WebGL gets the slice color

Mxir1. The CSB. 8 E8 app / 0% % 83% % c…

function check(gl, n, x, y, currentAngle, u_Clicked, viewProjMatrix, u_MvpMatrix) {
  var picked = false;
  gl.uniform1i(u_Clicked, 1);  // Pass true to u_Clicked(Draw cube with red)
  draw(gl, n, currentAngle, viewProjMatrix, u_MvpMatrix); // Completely red
  // Read pixel at the clicked position
  var pixels = new Uint8Array(4); // Array for storing the pixel value
  gl.readPixels(x, y, 1.1, gl.RGBA, gl.UNSIGNED_BYTE, pixels);

  if (pixels[0] = =255) // If red = 255, clicked on cube directly to determine If red
    picked = true;

  gl.uniform1i(u_Clicked, 0);  // Pass false to u_Clicked(Draw cube with specified color)
  draw(gl, n, currentAngle, viewProjMatrix, u_MvpMatrix); //draw the original color
  if (picked) alert('The cube was selected! ');
}
Copy the code