Moteur 3D

local screen = platform.window

local RGB = unpack

function addToGC(name, func)
    local tab = platform.withGC(getmetatable)
    tab[name] = func
end

Point2D = class()

function Point2D:init(x,y)
    self.x = x
    self.y = y
    self.zoom = 1
    self.colour = {0,0,0}
    self.inscreen = true
end

function Point2D:isInScreen()
    if self.x >= 0 and self.x < screen.width() and self.y >= 0 and self.y < screen.height() then
        self.inscreen = true
    else
        self.inscreen = false
    end
end

function Point2D:disp(gc)
    self:isInScreen()
    if self.inscreen then
        gc:setColorRGB(RGB(self.colour))
        gc:fillRect(self.x - ((self.zoom - 1) / 2), self.y - ((self.zoom - 1) / 2), self.zoom, self.zoom)
    end
end

Line2D = class()

function Line2D:init(x1,y1,x2,y2)
    self.p1 = Point2D(x1,y1)
    self.p2 = Point2D(x2,y2)
    self.colour = {0,0,0}
    self.inscreen = true
end

function Line2D:isInScreen()
    --a faire
end

function Line2D:disp(gc)
    local dx,dy,err,e2,sx,sy
    dx = math.abs(self.p2.x-self.p1.x)
    if self.p1.x < self.p2.x then sx = 1 else sx = -1 end
    dy = -math.abs(self.p2.y-self.p1.y)
    if self.p1.y < self.p2.y then sy = 1 else sy = -1 end
    err = dx + dy
    local point = Point2D(self.p1.x,self.p1.y)
    while point.x ~= self.p2.x or point.y ~= self.p2.y do
        point:disp(gc)
        e2 = 2*err
        if e2 >= dy then
            err = err + dy
            point.x = point.x + sx
        end
        if e2 <= dx then
            err = err + dx
            point.y = point.y + sy
        end
    end
end



Point3D = class()

function Point3D:init(x,y,z)
    self.x = x
    self.y = y
    self.z = z
    self.p2d = Point2D(0,0)
    self.zoom = 1
    self.inscreen = true
    self.colour = {0,0,0}
end

function Point3D:to2D()
    local t = (screen:width() / 2) / (self.z + 5)
    self.p2d.x = self.x * t + (screen:width() / 2)
    self.p2d.y = self.y * t + (screen:height() / 2)
end

function Point3D:isInScreen()
    self.p2d:isInScreen()
    self.inscreen = self.p2d.inscreen
end

function Point3D:disp(gc)
    self:isInScreen()
    self:to2D()
    if self.inscreen then
        gc:setColorRGB(RGB(self.colour))
        gc:fillRect(self.p2d.x - ((self.zoom - 1) / 2),self.p2d.y - ((self.zoom - 1) / 2),self.zoom,self.zoom)
    end
end

Line3D = class()

function Line3D:init(x1,y1,z1,x2,y2,z2)
    self.point1 = Point3D(x1,y1,z1)
    self.point2 = Point3D(x2,y2,z2)
    self.inscreen = true
    self.colour = {0,0,0}
    self.zoom = 1
end

function Line3D:to2D()
    self.point1:to2D()
    self.point2:to2D()
end

function Line3D:disp(gc)
    self:to2D()
    line2d = Line2D(self.point1.p2d.x, self.point1.p2d.y, self.point2.p2d.x, self.point2.p2d.y)
    line2d:disp(gc)
end



--main

lx = {-1,-1,-1,1,1,1,1,-1,-1,-1,-1,-1,1,1,1,1,-1,-1,-1,1,1,1,1,-1}
ly = {-1,-1,-1,-1,-1,-1,-1,-1,-1,1,-1,1,-1,1,-1,1,1,1,1,1,1,1,1,1}
lz = {-1,1,1,1,1,-1,-1,-1,-1,-1,1,1,1,1,-1,-1,-1,1,1,1,1,-1,-1,-1}

function on.paint(gc)
    for k = 1, (#lx - 1) do
        line = Line3D(lx[k],ly[k],lz[k],lx[k+1],ly[k+1],lz[k+1])
        line:disp(gc)
    end
end