我正在编写一个非常基本的绘图应用程序。
我的应用有一个图像，当我在任何地方触摸时，这个地方都会填充一种颜色。
我使用了泛洪填充算法（http://en.wikipedia.org/wiki/Flood_fill），特别是Alternative implementations部分的第二种方法。
我使用像素图来更新纹理。
这在我的电脑上工作正常，问题是在我的android上执行应用程序（motorola moto G，720p分辨率，Android 4.4），算法需要几秒钟，我不喜欢这样，我想要这个过程花费的时间更少。因此，问题是高分辨率（或填充大部分）算法需要几秒钟。
我做的一件事是检查每5个像素而不是1个像素，但我想知道是否还有其他优化。
我知道有应用程序可以执行此操作（例如https://play.google.com/store/apps/details?id=com.coloring.toddlers&hl=en）。有人可以告诉我任何建议吗？
感谢。
编辑：用一些代码更新问题（我已从界面中删除了空方法）。可能是有未使用的变量。这是检查每个像素的版本。
我的填充算法
import com.badlogic.gdx.*;
import com.badlogic.gdx.assets.AssetManager;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.input.GestureDetector;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.scenes.scene2d.Stage;
import es.angelluis..Actors.BackgroundActor;
import es.angelluis..Actors.ImageActor;
import es.angelluis..util.Pixel;
import java.util.ArrayList;
public class Images implements Screen, InputProcessor {
private Stage stage;
private ImageActor img = new ImageActor();
private AssetManager manager;
private Texture texture = null;
public Images(){
manager = new AssetManager();
stage = new Stage();
manager.load("dibujo1.png",Texture.class);
stage.addActor(img);
InputMultiplexer im = new InputMultiplexer();
im.addProcessor(this);
im.addProcessor(stage);
Gdx.input.setInputProcessor(im);
}
@Override
public void render(float delta) {
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
if (manager.update()){
if (!img.loaded){
texture = manager.get("dibujo1.png", Texture.class);
int x = (Gdx.graphics.getWidth()-texture.getWidth())/2;
int y = (Gdx.graphics.getHeight()-texture.getHeight())/2;
img.load(texture, x,y, texture.getWidth(), texture.getHeight());
texture.getTextureData().prepare();
pix = texture.getTextureData().consumePixmap();
}
stage.draw();
}
}
@Override
public boolean touchDown(int screenX, int screenY, int pointer, int button) {
int colorSelected = Color.rgba8888(Color.RED);
if (screenX < img.getX() || screenX > img.getX() + img.getWidth() || screenY < img.getY() || screenY > img.getY() + img.getHeight()){
return false;
}
//Get Texture to update.
Pixmap source = img.getPixmap();
// Obtenemos las coordenadas locales a la textura.
screenX = screenX - (int)img.getX();
screenY = screenY - (int)img.getY();
// Get Color.
int colorInicial = source.getPixel(screenX, screenY);
// If color is the same we will exit.
if (colorInicial == colorSelected){
return false;
}
ArrayList<Pixel> pixels = new ArrayList<Pixel>();
int colorPixel = source.getPixel(screenX, screenY);
if (colorPixel == colorInicial){
// Store the initial pixel in pixels linked list.
pixels.add(new Pixel(screenX, screenY));
while(!pixels.isEmpty()){
Pixel p = pixels.get(0);
source.setColor(Color.RED);
source.drawPixel(p.getX(), p.getY());
pixels.remove(0);
// Now get all pixel that I should be update in this y coords. So get west and east.
ArrayList<Pixel> line = new ArrayList<Pixel>();
int w = p.getX()-1;
colorPixel = source.getPixel(w, p.getY());
while (colorPixel == colorInicial && w != 0){
line.add(new Pixel(w, p.getY()));
w--;
colorPixel = source.getPixel(w, p.getY());
}
int e = p.getX() + 1;
colorPixel = source.getPixel(e, p.getY());
while (colorPixel == colorInicial && e != img.getWidth()){
line.add(new Pixel(e, p.getY()));
e++;
colorPixel = source.getPixel(e, p.getY());
}
// Draw the line that I store before.
while (!line.isEmpty()){
Pixel linePixel = line.get(0);
line.remove(0);
source.setColor(Color.RED);
source.drawPixel(linePixel.getX(), linePixel.getY());
// I check the north pixel and store it if they should be updated
colorPixel = source.getPixel(linePixel.getX(), linePixel.getY()+1);
if (colorPixel == colorInicial){
pixels.add(new Pixel(linePixel.getX(), linePixel.getY()+1));
}
// I check the south pixel and store it if they should be updated
colorPixel = source.getPixel(linePixel.getX(), linePixel.getY()-1);
if (colorPixel == colorInicial){
//System.out.println("Entramos en sur");
pixels.add(new Pixel(linePixel.getX(), linePixel.getY()-1));
}
}
}
}
img.setTexture(new Texture(source));
return false;
}
}
ImageActor
package es.angelluis..Actors;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.scenes.scene2d.Actor;
public class ImageActor extends Actor{
private Texture img;
public boolean loaded = false;
private int x,y,width,height;
public void load(Texture img, int x, int y, int width, int height){
this.img = img;
loaded = true;
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
public void setTexture(Texture img){
this.img = img;
}
public Pixmap getPixmap(){
if (!img.getTextureData().isPrepared()){
img.getTextureData().prepare();
}
return img.getTextureData().consumePixmap();
}
public float getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public float getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public float getWidth() {
return width;
}
public void setWidth(int width) {
this.width = width;
}
public float getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
@Override
public void draw(Batch batch, float alpha){
batch.draw(img, x, y, width, height);
}
}
答案 0 :(得分：0)
执行此类操作时常见的错误是您正在尝试更新屏幕位图，这会使进程大幅减慢，因为应用程序正在尝试同时更新屏幕。 此问题的解决方案是将屏幕复制到位图，在该位图上执行填充算法，并在完成后将结果复制回屏幕。 如果您提供一些代码，我们可以检查您的方法。