Created
March 19, 2013 14:22
-
-
Save tnlogy/5196504 to your computer and use it in GitHub Desktop.
Grass Simulation in Codea
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
--# Main | |
-- Grass | |
function setup() | |
displayMode(FULLSCREEN) | |
R,H = 40,1 | |
base = mesh() | |
base.vertices = { | |
vec3(-1,0,-1), vec3(1,0,-1), | |
vec3(1,0,1), vec3(1,0,1), | |
vec3(-1,0,1), vec3(-1,0,-1) | |
} | |
base:setColors( | |
color(27, 40, 30, 255)) | |
g = Grass() | |
end | |
function draw() | |
background(0, 0, 0, 255) | |
camera(0,H,5,0,0,0) | |
perspective(45) | |
rotate(R, 0,1,0) | |
g:draw() | |
scale(4) | |
base:draw() | |
end | |
function touched(touch) | |
if touch.state == MOVING then | |
R = R + touch.deltaX*.5 | |
H = math.max(H - touch.deltaY*.02, .5) | |
end | |
end | |
--# Grass | |
Grass = class() | |
function mult(m, v) | |
return vec3( | |
m[1]*v.x+m[2]*v.y+m[3]*v.z, | |
m[5]*v.x+m[6]*v.y+m[7]*v.z, | |
m[9]*v.x+m[10]*v.y+m[11]*v.z | |
) | |
end | |
function Grass:init(x) | |
self.m = mesh() | |
-- http.request("https://dl.dropbox.com/s/2kboo35minb8opx/Photo%202013-03-19%2010%2011%2028.jpg?token_hash=AAFsT-JmLRpPP5F0pet5tZHo2c0-aaOu7LpwzHCWXVPS_g&dl=1",function(data) | |
-- self.m.texture = data | |
-- end) | |
self.m.texture = readImage("Documents:Grasses") | |
self.m.shader = GrassShader | |
local sq = { | |
vec3(0,0,0), vec3(1,0,0), | |
vec3(1,1,0), vec3(1,1,0), | |
vec3(0,1,0), vec3(0,0,0) | |
} | |
local vs, uvs = {}, {} | |
for x=-5,5 do for z=-5,5 do | |
local r = vec3(math.random(-.5,.5), 0, math.random(-.5,.5)) | |
local h = math.random(1,1.3) | |
for j = 0,2 do | |
local m = matrix():rotate(60*j,0,1,0) | |
for i,v in ipairs(sq) do | |
local p = v - vec3(.5,0,0) | |
p.y = p.y * h | |
p = mult(m,p) + vec3(x,0,z)*.6 + r | |
table.insert(vs, p) | |
table.insert(uvs, v) | |
end | |
end | |
end end | |
self.m.vertices = vs | |
self.m.texCoords = uvs | |
self.m:setColors(255,255,255,255) | |
end | |
function Grass:draw() | |
self.m.shader.time = ElapsedTime | |
self.m:draw() | |
end | |
--# GrassShader | |
GrassShader = shader() | |
GrassShader.vertexProgram = [[ | |
uniform mat4 modelViewProjection; | |
attribute vec4 position; | |
attribute vec4 color; | |
attribute vec2 texCoord; | |
varying lowp vec4 vColor; | |
varying highp vec2 vTexCoord; | |
uniform highp float time; | |
// Noise | |
float hash( float n ) { | |
return fract(sin(n)*43758.5453); | |
} | |
float noise( in vec2 x ) { | |
vec2 p = floor(x); | |
vec2 f = fract(x); | |
f = f*f*(3.0-2.0*f); | |
float n = p.x + p.y*57.0; | |
float res = mix(mix( hash(n+ 0.0), hash(n+ 1.0),f.x), mix( hash(n+ 57.0), hash(n+ 58.0),f.x),f.y); | |
return res; | |
} | |
float fbm( vec2 p ) { | |
float f = 0.0; | |
f += 0.50000*noise( p ); p = p*2.02; | |
// f += 0.25000*noise( p ); p = p*2.03; | |
// f += 0.12500*noise( p ); p = p*2.01; | |
f += 0.06250*noise( p ); p = p*2.04; | |
f += 0.03125*noise( p ); | |
return f/0.984375; | |
} | |
void main() | |
{ | |
vColor = color; | |
vTexCoord = vec2(texCoord.x, texCoord.y); | |
vec4 p = modelViewProjection * position; | |
if(vTexCoord.y > .9) { | |
float n = fbm(p.xy*time*.2)*4. - 2.; | |
p = p + vec4(n,0.,0.,0.); | |
} | |
lowp vec4 nor = normalize(p); | |
lowp float vShade = (dot(nor.xyz,vec3(1.,0.,0.))+.4)/1.2; | |
if (vShade >1.0) {vShade=1.0;} | |
if (vShade <0.4) {vShade=0.4;} | |
vColor.rgb = vColor.rgb * vShade; | |
gl_Position = p; | |
} | |
]] | |
GrassShader.fragmentProgram = [[ | |
uniform lowp sampler2D texture; | |
varying lowp vec4 vColor; | |
varying highp vec2 vTexCoord; | |
void main() | |
{ | |
lowp vec4 col = texture2D( texture, vTexCoord ); | |
if(col.r > .5) discard; | |
gl_FragColor = col*vColor; | |
} | |
]] |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment