Processing Forum

How to find points on a curve and display them?

[6 Replies]
- 11-Mar-2012 10:49 AM
- Forum: Programming Questions
So I have this code which takes data from an array and draws a curve:
2. void drawDataLine(int row) {
3. beginShape();
4. for (int col = 0; col < colCount; col++) {
5. if (data.isValid(row, col)) {
6. float value = data.getPoint(row, col);
7. float x = map(years[col], yearMin, yearMax, plotX1, plotX2);
8. float y = map(value, dataMin, dataMax, plotY2, plotY1);
9. //vertex(x,y) ;
10. curveVertex(x, y);
11. // Double the curve points for the start and stop
12. if ((col == 0) || (col == colCount-1)) {
13. curveVertex(x, y);
14. }
15. }
16. }
17. endShape();
18. }
I have another function which displays the data values when the cursor is within 3 pixels of the point:
2. for (int col = 0; col < colCount; col++) {
4. if (data.isValid(row, col)) {
5. float radVal = ratio[col];
6. float value = data.getPoint(row, col);
7. float compareValue = compare.getPoint(row, col);
8. float x = map(years[col], yearMin, yearMax, plotX1, plotX2);
9. float y = map(value, dataMin, dataMax, plotY2, plotY1);
10. float ellipse1MapVal = map(value, ellipse1Min, ellipse1Max, 10, 80);
11. float ellipse2MapVal = map(compareValue, ellipse1Min, ellipse1Max, 10, 80);
12. radVal = map(radVal, radMin, radMax, 1, 7);
14. if (dist(mouseX, mouseY, x, y) < 3) {
15. if (drawCirclesPrimary || drawCirclesSecondary) {
16. noStroke();
17. if (drawCirclesPrimary) {
18. fill(0, 255, 0, 100);
19. ellipse(x, y, ellipse1MapVal, ellipse1MapVal);
20. }
21. if (drawCirclesSecondary) {
22. fill(255, 0, 0, 100);
23. ellipse(x, y, ellipse2MapVal, ellipse2MapVal);
24. }
25. fill(0);
26. stroke(0);
27. pushMatrix();
28. translate(x, y);
29. rotate(radians(radSec));
30. line(0, -ellipse1MapVal/2, 0, ellipse1MapVal/2);
31. popMatrix();
32. radSec += radVal;
33. textSize(10);
34. textAlign(CENTER);
35. text(nf(value, 0, 2) + " (" + years[col] + ")"+nf(compareValue, 0, 2), x, y-8);
36. }
37. else
38. text(nf(value, 0, 2) + " (" + years[col] + ")", x, y-8);
39. }
40. if ((mouseX < x+3)&&(mouseX > x-3))
41. {
42. stroke(150);
43. strokeWeight(1);
44. line(x, plotY1, x, plotY2);
45. } } }}
Now the problem is that curveVertex does its interpolation and makes nice curves but I cannot get the points on those curves other than the ones I already have. What I want is the cursor to show values on all the points on the graph rather than the 10 points which I have on the array, much like the graphs on google or yahoo finance. I am a noob when it comes to processing so any help with this will be greatly appreciated.
Regards

Interpolation between two points

[2 Replies]
- 29-Feb-2012 02:05 PM
- Forum: General Discussion
I need to interpolate between two points. Now I know that processing does it for you with the curve command. Can anyone please tell me what kind of interpolation is it.Also, is it possible to follow the curve numerically. What I mean is, if I have two points x,y and I give the command curve(x,y) processing will draw a curve for me. Now is there any way to get the points (x1,y1), (x2,y2),(x3,y3)....that lie between the two points so that I can follow the curve. If not, can anybody tell me a good interpolation function that can be used for this. Any help in this regard will be greatly appreciated

button press. Please help

[2 Replies]
- 29-Feb-2012 02:01 PM
- Forum: Programming Questions
So I have a ON-OFF button that draws a circle. The trouble I am encountering is that the ON OFF states are random depending on how long I press the button. I guess this is due to the draw() function which also loops my button function in time with framerate. What I want is for the button to turn on when pressed once and turn off when pressed again irrespective of how long the button is pressed. Here is the code.
1. else if (circle4.pressed()) {
        println("button 4 is pressed");
  
        if(drawCirclesPrimary){
        drawCirclesPrimary = false;
        }
        else{
        drawCirclesPrimary = true;
        }
        println("drawCirclesPrimary"+drawCirclesPrimary);
      }

Mouse-over text label

[6 Replies]
- 17-Dec-2011 02:44 AM
- Forum: Programming Questions
Hello,

I have a few small buttons on my sketch. I wish to have a text label appear on the screen when the user scrolls over the button. Kind of similar to how facebook shows the profile picture and basic info in a box when you move the mouse over a person's name on your newsfeed. Any help on this will be greatly welcome. Would I need to use javaScript?

Regards

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