
More advanced APIs include video:setSource(source), video:getStream(), and videostream:setSync.
To use a custom pixel shader when drawing a Video, call the new TexelVideo(texcoords) function instead of Texel(texture, texcoords) in order to get the pixel colors of a video frame.
Bart van Strien
Alex Szpakowski
Adam M