[bb] Isometric Terrain Loader by Mr Snidesmin [ 1+ years ago ]

[BlitzBot]

Title : Isometric Terrain Loader
Author : Mr Snidesmin
Posted : 1+ years ago

Description : Loads a BMP terrain using isometric triangles.

LoadIsoTerrain%(sBMP$, size%)
size is the number of tiles along one side. There are around 2/3 the number of tiles along the other side.

Code :

Code (blitzbasic) Select Expand

Type Bounds
Field x#
Field y#
Field z#

Field dx#
Field dy#
Field dz#
End Type

Function MakeIsoGrid%(size%, scale=1.0)
m% = CreateMesh()
s% = CreateSurface(m)

size = size/2

oristart% = 1
For x% = -size To +size
ori = oristart
oristart = -oristart
For y% = -size*0.6 To +size*0.6
ori = -ori
If ori < 0 Then
offy# = 0
Else
offy# = -Scale*Sin(30)
End If


x0# = 0.5*Tan(60)*x*scale+px + scale * Cos(0*120+90*ori)
y0# = offy + y*scale*(1+Sin(30))+py + scale * Sin(0*120+90*ori)

x1# = 0.5*Tan(60)*x*scale+px + scale * Cos(2*120+90*ori)
y1# = offy + y*scale*(1+Sin(30))+py + scale * Sin(1*120+90*ori)

x2# = 0.5*Tan(60)*x*scale+px + scale * Cos(1*120+90*ori)
y2# = offy + y*scale*(1+Sin(30))+py + scale * Sin(2*120+90*ori)

InsertTriangleXZ s, x0, y0, x1, y1, x2, y2, scale/12
Next
Next
Return m
End Function


Function DrawIsoGrid(size%, px%, py%, scale#=10.0)
size = size/2
oristart% = 1
For x% = -size To +size
ori = oristart
oristart = -oristart
For y% = -size*0.6 To +size*0.6
ori = -ori
If ori < 0 Then
offy# = 0
Else
offy# = -Scale*Sin(30)
End If
For i% = 0 To 2
x0# = 0.5*Tan(60)*x*scale+px + scale * Cos(i*120+90*ori)
y0# = offy + y*scale*(1+Sin(30))+py + scale * Sin(i*120+90*ori)

x1# = 0.5*Tan(60)*x*scale+px + scale * Cos((i+1)*120+90*ori)
y1# = offy + y*scale*(1+Sin(30))+py + scale * Sin((i+1)*120+90*ori)

Line x0, y0, x1, y1
Next
Next
Next
End Function

Function LoadIsoTerrain%(sBMP$, size%=100)
img%=LoadImage(sBMP)
m = MakeIsoGrid(size)
MapTexture m
FitMesh m, 0, 0, 0, ImageWidth(img), 0.001, ImageHeight(img), True
SetBuffer ImageBuffer(img)

s% = GetSurface(m, 1)
For i% = 0 To CountVertices(s)-1
x# = VertexX(s, i)
z# = VertexZ(s, i)
GetColor(x, z)
y# = (ColorRed()+ColorGreen()+ColorBlue())/20

If y < 2 Then y = 0
VertexCoords s, i, x, y, z
Next
SetBuffer BackBuffer()
FreeImage img
UpdateNormals m
Return m
End Function

Function GetSurfaceBounds.Bounds(surface)
b.Bounds = New Bounds

bx = VertexX(surface, 0)
by = VertexY(surface, 0)
bz = VertexZ(surface, 0)
bdx = VertexX(surface, 0)
bdy = VertexY(surface, 0)
bdz = VertexZ(surface, 0)

For i = 1 To CountVertices(surface) - 1
If VertexX(surface, i) < bx Then bx = VertexX(surface, i)
If VertexY(surface, i) < by Then by = VertexY(surface, i)
If VertexZ(surface, i) < bz Then bz = VertexZ(surface, i)

If VertexX(surface, i) > bdx Then bdx = VertexX(surface, i)
If VertexY(surface, i) > bdy Then bdy = VertexY(surface, i)
If VertexZ(surface, i) > bdz Then bdz = VertexZ(surface, i)
Next

bdx = bdx - bx
bdy = bdy - by
bdz = bdz - bz

bdx = bdx/2
bdy = bdy/2
bdz = bdz/2

bx = bx + bdx
by = by + bdy
bz = bz + bdz

Return b
End Function


Function InsertTriangleXZ(surface, x1#,z1#, x2#,z2#, x3#,z3#, approx#=0.0)
InsertTriangle(surface, x1,0,z1, x2,0,z2, x3,0,z3, approx)
End Function


Function InsertTriangle(surface, x1#,y1#,z1#, x2#,y2#,z2#, x3#,y3#,z3#, approx#=0.0)
v1% = -1
v2% = -1
v3% = -1

For i% = 0 To CountVertices(surface) - 1
x# = VertexX(surface, i)
y# = VertexY(surface, i)
z# = VertexZ(surface, i)

If approx = 0 Then
If x1=x And y1=y And z1=z Then v1 = i
If x2=x And y2=y And z2=z Then v2 = i
If x3=x And y3=y And z3=z Then v3 = i
Else
If Sqr((x1-x)*(x1-x)+(y1-y)*(y1-y)+(z1-z)*(z1-z)) < approx Then v1 = i
If Sqr((x2-x)*(x2-x)+(y2-y)*(y2-y)+(z2-z)*(z2-z)) < approx Then v2 = i
If Sqr((x3-x)*(x3-x)+(y3-y)*(y3-y)+(z3-z)*(z3-z)) < approx Then v3 = i
End If
Next

If v1 < 0 Then v1 = AddVertex(surface, x1, y1, z1)
If v2 < 0 Then v2 = AddVertex(surface, x2, y2, z2)
If v3 < 0 Then v3 = AddVertex(surface, x3, y3, z3)

AddTriangle surface, v1, v2, v3
End Function

Function MapTexture(mesh, mapType% = 0)
For i = 1 To CountSurfaces(mesh)
surface = GetSurface(mesh, i)

b.bounds = GetSurfaceBounds(surface)

Select mapType
Case 1: ;XZ/Y Cylinderical Mapping

For i = 0 To CountVertices(surface) - 1
x# = VertexX(surface, i)-bx
z# = VertexZ(surface, i)-bz

a# = ATan2(z,x)

v# = (VertexY(surface, i) - by) / bdy
v = v/2 + 0.5
u# = a/720 + 0.5

VertexTexCoords surface, i, u, v
Next

Default: ;Map UV to XZ
For i = 0 To CountVertices(surface) - 1
u# = (VertexX(surface, i) - bx) / bdx
v# = (VertexZ(surface, i) - bz) / bdz

VertexTexCoords surface, i, (u+1)/2, (v+1)/2
Next
End Select
Delete b
Next
End Function


;Quick Example
Graphics3D 800, 600, 0, 2

terrain = LoadIsoTerrain("height.bmp", 50)
cam = CreateCamera()
light = CreateLight()
RotateEntity light, 10, 50, 0
HidePointer()
PositionEntity cam, 200, 50, 200
PointEntity cam, terrain

SetBuffer BackBuffer()
While Not KeyHit(1)
dY# = EntityPitch(cam)+MouseYSpeed()/2
If dY > 89 Then dY = 89
If dY < -89 Then dY = -89

RotateEntity cam, dY, EntityYaw(cam)-(MouseXSpeed()/2), 0


MoveEntity cam, 0, 0, (MouseDown(1)-MouseDown(2))*5
MoveMouse GraphicsWidth()/2, GraphicsHeight()/2

UpdateWorld()
RenderWorld()
VWait()
Flip()
Wend
End

Comments :


FBEpyon(Posted 1+ years ago)

 Your code must not work full i can't seem to get any of it to work... :(Can you post a example???


Mr Snidesmin(Posted 1+ years ago)

 Oops, I'm sorry about that - I missed out a couple of other functions from my library.I put them in now:MapTexture is also included, but is not essential.(It just sets the UV coordinates so that a texture will fit the mesh properly)


thelizardking(Posted 1+ years ago)

 excellent! this one hardly uses any polygons, so its perfect 4 games!