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Topic: ... over my head? (Read 878 times) |
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mKoser
 
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Re: ... over my head?
« Reply #15 on: Jan 28th, 2004, 10:45am » |
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Quote:
say, if c is an integer with a bit packed color value inside,
r: c & 0xff
g: (c & 0xff00) >> 8
b: (c & 0xff0000) >> 16
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very handy indeed!... but, how do you do the reverse action? if you've got an RGB colour, how do you pack that into an integer of that format?
(sorry - a bit of topic here!)
+ mikkel
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mikkel crone koser | www.beyondthree.com | http://processing.beyondthree.com
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toxi_
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Re: ... over my head?
« Reply #16 on: Jan 28th, 2004, 1:13pm » |
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mikkel, have a look at my longish post about bits & shifts over here 
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mKoser
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Re: ... over my head?
« Reply #17 on: Jan 28th, 2004, 3:38pm » |
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thank you toxi - this forum it getting REALLY difficult to remember/find what i once read... so, i guess it is time to start making my own little tech-note archive
thanks for linking!
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mikkel crone koser | www.beyondthree.com | http://processing.beyondthree.com
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Charles Hinshaw
Guest
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Re: ... over my head?
« Reply #18 on: Jan 28th, 2004, 10:47pm » |
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two things...
First, I did a touch of optimization to my earlier code -- and it runs MUCH faster, so in case somebody stumbles upon this thread in the future and is using things as a resource, the following is better, but it will likely still hang on an image that is TOO dark... It is really designed for working with black text on a white background.
Code:
// User Control Variables
String imagename = "digidust2.jpg"; // Source Image
int seconds = 4; // length of animation
boolean recording = false; // record frames?
//Global Variables
particle p[];
int loopcount = 1;
// ------------------------------------------------------
void setup()
{
size(640,480);
smooth();
BImage startimage;
startimage = loadImage(imagename);
image(startimage, 0, 0);
int x, y, col, grey;
int i = 0;
int pgen = 0;
int[][] density = new int[width][height];
int particlesum = 0;
for (y = 0; y < height; y++){
for (x = 0; x < width; x++){
col=pixels[i];
grey=100-int(((77*(col>>16&0xff) + 151*(col>>8&0xff) + 28*(col&0xff)) >> 8)/2.55);
density[x][y] = grey;
particlesum += grey;
i++;
}
}
p = new particle[particlesum];
for (x = 0; x < width; x++){
for (y = 0; y < height; y++){
if(density[x][y] != 0){
for(i = 0; i < density[x][y]; i++){
p[pgen] = new particle(x,y,pgen);
pgen++;
}
}
}
}
}
// ------------------------------------------------------
void loop()
{
if (loopcount < (seconds*30)){
background(255);
for(int i = 0; i < p.length; i++) {
p[i].brownian();
p[i].paint();
}
if (recording = true){
saveFrame();
}
}
loopcount++;
}
// ------------------------------------------------------
class particle {
int x, y, id, index, col, grey;
particle(int xloc, int yloc, int ident) {
x = xloc;
y = yloc;
id = ident;
}
void paint() {
index = ((y-1)*width)+x;
col = pixels[index];
grey=int(((77*(col>>16&0xff) + 151*(col>>8&0xff) + 28*(col&0xff)) >> 8)-2.55);
if (grey < 0){
grey = 0;
}
pixels[index] = grey<<16 | grey<<8 | grey;
}
void brownian() {
x += random(-3,3);
y += random(-3,3);
}
}
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second, if you will take a look at my setup(), you will see two sets of for() loops which I would like to combine. The issue is that the first for() has to complete before I can know the length of my array.
I looked at fry's example of the growing array in the reference section, but does this work with an array of objects? I couldn't get it to. If anybody knows how to integrate those sections by doing something like that, it is a technique that I could sure stand to learn.
Cheers!
Charles Hinshaw
direction + repertoire
[r]evolve, US
http://www.everydayrevolution.com
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