luaengine: add HUD-like capabilities

[lucab]

These commits add a way to let LUA scripts register a callback
to be invoked before rendering each frame.
This callback typically makes use of other provided methods to draw
custom graphics on top of each frame.

The idea is to let LUA script provide HUD-like features, mostly used for
trainings and TAS runs development.

Signed-off-by: Luca Bruno lucab@debian.org

[lucab]

This is v2 of #71, OO-ified after some suggestions from @galibert.

Major changes:

• now using luabridge, more C++ friendly
• available screens now enumerable via manager():machine().screens
• instance methods to draw boxes/lines/text on a single screen separately

[lucab]

Just as a note, this is a very dumb LUA autoboot_script I'm using to test all of lua_engine current capabilities:

local g = {
        x = 0,
        y = 0
}

local mem=manager:machine().devices[":maincpu"].spaces["program"]
local gui=manager:machine().screens[":screen"]

emu.sethook(function()
        gui:draw_text(g.x, g.y, mem:read_i16(0x0000C000))
        gui:draw_box(20,20, g.x, g.y, 0, 0xffff0000)
        gui:draw_line(20,20, g.x, g.y, 0xff0000ff)
        g.x = g.x + 1;
        g.y = g.y + 1;
        if (g.x+5) >= gui:width() then
            g.x = 0
        end
        if g.y >= gui:height() then
            g.y = 0
        end
end, "frame")

[lucab]

@galibert @mmicko can I get a review on this?

[galibert]

Eventually the hook should be per-screen, because different screens can
theorically gave different frame rates. But the core is currently fucked
in that area, so you can't do it.

OG.

On Mon, Jan 5, 2015 at 5:54 PM, Luca Bruno notifications@github.com wrote:

@galibert https://github.com/galibert @mmicko
https://github.com/mmicko can I get a review on this?

—
Reply to this email directly or view it on GitHub
#90 (comment).