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Touch Explosion 2d
--# Main
-- Explosion
-- Use this function to perform your initial setup
function setup()
--first generate a spherical mesh radius 1 around the origin
--this uses an isosphere primitive code I made some time ago, but any sphere will do with sufficient vertices
--the parameter to Sphere is how much to subdivide the faces (more vertices, slower performance)
sphere = Primitive:Sphere(3)
--attach the explosion shader to the mesh
sphere.shader = shader(ExplosionShader.vertexShader,ExplosionShader.fragmentShader)
--the texture gives the color gradient for the fire
--get from http://www.clicktorelease.com/blog/vertex-displacement-webgl-glsl-perlin-noise-three-js/explosion.png
sphere.shader.texture = readImage("Dropbox:explosion")
size = 0.0
--since this is being run as "2d" the standard projection matrix clips it. This tweaked matrix makes it show
--but I don't understand the maths, I just tweaked it till it worked.
tweakOrthoProjMatrix = projectionMatrix()
tweakOrthoProjMatrix[11] = -.001
--an array to hold the currently active explosions
bang = {}
end
function touched(touch)
if touch.state == BEGAN then
--add an explosion when it's touched
table.insert(bang, {x = touch.x, y = touch.y, extraOffset = math.random(5000), startTime = ElapsedTime})
end
end
-- This function gets called once every frame
function draw()
output.clear()
--print(1/DeltaTime)
--print(size)
-- This sets a dark background color
background(0, 0, 0)
-- Do your drawing here
--set the custom projection matrix
projectionMatrix(tweakOrthoProjMatrix)
for k,v in pairs(bang) do
--get an arbitrary time to drive the animation
time = ElapsedTime - v.startTime
--move to touch location and scale to have a growing explosion
translate(v.x, v.y)
scale(30*time)
--pass time information to the shader for animation
sphere.shader.push = time / 5
sphere.shader.offset = .4 * ElapsedTime + v.extraOffset
sphere:draw()
resetMatrix()
if time > 4 then
--remove expired explosions to avoid degrading performance
bang[k] = nil
end
end
end
--shader is based on http://www.clicktorelease.com/blog/vertex-displacement-noise-3d-webgl-glsl-three-js
ExplosionShader = {
vertexShader = [[
//
// A basic vertex shader
//
//This is the current model * view * projection matrix
// Codea sets it automatically
uniform mat4 modelViewProjection;
//This is the current mesh vertex position, color and tex coord
// Set automatically
attribute vec4 position;
uniform float offset;
//
// GLSL textureless classic 3D noise "cnoise",
// with an RSL-style periodic variant "pnoise".
// Author: Stefan Gustavson (stefan.gustavson@liu.se)
// Version: 2011-10-11
//
// Many thanks to Ian McEwan of Ashima Arts for the
// ideas for permutation and gradient selection.
//
// Copyright (c) 2011 Stefan Gustavson. All rights reserved.
// Distributed under the MIT license. See LICENSE file.
// https://github.com/ashima/webgl-noise
//
vec3 mod289(vec3 x)
{
return x - floor(x * (1.0 / 289.0)) * 289.0;
}
vec4 mod289(vec4 x)
{
return x - floor(x * (1.0 / 289.0)) * 289.0;
}
vec4 permute(vec4 x)
{
return mod289(((x*34.0)+1.0)*x);
}
vec4 taylorInvSqrt(vec4 r)
{
return 1.79284291400159 - 0.85373472095314 * r;
}
vec3 fade(vec3 t) {
return t*t*t*(t*(t*6.0-15.0)+10.0);
}
// Classic Perlin noise
float cnoise(vec3 P)
{
vec3 Pi0 = floor(P); // Integer part for indexing
vec3 Pi1 = Pi0 + vec3(1.0); // Integer part + 1
Pi0 = mod289(Pi0);
Pi1 = mod289(Pi1);
vec3 Pf0 = fract(P); // Fractional part for interpolation
vec3 Pf1 = Pf0 - vec3(1.0); // Fractional part - 1.0
vec4 ix = vec4(Pi0.x, Pi1.x, Pi0.x, Pi1.x);
vec4 iy = vec4(Pi0.yy, Pi1.yy);
vec4 iz0 = Pi0.zzzz;
vec4 iz1 = Pi1.zzzz;
vec4 ixy = permute(permute(ix) + iy);
vec4 ixy0 = permute(ixy + iz0);
vec4 ixy1 = permute(ixy + iz1);
vec4 gx0 = ixy0 * (1.0 / 7.0);
vec4 gy0 = fract(floor(gx0) * (1.0 / 7.0)) - 0.5;
gx0 = fract(gx0);
vec4 gz0 = vec4(0.5) - abs(gx0) - abs(gy0);
vec4 sz0 = step(gz0, vec4(0.0));
gx0 -= sz0 * (step(0.0, gx0) - 0.5);
gy0 -= sz0 * (step(0.0, gy0) - 0.5);
vec4 gx1 = ixy1 * (1.0 / 7.0);
vec4 gy1 = fract(floor(gx1) * (1.0 / 7.0)) - 0.5;
gx1 = fract(gx1);
vec4 gz1 = vec4(0.5) - abs(gx1) - abs(gy1);
vec4 sz1 = step(gz1, vec4(0.0));
gx1 -= sz1 * (step(0.0, gx1) - 0.5);
gy1 -= sz1 * (step(0.0, gy1) - 0.5);
vec3 g000 = vec3(gx0.x,gy0.x,gz0.x);
vec3 g100 = vec3(gx0.y,gy0.y,gz0.y);
vec3 g010 = vec3(gx0.z,gy0.z,gz0.z);
vec3 g110 = vec3(gx0.w,gy0.w,gz0.w);
vec3 g001 = vec3(gx1.x,gy1.x,gz1.x);
vec3 g101 = vec3(gx1.y,gy1.y,gz1.y);
vec3 g011 = vec3(gx1.z,gy1.z,gz1.z);
vec3 g111 = vec3(gx1.w,gy1.w,gz1.w);
vec4 norm0 = taylorInvSqrt(vec4(dot(g000, g000), dot(g010, g010), dot(g100, g100), dot(g110, g110)));
g000 *= norm0.x;
g010 *= norm0.y;
g100 *= norm0.z;
g110 *= norm0.w;
vec4 norm1 = taylorInvSqrt(vec4(dot(g001, g001), dot(g011, g011), dot(g101, g101), dot(g111, g111)));
g001 *= norm1.x;
g011 *= norm1.y;
g101 *= norm1.z;
g111 *= norm1.w;
float n000 = dot(g000, Pf0);
float n100 = dot(g100, vec3(Pf1.x, Pf0.yz));
float n010 = dot(g010, vec3(Pf0.x, Pf1.y, Pf0.z));
float n110 = dot(g110, vec3(Pf1.xy, Pf0.z));
float n001 = dot(g001, vec3(Pf0.xy, Pf1.z));
float n101 = dot(g101, vec3(Pf1.x, Pf0.y, Pf1.z));
float n011 = dot(g011, vec3(Pf0.x, Pf1.yz));
float n111 = dot(g111, Pf1);
vec3 fade_xyz = fade(Pf0);
vec4 n_z = mix(vec4(n000, n100, n010, n110), vec4(n001, n101, n011, n111), fade_xyz.z);
vec2 n_yz = mix(n_z.xy, n_z.zw, fade_xyz.y);
float n_xyz = mix(n_yz.x, n_yz.y, fade_xyz.x);
return 2.2 * n_xyz;
}
// Classic Perlin noise, periodic variant
float pnoise(vec3 P, vec3 rep)
{
vec3 Pi0 = mod(floor(P), rep); // Integer part, modulo period
vec3 Pi1 = mod(Pi0 + vec3(1.0), rep); // Integer part + 1, mod period
Pi0 = mod289(Pi0);
Pi1 = mod289(Pi1);
vec3 Pf0 = fract(P); // Fractional part for interpolation
vec3 Pf1 = Pf0 - vec3(1.0); // Fractional part - 1.0
vec4 ix = vec4(Pi0.x, Pi1.x, Pi0.x, Pi1.x);
vec4 iy = vec4(Pi0.yy, Pi1.yy);
vec4 iz0 = Pi0.zzzz;
vec4 iz1 = Pi1.zzzz;
vec4 ixy = permute(permute(ix) + iy);
vec4 ixy0 = permute(ixy + iz0);
vec4 ixy1 = permute(ixy + iz1);
vec4 gx0 = ixy0 * (1.0 / 7.0);
vec4 gy0 = fract(floor(gx0) * (1.0 / 7.0)) - 0.5;
gx0 = fract(gx0);
vec4 gz0 = vec4(0.5) - abs(gx0) - abs(gy0);
vec4 sz0 = step(gz0, vec4(0.0));
gx0 -= sz0 * (step(0.0, gx0) - 0.5);
gy0 -= sz0 * (step(0.0, gy0) - 0.5);
vec4 gx1 = ixy1 * (1.0 / 7.0);
vec4 gy1 = fract(floor(gx1) * (1.0 / 7.0)) - 0.5;
gx1 = fract(gx1);
vec4 gz1 = vec4(0.5) - abs(gx1) - abs(gy1);
vec4 sz1 = step(gz1, vec4(0.0));
gx1 -= sz1 * (step(0.0, gx1) - 0.5);
gy1 -= sz1 * (step(0.0, gy1) - 0.5);
vec3 g000 = vec3(gx0.x,gy0.x,gz0.x);
vec3 g100 = vec3(gx0.y,gy0.y,gz0.y);
vec3 g010 = vec3(gx0.z,gy0.z,gz0.z);
vec3 g110 = vec3(gx0.w,gy0.w,gz0.w);
vec3 g001 = vec3(gx1.x,gy1.x,gz1.x);
vec3 g101 = vec3(gx1.y,gy1.y,gz1.y);
vec3 g011 = vec3(gx1.z,gy1.z,gz1.z);
vec3 g111 = vec3(gx1.w,gy1.w,gz1.w);
vec4 norm0 = taylorInvSqrt(vec4(dot(g000, g000), dot(g010, g010), dot(g100, g100), dot(g110, g110)));
g000 *= norm0.x;
g010 *= norm0.y;
g100 *= norm0.z;
g110 *= norm0.w;
vec4 norm1 = taylorInvSqrt(vec4(dot(g001, g001), dot(g011, g011), dot(g101, g101), dot(g111, g111)));
g001 *= norm1.x;
g011 *= norm1.y;
g101 *= norm1.z;
g111 *= norm1.w;
float n000 = dot(g000, Pf0);
float n100 = dot(g100, vec3(Pf1.x, Pf0.yz));
float n010 = dot(g010, vec3(Pf0.x, Pf1.y, Pf0.z));
float n110 = dot(g110, vec3(Pf1.xy, Pf0.z));
float n001 = dot(g001, vec3(Pf0.xy, Pf1.z));
float n101 = dot(g101, vec3(Pf1.x, Pf0.y, Pf1.z));
float n011 = dot(g011, vec3(Pf0.x, Pf1.yz));
float n111 = dot(g111, Pf1);
vec3 fade_xyz = fade(Pf0);
vec4 n_z = mix(vec4(n000, n100, n010, n110), vec4(n001, n101, n011, n111), fade_xyz.z);
vec2 n_yz = mix(n_z.xy, n_z.zw, fade_xyz.y);
float n_xyz = mix(n_yz.x, n_yz.y, fade_xyz.x);
return 2.2 * n_xyz;
}
varying float noise;
float turbulence( vec3 p ) {
float w = 100.0;
float t = -.5;
for (float f = 1.0 ; f <= 10.0 ; f++ ){
float power = pow( 2.0, f );
t += abs( pnoise( vec3( power * p ), vec3( 10.0, 10.0, 10.0 ) ) / power );
}
return t;
}
void main() {
// get a turbulent 3d noise using the normal, normal to high freq
noise = -1.0 * turbulence( 0.5 * position.xyz + offset );
// get a 3d noise using the position, low frequency
float b = 5.0 * pnoise( 1.3 * (position.xyz) + vec3( 2.0 * offset ), vec3( 100.0 ) );
// compose both noises
float displacement = -10. * noise + b;
vec3 newPosition = position.xyz + ((position.xyz * displacement) / 20.0);
gl_Position = modelViewProjection * vec4( newPosition, 1.0 );
}
]],
fragmentShader = [[
//
// A basic fragment shader
//
//Default precision qualifier
precision highp float;
//This represents the current texture on the mesh
uniform lowp sampler2D texture;
uniform float push;
varying float noise;
void main() {
// lookup vertically in the texture, using noise
// to get the right RGB colour
vec2 tPos = vec2( 0, 0.5 + 1.0 * noise - push);
vec4 color = texture2D( texture, tPos );
gl_FragColor = vec4( color.rgb, 1.0 );
}
]] }
--# Primitive
Primitive = class()
--primitves gives basic mesh building for cubes and isospheres
--triangles are wound consistently to avoid gl_facing issues
function Primitive:Cube()
m = mesh()
local vertices = {
vec3(-0.5, -0.5, 0.5), -- Left bottom front
vec3( 0.5, -0.5, 0.5), -- Right bottom front
vec3( 0.5, 0.5, 0.5), -- Right top front
vec3(-0.5, 0.5, 0.5), -- Left top front
vec3(-0.5, -0.5, -0.5), -- Left bottom back
vec3( 0.5, -0.5, -0.5), -- Right bottom back
vec3( 0.5, 0.5, -0.5), -- Right top back
vec3(-0.5, 0.5, -0.5), -- Left top back
}
-- now construct a cube out of the vertices above
m.vertices = {
-- Front
vertices[1], vertices[2], vertices[3],
vertices[1], vertices[3], vertices[4],
-- Right
vertices[2], vertices[6], vertices[7],
vertices[2], vertices[7], vertices[3],
-- Back
vertices[6], vertices[5], vertices[8],
vertices[6], vertices[8], vertices[7],
-- Left
vertices[5], vertices[1], vertices[4],
vertices[5], vertices[4], vertices[8],
-- Top
vertices[4], vertices[3], vertices[7],
vertices[4], vertices[7], vertices[8],
-- Bottom
vertices[5], vertices[6], vertices[2],
vertices[5], vertices[2], vertices[1],
}
return m
end
function Primitive:Sphere(depth)
m = mesh()
local t = (1 + math.sqrt(5)) / 2
--all the vertices of an icosohedron
local vertices = {
vec3(-1 , t, 0):normalize(),
vec3(1 , t, 0):normalize(),
vec3(-1 , -t, 0):normalize(),
vec3(1 , -t, 0):normalize(),
vec3(0 , -1, t):normalize(),
vec3(0 , 1, t):normalize(),
vec3(0 , -1, -t):normalize(),
vec3(0 , 1, -t):normalize(),
vec3(t , 0, -1):normalize(),
vec3(t , 0, 1):normalize(),
vec3(-t , 0, -1):normalize(),
vec3(-t , 0, 1):normalize()
}
--20 faces
icovertices = {
-- 5 faces around point 0
vertices[1], vertices[12], vertices[6],
vertices[1], vertices[6], vertices[2],
vertices[1], vertices[2], vertices[8],
vertices[1], vertices[8], vertices[11],
vertices[1], vertices[11], vertices[12],
-- 5 adjacent faces
vertices[2], vertices[6], vertices[10],
vertices[6], vertices[12], vertices[5],
vertices[12], vertices[11], vertices[3],
vertices[11], vertices[8], vertices[7],
vertices[8], vertices[2], vertices[9],
-- 5 faces around point 3
vertices[4], vertices[10], vertices[5],
vertices[4], vertices[5], vertices[3],
vertices[4], vertices[3], vertices[7],
vertices[4], vertices[7], vertices[9],
vertices[4], vertices[9], vertices[10],
--5 adjacent faces
vertices[5], vertices[10], vertices[6],
vertices[3], vertices[5], vertices[12],
vertices[7], vertices[3], vertices[11],
vertices[9], vertices[7], vertices[8],
vertices[10], vertices[9], vertices[2]
}
local finalVertices = {}
--divide each triangle into 4 sub triangles to make an isosphere
--this can be repeated (based on depth) for higher res spheres
for j=1,depth do
for i=1,#icovertices/3 do
midpoint1 = ((icovertices[i*3-2] + icovertices[i*3-1])/2):normalize()
midpoint2 = ((icovertices[i*3-1] + icovertices[i*3])/2):normalize()
midpoint3 = ((icovertices[i*3] + icovertices[i*3-2])/2):normalize()
--triangle 1
table.insert(finalVertices,icovertices[i*3-2])
table.insert(finalVertices,midpoint1)
table.insert(finalVertices,midpoint3)
--triangle 2
table.insert(finalVertices,midpoint1)
table.insert(finalVertices,icovertices[i*3-1])
table.insert(finalVertices,midpoint2)
--triangle 3
table.insert(finalVertices,midpoint2)
table.insert(finalVertices,icovertices[i*3])
table.insert(finalVertices,midpoint3)
--triangle 4
table.insert(finalVertices,midpoint1)
table.insert(finalVertices,midpoint2)
table.insert(finalVertices,midpoint3)
end
icovertices = finalVertices
finalVertices = {}
end
m.vertices = icovertices
return m
end
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