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как проверить, есть ли целевой пиксель в определенной области экрана, например, проверить, есть ли целевой пиксель x < 100, y > 320. x и y-ширина и высота экрана.

в следующем коде я могу отслеживать средние значения x,y в targetpixel. этот код использует программу обработки эскиза и шейдера (glsl) спасибо за любую помощь

     import processing.video.*;
    PShader colorFinder, colorPosShader;
    PGraphics overlay, posBuffer;
    // Variable for capture device
    Capture video;
    
    // A variable for the color we are searching for.
    color trackColor; 
    float threshold = 0.1;
    
    void setup() {
      //size(320, 240);
      size(640, 480, P2D);
      overlay = createGraphics(width, height, P2D);
      posBuffer = createGraphics(width, height, P2D);
      colorFinder = loadShader("colorDetect.glsl");
      colorPosShader = loadShader("colorPos.glsl");
      printArray(Capture.list());
      video = new Capture(this, width, height);
      video.start();
      video.loadPixels();
      // Start off tracking for red
      trackColor = color(255, 0, 0);
    }
    
    void captureEvent(Capture video) {
      // Read image from the camera
      video.read();
    }
    
    void draw() {
      colorFinder.set("threshold", threshold);
      colorFinder.set("targetColor", red(trackColor) / 255.0, green(trackColor) / 255.0, blue(trackColor) / 255.0, 1.0);
      colorPosShader.set("threshold", threshold);
      colorPosShader.set("targetColor", red(trackColor) / 255.0, green(trackColor) / 255.0, blue(trackColor) / 255.0, 1.0);
      overlay.beginDraw();
      overlay.shader(colorFinder);
      overlay.image(video, 0, 0);
      overlay.endDraw();
      posBuffer.beginDraw();
      posBuffer.shader(colorPosShader);
      posBuffer.image(video, 0, 0);
      posBuffer.endDraw();
      //compute average position by looking at pixels from position buffer
      posBuffer.loadPixels();
      PVector avg = new PVector(0, 0);
      int count = 0;
      for(int i = 0; i < posBuffer.pixels.length; i  ){
        // encoded so blue is > 0 if a pixel is within threshold
        if(blue(posBuffer.pixels[i]) > 0){
          count  ;
          // processing takes 0-1 (float) color values from shader to 0-255 (int) values for color
          // to decode, we need to divide the color by 255 to get the original value
          avg.add(red(posBuffer.pixels[i]) / 255.0, green(posBuffer.pixels[i]) / 255.0);
        }
      }
      if(count > 0){
        // we have the sum of positions, so divide by the number of additions
        avg.div((float) count);
        // convert 0-1 position to screen position
        avg.x *= width;
        avg.y *= height;
      } else {
        // appear offscreen
        avg = new PVector(-100, -100);
      }
      image(overlay, 0, 0);
      fill(trackColor);
      stroke(0);
      circle(avg.x, avg.y, 16);
      fill(0, 50);
      noStroke();
      rect(0, 0, 150, 30);
      fill(150);
      //text("avg,x"   avg.x, 0, 11);
      //text("Threshold: "   threshold, 0, 22);
      println(frameRate);
      println(count);
    }
    
    void mousePressed() {
      // Save color where the mouse is clicked in trackColor variable
      video.loadPixels();
      int loc = mouseX   mouseY*video.width;
      trackColor = video.pixels[loc];
    }
    
    void mouseWheel(MouseEvent e){
      threshold -= e.getCount() * 0.01;
      threshold = constrain(threshold, 0, 1);
    }
    


        // this shader for detect color
    //the shader to find pixels if they are within a threshold:
    In shaders, colors are stored with 4 component vectors with 
    //each component ranging from 0 to 1. The components are usually marked x, y, z, and w
    #ifdef GL_ES
    precision mediump float;
    precision mediump int;
    #endif
    
    uniform sampler2D texture;
    
    varying vec4 vertColor;
    varying vec4 vertTexCoord;
    //Uniform variables are constants in the shader, but can be modified by the external 
    //program that calls the shader, in this case the processing sketch
    uniform vec4 targetColor;
    uniform float threshold; //between 0 and 1
    
    void main() {
    // get pixel color
    vec4 texColor = texture2D(texture, vertTexCoord.st) * vertColor;
    vec3 a = texColor.xyz;
    vec3 b = targetColor.xyz;
    // compute "distance" between colors rgb components
    float dist = sqrt((b.x - a.x) * (b.x - a.x)   (b.y - a.y) * (b.y - a.y)   (b.z - a.z) * (b.z - a.z));
    // colors are from 0-1, so the max distance between colors is sqrt(3)
    if(dist < threshold * sqrt(3)){
    // display inverse color where pixels are within the threshold
    texColor = vec4(1) - texColor;
    }
    // force alpha to be 1 since inverting the color makes the alpha zero
    gl_FragColor = vec4(texColor.xyz, 1);
    }


    //this shader finding the positions of all detected pixels
#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif

uniform sampler2D texture;

varying vec4 vertColor;
varying vec4 vertTexCoord;//uv coordinates of the texture
    //or uv coordinate of the current pixel on the screen
    //uv coordinates are a 2D vector that ranges from 0-1 in each 
    //component, where a uv of (0, 0) means you are at 
    //the top-left corner of the texture and (1, 1) the bottom right
//To get the screen position, you multiply the uv by the screen width and height
uniform vec4 targetColor;
uniform float threshold; //between 0 and 1


void main() {
vec4 texColor = texture2D(texture, vertTexCoord.st) * vertColor;
vec3 a = texColor.xyz;
vec3 b = targetColor.xyz;
float dist = sqrt((b.x - a.x) * (b.x - a.x)   (b.y - a.y) * (b.y - a.y)   (b.z - a.z) * (b.z - a.z));
bool cond = dist < threshold * sqrt(3);
// if color is within threshold, encode the pixel's position into red and green components
// and use blue component as a marker that the pixel was in range
// vertTexCoord is from 0 to 1, so after computing average, multiply by width and height to get screen position
gl_FragColor = cond ? vec4(vertTexCoord.x, vertTexCoord.y, 1, 1) : vec4(0, 0, 0, 1);
}