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Index › Programming Questions & Help › Programs › simple program trouble
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simple program trouble (Read 445 times)
rb88
simple program trouble
Sep 6th, 2009, 6:45pm  
the program is supposed to draw a line with the width changing with the speed of the mouse. also the line is supposed to turn white when it goes over a black spot.
sorry im awful at explaining, please write back.




// program by jake lalalla

color co = color(0);
color cp = get(mouseX, mouseY);

void setup() {
 size(1920, 1200);
 background(255);
 smooth();
}

void draw() {
 stroke(0);
 strokeWeight(abs(pmouseX - mouseX));
 line(pmouseX, pmouseY, mouseX, mouseY);
 if (cp == co) {
   stroke(255);
 }
 else {
   stroke(0);
 }
}
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ben_hem
Re: simple program trouble
Reply #1 - Sep 6th, 2009, 7:58pm  
At the point you're creating that cp variable, the preprocessor can't deal with mouseX and mouseY yet, because they don't exist until your program starts.  You also want cp to be dynamic and change with each frame, so it needs to be in draw().  Also, the abs(mouseX-pmouseX) is just measuring horizontal distance...you can use dist() or a Pythagorean distance formula.

Quote:
color co = color(0);
color cp;

void draw() {
 stroke(0);
 strokeWeight(dist(pmouseX,pmouseY,mouseX,mouseY));
 line(pmouseX, pmouseY, mouseX, mouseY);
 cp = get(mouseX, mouseY);
 // etc...
}


--Ben
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