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https://github.com/processing/processing4.git
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42 lines
867 B
Plaintext
42 lines
867 B
Plaintext
/**
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* Follow 2
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* based on code from Keith Peters.
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*
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* A two-segmented arm follows the cursor position. The relative
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* angle between the segments is calculated with atan2() and the
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* position calculated with sin() and cos().
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*/
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float[] x = new float[2];
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float[] y = new float[2];
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float segLength = 50;
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void setup() {
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size(640, 360);
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strokeWeight(20.0);
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stroke(255, 100);
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}
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void draw() {
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background(0);
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dragSegment(0, mouseX, mouseY);
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dragSegment(1, x[0], y[0]);
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}
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void dragSegment(int i, float xin, float yin) {
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float dx = xin - x[i];
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float dy = yin - y[i];
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float angle = atan2(dy, dx);
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x[i] = xin - cos(angle) * segLength;
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y[i] = yin - sin(angle) * segLength;
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segment(x[i], y[i], angle);
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}
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void segment(float x, float y, float a) {
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pushMatrix();
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translate(x, y);
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rotate(a);
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line(0, 0, segLength, 0);
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popMatrix();
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}
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