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in former times all the rendering, context-management and window-managment was handled by gemwin

this should change!

(note: even though wiki supports history, i'd rather give several revisions of the ideas on one page at the same time, to see how they evolve)

Revision 2:


only handles the actual output: open output-device, generate openGL-context, associate device and openGL-context

when "render"-message from gemcontrol is received, it only makes its own display "current" and calls-back.

interaction with the devices (e.g. keyboard/mouse-input) is handled by this object (outlet)

DOES NOT handle any "openGL-specific" things, like viewpoints, lighting, fog, background... (this is done by gemcontrol)


"localized" via context "name" (symbol); name-association is handled globally, so gemheads can hook to a name, even if no corresponding gemcontrol is made (yet); several gemcontrols can be associated to the same name.

local data (not associated with the "name"): viewpoint, lighting, background,... ("openGL-things")

context data (associated with the "name"): which gemlists to execute

global data: none


no global data; "context"s but fully backwards-compatible (with default namespace "")


no solution yet for lighting

problem: what about timing ?? if each gemcontrol had it's own timer, how do we sync different gemcontrols together (e.g. if we want a CAVE with 6 views of one scene in sync!)

solution: think of something with an external sync-source, like a BANG

example patch revision 2

Revision 1:


manages the static GemMan, e.g. the render-tick

several gemcontrols manage the same! data, sending "1" to this gemcontrol will turn on rendering at the others too!

sends out a "render"-message to all connected GemOutputs


handles an output-devices, e.g. a gemwindow

interaction with the devices (e.g. keyboard/mouse-input) is handled by this object (outlet)

methods to change dimension, background, viewpoint of the GemOutput (as far as this is possible: e.g. ieee1393-output might not be able to change the dimension of the image and has no "offset")

receives a "render" message from gemcontrol, makes its openGL-context "current", set's up the viewport and calls the gemcontrol::render(), which in turn executes the gemlists

can be instantiated multiple times ("multiple windows")

pro: separation between global render-chain and "local" output-devices; multiple windows (with different views,...)

contra: why is the render-chain global ? window-handling and viewport-handling is something very different: think of further splitting

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