【作品No.45】画像の四隅の色を取得し、その中間色を表現する【Processing 2025年2月26日】

PImage img;

void setup() {
  size(800, 600);
  img = loadImage("7, Window, Slovenia, Ljubljana.jpg");
  img.loadPixels();

  int leftTopIndex = 0;
  int rightTopIndex = img.width - 1;
  int leftBottomIndex = img.width * (img.height - 1);
  int rightBottomIndex = img.width * img.height - 1;

  color leftTopColor = img.pixels[leftTopIndex];
  color rightTopColor = img.pixels[rightTopIndex];
  color leftBottomColor = img.pixels[leftBottomIndex];
  color rightBottomColor = img.pixels[rightBottomIndex];

  color middleColorTop = lerpColor(leftTopColor, rightTopColor, 0.5);
  color middleColorBottom = lerpColor(leftBottomColor, rightBottomColor, 0.5);
  color middleColor = lerpColor(middleColorTop, middleColorBottom, 0.5);

  tint(255, 127);
  image(img, 0, 0, width, height);

  fill(leftTopColor);
  ellipse(width / 4, height / 4, 100, 100);

  fill(rightTopColor);
  ellipse(3 * width / 4, height / 4, 100, 100);

  fill(leftBottomColor);
  ellipse(width / 4, 3 * height / 4, 100, 100);

  fill(rightBottomColor);
  ellipse(3 * width / 4, 3 * height / 4, 100, 100);

  fill(middleColor);
  ellipse(width / 2, height / 2, 100, 100);
}

void draw() {
}