Java游戏分辨率变化时鼠标坐标转世界坐标的正确计算方法

我正在开发一款Java游戏，需要在窗口分辨率变化时计算鼠标对应的世界空间坐标。当前使用的坐标计算代码仅在720x480窗口及全屏模式下可正常工作，提升分辨率后鼠标坐标会出现偏移（红色标记为鼠标光标）。

初始实现代码 #

鼠标世界坐标计算代码 #

Game.s2wX = (int)(((mouseX - (Window.REAL_WIDTH() / 2 - Window.SCALED_WIDTH() / 2)) / s) - (-x - width/2 + (Window.SCALED_WIDTH() / s) / 2));
Game.s2wY = (int)(((mouseY - (Window.REAL_HEIGHT() / 2 - Window.SCALED_HEIGHT() / 2)) / s) - (-y - height / 2 + (Window.SCALED_HEIGHT() / s) / 2));

游戏画面居中绘制代码 #

g.drawImage(image,
    Window.REAL_WIDTH()/2-Window.SCALED_WIDTH()/2,
    Window.REAL_HEIGHT()/2-Window.SCALED_HEIGHT()/2,
    Window.SCALED_WIDTH(), Window.SCALED_HEIGHT(),null);

迭代更新过程 #

第一次调整（引入缩放因子） #

@HassanUsman指出需考虑缩放因子，调整后仍存在小偏移问题：

double scalingFactorX = (double) Window.SCALED_WIDTH() / Window.REAL_WIDTH();
double scalingFactorY = (double) Window.SCALED_HEIGHT() / Window.REAL_HEIGHT();
Game.s2wX = (int)(Window.SCALED_WIDTH() +(mouseX/s)+scalingFactorX - (-x - width/2  + (Window.REAL_WIDTH() /s)/2));
Game.s2wY = (int)(Window.SCALED_HEIGHT()+(mouseY/s)+scalingFactorY - (-y - height/2 + (Window.REAL_HEIGHT()/s)/2));

10月1日更新 #

再次修改后，720x480窗口模式计算正确，但全屏模式存在1/2线偏移：

double scalingFactorX = (double) Window.SCALED_WIDTH() / Window.REAL_WIDTH();
double scalingFactorY = (double) Window.SCALED_HEIGHT() / Window.REAL_HEIGHT();

int translationX = (Window.REAL_WIDTH() - Window.SCALED_WIDTH()) / 2;
int translationY = (Window.REAL_HEIGHT() - Window.SCALED_HEIGHT()) / 2;

lineX = (int) (((mouseX - translationX) / scalingFactorX) / s - (-x - width / 2 + (Window.SCALED_WIDTH() / (scalingFactorX * s)) / 2));
lineY = (int) (((mouseY - translationY) / scalingFactorY) / s - (-y - height / 2 + (Window.SCALED_HEIGHT() / (scalingFactorY * s)) / 2));

最终解决代码（10月2日） #

将缩放因子的计算基准改为原始分辨率720x480后，问题完全解决：

double scalingFactorX = (double) Window.SCALED_WIDTH() / 720;
double scalingFactorY = (double) Window.SCALED_HEIGHT() / 480;

int translationX = (Window.REAL_WIDTH() - Window.SCALED_WIDTH()) / 2;
int translationY = (Window.REAL_HEIGHT() - Window.SCALED_HEIGHT()) / 2;

lineX = (int) (((mouseX - translationX) / scalingFactorX) / s - (-x - width / 2 + (Window.SCALED_WIDTH() / (scalingFactorX * s)) / 2));
lineY = (int) (((mouseY - translationY) / scalingFactorY) / s - (-y - height / 2 + (Window.SCALED_HEIGHT() / (scalingFactorY * s)) / 2));

内容的提问来源于stack exchange，提问作者GDjkhp