rem ====================
rem Isometric tile map
rem Author: Phaelax
rem Date: 18 Dec 2015
rem ====================

setVirtualResolution(800,600)


// Load the tile map
tm = loadImage("isometric_grass_and_water.png")
// Set image filter so image is sharp and tiles match/line up better
SetImageMagFilter(tm, 0)
// Create the base sprite and 'animate' it so we can use the frames as tiles
_Spr_Tiles = createSprite(tm)
setSpriteAnimation(_Spr_Tiles, 64, 64, 24)
setSpritePosition(_Spr_Tiles, 736, 0)

// Map dimensions
Global _MapWidth = 20
Global _MapHeight = 10
// for map scrolling
Global _MapOffsetX = 320
Global _MapOffsetY = 100


#CONSTANT TILESIZE   = 64  ` actual image size
#CONSTANT TILE_X     = 32  ` typically half of TILESIZE
#CONSTANT TILE_Y     = 16  ` typically half of TILE_X
#CONSTANT BASEOFFSET = 0   ` if graphic starts at bottom of image, this would be the same value as TILE_Y
#CONSTANT BASE_DEPTH = 10  ` Lowest sprite z-depth
#CONSTANT TILE_COUNT = _MapHeight*_MapWIDTH ` how many tiles make up this map (necessary for setting z-depth)


// Map array
dim map[_MapWidth, _MapHeight]


// Initialize map data
for i = 1 to _MapWidth
    for j = 1 to _MapHeight
        map[i,j] = 0
    next j
next i


showGrid    = 1 : `simple true or false to show iso grid
scrollSpeed = 4 : `map scroll speed

do

    // Map scroll controls
    if getRawKeyState(37) = 1 then positionMap(_MapOffsetX+scrollSpeed, _MapOffsetY)
    if getRawKeyState(38) = 1 then positionMap(_MapOffsetX, _MapOffsetY+scrollSpeed)
    if getRawKeyState(39) = 1 then positionMap(_MapOffsetX-scrollSpeed, _MapOffsetY)
    if getRawKeyState(40) = 1 then positionMap(_MapOffsetX, _MapOffsetY-scrollSpeed)


    // Scroll wheel cycles through tiles
    wheel = GetRawMouseWheelDelta()
    if wheel < 0
        f = GetSpriteCurrentFrame(_Spr_Tiles)
        if f < GetSpriteFrameCount(_Spr_Tiles)
            setSpriteFrame(_Spr_Tiles, f+1)
        else
            setSpriteFrame(_Spr_Tiles, 1)
        endif
    endif
    if wheel > 0
        f = GetSpriteCurrentFrame(_Spr_Tiles)
        if f > 1
            setSpriteFrame(_Spr_Tiles, f-1)
        else
            setSpriteFrame(_Spr_Tiles, GetSpriteFrameCount(_Spr_Tiles))
        endif
    endif




    // Mouse position relative to map
    mx = GetRawMouseX() - _MapOffsetX
    my = GetRawMouseY() - _MapOffsetY



    // 'g' to toggle grid
    if getRawKeyPressed(71) = 1
        showGrid = 1 - showGrid
    endif




    // Draws an isometric grid
    if showGrid = 1
        drawGrid()
    endif




    // Translate mouse coordinates into tile map coordinates [ix,iy]
    mx = GetRawMouseX()-_MapOffsetX
    my = GetRawMouseY()-_MapOffsetY
    ix = (TILESIZE*my + TILE_X*mx) / (TILESIZE*TILE_X)
    iy = (TILESIZE*my - TILE_X*mx) / (TILESIZE*TILE_X)




    // Place tile on map
    if GetRawMouseLeftPressed() = 1
        if ix >= 0 and ix < _MapWidth and iy >= 0 and iy < _MapHeight
            if map[ix+1, iy+1] > 0 then deleteSprite(map[ix+1, iy+1])

            map[ix+1, iy+1] = cloneSprite(_Spr_Tiles)
            tileDepth = (TILE_COUNT) - (ix*_MapHeight + iy) + BASE_DEPTH
            setSpriteDepth(map[ix+1, iy+1], tileDepth)

            tx = (ix-iy-1)*TILE_X
            ty = (ix+iy-1)*TILE_Y - BASEOFFSET
            setSpritePosition(map[ix+1, iy+1], _MapOffsetX + tx , _MapOffsetY + ty)
        endif
    endif





    print("FPS: "+str(screenfps()))
    print(str(ix)+":"+str(iy))
    print("Tile:# "+str(ix*_MapHeight + iy))
    sync()
loop




// ===============================================================
// Returns true if mouse is within the specified boundary
// ===============================================================
function mouseWithin(x1, y1, x2, y2)
    if GetRawMouseX() > x1 and GetRawMouseX() < x2 and GetRawMouseY() > y1 and GetRawMouseY() < y2 then exitfunction 1
endfunction 0




// ===============================================================
// Positions the sprites making up the map
// ===============================================================
function positionMap(x, y)
    _MapOffsetX = x
    _MapOffsetY = y

    for i = 0 to _MapWidth-1
        for j = 0 to _MapHeight-1
            if map[i+1,j+1] > 0
                tx = x + (i-j-1)*TILE_X
                ty = y + (i+j-1)*TILE_Y - BASEOFFSET
                setSpritePosition(map[i+1,j+1], tx, ty)
            endif
        next j
    next i
endfunction




// ===============================================================
// Draws an isometric grid
// ===============================================================
function drawGrid()
    height = _MapHeight*TILE_Y
    for x = 0 to _MapWidth
        lx = _MapOffsetX + x*TILE_X
        ly = _MapOffsetY + x*TILE_Y
        drawLine(lx, ly, lx-TILE_X*_MapHeight, ly+height, 48,48,48)
    next x
    width = _MapWidth*TILE_X
    for y = 0 to _MapHeight
        lx = _MapOffsetX - y*TILE_X
        ly = _MapOffsetY + y*TILE_Y
        drawLine(lx, ly, lx+width, ly+TILE_Y*_MapWidth, 48,48,48)
    next y
endfunction