TheGameCreators - CodeBase - Ye olde water algorithm

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Category: 3D Effects

Version: 1.1

Information

Uploaded: 10th May 2005 13:38

Modified: 10th May 2005 15:35

Author: Tinkerer

Summary

This is a simple demo of a well-known water algorithm.

Full Description

This is a simple demo of a well-known water algorithm. Mouse1 adjusts the interference level, and mouse2 adjusts the interference type. Further options can be set by adjusting variables.<br /> <br /> After an accidental typo, this algorithm started behaving a little like the memory foam you get on some wrist pads. I've preserved the alternate matrix behaviour, and it can be toggled by pressing the space bar.<br /> <br /> <update 1.1> camera motion smoothed out.

DarkBASIC Professional Source Code

` This code was downloaded from The Game Creators

` It is reproduced here with full permission

` http://www.thegamecreators.com

REM Project: water

REM Created: 10/05/2005 03:09:33

REM

REM ***** Main Source File *****

REM

rem set sync up

sync on : sync rate 60

rem hide the mouse pointer

hide mouse

rem declare the two arrays that will be used to hold height information

dim imgbuffer1(1024, 1024) AS FLOAT

dim imgbuffer2(1024, 1024) AS FLOAT

rem make this as big as your system can handle!

gridsize = 128

rem this value determines how large the matrix will be rendered

gridmultiplier = 8

rem fill the arrays with zeros

for z = 0 to gridsize + 1

for x = 0 to gridsize + 1

imgbuffer1(x, z) = 0.0

imgbuffer2(x, z) = 0.0

next x

next z

rem determine where the middle of the matrix will be

middle = gridsize / 2

rem set this to a value BELOW ZERO. Or don't and enjoy the fireworks.

rem 0.90 to 0.999 are "sensible" values.

damping AS FLOAT

damping = 0.99

rem making this higher will slow the wave frequency of the mouse+sine effect.

wavefreq AS FLOAT

wavefreq = 1

rem adjusting these two variables will determine how much mouse button 1 affects

rem the interference generators.

lowheight = 10

highheight = 100

rem you can customize your own water behaviour using the above three variables together

rem the current pattern value is stored here

pattern AS INTEGER

pattern = 0

rem the current algorithm (water or mousepad foam)

mtype = 0

rem the next two variables are used together to stop the pattern changing in a loop when

rem mouse 2 is held down.

clik AS INTEGER

clik = 0

lastclik AS INTEGER

lastclik = 0

rem the next two variables are used together to stop the matrix behaviour changing in a

rem loop when the spacebar is held down.

lastspace = 0

space = 0

rem a temporary variable. Used later on.

tmp AS FLOAT

rem current mouse position and mouse+sine wave generator height go here.

mouseposx AS INTEGER

mouseposz AS INTEGER

waveheight AS INTEGER

waveheight = lowheight

rem load matrix texture here

MImg = 1 : load image "wtex.jpg", MImg

rem calulate matrix size and place in these two variables

matrixsize AS FLOAT

matrixsize = gridsize * gridmultiplier

matrixmiddle AS FLOAT

matrixmiddle = matrixsize / 2.0

rem declare and set the matrix here

MObj = 1 : make matrix MObj, matrixsize, matrixsize, gridsize, gridsize

MImg = 1 : load image "wtex.jpg", MImg

prepare matrix texture MObj, MImg, 1,1

rem set the initial position of the camera here

position camera 0,(sin(timer() / 100.0) * 100.0) + matrixsize,300.0,(cos(timer() / 110.0) * 100.0) + matrixsize

rem main loop

rem get the new mouse position

mouseposx = mouseposx + (mousemovex() / 5)

mouseposz = mouseposz + -(mousemovey() / 5)

rem limit the mouse position to valid array indices

if mouseposx > gridsize then mouseposx = gridsize

if mouseposz > gridsize then mouseposz = gridsize

if mouseposx < 1 then mouseposx = 1

if mouseposz < 1 then mouseposz = 1

rem pan the camera around slowly

position camera 0,matrixmiddle - (sin(timer() / 100.0) * 200.0),300.0,(cos(timer() / 110.0) * 100.0)

point camera matrixmiddle,-300,matrixmiddle

rem calculate current wave generator values

sinfreq = timer() / wavefreq

sincalc = 0.0 + sin(sinfreq) * waveheight

coscalc = 0.0 + cos(sinfreq) * waveheight

rem capture mouse values and change pattern and waveheight values accordingly

lastclik = clik

clik = mouseclick()

if clik <> lastclik

select clik

case 0

waveheight = lowheight

endcase

case 1

waveheight = highheight

endcase

case 2

waveheight = lowheight

inc pattern

endcase

case 3

waveheight = highheight

inc pattern

endcase

endselect

endif

if pattern > 2 then pattern = 0

select pattern

case 0

print "Interference type: mouse + sine"

imgbuffer1(mouseposx, mouseposz) = imgbuffer1(mouseposx, mouseposz) + sincalc

endcase

case 1

print "Inteference type: rain"

randomize timer()

tx = rnd(gridsize - 1) + 1

ty = rnd(gridsize - 1) + 1

imgbuffer1(tx, ty) = imgbuffer1(tx, ty) + sincalc

endcase

case 2

print "Interference type: none"

endcase

endselect

rem get the spacebar state.

lastspace = space

space = spacekey()

rem ignore if state is same as last state.

if space <> lastspace

if space = 1

inc mtype

if mtype > 1 then mtype = 0

endif

select mtype

case 0

print "Matrix behaviour: water"

endcase

case 1

print "Matrix behaviour: memory foam"

endcase

endselect

rem this is the place where algorithms are applied. Remarks left out for speed.

rem the first set of embedded loops are for water, the second for a low rebound

rem foam-like behaviour. The third set of loops is used by both behaviours to

rem swap the contents of the two buffers.

select mtype

case 0

for z = 1 to gridsize

for x = 1 to gridsize

imgbuffer2(x, z) = (imgbuffer1(x - 1, z) + imgbuffer1(x + 1, z) + imgbuffer1(x, z + 1) + imgbuffer1(x, z - 1)) / 2 - imgbuffer2(x, z)

imgbuffer2(x, z) = imgbuffer2(x, z) * damping

next x

next z

endcase

case 1

for z = 1 to gridsize

for x = 1 to gridsize

imgbuffer2(x, z) = (imgbuffer1(x - 1, z) + imgbuffer1(x + 1, z) + imgbuffer1(x, z + 1) + imgbuffer1(x, z - 1)) / 2 - imgbuffer2(x, z)

imgbuffer2(x, z) = imgbuffer1(x, z) * damping

next x

next z

endcase

endselect

for z = 1 to gridsize

for x = 1 to gridsize

tmp = imgbuffer1(x, z)

imgbuffer1(x, z) = imgbuffer2(x, z)

imgbuffer2(x, z) = tmp

set matrix height MObj, x, z, imgbuffer2(x, z)

next x

next z

rem done with water algorithm. Update matrix with new values.

update matrix MObj

rem print out a status display.

set cursor 0,1 : print "mpx: "; mouseposx; " mpz: "; mouseposz; " fps: "; screen fps()

CodeBase - Ye olde water algorithm

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Author Name:	Tinkerer
CodeBase Entries:	2