我在旋转每个图像时遇到性能问题，在绘制它时FPS从1400下降到6.我可以在创建后立即旋转BufferedImage对象，所以计算只发生一次吗？
有我的网格控件类:(绘图类，问题方法是drawRotated（））
package cs.meowxiik.universes.graphics;
import java.awt.Canvas;
import java.awt.Graphics;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.awt.image.ImageObserver;
import java.util.Observer;
import cs.meowxiik.universes.map.Map;
import cs.meowxiik.universes.map.Tile;
public class GridControl {
int width;
int height;
int xcells;
int ycells;
int cellWidth;
int cellHeight;
int maxZoom = 80;
int minZoom = 30;
private Map activeMap;
public GridControl(int width, int height, int xcells, int ycells) {
this.width = width;
this.height = height;
this.xcells = xcells;
this.ycells = ycells;
cellWidth = width / xcells;
cellHeight= height/ ycells;
}
public GridControl(int width, int height, int cellWidth, int cellHeight, int thisDoesntMatterJustForOverloading) {
this.width = width;
this.height = height;
this.cellWidth = cellWidth;
this.cellHeight = cellHeight;
xcells = width / cellWidth;
ycells = height / cellHeight;
}
public void drawGrid(Graphics g){
for(int i = 0; i < xcells; i++){
for(int ii = 0; ii <ycells; ii++){
g.drawRect(i * cellWidth, ii * cellHeight, cellWidth, cellHeight);
}
}
}
public int getCellSize() {
return cellWidth;
}
public void editCellSize(int i) {
if(i == 0)return;
System.out.println("Resizing: " + i);
//Pokud je i menší jak 0 -> člověk se pokouší přibližovat
if(i < 0 && xcells > maxZoom)return;
if(i > 0 && xcells < minZoom)return;
this.cellWidth += i;
this.cellHeight += i;
xcells = width / cellWidth;
ycells = height / cellHeight;
}
public void setActiveMap(Map map){
this.activeMap = map;
}
public void drawMap(Graphics g, Canvas canvas){
if(activeMap != null){
for(int i = 0; i < xcells; i++){
for(int ii = 0; ii <ycells; ii++){
drawRotated(activeMap.getTiles()[i][ii].getTexture(),activeMap.getTiles()[i][ii].getDegrees(), i*cellWidth, ii*cellWidth,canvas, g, null);
//ImageObserver observer = null;
//g.drawImage(activeMap.getTiles()[i][ii].getTexture(), i*cellWidth, ii*cellWidth, observer);
}
}
}
}
public Tile getTileByCoordinate(int x, int y){
int cellx = x / this.cellWidth;
int celly = y / this.cellHeight;
return activeMap.getTiles()[cellx][celly];
}
public boolean isWalkable(int x, int y){
return getTileByCoordinate(x,y).getWalkable();
}
public void drawRotated(BufferedImage img,double rotationRequired,int x,int y,Canvas canvas, Graphics g, Observer observer){
//double rotationRequired = Math.toRadians(degrees);
double locationX = img.getWidth() / 2;
double locationY = img.getHeight() / 2;
AffineTransform tx = AffineTransform.getRotateInstance(rotationRequired, locationX, locationY);
AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);
// Drawing the rotated image at the required drawing locations
g.drawImage(op.filter(img, null), x, y, null);
}}
我的瓷砖方法：
public class Tile {
boolean walkable;
BufferedImage image;
double radians;
int ID; //0 - floor, 1 - wall
public Tile(boolean walkable, BufferedImage image, int ID) {
this.walkable = walkable;
this.image = image;
this.ID = ID;
}
public BufferedImage getTexture() {
return image;
}
public boolean getWalkable() {
return walkable;
}
public int getDegrees() {
return (int) Math.toDegrees(radians);
}
public int getID() {
return ID;
}
public void setTexture(BufferedImage image, int degrees) {
this.image = image;
this.radians = Math.toRadians(degrees);
}
}
我的地图创建者:(旋转部分坏了，我稍后会解决，现在我需要解决我的6-FPS问题）
package cs.meowxiik.universes.map;
import cs.meowxiik.universes.graphics.GraphicsManager;
public class MapCreator {
GraphicsManager graphics;
public MapCreator(GraphicsManager graphics) {
this.graphics = graphics;
}
public Map getSpaceStationMap(){
Map map;
int x = 32;
int y = 18;
Tile[][] tiles = new Tile[x][y];
for(int i = 0; i < x; i++){
for(int ii = 0; ii < y; ii++){
tiles[i][ii] = new Tile(true, graphics.floor, 0);
}
}
for(int i = 0; i < x; i++){
for(int ii = 0; ii < y; ii++){
if(i == 0 || ii == 0 || i == x-1 || ii == y-1)tiles[i][ii] = new Tile(false,graphics.stWallZero, 1); //tiles.get(i).set(ii, new Tile(false,graphics.wall));
}
}
for(int i = 0; i < x; i++){
for(int ii = 0; ii < y; ii++){
if(tiles[i][ii].getID() == 0)break;
boolean connectedUp = false;
boolean connectedLeft = false;
boolean connectedRight = false;
boolean connectedBottom = false;
if(i + 1 < tiles.length)
if(tiles[i + 1][ii + 0].getID() == 1)
connectedRight = true;
if(i != 0)
if(tiles[i - 1][ii + 0].getID() == 1)
connectedLeft = true;
if(ii + 1 < tiles[i].length)
if(tiles[i + 0][ii + 1].getID() == 1)
connectedBottom = true;
if(ii != 0)
if(tiles[i + 0][ii - 1].getID() == 1)
connectedUp = true;
if(connectedUp && !(connectedLeft || connectedRight || connectedBottom))tiles[i][ii].setTexture(graphics.stWallOne, 0);
if(connectedLeft && !(connectedUp || connectedRight || connectedBottom))tiles[i][ii].setTexture(graphics.stWallOne, 90);
if(connectedRight && !(connectedUp || connectedLeft || connectedBottom))tiles[i][ii].setTexture(graphics.stWallOne, 180);
if(connectedBottom && !(connectedUp || connectedRight || connectedLeft))tiles[i][ii].setTexture(graphics.stWallOne, 270);
if((connectedUp && connectedBottom) && !(connectedLeft || connectedRight))tiles[i][ii].setTexture(graphics.stWallTwo, 90);
if(!(connectedUp && connectedBottom) && !(connectedLeft || connectedRight))tiles[i][ii].setTexture(graphics.stWallTwo, 0);
}
}
map = new Map(x,y,tiles);
return map;
}
}
答案 0 :(得分：2)
鉴于此代码
public void drawRotated(BufferedImage img,double rotationRequired,int x,int y,Canvas canvas, Graphics g, Observer observer) {
//double rotationRequired = Math.toRadians(degrees);
double locationX = img.getWidth() / 2;
double locationY = img.getHeight() / 2;
AffineTransform tx = AffineTransform.getRotateInstance(rotationRequired, locationX, locationY);
AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);
BufferedImage rotatedImage = op.filter(img, null); // my edit here
// Drawing the rotated image at the required drawing locations
g.drawImage(rotatedImage , x, y, null);
}
图像旋转到rotatedImage只取决于它的大小（宽度/高度）和所需的旋转。
从我的代码阅读中，所需的轮换基本上是固定的。当调用setTexture Title方法时，旋转是已知的。
正是这种情况，可以在rotatedImage方法中计算setTexture。只需创建一个存储计算出的旋转图像的新属性。不要破坏原件。
如果setTexture经常调用drawRotated，则无法提供您想要的性能提升。