3DSoftEngine

--debug
local debug = false
--debug

local RGB = unpack
local abs = math.abs

local defaultColor = { 0, 0, 0 }

local screen = platform.window

function def(var)
    return (var ~= nil)
end

function undef(var)
    return (var == nil)
end

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

function setPixel(gc, x, y)
    gc:drawLine(x, y, x, y)
end

addToGC("setPixel", setPixel)

--moteur 2D
--point 2D

Point2D = class()

function Point2D:init(x, y, ...)
    self.x = x
    self.y = y
    local args = { ... }
    if def(args[1]) then
        self.color = args[1] else self.color = defaultColor
    end
    self.inscreen = true
end

function Point2D:changeColor(newcolor)
    self.color = newcolor
end

function Point2D:isInScreen()
    self.inscreen = (self.x >= 0 and self.x <= screen:width() and self.y >= 0 and self.y <= screen:height())
    return self.inscreen
end

function Point2D:move(x,y)
    self.x = self.x + x
    self.y = self.y + y
end

function Point2D:disp(gc)
    if self:isInScreen() then
        gc:setColorRGB(RGB(self.color))
        if debug then gc:drawString("Disp Point2D", 0, 0, "top") end
        gc:setPixel(self.x, self.y)
    end
end

--ligne 2D

Line2D = class()

--Line2D(Point2D,Point2D[,color]) or Line2D(Point1x,Point1y,Point2x,Point2y[,color,...])

function Line2D:init(point1orx, point2or1y, ...)
    local args = { ... }
    if def(args[2]) then
        if def(args[3]) then
            self.color = args[3]
        else
            self.color = defaultColor
        end
        self.point1 = Point2D(point1orx, point2or1y, self.color)
        self.point2 = Point2D(args[1], args[2], self.color)
    else
        if def(args[1]) then
            self.color = args[1]
        else
            self.color = defaultColor
        end
        self.point1 = point1orx
        self.point2 = point2or1y
        self.point1:changeColor(self.color)
        self.point2:changeColor(self.color)
    end
end

function Line2D:changeColor(newcolor)
    self.point1:changeColor(newcolor)
    self.point2:changeColor(newcolor)
    self.color = newcolor
end

function Line2D:move(x,y)
    self.point1:move(x,y)
    self.point2:move(x,y)
end

function Line2D:disp(gc)
    if debug then gc:drawString("disp Line2D",0,0,"top") end
    local dx, dy, sx, sy, err, e2, ptemp
    dx = abs(self.point2.x - self.point1.x)
    sx = (self.point1.x < self.point2.x) and 1 or -1
    dy = -abs(self.point2.y - self.point1.y)
    sy = (self.point1.y < self.point2.y) and 1 or -1
    err = dx + dy
    ptemp = self.point1
    ptemp:disp(gc)
    while ptemp.x ~= self.point2.x or ptemp.y ~= self.point2.y do
        e2 = 2 * err
        if e2 >= dy then
            err = err + dy
            ptemp.x = ptemp.x + sx
        end
        if e2 <= dx then
            err = err + dx
            ptemp.y = ptemp.y + sy
        end
        ptemp:disp(gc)
    end
    --gc:drawLine(self.point1.x,self.point1.y,self.point2.x,self.point2.y)
end

--moteur 3D
--point 3D

Point3D = class()

function Point3D:init(x, y, z, ...)
    self.x = x
    self.y = y
    self.z = z
    local args = { ... }
    if ... then
        self.color = args[1]
    else
        self.color = defaultColor
    end
    self.inscreen = true
    self.proj2d = Point2D(0, 0, self.color)
end

function Point3D:changeColor(newcolor)
    self.color = newcolor
    self.proj2d:changeColor()
end

function Point3D:projection()
    local tan35 = 0.70020753820970977945852271944483
    local f = (screen:width() / 2) / tan35
    self.proj2d.x = math.floor(self.x * f / (self.z + 5) + (screen:width() / 2))
    self.proj2d.y = math.floor((screen:height() / 2) - (self.y * f / (self.z + 5)))
    return self.proj2d
end

function Point3D:isInScreen()
    self:projection()
    self.inscreen = ((0 <= self.proj2d.x <= screen:width()) and (0 <= self.proj2d.y <= screen:height()))
    return self.inscreen
end

function Point3D:move(x,y,z)
    self.x = self.x + x
    self.y = self.y + y
    self.z = self.z + z
end

function Point3D:disp(gc)
    if self:isInScreen() then
        if debug then gc:drawString("disp Point3D",0,0,"top") end
        self.proj2d:disp(gc)
    end
end

--ligne 3D

Line3D = class()

function Line3D:init(point1orx, point2or1y, ...)
    local args = { ... }
    if def(args[4]) then
        if def(args[5]) then
            self.color = args[5]
        else
            self.color = defaultColor
        end
        self.point1 = Point3D(point1orx, point2or1y, args[1], self.color)
        self.point2 = Point3D(args[2], args[3], args[4], self.color)
    else
        if def(args[1]) then
            self.color = args[1]
        else
            self.color = defaultColor
        end
        self.point1 = point1orx
        self.point2 = point2or1y
        self.point1:changeColor(self.color)
        self.point2:changeColor(self.color)
    end
    self.proj2d = Line2D(Point2D(0, 0), Point2D(0, 0), self.color)
end

function Line3D:changeColor(newcolor)
    self.point1:changeColor(newcolor)
    self.point2:changeColor(newcolor)
    self.proj2d:changeColor(newcolor)
    self.color = newcolor
end

function Line3D:projection()
    self.point1:projection()
    self.point2:projection()
    self.proj2d = Line2D(self.point1.proj2d, self.point2.proj2d, self.color)
end

function Line3D:move(x,y,z)
    self.point1:move(x,y,z)
    self.point2:move(x,y,z)
end

function Line3D:disp(gc)
    if debug then gc:drawString("disp Line3D",0,0,"top") end
    self:projection()
    self.proj2d:disp(gc)
end

--objet
--triangle 3D

Triangle = class()

function Triangle:init(point1, point2, point3, ...)
    local args = {...}
    if def(args[1]) then
        self.color = args[1]
    else
        self.color = defaultColor
    end
    self.point1 = point1
    self.point2 = point2
    self.point3 = point3
    self.point1:changeColor(self.color)
    self.point2:changeColor(self.color)
    self.point3:changeColor(self.color)
    self.proj2d1 = Point2D(0,0,self.color)
    self.proj2d2 = Point2D(0,0,self.color)
    self.proj2d3 = Point2D(0,0,self.color)
end

function Triangle:changeColor(newcolor)
    self.point1:changeColor(newcolor)
    self.point2:changeColor(newcolor)
    self.point3:changeColor(newcolor)
    self.proj2d1:changeColor(newcolor)
    self.proj2d2:changeColor(newcolor)
    self.proj2d3:changeColor(newcolor)
    self.color = newcolor
end

function Triangle:projection()
    self.point1:projection()
    self.point2:projection()
    self.point3:projection()
    self.proj2d1 = self.point1.proj2d
    self.proj2d2 = self.point2.proj2d
    self.proj2d3 = self.point3.proj2d
end

function Triangle:move(x,y,z)
    self.point1:move(x,y,z)
    self.point2:move(x,y,z)
    self.point3:move(x,y,z)
end

local function torad(a) return (a * 180 / math.pi) end

function Triangle:rotationX(mat) -- pour la rotation dans le plan (y,z)
    local cosAngle,sinAngle = math.cos(torad(mat[3])),math.sin(torad(mat[3]))
    local newy = self.point3.y * cosAngle - self.point3.z * sinAngle
    local newz = self.point3.z * cosAngle + self.point3.y * sinAngle
    self.point3.y = self.point3.y + newy
    self.point3.z = self.point3.z + newz
    local cosAngle,sinAngle = math.cos(torad(mat[2])),math.sin(torad(mat[2]))
    local newy = self.point2.y * cosAngle - self.point2.z * sinAngle
    local newz = self.point2.z * cosAngle + self.point2.y * sinAngle
    self.point2.y = self.point2.y + newy
    self.point2.z = self.point2.z + newz
    local cosAngle,sinAngle = math.cos(torad(mat[1])),math.sin(torad(mat[1]))
    local newy = self.point1.y * cosAngle - self.point1.z * sinAngle
    local newz = self.point1.z * cosAngle + self.point1.y * sinAngle
    self.point1.y = self.point1.y + newy
    self.point1.z = self.point1.z + newz
end

function Triangle:rotationY(mat) -- pour la rotation dans le plan (x,z)
    local cosAngle,sinAngle = math.cos(torad(mat[3])),math.sin(torad(mat[3]))
    local newx = self.point3.x * cosAngle - self.point3.z * sinAngle
    local newz = self.point3.z * cosAngle + self.point3.x * sinAngle
    self.point3.x = self.point3.x + newx
    self.point3.z = self.point3.z + newz
    local cosAngle,sinAngle = math.cos(torad(mat[2])),math.sin(torad(mat[2]))
    local newx = self.point2.x * cosAngle - self.point2.z * sinAngle
    local newz = self.point2.z * cosAngle + self.point2.x * sinAngle
    self.point2.x = self.point2.x + newx
    self.point2.z = self.point2.z + newz
    local cosAngle,sinAngle = math.cos(torad(mat[1])),math.sin(torad(mat[1]))
    local newx = self.point1.x * cosAngle - self.point1.z * sinAngle
    local newz = self.point1.z * cosAngle + self.point1.x * sinAngle
    self.point1.x = self.point1.x + newx
    self.point1.z = self.point1.z + newz
end

function Triangle:rotationZ(mat) -- pour la rotation dans le plan (x,y)
    local cosAngle,sinAngle = math.cos(torad(mat[3])),math.sin(torad(mat[3]))
    local newx = self.point3.x * cosAngle - self.point3.y * sinAngle
    local newy = self.point3.y * cosAngle + self.point3.x * sinAngle
    self.point3.x = self.point3.x + newx
    self.point3.y = self.point3.y + newy
    local cosAngle,sinAngle = math.cos(torad(mat[2])),math.sin(torad(mat[2]))
    local newx = self.point2.x * cosAngle - self.point2.y * sinAngle
    local newy = self.point2.y * cosAngle + self.point2.x * sinAngle
    self.point2.x = self.point2.y + newx
    self.point2.y = self.point2.y + newy
    local cosAngle,sinAngle = math.cos(torad(mat[1])),math.sin(torad(mat[1]))
    local newx = self.point1.x * cosAngle - self.point1.y * sinAngle
    local newy = self.point1.y * cosAngle + self.point1.x * sinAngle
    self.point1.x = self.point1.x + newx
    self.point1.y = self.point1.y + newy
end

function Triangle:fillBottomFlatTriangle(gc,v1,v2,v3,color)
    local invslope1 = (v2.x - v1.x) / (v2.y - v1.y)
    local invslope2 = (v3.x - v1.x) / (v3.y - v1.y)

    local curx1 = v1.x
    local curx2 = v1.x

    local scanlineY,line
    for scanlineY = v1.y, v2.y do
        line = Line2D(curx1,scanlineY,curx2,scanlineY,color)
        line:disp(gc)
        curx1 = curx1 + invslope1
        curx2 = curx2 + invslope2
    end
end

function Triangle:fillTopFlatTriangle(gc,v1,v2,v3,color)
    local invslope1 = (v3.x - v1.x) / (v3.y - v1.y)
    local invslope2 = (v3.x - v2.x) / (v3.y - v2.y)

    local curx1 = v3.x
    local curx2 = v3.x

    local scanlineY,line
    for scanlineY = v3.y, (v1.y + 1), -1 do
        line = Line2D(curx1,scanlineY,curx2,scanlineY,color)
        line:disp(gc)
        curx1 = curx1 - invslope1
        curx2 = curx2 - invslope2
    end
end

function Triangle:fillTriangle(gc,color)
    self.point1:projection()
    self.point2:projection()
    self.point3:projection()

    local v1,v2,v3 = self.proj2d1,self.proj2d2,self.proj2d3
    local i = {v1,v2,v3}
    local f = function(a1,a2) return (a1.y >= a2.y) end
    i = table.sort(i, f)

    v1,v2,v3 = i[1],i[2],i[3]

    v1:changeColor(color)
    v2:changeColor(color)
    v3:changeColor(color)

    if v2.y == v3.y then
        self:fillBottomFlatTriangle(gc,v1,v2,v3,color)
    elseif v1.y == v2.y then
        self:fillTopFlatTriangle(gc,v1,v2,v3,color)
    else
        local v4 = Point2D(math.floor(v1.x + (v2.y - v1.y) / (v3.y - v1.y) * (v3.x - v1.x)),v2.y,color)
        self:fillBottomFlatTriangle(gc,v1,v2,v4,color)
        self:fillTopFlatTriangle(gc,v2,v4,v3,color)
    end
end

function Triangle:disp(gc)
    if debug then gc:drawString("disp Triangle",0,0,"top") end
    local line1, line2, line3
    line1 = Line3D(self.point1,self.point2,self.color)
    line2 = Line3D(self.point2,self.point3,self.color)
    line3 = Line3D(self.point1,self.point3,self.color)
    line1:disp(gc)
    line2:disp(gc)
    line3:disp(gc)
end

--main

local k = Triangle(Point3D(-1,-1,-1),Point3D(-1,1,-1),Point3D(1,-1,-1),{255,0,0})
local k1 = Triangle(Point3D(-1,1,-1),Point3D(1,1,-1),Point3D(1,-1,-1),{0,0,255})

function on.paint(gc)
    if debug then gc:drawString("test",0,0,"top") end
    k:fillTriangle(gc, {255,0,0})
    --k1:fillTriangle(gc, k1.color)
    k:disp(gc)
    k1:disp(gc)
end

function on.charIn(ch)
    if ch == '+' then
        k:move(0,0,-1)
        k1:move(0,0,-1)
    elseif ch == '-' then
        k:move(0,0,1)
        k1:move(0,0,1)
    elseif ch == '6' then
        k:rotationY(5)
        k1:rotationY(5)
    elseif ch == '4' then
        k:rotationY(-5)
        k1:rotationY(-5)
    end
    screen:invalidate()
end

function on.arrowLeft()
    k:move(-1,0,0)
    screen:invalidate()
end

function on.arrowRight()
    k:move(1,0,0)
    screen:invalidate()
end

function on.arrowUp()
    k:move(0,1,0)
    screen:invalidate()
end

function on.arrowDown()
    k:move(0,-1,0)
    screen:invalidate()
end