How to make a race track ?

[Marcus]

I checked the code I wrote a while ago and replaced the texture with one generated by code. But this truely isn't much to look at, it was just a test for creating a road from a curve (polyline library, which is full of bugs btw).

Code:

include "s3d.n7"
include "file.n7"
include "polyline.n7"

visible vRes = 480

set window "Futuracer", vRes*screenw()/screenh(), vRes, false
set redraw off

texture = createimage(128, 128)
set image texture
for y = 0 to 127  for x = 0 to 127
    i = 16 + rnd(64)
    set color i, i, i
    set pixel x, y
next
set image primary
BoxBlur(texture, 2, 2)
set image texture
set color 255, 255, 255, 128
draw rect 60, 0, 8, 64, true
set image primary
BoxBlur(texture, 1, 1)

p = PolyLine([[-50, 50], [50, 50], [50, -50], [-50, -50]], true)

mesh = S3D_BeginMesh()
S3D_Begin(S3D_QUADS)
hrw = 8
stp = 15
i = 0
while i < p.GetLength()
    pos = p.GetPoint(i, true)
    dir = p.GetDirection(i, true)
    x0 = pos[0]; y0 = pos[1]
    tx0 = dir[1]; ty0 = -dir[0]
    j = i + stp
    if j > p.GetLength() j = 0   
    pos = p.GetPoint(j, true)
    dir = p.GetDirection(j, true)               
    x1 = pos[0]; y1 = pos[1]
    tx1 = dir[1]; ty1 = -dir[0]
    S3D_Vertex(x0 - tx0*hrw, 0, y0 - ty0*hrw, 0, 1)
    S3D_Vertex(x1 - tx1*hrw, 0, y1 - ty1*hrw, 0, 0)
    S3D_Vertex(x1 + tx1*hrw, 0, y1 + ty1*hrw, 1, 0)
    S3D_Vertex(x0 + tx0*hrw, 0, y0 + ty0*hrw, 1, 1)
    i = i + stp
wend
S3D_End()
S3D_EndMesh()

S3D_SetView(primary, rad(74), 0.1, 100)

x = -70
z = 0
a = 0
lastTick = clock()

while not keydown(KEY_ESCAPE, true)
    t = clock()
    dt = (min(t - lastTick, 100))/1000
    lastTick = t

    if keydown(KEY_LEFT) a = a - 90*dt
    if keydown(KEY_RIGHT) a = a + 90*dt
    if keydown(KEY_UP)
        x = x + sin(rad(a))*10*dt
        z = z + cos(rad(a))*10*dt
    elseif keydown(KEY_DOWN)
        x = x - sin(rad(a))*10*dt
        z = z - cos(rad(a))*10*dt
    endif
    set color 0, 0, 0
    cls
   
    S3D_Clear()
    S3D_RotateY(-rad(a))
    S3D_Translate(-x, 2, -z)
    S3D_Texture(texture)
    S3D_Mesh(mesh, 0)   
    S3D_Render()
    S3D_RenderFog(0, 0, 0, false)
   
    set caret width(primary) - fwidth(" "), height(primary) - fheight()
    set justification right
    set color 0, 255, 0
    write "FPS: " + str(round(1/dt))
    set justification left

    redraw
    wait 1
wend

' BoxBlur
' -------
function BoxBlur(img, rx, ry)
    rx = max(int(rx), 0); ry = max(int(ry), 0)
    set image img
    w = width(img); h = height(img)
    data = dim(w, h)

    ' Blur vertically
    for y = 0 to h - 1  for x = 0 to w - 1  data[x][y] = pixeli(img, x, y)
    count = ry*2 + 1
    for x = 0 to w - 1
        sr = 0; sg = 0; sb = 0; sa = 0
        for y = -ry to ry
            p = data[x][y%h];
            sr = sr + Red(p); sg = sg + Green(p); sb = sb + Blue(p); sa = sa + Alpha(p)
        next
        for y = 0 to h - 1
            set color sr/count, sg/count, sb/count, sa/count
            set pixel x, y
            p = data[x][(y - ry)%h]
            sr = sr - Red(p); sg = sg - Green(p); sb = sb - Blue(p); sa = sa - Alpha(p)
            p = data[x][(y + ry + 1)%h]
            sr = sr + Red(p); sg = sg + Green(p); sb = sb + Blue(p); sa = sa + Alpha(p)
        next
    next
    ' Blur horizontally.
    for y = 0 to h - 1  for x = 0 to w - 1  data[x][y] = pixeli(img, x, y)
    count = rx*2 + 1
    for y = 0 to h - 1
        sr = 0; sg = 0; sb = 0; sa = 0
        for x = -rx to rx
            p = data[x%w][y]
            sr = sr + Red(p); sg = sg + Green(p); sb = sb + Blue(p); sa = sa + Alpha(p)
        next
        for x = 0 to w - 1
            set color sr/count, sg/count, sb/count, sa/count
            set pixel x, y
            p = data[(x - rx)%w][y]
            sr = sr - Red(p); sg = sg - Green(p); sb = sb - Blue(p); sa = sa - Alpha(p)
            p = data[(x + rx + 1)%w][y]
            sr = sr + Red(p); sg = sg + Green(p); sb = sb + Blue(p); sa = sa + Alpha(p)
        next
    next
    set image primary

    ' Pixeli helpers.
    function Alpha(c); return int(c/16777216); endfunc
    function Red(c); return int((c/65536))%256; endfunc
    function Green(c); return int((c/256))%256; endfunc
    function Blue(c); return c%256; endfunc
endfunc

I have never made a racing game, except for a mode7 experiment. And I frankly don't know what is the best way to store a track in memory or how to render it in a good way. It probably depends on what type of racing game you're doing.

Anyhow, as I wrote earlier, the thing I wrote this spring is not good for anything. I'll see if I can think of a good way to make a racing game, either based on road segments (like above, but with heights) or a heightmap.

Sorry for not being to any help here, it's an unexplored area for me.