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Topic: rotate BImage (Read 525 times) |
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eskimoblood
 
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rotate BImage
« on: Feb 28th, 2005, 1:49pm » |
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Is there a way to rotate a BImage object like:
BImage a=get (0,0,20,20);
rotate(180);
set(0,0,a);
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fjen
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Re: rotate BImage
« Reply #1 on: Feb 28th, 2005, 2:31pm » |
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Code:// freely rotate a BImage
// fjenett, feb 2005, offenbach-main, germany
// www.florianjenett.de
BImage img;
void setup() {
size(200,200);
img = loadImage("house.jpg");
}
float rotation = 0.0;
void loop(){
background(0);
image(rotateImage(img, rotation), 0, 0);
rotation += 0.02;
}
BImage rotateImage (BImage _img, float _rad)
{
if (_rad == 0) return _img;
int xm = _img.width;
int ym = _img.height;
BGraphics _bimg = new BGraphics(xm, ym); _bimg.format = RGB;
_bimg.background(255);
_bimg.noStroke();
_bimg.translate(xm/2.0, ym/2.0);
_bimg.rotateZ(_rad);
_bimg.beginShape(QUADS);
_bimg.texture(img);
_bimg.vertex( -(xm/2), -(ym/2),0, 0,0);
_bimg.vertex( (xm/2), -(ym/2),0, xm,0);
_bimg.vertex( (xm/2), (ym/2),0, xm,ym);
_bimg.vertex( -(xm/2), (ym/2),0, 0,ym);
_bimg.endShape();
return (BImage) _bimg;
}
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if you rotate exactly 90, 180 or 270 degree, then you can just mirror the pixels array ... i think that's faster.
/F
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eskimoblood
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Re: rotate BImage
« Reply #2 on: Mar 1st, 2005, 12:37pm » |
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Here is the code to mirror an image horizontal and vertical:
Code:
void setup(){
size(702,482);
BImage b1=loadImage("pic1.jpg");
BImage b2=new BImage(b1.width,b1.height );
BImage b3=new BImage(b1.width,b1.height );
BImage b4=new BImage(b1.width,b1.height );
for(int j=0;j<b1.width;j++){
for(int i=0;i<b1.height;i++){
int indexNew;
int indexOld=i*b1.width+j;
indexNew=i*b1.width+b1.width-j-1;
b2.pixels[indexNew]=b1.pixels[indexOld];
indexNew=(b1.height-i-1)*b1.width+j;
b3.pixels[indexNew]=b1.pixels[indexOld];
indexNew=b1.pixels.length-1-(i*b1.width+j);
b4.pixels[indexNew]=b1.pixels[indexOld];
}
}
image(b1,0,0);
image(b2,b1.width,0);
image(b3,0,b1.height);
image(b4,b1.width,b1.height);
}
}
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JohnG
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Re: rotate BImage
« Reply #3 on: Mar 1st, 2005, 5:11pm » |
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you can actually use the rotateZ command to rotate an image:
Code:
BImage MyImage=loadImage("whatever");
float angle=0;
void loop()
{
angle+=0.01;
background(0);
translate(width/2,height/2);
rotateZ(angle);
image(MyImage, -MyImage.width/2, -MyImage.height/2, MyImage.width, MyImage.height);
}
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Much easier than trying to work out the maths for yourself.
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| « Last Edit: Mar 1st, 2005, 5:13pm by JohnG » |
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